Schlumberger Technology Corporation

Services Petroliers Schlumberger

Schlumberger Holdings Limited

Prad Research and Development Limited

Richard Dan Ward

Bulent Finci

John F Hunka

Andrei Davydychev

Scott S Chesser

William B Vandermeer

Thomas D Barber

Qingyan He

Jingjing (Karen) Sun

Jean-Michel Hache

Mark Milkovisch

Steven E Buchanan

Warren E Askew

Chris Del Campo

Adam Cygan

Bo Yang

Gokhan Erol

Jingjing Karen Sun

Denis Lebreton

A downhole coring tool conveyable within a borehole extending into a subterranean formation, wherein the downhole coring tool comprises a housing, a hollow coring bit extendable from the housing, a first motor operable to rotate the coring bit, and a second motor operable to extend the coring bit into the subterranean formation through a sidewall of the borehole in a direction not substantially parallel to a longitudinal axis of the borehole proximate the downhole coring tool. A static sleeve disposed in but rotationally independent of the coring bit receives a portion of a core sample of the formation resulting from extension of the coring bit into the formation. The static sleeve comprises a protrusion extending radially inward toward the core sample sufficiently to mark the core sample.

Downhole coring tools and methods of coring

A logging sonde includes a tube defining a sealed chamber inside. An isolation layer is disposed on an exterior of the tube. At least one sensor is disposed on an exterior of the isolation layer. The sensor includes a lead in passing through a wall of the tube. An elastomer jacket is disposed on an exterior of the sensor and the isolation layer. A method for making a sonde includes affixing an electrically insulating isolator to an exterior of a tube. An hydraulic seal layer is affixed over an exterior of the isolator. A sensor is affixed over the exterior of the seal layer. An electrical connection is made from the sensor to an interior of the tube through the hydraulic seal layer and through the isolator. An elastomer jacket is applied over the exterior of at least part of the sensor and the exterior of the seal layer.

Sensor and insulation layer structure for well logging instruments

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

Transducer apparatus for subsurface use. A tubular configured for subsurface disposal is equipped with a cylindrical transducer module formed of a non-conductive material. The module is mounted to surround a section of the tubular and includes a transducer element disposed thereon such that only a surface of the element is exposed along the exterior of the module body. The transducer element is linked to a lead routed through the cylindrical body to exit near the inner bore of the body. The ends of the cylindrical body are covered with a material to form a hydraulic seal. A method for constructing the transducer apparatus.

Transducer assemblies for subsurface use

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.

Growing community of inventors

LaPorte, TX, United States of America

Richard Dan Ward