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Method and apparatus for testing wells |
| RE29562 |
Method and apparatus for testing wells
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| Patent Drawings: | |
| Inventor: |
Wray, et al. |
| Date Issued: |
March 7, 1978 |
| Application: |
05/679,256 |
| Filed: |
April 22, 1976 |
| Inventors: |
Petty; George E. (Ventura, CA)
Wray; Gary Q. (Duncan, OK)
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| Assignee: |
Halliburton Company (Duncan, OK) |
| Primary Examiner: |
Purser; Ernest R. |
| Assistant Examiner: |
Favreau; Richard E. |
| Attorney Or Agent: |
Gonzalez; Floyd A.Cockfield; James E.Tregoning; John H. |
| U.S. Class: |
166/162; 166/164; 166/336; 166/352; 251/63 |
| Field Of Search: |
166/.5; 166/.6; 166/72; 166/162; 166/165; 166/169; 166/224R; 166/224A; 166/264; 166/164; 73/151; 137/495; 251/63 |
| International Class: |
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| U.S Patent Documents: |
2033563; 2951536; 3236255; 3273647; 3327781; 3353605; 3358755; 3410346; 3451475; 3456726 |
| Foreign Patent Documents: |
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| Other References: |
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| Abstract: |
A method and apparatus for testing offshore wells where variations in well annulus pressure are utilized to control the valving operation of a testing tool and entrap a formation sample.A confined body of pressurized fluid positoned in a testing string is utilized to predetermine the annulus pressure changes which will effect said valving and sample entrapping operations. |
| Claim: |
What is claimed is: .[.1. A method of testing a formation intersected by a well bore, said method comprising:
maintaining a pressure in a body of fluid in a well bore, disposed adjacent a conduitmeans, at one level while maintaining said body of fluid isolated from a submerged formation to be tested and the interior of said conduit means;
in response to said one level of pressure in said body of fluid, maintaining a flow path leading from said formation through said conduit means in said well bore in a closed condition;
changing the pressure of said fluid body while isolating said change in pressure of said fluid body from said formation;
in response to said change in pressure, permitting fluid to flow from said formation through said conduit means;
further changing the pressure of fluid in said fluid body while isolating said further change in pressure from said formation and the interior of said conduit means;
in response to said first change of pressure of said fluid body, entrapping within said conduit means a sample of fluid from said formation..]. .[.2. A method of testing a submerged formation from an offshore test site, said method comprising:
maintaining pressure in a body of fluid in a submerged well bore, disposed adjacent a conduit means, at a relatively low level while maintaining said body of fluid isolated from a submerged formation to be tested;
in response to said relatively low level of pressure in said body of fluid, maintaining a flow path leading from said formation through said conduit means in said well bore in a closed condition;
increasing the pressure of said fluid body while isolating said increase in pressure of said fluid body from said formation; in response to said increase in pressure, permitting fluid to flow from said formation through said conduit means;
further decreasing the pessure of fluid in said fluid body while isolating said further decrease in pressure from said formation; and
in response to said further decrease of pressure of said fluid body, entrapping within said conduit means a sample of fluid from said
formation..]. 3. A method of testing a submerged formation from an offshore test site, said method comprising:
disposing a test string including tester valve controlled conduit means between a floating vessel and a submerged formation;
maintaining pressure in a body of liquid in a submerged well bore, disposed adjacent said conduit means, at a relatively low level while maintaining said body of liquid isolated .[.form.]. .Iadd.from .Iaddend.a submerged formation to be tested;
in response to said relatively low level of pressure in said body of liquid, maintaining a flow path leading from said formation through said conduit means in said well bore in a closed condition;
increasing the pressure of said liquid body while isolating said increase in pressure of said liquid body from said formation;
in response to said increase in pressure, permitting fluid to flow from said formation through said conduit means;
further .[.decreasing.]. .Iadd.increasing .Iaddend.the pressure of liquid in said liquid body while isolating said further .[.decrease.]. .Iadd.increase .Iaddend.in pressure from said formation;
in response to said further .[.decrease.]. .Iadd.increase .Iaddend.of pressure of said liquid body, entrapping within said conduit means a sample of fluid from said formation;
maintaining a confined body of pressurized gas in said conduit means operable to determine the pressure level in said liquid body operable to permit said liquid to flow from said formation through said conduit means; and
maintaining yieldable means in said conduit means operable to determine the
pressure level in said liquid body operable to cause said entrapping. 4. A method as described in claim 3 further comprising:
effecting said testing while concurrently substantially preventing wave action induced forces from being transmitted through said test string from
said floating work station to said conduit means. 5. A method of testing a formation, intersected by a well bore site, said method comprising:
providing a well testing assembly including:
conduit means communicating with a formation to be tested, with said conduit means being disposed in a well bore and selectively removable therefrom,
wall means encircling at least a portion of said conduit means, and
selectively releasable sealing means extending between said conduit means and said wall means and cooperating with said conduit means and said wall means to provide a well annulus isolated from the interior of said conduit means;
regulating flow from said formation through said conduit means with an assembly including:
first, valve seat means carried by a wall portion of said conduit means,
second, valve seat means carried by another interior wall portion of said conduit means, and spaced longitudinally of and above said first valve seat means,
slidable sample chamber side wall means mounted on said first and second valve seat means for sliding movement longitudinally of said conduit means,
first valve means carried by a lower portion of said slidable sample chamber side wall means and disposed in valving cooperation with said first valve seat means,
second valve means carried by an upper portion of said slidable sample chamber side wall means and disposed in valving cooperation with said second valve seat means,
formation fluid inlet passage means operable to transmit formation fluid from said formation to the interior of said slidable sample chamber side wall means under valving control of said first sleeve valve means,
formation fluid output passage means operable to transmit formation fluid from the interior of said slidable sample chamber side wall means to the interior of said conduit means under valving control of said second sleeve valve means,
said first and second sleeve valve means being concurrently operable in response to movement of said slidable sample chamber side wall means,
said first and second sleeve valve means being sequentially movable from
a first position closing said inlet and outlet passage means, to
a second position opening said inlet and outlet passage means, and to
a third position closing said inlet and outlet passage means;
providing a formation sample trapping chamber means including:
wall means cooperating with said first and second valve seat means and said slidable sample chamber side wall means to define a sample receiving cavity;
providing formation testing actuating means including:
pressurizing means selectively operable to increase the pressure of fluid in said well annulus, with said sealing means isolating said well annulus from said formation,
piston means carried by said sample chamber side wall means,
cylinder means defined by a portion of said conduit means with said piston means being slidably mounted therein,
first expansible and contractible cavity means included in said cylinder means and containing a body of expansible and contractible pressurized fluid yieldably biasing said piston means and slidable sample chamber side wall means in onedirection,
second expansible and contractible cavity means included in said cylinder means operable to receive formation fluid to bias said piston means in another direction opposite to said one direction,
communicating means providing pressure-change transmitting fluid communication between said second expansible and contractible cavity means and said well annulus; and
testing said formation by:
imparting the pressure of said pressurized fluid to said piston means to urge said slidable sample chamber side walls means in said one direction and hold said first and second sleeve valve means in said first, position to prevent a flow offormation fluid through said sample trapping chamber means from said formation, while maintaining said relatively low pressure level in said well annulus,
operating said pressurizing means to increase the pressure of fluid in said well annulus, with said increase in pressure being operable to provide said relatively intermediate pressure in said well annulus and effect movement of said samplechamber side wall means in said opposite direction and move said first and second valve means from said first position to said second position to permit a flow of fluid consecutively through said inlet passage means, interior of said sample trappingchamber means, and outlet passage means, and
operating said pressurizing means to provide said relatively high pressure level in said well annulus to cause said first and second valve means to move in said opposite direction from said second position to said third position and entrap asample of formation fluid in said sample trapping
chamber means. 6. A method of testing a formation as described in claim 5, said method further comprising:
providing valve latching means including:
socket means carried by said conduit means above said slidable sample chamber side wall means, and
1atching means carried by said slidable sample chamber side wall means and operable to releasably latch said sample chamber side wall means in said socket means when said first and second valve means are moved to said third position;
providing venting valve means in said conduit means below said first valve means and operable to vent pressurized fluid from the interior of said conduit means to the exterior thereof in response to a decrease in pressure of fluid adjacent theexterior of said conduit means;
providing yieldable restraining means carried by said sample chamber side wall means, said restraining means being operable to yieldably prevent movement of said first and second sleeve valve means from said second position to said said thirdposition, said restraining means being further operable to position said first and second sleeve valve means
at said first position in response to a relatively low pressure level in said well annulus,
at said second position in response to a relatively intermediate pressure level in said well annulus, and
at said third position in response to a relatively high pressure level in said well annulus;
providing yieldable movement impedance means operable to yieldably impede initial upward movement of said piston means in said cylinder means and permit relatively unimpeded downward movement of said piston means in said cylinder means,
operating said impedance means during said movement of said first and second valve means from said first position to said second position to impede movement of said first and second valve means,
operating said pressurizing means to decrease the pressure of fluid in said well annulus and provide said relatively low pressure therein and effect movement of said first and second valve means in said one direction from said second position tosaid first position,
operating said impedance means during said movement of said first and second valve means from said second position to said first position to permit relatively unimpeded downward movement of said first and second valve means,
operating said valve latching means to secure said first and second valve means in said third position; and
after said testing of said formation, releasing said sealing means from said wall means and permitting said venting valve means to vent the interior of said conduit means to the well bore interior in response to raising of said conduit meansupwardly through said well bore and a reduction in the hydrostatic pressure of fluid in said well bore adjacent
said venting valve means. 7. A method of testing a submerged formation from an offshore test site, said method comprising:
providing a well testing assembly including:
tubular conduit means communicating with a formation to be tested with said conduit means being disposed in a well bore and selectively removable therefrom to a floating work station,
wall means encircling at least a portion of said conduit means, and
selectively releasable sealing means extending between said conduit means and said wall means and cooperating with said conduit means and said wall means to provide a well annulus isolated from the interior of said conduit means;
regulating flow from said formation through said conduit means with an assembly including:
first, generally tubular valve seat means carried by and spaced inwardly from an interior wall portion of said conduit means and mounted concentrically therewith,
second, generally tubular valve seat means carried by and spaced inwardly from another interior wall portion of said conduit means, mounted concentrically therewith, and spaced longitudinally of and above said first valve seat means,
slidable sample chamber side wall means mounted on said first and second valve seat means for sliding movement longitudinally of said conduit means,
first sleeve valve means carried by a lower portion of said slidable sample chamber side wall means and disposed in valving cooperating with said first valve seat means,
second sleeve valve means carried by an upper portion of said slidable sample chamber side wall means and disposed in valving cooperation with said second valve seat means,
formation fluid inlet passage means carried by said first valve seat means, and operable to transmit formation fluid from said formation to the interior of said slidable sample chamber side wall means under valving control of said first sleevevalve means,
formation fluid outlet passage means carried by said first valve seat means, and operable to transmit formation fluid from the interior of said slidable sample chamber side wall means to the interior of said conduit means under valving control ofsaid second sleeve valve means,
said first and second sleeve valve means being concurrently operable in response to movement of said slidable sample chamber side wall means, said first and second sleeve valve means being sequentially movable from
a first, lower position closing said inlet and outlet passage means, to
a second, intermediate position above said first position opening said inlet and outlet passage means, and to
a third, upper position above said second position closing said inlet and outlet passage means;
providing a formation sample trapping chamber means including:
first barrier means closing a lower portion of said first valve seat means,
second barrier means closing an upper portion of said second valve seat means,
said first and second barrier means cooperating with said first and second valve seat means to provide sample entrapping closures at upper and lower ends, respectively, of said slidable sample chamber side wall means; .Iadd.
providing yieldable restraining means carried by said sample chamber side wall means, said restraining means being operable to yieldably prevent movement of said first and second sleeve valve means from said second position to said thirdposition, .Iaddend.
providing formation testing actuating means including:
pump means selectively operable from said floating work station to increase the pressure of fluid in said well annulus, with said sealing means isolating said well annulus from said formation,
annular piston means carried on the exterior of said sample chamber side wall means and mounted coaxially thereof,
cylinder means defined by a portion of said conduit means with said piston means being slidably mounted therein,
first expansible and contractible cavity means included in said cylinder means above said piston means and containing a body of expansible and contractible pressurized fluid yieldably biasing said piston means and slidable sample chamber sidewall means downwardly,
second expansible and contractible cavity means included in said cylinder means below said piston means,
communicating means provide pressure-change transmitting fluid communication between said second expansible and contractible cavity means and said well annulus;
testing said formation by:
imparting the pressure of said pressurized fluid to said piston means to urge said slidable sample chamber side wall means downwardly and hold said first and second sleeve valve means in said first, lower position to prevent a flow of formationfluid through said sample trapping chamber means from said formation, while maintaining .[.said.]. .Iadd.a .Iaddend.relatively low pressure level in said well annulus,
operating said pump means at said floating work station to increase the pressure of fluid in said well annulus, with said increase in pressure being operable to provide .[.said.]. .Iadd.a .Iaddend.relatively intermediate pressure in said wellannulus and effect upward movement of said sample chamber side wall means and move said first and second valve means from said first lower position to said second, intermediate position to permit a flow of fluid consecutively through said inlet passagemeans, interior of said sample trapping chamber means, and outlet passage means,
operating said pump means at said floating work station to provide .[.said.]. .Iadd.a .Iaddend.relatively high pressure level in said well annulus to cause said restraining means to yield, and move said first and second valve means from saidsecond intermediate position to said third, upper position and entrap a sample of formation fluid in said sample trapping chamber means,
after said testing of said formation, releasing said sealing means from said wall means, and raising said conduit means to said floating work station; and
effecting said testing while concurrently substantially preventing wave action induced forces from being transmitted from said floating work
station to said conduit means. 8. A method of testing a submerged formation from an offshore test site, said method comprising:
providing a well testing assembly including:
tubular conduit means communicating with a formation to be tested with said conduit means being disposed in a well bore and selectively removable therefrom to a floating work station,
wall means encircling at least a portion of said conduit means, and
selectively releasable sealing means extending between said conduit means and said wall means and cooperating with said conduit means and said wall means to provide a well annulus isolated from the interior of said conduit means;
regulating flow from said formation through said conduit means with an assembly including:
first, generally tubular valve seat means carried by and spaced inwardly from an interior wall portion of said conduit means and mounted concentrically therewith,
second, generally tubular valve seat means carried by and spaced inwardly from another interior wall portion of said conduit means, mounted concentrically therewith, and spaced longitudinally of and above said first valve seat means,
slidable sample chamber side wall means mounted on said first and second valve seat means for sliding movement longitudinally of said conduit means,
first sleeve valve means carried by a lower portion of said slidable sample chamber side wall means and disposed in valving cooperation with said first valve seat means,
second sleeve valve means carried by an upper portion of said slidable sample chamber side wall means and disposed in valving cooperation with said second valve seat means,
formation fluid inlet passage means carried by said first valve seat means, and operable to transmit formation fluid from said formation to the interior of said slidable sample chamber side wall means under valving control of said first sleevevalve means,
formation fluid outlet passage means carried by said first valve seat means, and operable to transmit formation fluid from the interior of said slidable sample chamber side wall means to the interior of said conduit means under valving control ofsaid second sleeve valve means,
said first and second sleeve valve means being concurrently operable in response to movement of said slidable sample chamber side wall means, said first and second sleeve valve means being sequentially movable from
a first, lower position closing said inlet and outlet passage means, to
a second, intermediate position above said first position opening said inlet and outlet passage means, and to
a third, upper position above said second position closing said inlet and outlet passage means,
first valve shielding means defined by a first wall portion of said conduit means, spaced outwardly of said inlet passage means and first valve seat means, and cooperating with said first valve seat means to define
a first annular passage leading to said inlet passage means,
second valve shielding means defined by a second wall portion of said conduit means, spaced outwardly of said outlet passage means and second valve seat means and cooperating with said second valve seat means to define
a second annular passage leading from said outlet passage means;
providing a formation sample trapping chamber means including:
first barrier means closing a lower portion of said first valve seat means,
second barrier means closing an upper portion of said second valve seat means,
said first and second barrier means cooperating with said first and second valve seat means to provide sample entrapping closures at upper and lower ends, respectively, of said slidable sample chamber side wall means,
first, passage means carried by said first barrier means and disposed axially thereof,
first plug valve means valvingly mounted in said first passage means,
second, passage means carried by said second barrier means and disposed axially thereof and
second plug valve means valvingly mounted in said second passage means,
said first valve shielding means being removable from said conduit means to provide access to said first plug valve means, and
said second valve shielding means being removable from said conduit means to provide access to said second plug valve means;
providing formation testing actuating means including:
pump means selectively operable from said floating work station to increase the pressure of fluid in said well annulus, with said sealing means isolating said well annulus from said formation,
annular piston means carried on the exterior of said sample chamber side wall means and mounted coaxially thereof,
cylinder means defined by a portion of said conduit means with said piston means being slidably mounted therein,
first expansible and contractible cavity means included in said cylinder means above said piston means and containing a body of expansible and contractible pressurized nitrogen yieldably biasing said piston means and slidable sample chamber sidewall means downwardly,
second expansible and contractible cavity means included in said cylinder means below said piston means,
communicating means provide pressure-change transmitting fluid communication between said second expansible and contractible cavity means and said well annulus;
providing valve latching means including:
first latching means carried by said sample trapping chamber means, and
second latching means carried by said slidable sample chamber side wall means and operable to engage said first latching means and latch said sample chamber side wall means with said sample trapping chamber means and secure said first and secondsleeve valve means in said third, upper position;
providing venting valve means in said conduit means below said first valve means and operable to vent pressurized fluid from the interior of said conduit means to the exterior thereof in response to a decrease in pressure of fluid adjacent theexterior of said conduit means;
providing yieldable restraining means carried by said sample chamber side wall means, said restraining means being operable to yieldably prevent movement of said first and second sleeve valve means from said second, intermediate position to saidthird upper position, said restraining means being further operable to position said first and second sleeve valve means
at said first, lower position in response to a relatively low pressure level in said well annulus,
at said second, intermediate position in response to a relatively intermediate pressure level in said well annulus, and
at said third, upper position in response to a relatively high pressure level in said well annulus;
providing yieldable movement impedance means operable to relatively impede initial upward movement of said piston means in said cylinder means and permit relatively unimpeded downward movement of said piston means in said cylinder means, saidimpedance means including
disabling means operable to substantially vitiate the movement impeding operation of said impedance means after said yieldable restraining means has yielded to permit said first and second sleeve valve means to move from said second, intermediateposition toward said third, upper position;
supporting said conduit means at said floating work station while providing:
collapsible and extensible coupling means between said conduit means and said floating work station; and
testing said formation by:
imparting the pressure of said pressurized nitrogen to said piston means to urge said slidable sample chamber side wall means downwardly and hold said first and second sleeve valve means in said first, lower position to prevent a flow offormation fluid through said sample trapping chamber means from said formation, while maintaining said relatively low pressure level in said well annulus,
operating said pump means at said floating work station to increase the pressure of fluid in said well annulus, with said increase in pressure being operable to provide said relatively intermediate pressure in said well annulus and effect upwardmovement of said sample chamber side wall means and move said first and second valve means from said first lower position to said second, intermediate position to permit a flow of fluid consecutively through said inlet passage means, interior of saidsample trapping chamber means, and outlet passage means, with said fluid approaching said sample trapping chamber means through said first annular passage and leaving said sample trapping chamber means through said second annular passage,
operating said impedance means during said movement of said first and second valve means from said first lower position to said second intermediate position to impede movement of said first and second valve means,
operating said pump means at said floating work station to decrease the pressure of fluid in said well annulus and provide said relatively low pressure therein and effect downward movement of said first and second valve means from said second,intermediate position to said first, lower position,
operating said impedance means during said downward movement of said first and second valve means from said second, intermediate position to said first lower position to permit relatively unimpeded downward moement of said first and second valvemeans,
operating said pump means at said floating work station to provide said relatively high pressure level in said well annulus to cause said restraining means to yield, and move said first and second valve means from said second intermediateposition to said third, upper position and entrap a sample of formation fluid in said sample trapping chamber means,
operating said disabling means during said movement of said first and second valve means from said second, intermediate position to said third, upper position to substantially vitiate the movement impeding operation of said impedance means,
operating said valve latching means to secure said first and second valve means in said third, upper position;
after said testing of said formation, releasing said seating means from said wall means, raising said conduit means to said floating work station, and permitting said venting valve means to vent the interior of said conduit means to the well boreinterior in response to the raising of said conduit means upwardly through said well bore and a reduction in the hydrostatic pressure of fluid in said well bore adjacent said venting valve means;
removing said first and second valve shielding means from said conduit means to provide substantially unobstructed access to said first and second plug valve means; and
operating at least one of said first and second plug valve means to remove
formation fluid from said formation sample trapping chamber means. 9. A method as described in claim 8 further comprising:
providing first relatively large, fluid reaction surface means carried by said annular piston means and disposed in fluid communicating relation with said expansible and contractible cavity
providing second relatively small, fluid reaction surface means carried by said annular piston means and disposed in fluid communicating relation with said second expansible and contractible cavity means;
inducing movement of said annular piston means in response to fluid forces
generated within said first and second cavity means. 10. A method as described in claim 9 further comprising:
effecting said testing while concurrently, substantially preventing wave action induced forces from being transmitted from said floating work station to said conduit means. .[.11. Apparatus for testing a formation intersected by a well bore,said apparatus comprising:
means for maintaining pressure in a body of fluid in a well bore, disposed adjacent a conduit means, at one level while maintaining said body of fluid isolated from a submerged formation to be tested and the interior of said conduit means;
means operable in response to said one level of pressure in said body of fluid, to maintain a flow path leading from said formation through said conduit means in said well bore in a closed condition;
means for changing the pressure of said fluid body while isolating said change in pressure of said fluid body from said formation;
means operable in response to said change in pressure, to permit fluid to flow from said formation through said conduit means;
means for further changing the pressure of fluid in said fluid body while isolating said further change in pressure from said formation and the interior of said conduit means; and
means operable in response to said further change of pressure of said fluid body, to entrap within said conduit means a sample of fluid from said formation..]. .[.12. Apparatus for testing a submerged formation from an comprising: test site,said apparatus comprising:
means for maintaining pressure in a body of fluid in a submerged well bore, disposed adjacent a conduit means, at a relatively low level while maintaining said body of fluid isolated from a submerged formation to be tested;
means operable in response to said relatively low level of pressure in said body of fluid, to maintain a flow path leading from said formation through said conduit means in said well bore in a closed condition;
means for increasing the pressure of said fluid body while isolating said increase in pressure of said fluid body from said formation;
means operable in response to said increase in pressure to permit fluid to flow from said formation through said conduit means;
means for further decreasing the pressure of fluid in said fluid body while isolating said further decrease in pressure from said formation; and
means operable in response to said further decrease of pressure of said fluid body, to entrap within said conduit means a sample of fluid from
said formation..]. 13. Apparatus for testing a submerged formation from an offshore test site, said apparatus comprising:
means for disposing a test string including tester valve controlled conduit means between a floating vessel and a submerged formation;
means for maintaining pressure in a body of liquid in a submerged well bore, disposed adjacent said conduit means, at a relatively low level while maintaining said body of liquid isolated from a submerged formation to be tested;
means operable in response to said relatively low level of pressure in said body of .[.liquie.]. .Iadd.liquid.Iaddend., to maintain a flow path leading from said formation through said conduit means in said well bore is a closed condition;
means for increasing the pressure of said liquid body while isolating said increase in pressure of said liquid body from said formation;
means operable in response to said increase in pressure, to permit fluid to flow from said formation through said conduit means;
means for further .[.decreasing.]. .Iadd.increasing .Iaddend.the pressure of liquid in said liquid body while isolating said further .[.decrease.]. .Iadd.increase .Iaddend.in pressure from said formation;
means operable in response to said further .[.decrease.]. .Iadd.increase .Iaddend.of pressure of said liquid body, to entrap within said conduit means of sample of fluid from said formation;
means providing and maintaining a confined body of pressurized gas in said conduit means, with said body being operable to determine the pressure level in said liquid body operable to permit said liquid to flow from said formation through saidconduit means;
yieldable means in said conduit means operable to determine the pressure
level in said liquid body operable to cause said entrapping. 14. Apparatus as described in claim 13 further comprising:
means for effecting said testing whle concurrently substantially preventing wave action induced forces from being transmitted through said test string
form said floating work station to said conduit means. 15. Apparatus for testing a formation, intersected by a well bore site, said apparatus comprising:
a well testing assembly including
conduit means communicating with a formation to be tested, with said conduit means being disposed in a well bore and selectively removable therefrom,
wall means encircling at least a portion of said conduit means, and
selectively releasable sealing means extending between said conduit means and said wall means and cooperating with said conduit means and said wall means to provide a well annulus isolated from the interior of said conduit means;
means for regulating flow from said formation through said conduit means and including
first, valve seat means carried by a wall portion of said conduit means,
second, valve seat means carried by another interior wall portion of said conduit means, and spaced longitudinally of and above said first valve seat means,
slidable sample chamber side wall means mounted on said first and second valve seat means for sliding movement longitudinally of said conduit means,
first valve means carried by a lower portion of said slidable sample chamber side wall means and disposed in valving cooperation with said first valve seat means,
second valve means carried by an upper portion of said slidable sample chamber side wall means and disposed in valving cooperation with said second valve seat means,
formation fluid inlet passage means operable to transmit formation fluid from said formation to the interior of said slidable sample chamber side wall means under valving control of said first sleeve valve means,
formation fluid outlet passage means operable to transmit formation fluid from the interior of said slidable sample chamber side wall means to the interior of said conduit means under valving control of said second sleeve valve means,
said first and second sleeve valve means being concurrently operable in response to movement of said slidable sample chamber side wall means,
said first and second sleeve valve means being sequentially movable from
a first position closing said inlet and outlet passage means, to
a second position opening said inlet and outlet passage means, and to
a third position closing said inlet and outlet passage means;
a formation sample trapping chamber means including:
wall means cooperating with said first and second valve seat means and said slidable sample chamber side wall means to define a sample receiving cavity; and
formation testing actuating means including
pressurizing means selectively operable to increase the pressure of fluid in said well annulus, with said sealing means isolating said well annulus from said formation,
piston means carried by said sample chamber side wall means,
cylinder means defined by a portion of said conduit means with said piston means being slidably mounted therein,
first expansible and contractible cavity means included in said cylinder means and containing a body of expansible and contractible pressurized fluid yieldably biasing said piston means and slidable sample chamber side wall means in onedirection,
second expansible and contractible cavity means included in said cylinder means operable to receive formation fluid to bias said piston means in another direction opposite to said one direction,
communicating means providing pressure-change transmitting fluid communication between said second expansible and contractible cavity means
and said well annulus. 16. Apparatus for testing a formation as described in claim 15, said apparatus further comprising:
valve latching means including:
socket means carried by said conduit means above said slidable sample chamber side wall means, and
1atching means carried by said slidable sample chamber side wall means and operable to releasably latch said sample chamber side wall means in said socket means when said first and second valve means are moved to said third position;
venting valve means in said conduit means below said first valve means and operable to vent pressurized fluid from the interior of said conduit means to the exterior thereof in response to a decrease in pressure of fluid adjacent the exterior ofsaid conduit means;
yieldable restraining means carried by said sample chamber side wall means, said restraining means being operable to yieldably prevent movement of said first and second sleeve valve means from said second position to said third position, saidrestraining means being further operable to position said first and second sleeve valve means
at said first position in response to a relatively low pressure level in said well annulus,
at said second position in response to a relatively intermediate pressure level in said well annulus, and
at said third position in response to a relatively high pressure level in said well annulus; and
yieldable movement impedance means operable to yieldably impede initial upward movement of said piston means in said cylinder means and permit relatively unimpeded downward movement of said piston means in said
cylinder means. 17. Apparatus for testing a submerged formation from an offshore test site, said apparatus comprising:
a well testing assembly including
tubular conduit means communicating with a formation to be tested with said conduit means being disposed in a well bore and selectively removable therefrom to a floating work station,
wall means encircling at least a portion of said conduit means, and
selectively releasable sealing means extending between said conduit means and said wall means and cooperating with said conduit means and said wall means to provide a well annulus isolated from the interior of said conduit means;
means for regulating flow from said formation through said conduit means and including
first, generally tubular valve seat means carried by and spaced inwardly from an interior wall portion of said conduit means and mounted concentrically therewith,
second, generally tubular valve seat means carried by and spaced inwardly from another interior wall portion of said conduit means, mounted concentrically therewith, and spaced longitudinally of and above said first valve seat means,
slidable sample chamber side wall means mounted on said first and second valve seat means for sliding movement longitudinally of said conduit means,
first sleeve valve means carried by a lower portion of said slidable sample chamber side wall means and disposed in valving .[.cooperating.]. .Iadd.cooperation .Iaddend.with said first valve seat means,
second sleeve valve means carried by an upper portion of said slidable sample chamber side wall means and disposed in valving cooperating with said second valve seat means,
formation fluid inlet passage means carried by said first valve seat means, and operable to transmit formation fluid from said formation to the interior of said slidable sample chamber side wall means under valving control of said first sleevevalve means,
formation fluid outlet passage means carried by said first valve seat means, and operable to transmit formation fluid from the interior of said slidable sample chamber side wall means to the interior of said conduit means under valving control ofsaid second sleeve valve means,
said first and second sleeve valve means being concurrently operable in response to movement of said slidable sample chamber side wall means, said first and second sleeve valve means being sequentially movable from
a first, lower position closing said inlet and outlet passage means, to
a second, intermediate position above said first position opening said inlet and outlet passage means, and to
a third, upper position above said second position closing said inlet and outlet passage means;
a formation sample trapping chamber means including
first barrier means closing a lower portion of said first valve seat means,
second barrier means closing an upper portion of said second valve seat means,
said first and second barrier means cooperating with said first and second valve seat means to provide sample entrapping closures at upper and lower ends, respectively, of said slidable sample chamber side wall means; and
formation testing actuating means including
pump means selectively operable from said floating work station to increase the pressure of fluid in said well annulus, with said sealing means isolating said well annulus from said formation,
annular piston means carried on the exterior of said sample chamber side wall means and mounted coaxially thereof,
cylinder means defined by a portion of said conduit means with said piston means being slidably mounted therein,
first expansible and contractible cavity means included in said cylinder means above said piston means and containing a body of expansible and contractible pressurized fluid yieldably biasing said piston means and slidable sample chamber sidewall means downwardly,
second expansible and contractible cavity means included in said cylinder means below said piston means, and
communicating means provide pressure-change transmitting fluid communication between said second expansible and contractible cavity means
and said well annulus. 18. Apparatus for testing a submerged formation from an offshore test site, said apparatus comprising:
a well testing assembly including
tubular conduit means communicating with a formation to be tested with said conduit means being disposed in a well bore and selectively removable therefrom to a floating work station,
wall means encircling at least a portion of said conduit means, and
selectively releasable sealing means extending between said conduit means and said wall means and cooperating with said conduit means and said wall means to provide a well annulus isolated from the interior of said conduit means;
means for regulating flow from said formation through said conduit means and including
first, generally tubular valve seat means carried by and spaced inwardly from an interior wall portion of said conduit means and mounted concentrically therewith,
second, generally tubular valve seat means carried by and spaced inwardly from another interior wall portion of said conduit means, mounted concentrically therewith, and spaced longitudinally of and above said first valve seat means,
slidable sample chamber side wall means mounted on said first and second valve seat means for sliding movement longitudinally of said conduit means,
first sleeve valve means carried by a lower portion of said slidable sample chamber side wall means and disposed in valving cooperation with said first valve seat means,
second sleeve valve means carried by an upper portion of said slidable sample chamber side wall means and disposed in valving cooperation with said second valve seat means,
formation fluid inlet passage means carried by said first valve seat means, and operable to transmit formation fluid from said formation to the interior of said slidable sample chamber side wall means under valving control of said first sleevevalve means,
formation fluid outlet passage means carried by said first valve seat means, and operable to transmit formation fluid from the interior of said slidable sample chamber side wall means to the interior of said conduit means under valving control ofsaid second sleeve valve means,
said first and second sleeve valve means being concurrently operable in response to movement of said slidable sample chamber side wall means, said first and second sleeve valve means being sequentially movable from
a first, lower position closing said inlet and outlet passage means, to
a second, intermediate position above said first position opening said inlet and outlet passage means, and to
a third, upper position above said second position closing said inlet and outlet passage means,
first valve shielding means defined by a first wall portion of said conduit means, spaced outwardly of said inlet passage means and first valve seat means, and cooperating with said first valve seat means to define
a first annular passage leading to said inlet passage means,
second valve shielding means defined by a second wall portion of said conduit means, spaced outwardly of said outlet passage means and second valve seat means and cooperating with said second valve seat means to define
a second annular passage leading from said outlet passage means;
a formation sample trapping chamber means including
first barrier means closing a lower portion of said first valve seat means,
second barrier means closing an upper portion of said second valve seat means,
said first and second barrier means cooperating with said first and second valve seat means to provide sample entrapping closures at upper and lower ends, respectively, of said slidable sample chamber side wall means,
first, passage means carried by said first barrier means and disposed axially thereof,
first plug valve means valvingly mounted in said first passage means,
second, passage means carried by said second barrier means and disposed axially thereof, and
second plug valve means valvingly mounted in said second passage means,
said first valve shielding means being removable from said conduit means to provide access to said first plug valve means, and
said second valve shielding means being removable from said conduit means to provide access to said second plug valve means;
formation testing actuating means including
pump means selectively operable from said floating work station to increase the pressure of fluid in said well annulus, with said sealing means isolating said well annulus from said formation,
annular piston means carried on the exterior of said sample chamber side wall means and mounted coaxially thereof,
cylinder means defined by a portion of said conduit means with said piston means being slidably mounted therein,
first expansible and contractible cavity means included in said cylinder means above said piston means and containing a body of expansible and contractible pressurized nitrogen yieldably biasing said piston means and slidable sample chamber sidewall means downwardly,
second expansible and contractible cavity means included in said cylinder means below said piston means,
communicating means provide pressure-change transmitting fluid communication between said second expansible and contractible cavity means and said well annulus;
valve latching means including
first latching means carried by said sample trapping chamber means, and
second latching means carried by said slidable sample chamber side wall means and operable to engage said first latching means and latch said sample chamber side wall means with said sample trapping chamber means and secure said first and secondsleeve valve means in said third, upper position;
venting valve means in said conduit means below said first valve means and operable to vent pressurized fluid from the interior of said conduit means to the exterior thereof in response to a decrease in pressure of fluid adjacent the exterior ofsaid conduit means;
yieldable restraining means carried by said sample chamber side wall means, said restraining means being operable to yieldably prevent movement of said first and second sleeve valve means from said second, intermediate position to said thirdupper position, said restraining means being further operable to position said first and second sleeve valve means
at said first, lower position in response to a relatively low pressure level in said well annulus,
at said second, intermediate position in response to a relatively intermediate pressure level in said well annulus, and
at said third, upper position in response to a relatively high pressure level in said well annulus;
yieldable movement impedance means operable to relatively impede initial upward movement of said piston means in said cylinder means and permit relatively unimpeded downward movement of said piston means in said cylinder means, said impedancemeans including
disabling means operable to substantially vitiate the movement impeding operation of said impedance means after said yield-able restraining means has yielded to per-mit said first and second sleeve valve means to move from said second,intermediate position toward said third, upper position; and
collapsible and extensible coupling means disposed between said conduit
means and said floating work station. 19. Apparatus as described in claim 18 further comprising:
first, relatively large, fluid reaction surface means carried by said annular piston means and disposed in fluid communicating relation with said first expansible and contractible cavity means; and
second, relatively small, fluid reaction surface means carried by said annular piston means and disposed in fluid communicating relation with
said second expansible and contractible cavity means. 20. Apparatus as described in claim 19 further comprising:
submerged means operable to substantially prevent wave action induced forces from being transmitted from said floating work station to said conduit means. .Iadd. 21. A method of testing a formation intersected by a well bore, said methodcomprising:
maintaining pressure in a body of fluid in a well bore, disposed adjacent a conduit means, at one level while maintaining said body of fluid isolated from a submerged formation to be tested and the interior of said conduit means;
in response to said one level of pressure in said body of fluid, maintaining a flow path leading from said formation through said conduit means in said well bore in a closed condition;
changing the pressure of said fluid body while isolating said change in pressure of said fluid body from said formation;
in response to said change in pressure, permitting fluid flow from said formation through said conduit means;
further changing the pressure of fluid in said fluid body while isolating said further change in pressure from said formation and the interior of said conduit means; and
in response to said further change of pressure of said fluid body,
entrapping within a closed sample chamber provided in said conduit means a sample of fluid from said formation, and
securing said sample chamber in said sample entrapping closed condition and preventing any subsequent opening thereof in response to subsequent pressure changes of said fluid body..Iaddend..Iadd. 22. Apparatus for testing a formationintersected by a well bore, said apparatus comprising:
means for maintaining pressure in a body of fluid in a well bore, disposed adjacent a conduit means, at one level while maintaining said body of fluid isolated from a submerged formation to be tested and the interior of said conduit means;
means operable in response to said one level of pressure in said body of fluid, to maintain a flow path leading from said formation through said conduit means in said well bore in a closed condition;
means for changing the pressure of said fluid body while isolating said change in pressure of said fluid body from said formation;
means operable in response to said change in pressure, to permit fluid flow from said formation through said conduit means;
means for further changing the pressure of fluid in said fluid body while isolating said further change in pressure from said formation and the interior of said conduit means;
means, including a closeable sample chamber within said conduit means, operable in response to said further change of pressure of said fluid body, to close and entrap within said closeable sample chamber a sample of fluid from said formation; and
means for securing said sample chamber in said sample entrapping closed condition and for preventing any subsequent opening thereof in response to subsequent pressure changes of said fluid body..Iaddend..Iadd. 23. In a method of offshoretesting a submerged formation intersected by a submerged well bore, which method includes:
providing a formation fluid sample entrapping test string extending downwardly from floating vessel means; and
1owering said formation fluid sample entrapping test string from said floating vessel means through conduit means extending upwardly from a submerged well head installation to said floating vessel means;
the improvement in said method comprising:
providing a first annular fluid body within said formation fluid sample entrapping test string spaced from and disposed beneath said floating vessel means;
retrievably supporting said formation fluid sample entrapping test string within a submerged well bore intersecting a submerged formation to be tested,
with said first annular fluid body being located in said submerged well bore beneath a submerged well head installation and above a packer means, and with said packer means and said submerged well head installation isolating a well annulusportion of said submerged well bore beneath said submerged well head installation and above said packer means from the pressure of said submerged formation to be tested, which annulus portion encircles the outer periphery of said formation fluid sampleentrapping test string;
said annulus portion
being wholly external of said formation fluid sample entrapping test string,
being located immediately adjacent a casing wall of said submerged well bore, and
defining a second annular body of fluid isolated from said submerged formation and from said conduit means extending upwardly from said submerged well head installation;
providing pressure opposing cooperation between said second annular body of fluid and said first annular body of fluid;
providing within said formation fluid sample entrapping test string a closeable sample chamber having
concurrently closeable and openable upper and lower ends, and
opening and closing means responsive to changes in pressure of said second annular body of fluid for alternately, concurrently opening and closing said upper and lower ends,
providing a flow path in said formation fluid sample entrapping test string operable to transmit formation fluid from said submerged formation to said closeable sample chamber within said formation fluid sample entrapping test string,
with said flow path extending axially of and through said first annular body of fluid and comprising the interior of said formation fluid sample entrapping test string;
continuously isolating said first annular body of fluid and said second annular body of fluid from fluid pressure of said submerged formation and fluid pressure of said interior of said formation fluid sample entrapping test string;
opposing the pressure of fluid in said first annular fluid body with the pressure of fluid in said second annular fluid body and transmitting the resultant force of said opposing pressures to said closeable fluid sample chamber opening andclosing means;
in response to the opposing influences of a lower pressure in said second annular body of fluid in said submerged well bore and pressure of said first annular fluid body, and while said first and second annular fluid bodies are continuouslyisolated from the fluid pressure of said submerged formation to be tested and said interior of said formation fluid sample entrapping test string,
causing said opening and closing means to close said upper and lower ends of said closeable sample chamber;
from said floating vessel means, raising the pressure of said second annular fluid body while continuously isolating said raise in pressure of said second annular fluid body from said submerged formation and said interior of said formation fluidsample entrapping test string;
in response to said raising of pressure in said second annular fluid body, and independent of pressure in said submerged formation and said interior of said formation fluid sample entrapping test string and, while isolating pressures in saidsubmerged formation and said interior of said formation fluid sample entrapping test string from each of said first and second annular fluid bodies,
causing said opening and closing means to permit fluid to flow from said submerged formation through said flow path and axially through said first annular fluid body and through said closeable sample chamber;
from said floating vessel means, reducing the pressure of fluid in said second annular fluid body, while isolating said reduction in pressure therein from said submerged formation and from said interior of said formation fluid sample entrappingtest string;
in response to said reducing of pressure in said second annular fluid body, and independent of pressures in said submerged formation and said interior of said formation fluid sample entrapping test string, and while isolating pressures in saidsubmerged formation and said interior of said formation fluid entrapping test string from each of said first and second annular fluid bodies,
causing said opening and closing means to close said upper and lower ends of said closeable sample chamber and entrap a sample of fluid from said submerged formation therewithin;
from said floating vessel means, effecting a subsequent increase in pressure in said second annular fluid body; and
in response to said subsequent increase in pressure said second annular fluid body,
securing said opening and closing means in a condition closing said upper and lower ends of said closeable sample chamber, and
preventing further opening of said upper and lower ends of said closeable sample chamber while said closeable sample chamber remains in said submerged well bore, regardless of further pressure changes in said second
annular fluid body..Iaddend..Iadd. 24. In a method of offshore testing a submerged formation intersected by a submerged well bore, which method includes:
providing a formation fluid sample entrapping test string extending downwardly from floating vessel means; and
1owering said formation fluid sample entrapping test string from said floating vessel means through conduit means extending upwardly from a submerged well head installation to said floating vessel means;
the improvement in said method comprising:
providing a first fluid body within said formation fluid sample entrapping test string spaced from and disposed beneath said floating vessel means;
retrievably supporting said formation fluid sample entrapping test string within a submerged well bore intersecting a submerged formation to be tested,
with said first fluid body being located in said submerged well bore beneath a submerged well head installation and above a packer means, and
with said packer means and said submerged well head installation being disposed, respectively, below and above a well annulus portion of said submerged well bore, which annulus portion encircles the outer periphery of said formation fluid sampleentrapping test string;
said annulus portion
being external of said formation fluid sample entrapping test string,
being located immediately adjacent a casing wall of said submerged well bore, and
defining a second annular body of fluid isolated from said submerged formation;
providing pressure opposing cooperation between said second annular body of fluid and said first body of fluid;
providing within said formation fluid sample entrapping test string a closeable sample chamber having
closeable and openable upper and lower ends, and
opening and closing means responsive to changes in pressure of said second annular body of fluid for alternately, opening and closing said upper and lower ends,
providing a flow path in the interior of said formation fluid sample entrapping test string operable to transmit formation fluid from said submerged formation to said closeable sample chamber within said formation fluid sample entrapping teststring;
continuously isolating said first body of fluid and said second annular body of fluid from fluid pressure of said submerged formation and fluid pressure of said flow path of said formation fluid sample entrapping test string;
opposing the pressure of fluid in said first fluid body with the pressure of fluid in said second annular fluid body and transmitting the resultant force of said opposing pressures to said closeable fluid sample chamber opening and closing means;
in response to the opposing influences of a lower pressure in said second annular body of fluid in said submerged well bore and pressure of said first fluid body, and while said first fluid body and second annular fluid body are continuouslyisolated from the fluid pressure of said submerged formation to be tested and said flow path of sad formation fluid sample entrapping test string,
causing said opening and closing means to close said upper and lower ends of said closeable sample chamber;
from said floating vessel means, raising the pressure of said second annular fluid body while continuously isolating said raise in pressure of said second annular fluid body from said submerged formation and said flow path of said formation fluidsample entrapping test string;
in response to said raising of pressure in said second annular fluid body, and independent of pressure in said submerged formation and said flow path of said formation fluid sample entrapping test string and while isolating pressures in saidsubmerged formation and said flow path of said formation fluid sample entrapping test string from each of said first fluid body and second annular fluid bodies,
causing said opening and closing means to permit fluid to flow from said submerged formation through said flow path and through said closeable sample chamber;
from said floating vessel means, reducing the pressure of fluid in said second annular fluid body, while isolating said reduction in pressure therein from said submerged formation and from said flow path of said formation fluid sample entrappingtest string;
in response to said reducing of pressure in said second annular fluid body, and independent of pressures in said submerged formation and said flow path of said formation fluid sample entrapping test string, and while isolating pressures in saidsubmerged formation and said flow path of said formation fluid entrapping test string from each of said first fluid body and second annular fluid body,
causing said opening and closing means to close said upper and lower ends of said closeable sample chamber and entrap a sample of fluid from said submerged formation therewithin;
from said floating vessel means, effecting a subsequent increase in pressure in said second annular fluid body; and
in response to said subsequent increase in pressure in said second annular fluid body,
securing said opening and closing means in a condition closing said upper and lower ends of said closeable sample chamber, and
preventing further opening of said upper and lower ends of said closeable sample chamber while said closeable sample chamber remains in said submerged well bore, regardless of further pressure changes in said second
annular fluid body..Iaddend. .Iadd. 25. A method of offshore testing a submerged formation intersected by a submerged well bore, which method includes:
providing a formation fluid sample entrapping test string extending downwardly from floating vessel means; and
1owering said formation fluid sample entrapping test string from said floating vessel means through conduit means extending upwardly from a submerged well head installation to said floating vessel means;
the improvement in said method comprising:
providing a first fluid body within said formation fluid sample entrapping test string spaced from and disposed beneath said floating vessel means;
retrievably supporting said formation fluid sample entrapping test string within a submerged well bore intersecting a submerged formation to be tested,
with said first fluid body being located in said submerged well bore beneath a submerged well head installation and above a packer means, and
with said packer means and said submerged well head installation being disposed, respectively, below and above a well annulus portion of said submerged well bore, which annulus portion encircles the outer periphery of said formation fluid sampleentrapping test string;
said annulus portion
being external of said formation fluid sample entrapping test string,
being located immediately adjacent a casing wall of said submerged well bore, and
defining a second annular body of fluid isolated from said submerged formation;
providing pressure opposing cooperation between said second annular body of fluid and said first body of fluid;
providing within said formation fluid sample entrapping test string a closeable sample chamber having
closeable and openable upper and lower ends, and
opening and closing means responsive to changes in pressure of said second annular body of fluid for alternately, opening and closing said upper and lower ends,
providing a flow path in tne interior of said formation fluid sample entrapping test string operable to transmit formation fluid from said submerged formation to said closeable sample chamber within said formation fluid sample entrapping teststring;
continuously isolating said first body of fluid and said second annular body of fluid from fluid pressure of said submerged formation and fluid pressure of said flow path of said formation fluid sample entrapping test string;
opposing the pressure of fluid in said first fluid body with the pressure of fluid in said second annular fluid body and transmitting the resultant force of said opposing pressures to said closeable fluid sample chamber opening and closing means;
in response to the opposing influences of pressure in said second annular body of fluid in said submerged well bore and pressure of said first fluid body, and while said first fluid body and second annular fluid body are continuously isolatedfrom the fluid pressure of said submerged formation to be tested and said flow path of said formation fluid sample entrapping test string,
causing said opening and closing means to close said upper and lower ends of said closeable sample chamber;
from said floating vessel means, raising the pressure of said second annular fluid body while continuously isolating said raise in pressure of said second annular fluid body from said submerged formation and said flow path of said formation fluidsample entrapping test string;
in response to said raising of pressure in said second annular fluid body, and independent of pressure in said submerged formation and said flow path of said formation fluid sample entrapping test string and, while isolating pressures in saidsubmerged formation and said flow path of said formation fluid sample entrapping test string from each of said first fluid body and second annular fluid body,
causing said opening and closing means to permit fluid to flow from said submerged formation through said flow path and through said closeable sample chamber;
from said floating vessel means, changing the pressure of fluid in said second annular fluid body, while isolating said change in pressure therein from said submerged formation and from said flow path of said formation fluid sample entrappingtest string;
in response to said changing of pressure in said second annular fluid body, and independent of pressures in said submerged formation and said flow path of said formation fluid sample entrapping test string, and while isolating pressures in saidsubmerged formation and said flow path of said formation fluid entrapping test string from each of said first fluid body and second annular fluid body,
causing said opening and closing means to close said upper and lower ends of said closeable sample chamber and entrap a sample of fluid from said
submerged formation therewith..Iaddend..Iadd. 26. In an apparatus for offshore testing a submerged formation intersected by a submerged well bore, said apparatus includes:
floating vessel means;
a submerged well head installation;
a casing wall extending downwardly from said submerged well head installation into a submerged well bore; with
said submerged well bore intersecting a submerged formation to be tested;
conduit means extending upwardly from said submerged well head installation to said floating vessel means; and
a formation fluid sample entrapping test string extending downwardly from said floating vessel means through said conduit means and into said submerged well bore, said sample entrapping test string
including and supporting releasable packer means,
extending through said submerged well head installation, and
being sealingly and releasably connected to said casing wall by said packer means;
the improvement in said apparatus comprising:
a first annular fluid body disposed within said formation fluid sample entrapping test string spaced from and disposed beneath said floating vessel means;
means retrievably supporting said formation fluid sample entrapping test string within said submerged well bore,
with said first annular fluid body being located in said submerged well bore beneath said submerged well head installation and above said packer means, and
with said packer means and said submerged well head installation isolating a well annulus portion of said submerged well bore beneath said submerged well head installation and above said packer means from the pressure of said submerged formationto be tested, which annulus portion encircles the outer periphery of said formation fluid sample entrapping test string;
said annulus portion
being wholly external of said formation fluid sample entrapping test string,
being located immediately adjacent a casing wall of said submerged well bore, and
defining a second annular body of fluid isolated from said submerged formation and from said conduit means extending upwardly from said submerged well head installation;
means providing pressure opposing cooperation between said second annular body of fluid and said first annular body of fluid;
means providing, within said formation fluid sample entrapping test string, a closeable sample chamber having
concurrently closeable and openable upper and lower ends, and
opening and closing means responsive to changes in pressure of said second annular body of fluid for alternately, concurrently opening and closing said upper and lower ends,
means providing a flow path in said formation fluid sample entrapping test string operable to transmit formation fluid from said submerged formation to said closeable sample chamber within said formation fluid sample entrapping test string,
with said flow path extending axially of and through said first annular body of fluid and comprising the interior of said formation fluid sample entrapping test string;
means for continuously isolating said first annular body of fluid and said second annular body of fluid from fluid pressure of said submerged formation and fluid pressure of said interior of said formation fluid sample entrapping test string;
means for opposing the pressure of fluid in said first annular fluid body with the pressure of fluid in said second annular fluid body and transmitting the resultant force of said opposing pressures to said closeable fluid sample chamber openingand closing means;
means operable in response to the opposing influences of a lower pressure in said second annular body of fluid in said submerged well bore and pressure of said first annular fluid body, and while said first and second annular fluid bodies arecontinuously isolated from the fluid pressure of said submerged formation to be tested and said interior of said formation fluid sample entrapping test string, to
cause said opening and closing means to close said upper and lower ends of said closeable sample chamber;
means operable from said floating vessel means to raise the pressure of said second annular fluid body while continuously isolating said raise in pressure of said second annular fluid body from said submerged formation and said interior of saidformation fluid sample entrapping test string;
means operable, in response to said raising of pressure in said second annular fluid body, and independent of pressure in said submerged formation and said interior of said formation fluid sample entrapping test string and, while isolatingpressures in said submerged formation and said interior of said formation fluid sample entrapping test string from each of said first and second annular fluid bodies, to
cause said opening and closing means to permit fluid to flow from said submerged formation through said flow path and axially through said first annular fluid body and through said closeable sample chamber;
means operable from said floating vessel means to reduce the pressure of fluid in said second annular fluid body, while isolating said reduction in pressure therein from said submerged formation and from said interior of said formation fluidsample entrapping test string;
means operable in response to said reducing of pressure in said second annular fluid body, and independent of pressures in said submerged formation and said interior of said formation fluid sample entrapping test string, and while isolatingpressures in said submerged formation and said interior of said formation fluid entrapping test string from each of said first and second annular fluid bodies, to
cause said opening and closing means to close said upper and lower ends of said closeable sample chamber and entrap a sample of fluid from said submerged formation therewithin;
means operable from said floating vessel means to effect a subsequent increase in pressure in said second annular fluid body; and
means operable in response to said subsequent increase in pressure in said second annular fluid body, to
secure said opening and closing means in a condition closing said upper and lower ends of said closeable sample chamber, and
prevent further opening of said upper and lower ends of said closeable sample chamber while said closeable sample chamber remains in said submerged well bore, regardless of further pressure changes in said second
annular fluid body. .Iaddend..Iadd. 27. In an apparatus for offshore testing a submerged formation intersected by a submerged well bore, which apparatus includes:
a floating vessel means;
a submerged well head installation;
a casing wall exending downwardly from said submerged well head installation into a submerged well bore; with
said submerged well bore intersecting a submerged formation to be tested;
conduit means extending upwardly from said submerged well head installation to said floating vessel means; and
a formation fluid sample entrapping test string extending downwardly from said floating vessel means through said conduit means and into said submerged well bore, said sample entrapping test string
including and supporting releasable packer means,
extending through said submerged well head installation, and
being sealingly and releasably connected to said casing wall by said packer means;
the improvement in said apparatus comprising:
a first fluid body disposed within said formation fluid sample entrapping test string spaced from and disposed beneath said floating vessel means;
means retrievably supporting said formation fluid sample entrapping test string within said submerged well bore,
with said first fluid body being located in said submerged well bore beneath aid submerged well head installation and above said packer means, and
with said packer means and said submerged well head installation being disposed, respectively, below and above a well annulus portion of said submerged well bore, which annulus portion encircles the outer periphery of said formation fluid sampleentrapping test string;
said annulus portion
being external of said formation fluid sample entrapping test string,
being located immediately adjacent a casing wall of said submerged well bore, and
defining a second annular body of fluid isolated from said submerged formation;
means providing pressure opposing cooperation between said second annular body of fluid and said first body of fluid;
means providing, within said formation fluid sample entrapping test string, a closeable sample chamber having
closeable and openable upper and lower ends, and
opening and closing means responsive to changes in pressure of said second annular body of fluid for alternately, opening and closing said upper and lower ends,
means providing a flow path in the interior of said formation fluid sample entrapping test string operable to transmit formation fluid from said submerged formation to said closeable sample chamber within said formation fluid sample entrappingtest string;
means for continuously isolating said first body of fluid and said second annular body of fluid from fluid pressure of said submerged formation and fluid pressure of said flow path of said formation fluid sample entrapping test string;
means for opposing the pressure of fluid in said first fluid body with the pressure of fluid in said second annular fluid body and transmitting the resultat force of said opposing pressures to said closeable fluid sample chamber opening andclosing means;
means operable in response to the opposing influences of a lower pressure in said second annular body of fluid in said submerged well bore and pressure of said first fluid body, and while said first fluid body and second annular fluid body arecontinuously isolated from the fluid pressure of said submerged formation to be tested and said flow path of said formation fluid sample entrapping test string,
to cause said opening and closing means to close said upper and lower ends of said closeable sample chamber;
means operable from said floating vessel means to raise the pressure of said second annular fluid body while continuously isolating said raise in pressure of said second annular fluid body from said submerged formation and said flow path of saidformation fluid sample entrapping test string;
means operable, in response to said raising of pressure in said second annular fluid body, and independent of pressure in said submerged formation and said flow path of said formation fluid sample entrapping test string and, while isolatingpressures in said submerged formation and said flow path of said formation fluid sample entrapping test string from each of said first fluid body and second annular fluid body, to
cause said opening and closing means to permit fluid to flow from said submerged formation through said flow path and through said closeable sample chamber;
means operable from said floating vessel means to reduce the pressure of fluid in said second annular fluid body, while isolating said reduction in pressure therein from said submerged formation and from said flow path of said formation fluidsample entrapping test string;
means operable in response to said reducing of pressure in said second annular fluid body, and independent of pressures in said submerged formation and said flow path of said formation fluid sample entrapping test string, and while isolatingpressures in said submerged formation and said flow path of said formation fluid entrapping test string from each of said first fluid body and second annular fluid body, to
cause said opening and closing means to close said upper and lower ends of said closeable sample chamber and entrap a sample of fluid from said submerged formation therewithin;
means operable from said floating vessel means to effect a subsequent increase in pressure in said second annular fluid body; and
means operable in response to said subsequent increase in pressure in said second annular fluid body, to
secure said opening and closing means in a condition closing said upper and lower ends of said closeable sample chamber, and
prevent further opening of said upper and lower ends of said closeable sample chamber while said closeable sample chamber remains in said submerged well bore, regardless of further pressure changes in said second
annular fluid body..Iaddend..Iadd. 28. In an apparatus for offshore testing a submerged formation intersected by a submerged well bore, which apparatus includes:
floating vessel means;
a submerged well head installation;
a casing wall extending downwardly from said submerged well head installation into a submerged well bore; with
said submerged well bore intersecting a submerged formation to be tested
conduit means extending upwardly from said submerged well head installation to said floating vessel means; and
a formation fluid sample entrapping test string extending downwardly from said floating vessel means through said conduit means and into said submerged well bore, and said sample entrapping test string
including and supporting releasable packer means
extending through said submerged well head installation, and
being sealingly and releasably connected to said casing wall by said packer means;
the improvement in said apparatus comprising:
a first fluid body disposed within said formation fluid sample entrapping test string spaced from and disposed beneath said floating vessel means;
means retrievable supporting said formation fluid sample entrapping test string within said submerged well bore,
with said first fluid body being located in said submerged well bore beneath said submerged well head installation and above said packer means, and
with said packer means and said submerged well head installation being disposed, respectively, below and above a well annulus portion of said submerged well bore, which annulus portion encircles the outer periphery of formation fluid sampleentrapping test string;
said annulus portion
being external of said formation fluid sample entrapping test string,
being located immediately adjacent a casing wall of said submerged well bore, and
defining a second annular body of fluid isolated from said submerged formation;
means providing pressure opposing cooperation between said second annular body of fluid and said first body of fluid;
means providing, within said formation fluid sample entrapping test string, a closeable sample chamber having
closeable and openable upper and lower ends, and
opening and closing means responsive to changes in pressure of said second annular body of fluid for alternately opening and closing said upper and lower ends,
means providing a flow path in the interior of said formation fluid sample entrapping test string operable to transmit formation fluid from said submerged formation to said closeable sample chamber within said formation fluid sample entrappingtest string;
means for continuously isolating said first body of fluid and said second annular body of fluid from fluid pressure of said submerged formation and fluid pressure of said flow path of said formation fluid sample entrapping test string;
means for opposing the pressure of fluid in said first fluid body with the pressure of fluid in said second annular fluid body and transmitting the resultant force of said opposing pressures to said closeable fluid sample chamber opening andclosing means;
means operable in response to the opposing influences of pressure in said second annular body of fluid in said submerged well bore and pressure of said first fluid body, and while said first fluid body and second annular fluid body arecontinuously isolated from the fluid pressure of said submerged formation to be tested and said flow path of said formation fluid sample entrapping test string, to
cause said opening and closing means to close said upper and lower ends of said closeable sample chamber;
means operable from said floating vessel means to raise the pressure of said second annular fluid body while continuously isolating said raise in pressure of said second annular fluid body from said submerged formation and said flow path of saidformation fluid sample entrapping test string;
means operable, in response to said raising of pressure in said second annular fluid body, and independent of pressure in said submerged formation and said flow path of said formation fluid sample entrapping test string and while isolatingpressures in said submerged formation and said flow path of said formation fluid sample entrapping test string from each of said first fluid body and second annular fluid body, to
cause said opening and closing means to permit fluid to flow from said submerged formation through said flow path and through said closeable sample chamber;
means operable from said floating vessel means to change the pressure of fluid in said second annular fluid body, while isolating said change in pressure therein from said submerged formation and from said flow path of said formation fluid sampleentrapping test string;
means operable in response to said changing of pressure in said second annular fluid body, and independent of pressures in said submerged formation and said flow path of said formation fluid sample entrapping test string, and while isolatingpressures in said submerged formation and said flow path of said formation fluid entrapping test string from each of said first fluid body and second annular fluid body, to
cause said opening and closing means to close said upper and lower ends of said closeable sample chamber and entrap a sample of fluid from said
submerged formation therewithin. .Iaddend. .Iadd.29. A method of testing a submerged formation intersected by a well bore having a lower portion extending from the sea floor to the formation to be tested and an upper well bore portionextending from the sea floor to a work station at the surface of the sea, said method comprising:
maintaining pressure in a body of fluid in said well bore, disposed in an annulus of said well bore external of a conduit means and adjacent a casing lining the lower portion of said well bore, at one level while maintaining said body of fluidisolated from said submerged formation to be tested, the interior of said conduit means and said upper well bore portion;
in response to said one level of pressure in said body of fluid, maintaining a flow path leading from said formation through said conduit means in said well bore in a closed condition;
changing the pressure of said fluid body while isolating said change in pressure of said fluid body from said formation, the flow path through said conduit means and said upper well bore portion;
in response to said change in pressure, permitting fluid to flow from said formation through said conduit means;
further changing the pressure of fluid in said fluid body while isolating said further change in pressure from said formation, the flow path through said conduit means and said upper well bore portion;
in response to said further change of pressure of said fluid body and independent of the pressure in the flow path through said conduit means, entrapping between upper and lower valve means within said conduit means located in said well boreadjacent said fluid filled annulus, a sample of
fluid from said formation. .Iaddend..Iadd. 30. A method of testing a submerged formation from an offshore test site having an upper well bore portion extending from a work station at the surface of the sea to the sea floor and a submergedwell bore extending from the sea floor to the formation to be tested, said method comprising:
maintaining pressure in a body of fluid in said submerged well bore, disposed in an annulus of said submerged well bore external of a conduit means and adjacent a casing lining said submerged well bore, at a relatively low level while maintainingsaid body of fluid isolated from said submerged formation to be tested, the interior of said conduit means and said upper well bore portion;
in response to said relatively low level of pressure in said body of fluid, maintaining a flow path leading from said formation through said conduit means in said submerged well bore in a closed condition;
increasing the pressure of said fluid body while isolating said increase in pressure of said fluid body from said formation, the flow path through said conduit means and said upper well bore portion;
in response to said increase in pressure, permitting fluid to flow from said formation through said conduit means;
decreasing the pressure of fluid in said fluid body while isolating said decrease in pressure from said formation, the flow path through said conduit means and said upper well bore portion; and
in response to said decrease of pressure of said fluid body and independent of the pressure in the flow path through said conduit means, entrapping between upper and lower valve means within said conduit means located in said well bore adjacentsaid fluid filled annulus, a sample of fluid from
said formation. .Iaddend..Iadd. 31. Apparatus for testing a submerged formation intersected by a well bore having a lower portion extending from the sea floor to the formation to be tested and an upper well bore portion extending from the seafloor to a work station at the surface of the sea, said apparatus comprising:
conduit means in said well bore having a flow path therethrough for providing a fluid passageway from said formation through said well bore;
means for maintaining pressure in a body of fluid in said well bore, disposed in an annulus of said well bore external of said conduit means and adjacent a casing lining the lower portion of said well bore, at one level while maintaining saidbody of fluid isolated from said submerged formation to be tested, the flow path through said conduit means and said upper well bore portion;
means operable in response to said one level of pressure in said body of fluid, to maintain said flow path leading from said formation through said conduit means in said well bore in a closed condition;
means for changing the pressure of said fluid body while isolating said change in pressure of said fluid body from said formation, the flow path through said conduit means and said upper well bore portion;
means operable in response to said change in pressure, to permit fluid to flow from said formation through said conduit means;
means for further changing the pressure of fluid in said fluid body while isolating said further change in pressure from said formation, the flow path through said conduit means and said upper well bore portion; and
means, including upper and lower valve means located in said conduit means adjacent said fluid filled annulus, operable in response to said further change of pressure of said fluid body independent of the pressure in the flow path through saidconduit means, to entrap between said upper and lower valve means within said conduit means a sample of fluid from said
formation. .Iaddend..Iadd. 32. Apparatus for testing a submerged formation from an offshore test site having an upper well bore portion extending from a work station at the surface of the sea to the sea floor and a submerged well boreextending from the sea floor to the formation to be tested, said apparatus comprising:
conduit means in said well bores having a flow path therethrough for providing a fluid passageway from said formation through said well bores;
means for maintaining pressure in a body of fluid in said submerged well bore, disposed in an annulus of said submerged well bore external of said conduit means and adjacent a casing lining said submerged well bore, at a relatively low levelwhile maintaining said body of fluid isolated from said formation to be tested, the flow path through said conduit means and said upper well bore portion;
means operable in response to said relatively low level of pressure in said body of fluid, to maintain said flow path leading from said formation through said conduit means in said submerged well bore in a closed condition;
means for increasing the pressure of said fluid body while isolating said increase in pressure of said fluid body from said formation, the flow path through said conduit means and said upper well bore portion;
means operable in response to said increase in pressure to permit fluid to flow from said formation through said conduit means;
means for decrasing the pressure of fluid in said fluid body while isolating said decrease in pressure from said formation, the flow path through said conduit means and said upper well bore portion;
means, including upper and lower valve means located in said conduit means adjacent said fluid filled annulus, operable in response to said decrease of pressure of said fluid body independent of the pressure in the flow path through said conduitmeans, to entrap between said upper and lower valve means within said conduit means a sample of fluid from said formation..Iaddend. |
| Description: |
GENERAL BACKGROUND OF INVENTION
For several decades those skilled in the oil and gas well art have utilized techniques for predicting the characteristics of oil and gas bearing formations.
One such technique, generally known as formation testing, entails the insertion of a testing string or conduit into a well, which well intersects a formation to be tested.
The conduit string is sealed to the well wall by a selectively operable packer. This sealing places the interior of the conduit string in communication with the formation, with the formation and interior of the conduit string being isolated froma well annulus which is located above the packer and encircles the conduit string.
Conventionally, rotary or linear reciprocations of the conduit string, or combined manipulations of this nature, or the utilization of separate actuating tools, have been employed to effect a sequence of testing operations.
This sequence of testing operations often entails the opening and closing of a valve in the conduit string, during which time the pressure of formation fluid flowing through the conduit string is measured. When the interior of the conduit stringis closed, pressure of fluid below the closed portion of the conduit string will be measured as "closed-in" pressure. When the conduit string is opened, pressure formation flowing through the conduit string will be measured as "flowing" pressure.
In conjunction with such pressure measurements, it has been conventional to entrap a sample of formation fluid flowing through the conduit string. After the sample chamber has been trapped, the trapped sample has been moved, with the conduitstring, through the well to a work site where the sample was analyzed, or transported to an analysis station.
The sample entrapping operation, like the pressure measuring operation, usually has requred manipulations of the conduit string and/or the use of a separate actuating tool.
Even in connection with conventional "dry land" operations, the conduit string manipulations generally utilized in conducting pressure evaluations and sample entrapment have created substantial difficulties and uncertainties. Indeed, the historyof the testing art is replete with attempts to provide more reliable testing tools, with manipulations being reduced to a minimum level.
As the petroleum industry moved offshore in recent years, the problems involved in formation testing have assumed even greater difficulty and uncertainty. In addition to the conventional problems associated with formation testing, offshoreoperations introduced additional complications, some attributable to wave action induced movement of floating drilling vessels, from which vessels testing operations are often conducted.
With particular reference to offshore testing operations, but with a perspective directed to overall testing operations of an offshore or dry land nature, it has been a basic goal of the industry to provide a formation testing technique where theproblems of conduit string manipulations would be eliminated or minimized and optimum control and safety maintained during a testing operation.
It is with respect to this basic goal that this invention is concerned.
GENERAL SUMMARY OF INVENTION
To a substantial extent, fulfillment of the basic goal outlined above is achieved through the presentation of a method and apparatus for testing a formation where changes in well annulus pressure are selectively employed. These changes inducevalving and sample entrapping movements of components contained within a stationary testing tool disposed in a well bore.
Predetermined control of the reponse to the testing tool components to such pressure changes is desirably effected by the utilization of a pre-pressurized body of fluid contained within the testing means. It is contemplated that particularlyeffective results are achieved when the pressurized fluid constitutes a body of pressurized nitrogen.
A most significant facet of the invention is directed to a method of testing a submerged formation from an offshore test site. In this optimum method, an operator maintains pressure in a body of fluid in a submerged well bore, disposed adjacenta conduit means, at a relatively low level, while maintaining this body of fluid isolated from a submerged formation to be tested. In response to this relatively low level of pressure in the body of fluid, a flow path leading from the formation, throughthe conduit means, is maintained in a closed condition.
The pressure of the fluid body is increased, while isolating the increase in pressure of the fluid body from the formation. In response to this pressure increase, fluid is permitted to flow from the formation through the conduit means. Thepressure of fluid in the fluid body is further changed, while isolating the further increase in pressure from the formation. In response to this further change in pressure, a sample of formation fluid is entrapped within the conduit means.
Additionally, significant facets of the invention are directed to releasable restraining means and impedance mechanisms for providing reliability and predictability with respect to the response of tool components to variations of pressure in thefluid body.
A pressure and volume balanced, selectively expansible and contractible coupling means may be employed to effectively prevent wave action generated force from being transmitted from a floating test control site to test string conduit meanscontaining a sample entrapping chamber and sample flow controlling valve mechanism. This isolation may be enhanced by supporting an upper portion of the string in a submerged well head, with the floating test site being free to move up and down inlongitudinally movable relation with the test string.
An automatic venting arrangement may be utilized to vent pressure trapped in a test string below the test string conduit means housing the sample entrapping chamber and valve mechanism. This venting may automatically occur as the conduit meansis raised upwardly through a well bore at the conclusion of a testing operation.
Additional significant facets of the invention are directed to unique combinations of elements which interact to perform the functions above noted.
A major contribution is believed to be attributable to a control method and apparatus where a differential piston is concurrently acted upon by a test string carried body of pressurized fluid and annulus pressure. Selective variations in anannulus pressure are employed to induce manipulation of this differential piston so as to perform valving and sample entrapping manipulations.
DRAWINGS
In describing the invention, reference will be made to a preferred embodiment shown in the appended drawings.
In the drawings:
FIG. 1 provides a schematic, vertical, elevational view of an offshore test site, illustrating a testing string disposed in a submerged well and intersecting a submerged formation whose productivity is to be evaluated;
FIG. 1a provides an enlarged, vertically sectioned, fragmentary, elevational view of a well head portion of the FIG. 1 assembly, located on the floating vessel or work station, and a submerged well head portion, illustrating an annulus pressuringsystem;
FIG. 2a provides a schematic illustration, vertical cross section, of a valve and sample entrapping mechanism of the present invention, incorporated in the testing string of FIG. 1, and disposed in a flow blocking or closed condition;
FIG. 2b provides a schematic illustration, in vertical cross section, of a valve and sample entrapping mechanism of the present invention, incorporated in the testing string of FIG. 1, and disposed in a flow permitting or open condition;
FIG. 2c provides a schematic illustration, in vertical cross section, of a valve and sample entrapping mechanism of the present invention, incorporated in the testing string of FIG. 1, and disposed in a different, flow preventing or closedposition, operable to entrap a sample of formation fluid;
FIGS. 3a through 3g, when joined along the dividing lines a--a through f--f provide an enlarged, vertically sectioned, "right-side only" view of the cylindrical valve and sample entrapping mechanism schematically shown in FIGS. 2a through 2c;
FIG. 4 provides a transverse sectional view of the FIGS. 3a-3g mechanism, illustrating a valve mechanism which facilitates the injection of a body of pressurized nitrogen into a control cavity of the valving and sample entrapping mechanism;
FIG. 5 discloses a modification of the FIGS. 3a-3g mechanism comprising an impedance mechanism which provides optimum control over valving and sample entrapping operations; and
FIG. 6 provides a transverse sectional view of the FIG. 5 mechanism, as viewed along the section line 6--6 of FIG. 5.
OVERALL INSTALLATION
FIG. 1 schematically illustrates a representative offshore test operation.
As shown in FIG. 1, a floating drilling vessel or work station 1 is anchored or otherwise secured in position over a submerged well site 2. Submerged well site 2 comprises a bore hole 3, the interior of which may be lined by a casing string 4 ina conventional fashion.
Well bore 3, usually casing 4, intersect a formation 5 whose productivity is to be tested.
Where casing 3 intersects formation 5, at area 3a, .[.performations.]. .Iadd.perforations .Iaddend.will usually be provided to ensure fluid communication between the formation 5 and the interior 6 of the well bore 3.
At the submerged "mud-line" a submerged wellhead installation 7 may be provided. Installation 7 may be provided with a variety of blow-out preventer mechanisms of both the partial closing and "blind" type, the structure and operation of whichare generally shown in FIG. 2 of pending U.S. Manes et al. application, Ser. No. 882,856, filed Dec. 8, 1969. This Manes et al disclosure is assigned to the assignee of the present application, and its entire disclosure is herein incorporated byreference.
As will be understood, submerged wellhead 7 may also comprise any of several conventional "off the shelf" submerged wellhead units now available.
A marine conductor 8 extends upwardly from wellhead 7 to floating work station 1 and may be laterally supported on deck means 9 of work station 1, generally as schematically shown in FIG. 1a. The upper end of conductor 8 may pass slidablythrough a gimbal connection on deck 9. Such an arrangement, known in the art, provides lateral support for conductor 8 while permitting wave action induced, vertical movement of station 1 relative to the conductor. Conductor slip joints might also beused to accommodate wave action.
A testing string 10 is manipulated at work station 1 by conventional hoisting means 11, conventionally operated from a derrick-like structure 12, as shown in FIG. 1. The usual control head, manifold and swivel arrangements may be provided in theupper end of string 10 to permit conventional circulation of fluid through the testing string and rotary testing string manipulations.
This hoisting means, in conjunction with conventional rotary table slip means would be employed to threadably interconnect sections of the test string 10 and lower the test string 10 through the marine .[. conduction.]. .Iadd.conductor.Iaddend.8 and casing 4 to the general disposition shown in FIG. 1.
As shown in FIG. 1a, test string 10 will be disposed in slidable but sealing engagement with a wellhead seal 12. Wellhead seal 12 may comprise a conventional flow head or circulating head mounted on a wellhead closure 13 and defining atransverse annular barrier extending across the upper end of marine conductor 8. As will thus be appreciated, elements 13 and 12 cooperate to provide a seal between the upper end of marine conductor 18 and the exterior of the conduit or test string 10.
A pressuring fluid supply conduit 14, possibly a conventional, safety valve controlled, mud or "kill" line may extend from site 1, downwardly along the exterior of conductor 8, and intersect the wellhead 7 below its blowout preventors, generallyas shown in FIG. 1b. Such a "kill" line would usually be attached to the exterior of conductor 8 and would communicate with the upper interior of casing 4. Conduit 14 extends to a conventional "mud pump" 15 on floating site 1. Pump 15 is used toimpart pressure to fluid, possibly of a conventional drilling mud nature, contained within and substantially filling the annular void or space 16 surrounding the conduit string 10, and disposed between the string 10 and casing 4 beneath the well head 7.
String 10 may include the following components, disposed in consecutively downwardly spaced relation:
______________________________________ Reference Item Numeral ______________________________________ Upper conduit string extending to floating work site 1 (threadably interconnected conduit sections) 17 Hydraulically operated, conduitstring test tree 18 Intermediate conduit portion 19 Torque transmitting pressure and volume balanced slip joint 20 Intermediate conduit portion imparting packer setting weight to lower portion of string 21 Circulating valve 22 Intermediateconduit portion 23 Upper pressure recorder and housing 24 Valving and sample entrapping mechanism 25 Lower pressure recorder and housing 26 Packer mechanism 27 Perforate "tailpipe" providing fluid communication between interior of conduit string 10 and formation 5 28 ______________________________________
As shown in FIG. 1, with the testing string 10 installed in position, the packer 27 will have been manipulated to expanded condition so as to provide a seal between the conduit string 10 and the bore hole wall 4. Packer 27 may desirably be ofthe type shown in United States Anderson et al. application, Ser. No. 829,388, filed June 2, 1969, assigned to the assignee of the present application, and the disclosure of which is herein incorporated by reference.
This packer mechanism is operated in response to rotary and linear manipulations of the conduit string as described in the aforesaid Anderson et al application, with sufficient operating weight or movement being transmitted through the string byvirtue of the presence of such weight providing elements in the string as the conduit means 21. Such weight is desirable in a testing string of this nature because of the expansible and contractible character of the torque transmitting, but telescoping,slip joint coupling 20. With the weighting elements included in string 10 below coupling 20, downward or upward movement of the conduit string, during its installation, will be effectively transmitted through the string to the operating components ofthe packer mechanism 27.
After setting of the packer has been initiated, the slip joint 20 will be disposed in a partially contracted condition, the weight of upper elements 17 and 18 of string 10 will be supported by closed blowout preventor rams in wellhead 7, and thedrilling vessel 1 will be free to move up and down in relation to the upper end of test string 10. The manner of effecting packer setting as above indicated and the manner in which wellhead rams provide upper test string support by engaging test treeassociated abutment means is fully described in the aforesaid Manes et al. application.
During the packer setting, the slip joint 20 effectively isolates wave action induced force from being transmitted through the upper portion of string 10 to the packer 27, as described in the aforesaid Manes et al application. The slip joint 20also permits some tolerance in the extent of downward movement of the upper conduit string portion, after initiation of packer setter, required to "seat" test tree abutment means on the closed rams in well head 7.
Since the slip joint 20 permits the upper end of the string 10 to be seated on, i.e. supported by, wellhead 7, it permits the string 10 to be disconnected from fully supported relation with the hoisting mechanism of the vessel 1 and thus isolatedfrom wave actions acting on this vessel. Even if string 10 should remain supported by this hoisting mechanism, the telescoping action of the slip joint would prevent the transmission of wave actions to the portion of string 10 below the slip joint.
With the testing string 10 manipulated so as to "seat" or expand the packer 27, the expanded packer will provide a seal between the conduit string 10 and the casing or bore hole wall 4, defining the closed lower end of annular void or space 16. With this arrangement, annular space 16 will be effectively isolated from the interior of the conduit string 10 and from the formation 5. In the embodiment described, the closed rams in wellhead 7, upon which test tree abutment means is seated, willprovide an annular closure in wellbore 3, defining a closed upper end of annulus 16. Thus, with annulus 16 filled with fluid, such as mud, line 14 will serve to convey pressurized fluid to annulus 16 and increase its pressure, depending on the height ofline 14 and the pressure of fluid it conveys.
Even if the support rams in wellhead 7 should not define an annulus seal at wellhead 7, the annular cavity above wellhead 7 between string 10 and casing 4 will be filled with fluid, possibly mud. This body of fluid will define an upper extensionor portion of annulus 16, sealed at its upper end by means 12 and 13.
Indeed, in certain circumstances, it may be desirable for the entire weight of the portion of conduit string 10 above slip joint 20 to be supported by hoist mechanism 11, with slip joint 20 being partially contracted to absorb wave action and therams of wellhead 7 open. This arrangement would provide an annulus 16 extending from packer 27 to conductor closure 13. Pressurizing of such an elongated annulus 16 could be effected by a pressurizing line 14 communicating with the interior of theconductor 8 at the elevation of the vessel 1.
The test tree mechanism 18 incorporated in the conduit string may comprise the safety mechanism described in the aforesaid Manes et al. application, assigned reference numeral 801 in the Manes et al. application, and commercially available fromOtis Engineering Corporation, Post Office Box 34380, Dallas, Tex. 75234 U.S.A. This mechanism 18 comprises an hydraulically operable valve assembly for selectively closing off or opening the interior passage of the string 10 in the vicinity of thesubmerged wellhead installation 7. The mechanism 18 is designated by Otis Engineering Corporation as a retrievable "subsea test tree," the structure and function of the apparatus being described in greater detail in the aforesaid Manes et alapplication.
The slip joint mechanism 20 may desirably comprise a pressure and volume balanced slip joint of the type described in U.S. Hyde Pat., No. 3,354,950. The Hyde slip joint comprises an extensible and contractible, telescoping coupling in theconduit string 10, which coupling is pressure and volume balanced, telescoping in nature, and operable to effectively minimize or eliminate the transmission of wave action induced force acting on the upper portion of the conduit string 10 and thefloating vessel 1 from being transmitted through the conduit string 10 to the packer 27 and the valving and sample entrapping mechanism 25.
With this basic disposition of components, a valving mechanism included in the device 25 may be operated so as to close the longitudinally extending interior passage of the conduit string 10, open this passage, or close the passage so as toentrap a sample of formation fluid within the body or conduit means portion of the mechanism 25.
As the valving elements of the mechanism 25 are manipulated, the pressure recorders 24 and 26, disposed respectively above and below the mechanism 25, will continuously record the pressure of formation fluid at these sites in the conduit sstring,in a well recognized fashion.
During the testing operation, or during the removal of the testing string, or during its installation, it may be desirable to effect a circulation of fluid between the interior of the conduit string and the annular space 16. Such circulation offluid is permitted by the circulating valve 22, which no | | | |
