Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Method and apparatus for determining compressional first arrival times from waveform threshold crossings provided by apparatus disposed in a sonic well tool










Image Number 15 for United States Patent #4985873.

A well logging system includes a digital threshold crossing data generation system (TCDG System) disposed in a well tool, adapted to be disposed in a borehole, and a digital first motion detection (DFMD) software disposed in a memory of a well truck computer. The TCDG system generates a series of threshold crossings for each analog signal received from a receiver of the well tool, the threshold crossings including a plurality of threshold crossing events for each analog signal and representing compressed versions of digitized analog waveforms. The well logging truck computer receives the threshold crossing data from the TCDG system and executes the DFMD software. When the software is executed, a first set of compressional wave first arrival times are determined from a startup routine in the software using the threshold crossing data. A second set of compressional wave first arrival times are determined from a tracking routine in the software using four different prediction methods and a voting procedure to select the second set of arrival times from among the four predictions. A cycle skip detection routine in the software determines if any cycle skips are associated with either the first or second set of compressional first arrival times. Finally, a cycle skip recovery routine determines which set of compressional first arrival times to select depending upon the outcome of the cycle skip detection routine.








 
 
  Recently Added Patents
Workability of an aqueous formulation with a hydraulic binder base using a combination of comb-branched polymers
Hard disc device
Refreshing group membership information for a user identifier associated with a security context
Double extension for a tree stand
Hydrocarboxylation of methylene dipropionate in the presence of propionic acid and a heterogeneous catalyst
Electronic control enclosure
Battery pack having thermoelectric device
  Randomly Featured Patents
Air purification devices
Fifth wheel kingpin deflector and catcher
Circuits, architectures, apparatuses, systems, algorithms and methods and software for optimum power calibration for optical disc recording
Electrical connection structure and antenna apparatus
Broadband ferrite loaded loop antenna
Radio frequency receiver
Digital recording and/or reproducing apparatus which rearranges error correction blocks representing video signal and corresponding to data blocks of image represented by video signal
Process for the preparation of porous membrane
New guinea impatiens plant named `Kimptol`
Athletic shoe with visible arch bridge