Edward M Pierce

US Patent:

49858734, Jan 15, 1991

Filed:

Oct 20, 1989

Appl. No.:

7/425661

Inventors:

Kevin A. Eyl - Boulogne, FR
Andrew L. Kurkjian - Saint Cloud, FR
David J. Lineman - Houston TX
Edward A. Pierce - Houston TX
Joseph M. Steiner - Houston TX

Assignee:

Schlumberger Technology Corporation - Houston TX

International Classification:

G01V 140

US Classification:

367 27

Abstract:

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.

US Patent:

50580787, Oct 15, 1991

Filed:

Aug 13, 1990

Appl. No.:

7/566740

Inventors:

Kevin A. Eyl - Boulogne, FR
Andrew L. Kurkjian - Saint Cloud, FR
David J. Lineman - Houston TX
Edward A. Pierce - Houston TX
Joseph M. Steiner - Houston TX

Assignee:

Schlumberger Technology Corporation - Houston TX

International Classification:

G01V 140

US Classification:

367 26

Abstract:

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.