摘要 |
A logging tool has three seismic sensors that generate seismic signals in response to microseismic events and can be a Triaxial Borehole Seismic system. The tool also has additional sensors, such as a wireline tension measuring circuit, a gamma ray sensor, an inclinometer, and a gyroscope. The tool deploys downhole with a multi-conductor (i.e., seven conductor) wirelin e. For the seismic signals, a telemetry unit on the tool derives frequency- modulated carrier signals from the seismic signals, and a transformer of the unit transmits these carrier signals to surface acquisition equipment using cross-wired pai rs of conductors in the wireline connected to the transformer's terminals. For the signals from the other sensors, the telemetry unit derives analog carrier signals from their signals and transmits the analog carrier signals to the surface acquisition equipment using remaining conductors of the wireline.
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