摘要:
A transmitter on a bottomhole assembly (BHA) is used for generating a transient electromagnetic signal in an earth formation. A pair of receivers on the BHA receive signals that are indicative of formation resistivity and distances to bed boundaries. A time dependent calibration factor or a time-independent calibration factor may be used to combine the two received signals and estimate the distance to bed boundaries that are unaffected by the drill conductive body. Further improvement can be obtained by using copper shielding.
摘要:
A transmitter on a bottomhole assembly (BHA) is used for generating a transient electromagnetic signal in an earth formation. A pair of receivers on the BHA receive signals that are indicative of formation resistivity and distances to bed boundaries. A time dependent calibration factor or a time-independent calibration factor may be used to combine the two received signals and estimate the distance to bed boundaries that are unaffected by the drill conductive body. Further improvement can be obtained by using copper shielding.
摘要:
A method and apparatus provide a time-dependent calibration to essentially eliminate pipe effect in pulse-induction logging while drilling. Use of two receivers to provide calibration and measurement information allows determination of formation properties in a downhole environment while eliminating the effect of tool effects.
摘要:
A method and apparatus provide a time-dependent calibration to essentially eliminate pipe effect in pulse-induction logging while drilling. Use of two receivers to provide calibration and measurement information allows determination of formation properties in a downhole environment while eliminating the effect of tool effects.
摘要:
The disclosure provides a resistivity tool for use in a wellbore, wherein at least two orthogonal antennas are located at the same or substantially the same location of the tool. A single set of vertically aligned grooves is provided for the at least two orthogonal antennas. Each antenna may be configured to operate as a transmitter or receiver. A tool with collocated antennas may be used to provide azimuthally sensitive measurements even if the tool is non-rotating.
摘要:
The disclosure provides a resistivity tool for use in a wellbore, wherein at least two orthogonal antennas are located at the same or substantially the same location of the tool. A single set of vertically aligned grooves is provided for the at least two orthogonal antennas. Each antenna may be configured to operate as a transmitter or receiver. A tool with collocated antennas may be used to provide azimuthally sensitive measurements even if the tool is non-rotating.
摘要:
Transient measurements made at two spaced apart receivers responsive to separate activation of two transmitters symmetrically disposed about the two receivers. The transmitters and receivers are on an instrument having a conductive body induces currents in the earth formation. The effect of the conductive body is removed by using deconvolving the signal at one receiver using the measured signal at the other receiver. The symmetric transmitter configuration also enables compensation for receiver differences.
摘要:
A phase error in measurements made by a resistivity logging tool is estimated by positioning the tool above a conducting surface. Deviation of the measured phase difference between the transmitter and the receiver from 90° gives the phase error in the electronics. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
摘要:
A pseudo-image is produced by combining deep-reading azimuthally sensitive resistivity measurements with azimuthally insensitive resistivity measurements made by a multiple propagation resistivity tool. This image is useful in reservoir navigation. Features on the azimuthally sensitive measurements such as saddle-points and mid-points are diagnostic of bed geometry relative to the borehole.
摘要:
A combination of a shallow-reading and a deep-reading, azimuthally sensitive, multiple propagation devices is used for providing depth images the earth formation with different depth of investigation. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).