Communications – electrical: acoustic wave systems and devices – Seismic prospecting – Well logging
Patent
1991-09-05
1992-10-27
Lobo, Ian J.
Communications, electrical: acoustic wave systems and devices
Seismic prospecting
Well logging
367 34, 73151, G01V 140
Patent
active
051595770
ABSTRACT:
Improved techniques are provided for correcting signals from a downhole sensor on a drill collar eccentrically rotating within a borehole. The corrected sensor signal may be used to generate a well log which more accurately represents the conditions which the sensor would have generated had the tool been rotating such that the spacing between the sensor and the borehole well remained constant. The sensor signals are generated at time intervals of less than half the period of rotation of the drill collar. The frequency components of the time-varying sensor signals are plotted, and the frequency component attributable to the eccentric rotation between the drill collar and the borehole may be determined. The magnitude of this frequency component may be used to generate a correcting sensor signal, which then modifies the average sensor signal so that a more accurate well log may be obtained. The techniques of the present invention may be used to determine actual rotational speed of the drill collar and the spacing between the sensor and the wall, and are particularly well suited to determining a whirling condition in real time and alter drilling parameters in response thereto.
REFERENCES:
patent: 3876016 (1975-04-01), Stinson
patent: 4017859 (1977-04-01), Medwin
patent: 4661933 (1987-10-01), Seeman et al.
patent: 4698501 (1988-02-01), Paske et al.
patent: 4773263 (1988-09-01), Lesage et al.
patent: 4829176 (1989-05-01), Paske et al.
patent: 4864129 (1989-09-01), Paske et al.
patent: 4894534 (1990-01-01), Paske et al.
patent: 4903245 (1990-02-01), Close et al.
patent: 5058077 (1991-10-01), Twist
Vandiver et al., "Case Studies of the . . . Motion of Drill Collars", SPE/IADC 18652, Feb. 22, 1989, 291-304.
Milheim et al, "The Effect of Bottomhole . . . Trajectory of a Bit", Dec. 1981, 2323-2338.
Wolf et al, "Field Measurements of Downhole Drillstring Vibrations", Sep. 22, 1985.
Paske et al, "Theory and Implementation . . . Made While Drilling", Sep. 23, 1990.
Paske, et al, "Measurement of Hole Size While Drilling". Jun. 24, 1990.
Best et al., "An Innovative Approach . . . For Hole Size Effect", Jun. 24-27, 1990, 1-21.
Paske et al, "Formation Density Logging While Drilling", Sep. 27, 1987.
Wraight et al, "Combination Formation . . . While Drilling", Jun. 11, 1989.
Baroid Technology Inc.
Lobo Ian J.
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