| Patent Number |
Title Of Patent |
Date Issued |
| 7520324 |
Completion apparatus for measuring streaming potentials and determining earth formation characteristics |
Apr. 21, 2009 |
| 7388382 |
System for measuring Earth formation resistivity through an electrically conductive wellbore casing |
Jun. 17, 2008 |
| 7298147 |
Device and process for determination of the resistivity of a formation surrounding a cased borehole |
Nov. 20, 2007 |
| 7215125 |
Method for measuring a formation parameter while inserting a casing into a wellbore |
May. 8, 2007 |
| 7151377 |
Permanent apparatus for monitoring a well by injecting current through the casing into the formations |
Dec. 19, 2006 |
| 7095232 |
Determination of borehole geometry inside cased wells with crosswell electromagnetics |
Aug. 22, 2006 |
| 7071697 |
Centralizer including measurement means |
Jul. 4, 2006 |
| 7064551 |
Process for determining the resistivity of a formation through which a well equipped with a casing passes |
Jun. 20, 2006 |
| 7026820 |
Method and apparatus for minimizing direct coupling for downhole logging devices |
Apr. 11, 2006 |
| 7027967 |
Method and system for indicating anisotropic resistivity in an earth formation |
Apr. 11, 2006 |
| 6987386 |
Determining resistivity of a geological formation using circuitry located within a borehole casing |
Jan. 17, 2006 |
| 6894500 |
Method and apparatus for determining the resistivity of a formation surrounding a cased well |
May. 17, 2005 |
| 6894499 |
Device for measuring an electrical parameter through electrically-conductive casing |
May. 17, 2005 |
| 6765387 |
System and method for measuring resistivity through casing |
Jul. 20, 2004 |
| 6667621 |
Method and apparatus for determining the resistivity of a formation surrounding a cased well |
Dec. 23, 2003 |
| 6633164 |
Measuring focused through-casing resistivity using induction chokes and also using well casing as the formation contact electrodes |
Oct. 14, 2003 |
| 6603314 |
Simultaneous current injection for measurement of formation resistance through casing |
Aug. 5, 2003 |
| 6597177 |
Through casing resistivity measurement in permanently installed downhole production environment |
Jul. 22, 2003 |
| 6545477 |
Method and apparatus for determining the resistivity of a formation through which a cased well passes |
Apr. 8, 2003 |
| 6445187 |
System for the measurement of electrical characteristics of geological formations from within steel cased wells using magnetic circuits |
Sep. 3, 2002 |
| 6430040 |
Foldable bicycle computer |
Aug. 6, 2002 |
| 6396276 |
Apparatus and method for electric field telemetry employing component upper and lower housings in a well pipestring |
May. 28, 2002 |
| 6351129 |
Methods of determining resistivity of a formation through which a cased borehole passes |
Feb. 26, 2002 |
| 6295512 |
Subsurface mapping apparatus and method |
Sep. 25, 2001 |
| 6249122 |
Electrical voltages and resistances measured to inspect metallic cased wells and pipelines |
Jun. 19, 2001 |
| 6246240 |
Determining resistivity of a formation adjacent to a borehole having casing with an apparatus having all current conducting electrodes within the cased well |
Jun. 12, 2001 |
| 6188223 |
Electric field borehole telemetry |
Feb. 13, 2001 |
| 6157195 |
Formation resistivity measurements from within a cased well used to quantitatively determine the amount of oil and gas present |
Dec. 5, 2000 |
| 6114972 |
Electromagnetic resistivity tool and method for use of same |
Sep. 5, 2000 |
| 6114857 |
System and method for monitoring corrosion in oilfield wells and pipelines utilizing time-domain-reflectometry |
Sep. 5, 2000 |
| 6084403 |
Slim-hole collar locator and casing inspection tool with high-strength pressure housing |
Jul. 4, 2000 |
| 6025721 |
Determining resistivity of a formation adjacent to a borehole having casing by generating constant current flow in portion of casing and using at least two voltage measurement electrodes |
Feb. 15, 2000 |
| 5914603 |
Electrical resistance tomography using steel cased boreholes as electrodes |
Jun. 22, 1999 |
| 5883516 |
Apparatus and method for electric field telemetry employing component upper and lower housings in a well pipestring |
Mar. 16, 1999 |
| 5717334 |
Methods and apparatus to produce stick-slip motion of logging tool attached to a wireline drawn upward by a continuously rotating wireline drum |
Feb. 10, 1998 |
| 5680049 |
Apparatus for measuring formation resistivity through a conductive casing having a coaxial tubing inserted therein |
Oct. 21, 1997 |
| 5654639 |
Induction measuring device in the presence of metal walls |
Aug. 5, 1997 |
| 5633590 |
Formation resistivity measurements from within a cased well used to quantitatively determine the amount of oil and gas present |
May. 27, 1997 |
| 5608323 |
Arrangement of the electrodes for an electrical logging system for determining the electrical resistivity of a subsurface formation |
Mar. 4, 1997 |
| 5592090 |
Compact, open geometry U-shaped magnet for magnetic resonance imaging |
Jan. 7, 1997 |
| 5570024 |
Determining resistivity of a formation adjacent to a borehole having casing using multiple electrodes and with resistances being defined between the electrodes |
Oct. 29, 1996 |
| 5563514 |
Method and apparatus for determining formation resistivity in a cased well using three electrodes arranged in a wheatstone bridge |
Oct. 8, 1996 |
| 5543715 |
Method and apparatus for measuring formation resistivity through casing using single-conductor electrical logging cable |
Aug. 6, 1996 |
| 5510712 |
Method and apparatus for measuring formation resistivity in cased holes |
Apr. 23, 1996 |
| 5426367 |
Logging of cased well by induction logging to plot an induction log of the well |
Jun. 20, 1995 |
| 5223794 |
Methods of operation of apparatus measuring formation resistivity from within a cased well having one measurement and two compensation steps |
Jun. 29, 1993 |
| 5218301 |
Method and apparatus for determining distance for magnetic and electric field measurements |
Jun. 8, 1993 |
| 5187440 |
Measuring resistivity changes from within a first cased well to monitor fluids injected into oil bearing geological formations from a second cased well while passing electrical current between |
Feb. 16, 1993 |
| 5075626 |
Electronic measurement apparatus movable in a cased borehole and compensating for casing resistance differences |
Dec. 24, 1991 |
| 5043668 |
Methods and apparatus for measurement of electronic properties of geological formations through borehole casing |
Aug. 27, 1991 |
