Schlumberger Technology Corporation

Scott S Chesser

Thomas D Barber

Bulent Finci

John F Hunka

Andrei Davydychev

Richard Dan Ward

William B Vandermeer

Brian Oliver Clark

Dean M Homan

Dzevat Omeragic

Richard A Rosthal

Stephen D Bonner

Jingjing (Karen) Sun

Gary A Hazen

Richard W Oldigs

Harry L Vanscoder

Ricky Y Torres

Jingjing Karen Sun

Denis Lebreton

An electromagnetic logging tool is disclosed that includes a support; and at least one four-coil array disposed on the support, wherein the at least one four-coil array comprises: a transmitter, a bucking coil, a receiver, and a trim coil. A method for balancing an induction array is disclosed that includes applying an alternating current to a transmitter of the induction array that comprises the transmitter, a bucking coil and a receiver; measuring a mutual coupling between the transmitter and the receiver; and adding an extra bucking coil, if the mutual coupling exceeds a selected criterion.

Extra bucking coils to balance induction arrays

An electromagnetic logging tool includes a support configured for disposal in a well; at least one antenna mounted on the support; and a plurality of coils mounted on the support proximate the at least one antenna, wherein the plurality of the coils are configured for selective connection with the at least one antenna. A methods for balancing an induction array on an electromagnetic logging tool includes measuring a mutual coupling between a transmitter and a receiver on the electromagnetic logging tool; and selectively connecting a subset of a plurality of coils on the electromagnetic logging tool to the transmitter or the receiver based on the measured mutual coupling.

Selectable tap induction coil

A composite encased tool for making subsurface measurements in a borehole traversing a subsurface formation includes a conductive mandrel, a first composite layer wrapped around the conductive mandrel, the first composite layer having one or more slots, a source or sensor disposed in each of the one or more slots, and a second composite layer wrapped around the first composite layer with the source or sensor in the one or more slots.

Composite encased tool for subsurface measurements

An electromagnetic logging that includes a support; and at least one four-coil array disposed on the support, wherein the at least one four-coil array comprises: a transmitter, a bucking coil, a receiver, and a trim coil. A method for balancing an induction array includes applying an alternating current to a transmitter of the induction array that comprises the transmitter, a bucking coil and a receiver; measuring a mutual coupling between the transmitter and the receiver; and adding an extra bucking coil, if the mutual coupling exceeds a selected criterion.

Extra bucking coils as an alternative way to balance induction arrays

An electromagnetic logging tool includes a support configured for disposal in a well; at least one antenna mounted on the support; and a plurality of coils mounted on the support proximate the at least one antenna, wherein the plurality of the coils are configured for selective connection with the at least one antenna. A method for balancing an induction array on an electromagnetic logging tool includes measuring a mutual coupling between a transmitter and a receiver on the electromagnetic logging tool; and selectively connecting a subset of a plurality of coils on the electromagnetic logging tool to the transmitter or the receiver based on the measured mutual coupling.

An apparatus for stripping an insulated wire includes a resistive heater element having a first end, a second end, and a coil formed between the first end and the second end. The coil has an inner diameter that is large enough to receive a section of the insulated wire. The apparatus further includes an electronic circuit connected to the first and second ends to deliver power to the resistive heater element such that the coil uniformly distributes heat about the section of the insulated wire to thermally decompose insulation on the section of insulated wire.

Apparatus and method for stripping insulated wire

A shield apparatus for use in conjunction with a well tool to selectively attenuate one or more electromagnetic energy field components as the components interact with the shield. The shield composed of a flexible strip or conductive body and comprising at least one sloped slot or sloped conductive element therein. The shield being adapted to surround an antenna mounted on a well tool. A method for rotating the axis of the magnetic dipole of a transmitter or receiver coil. A method for winding and shielding an electric coil such that the resultant coil emits or receives selected electromagnetic energy field components.

Coil shielding method for selective attenuation of an electromagnetic energy field component

Shielding apparatus for selective attenuation of an electromagnetic energy field component

Shielding method and apparatus for selective attenuation of an electromagnetic energy field component

Methods and apparatus for making directional measurements of earth formations surrounding a borehole. New antenna coil shield designs are utilized to provide selective attenuation of at least one electromagnetic energy field component as the component interacts with the shield. The new shields are implemented in several downhole tool configurations to provide azimuthally focused formation measurements. In effect, the new shield filters interacting electromagnetic energy field components to pass those components corresponding to a magnetic dipole oriented at an angle from the tool axis. The shields thereby alter a coil's envelope of influence to electromagnetic energy. The new shields also form part of a system for making directional measurements while drilling.

Growing community of inventors

Richmond, TX, United States of America

Scott S Chesser