Method and apparatus for active suppression of pipe signals in transient electromagnetic measurements

摘要

Methods and systems for estimating properties of formations including conveying a carrier through a borehole having a first transmitter, a second transmitter collocated with the first transmitter, a first receiver, and a second receiver, the first receiver positioned a first distance from the first transmitter and the second receiver positioned a second distance therefrom, generating a transient electromagnetic field with the first transmitter, generating a suppression signal with the second transmitter, the suppression signal configured to suppress a response received by the first and second receivers that is caused by the transient electromagnetic field interacting with the carrier, measuring a signal with suppressed pipe signal at the first and second receivers, the measured signal representing the formation response to the transient electromagnetic field, estimating a formation property from the measured signal to select a model, and adjusting a drilling operation based on the estimated property of the formation.