US 8,134,477 B2 · Downhole telemetry through multi-conductor wireline

Abstract

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) wireline. 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 pairs 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.

Claims31

Dependent claims

A downhole data telemetry method, comprising:

deploying a logging tool downwhole with a wireline, the logging tool having a plurality of seismic sensors and having at least one second sensor;
generating first signals with the seismic sensors;
generating second signals with the at least one second sensor;
deriving frequency-modulated carrier signals from both the first and second signals;
transmitting the frequency-modulated carrier signals from a first telemetry output to the surface via first conductors of the wireline;
deriving analog carrier signals from the second signals;
and
transmitting the analog carrier signals from a second telemetry output to the surface via at least one second conductor of the wireline.

5 more elements

Dependencies are inferred from the claim text.

Downhole telemetry through multi-conductor wireline

Life of this patent

Downhole telemetry through multi-conductor wireline

Life of this patent

Abstract

Claims31