Integrated Electrode Resistivity and EM Telemetry Tool
AssigneeSchlumberger Technology Corporation
InventorsBrian Clark, Jan W. Smits
Life of this patent
Estimating the term…
Abstract
An integrated electrode resistivity and EM telemetry tool and obtaining both formation resistivity and telemetry data from the integrated tool. An integrated electrode resistivity and EM telemetry tool having a drill collar including a first portion and a second portion separated by an insulated gap and telemetry cartridge carrying telemetry circuitry including a voltage source generating a voltage drop across the insulated gap and an axial current on a drill string that returns through an earthen formation includes an insulated measure electrode connected to the first portion, and resistivity measurement circuitry functionally connected to the measure electrode and the telemetry circuitry.
Claims26
1-22. (canceled)
The method of claim 21, further comprising retrieving the electronics cartridge.
The method of claim 21, further comprising maintaining the measure electrode at substantially the same potential as the lower portion.
The method of claim 21, further comprising selecting a separation distance between the measure electrode and the insulated gap to provide a desired depth of investigation.
The method of claim 21, further comprising:
- providing a sense electrode on the lower portion proximate to the measure electrode;
- measuring the voltage difference between the sense electrode and the measure electrode;
- and
- driving the current on the measure electrode so that the voltage difference is zero.
The method of claim 21, further comprising providing voltages at multiple frequencies for telemetry operations and resistivity operations.
A resistivity tool for use in a wellbore, comprising:
- a drill collar including an upper portion and a lower portion separated by an insulated gap;
- a measure electrode carried on the drill collar;
- and
- a sense electrode proximate to the measure electrode and carried on the portion of the drill collar on which the measure electrode is carried.
A resistivity tool for use in a wellbore, comprising:
- a drill collar including an upper portion and a lower portion separated by an insulated gap;
- a driving circuitry to produce a voltage difference across the insulated gap;
- and
- a measurement sub having a measure electrode and a measurement circuitry.
47-58. (canceled)
Dependencies are inferred from the claim text.