Method for signal enhancement in azimuthal propagation resistivity while drilling
AssigneeBaker Hughes Incorporated
InventorsRoland Chemali, Paul Cairns, Tsili Wang, Wallace Meyer, Andrew Brooks, Otto Fanini, Gulamabbas Merchant
Life of this patent
Estimating the term…
Abstract
Cross-component measurements made at a plurality of toolface angles are processed to remove bias. The amplitude of the resulting sinusoid is used to estimate a distance to an interface in an earth formation.
Claims19
A method of determining a resistivity of an earth formation penetrated by a borehole, the method comprising:
- (a) conveying a logging tool to at least one depth within said borehole;
- (b) obtaining at least one principal cross-component measurement at each of a plurality of tool-face angles of the logging tool at the least one depth in the borehole;
- and
- (c) determining said resistivity from said measurements, the determination correcting for a bias in each of the measurements.
An apparatus for evaluating an earth formation penetrated by a borehole, the apparatus comprising:
- (a) at least one transmitter and at least one receiver on a logging tool conveyed to at least one depth within said borehole;
- and
- (b) a processor which obtains an estimate of a resistivity of the formation from at least one principal cross-component measurement obtained from the at least one transmitter and the at least one receiver at each of a plurality of tool-face angles of the logging tool at the least one depth in the borehole, the estimate correcting for a bias in the measurements.
A computer readable medium for use with an apparatus for determining a resistivity of an earth formation penetrated by a borehole, the apparatus comprising:
- (a) at least one transmitter and at least one receiver on a logging tool conveyed to at least one depth within said borehole;
- the medium comprising instructions which enable a processor to:
- (b) estimate of the resistivity from at least one principal cross-component measurement made by the at least one transmitter and the at least one receiver at each of a plurality of tool-face angles of the logging tool at the least one depth in the borehole, the estimate correcting for a bias in the measurements.
Dependencies are inferred from the claim text.