Schlumberger Technology Corporation

Other

Intelliserv, Inc.

Services Petroliers Schlumberger

Schlumberger Holdings Limited

Prad Research and Development Limited

Prad Research Development Limited

Gerald N Minerbo

Dean M Homan

Richard A Rosthal

Hanming Wang

Sofia N Davydycheva

Thomas D Barber

Robert C Smith

Brian Oliver Clark

Dzevat Omeragic

Emmanuel Legendre

Christophe Dupuis

John C Rasmus

Stephen D Bonner

Peter T Wu

Kuo-Chiang Chen

Jian Yang

Andrei Davydychev

Thilo Michael Brill

Siddharth Misra

Tracy E Broussard

Reza Taherian

Robert Freedman

Jean P Seydoux

Anthony Louis Collins

Martin G Luling

Jean-Marc Donadille

Gary A Hazen

Keli Sun

Steven F Crary

Darren Wall

Ted Christiansen

Joshua Wayne Gibson

Sergiy Kryukov

Trent Hassell

Craig Newell Thorne

Zlatko Sijercic

Sterling Beck

Jonatan Jalfin

Charles Horton

Dean M Horman

Shu-Kong (Steve) Chang

John W Miles

Eunmi Choi

R Bruce McCann

Aditya Gupta

Xiaoyan Zhong

Rober C Smith

Brill Thilo

Inductive coupler assemblies for controlling the stray magnetic fields of an inductive coupler to reduce the associated losses are disclosed. This results in reduced attenuation (increased efficiency) of the inductive coupler even in the presence of gaps. The assembly includes an inductive coupler having a housing, a biasing element, and a retention mechanism. The assembly further includes a wire surrounded by a ring of flux channel material disposed in the housing. In some embodiments, the retention mechanism is adapted for removal of the inductive coupler from a pipe joint end. The biasing element may be a circumferential spring disposed between the housing and the pipe joint end. The retention mechanism may be a retention snap ring, press fit, or threaded, to removably couple the housing to the pipe joint end.

Inductive coupler assembly for downhole transmission line

A method to obtain gain-corrected measurements. A measurement tool having one or more arrays is provided, wherein the arrays include two co-located triaxial transmitters and two co-located triaxial receivers. Measurements are obtained using the transmitters and the receivers. Impedance matrices are formed from the obtained measurements and the impedance matrices are combined to provide gain-corrected measurements. The apparatus may alternatively be a while-drilling logging tool having one or more arrays, wherein each array comprises a transmitter, a receiver, and a buck, and wherein the signal received by the receiver is subtracted from the signal received by the buck or vice versa. A slotted shield may be incorporated into either embodiment of the tool. The slots may form one or more island elements. A material is disposed in the slots. The islands and shield body have complementary tapered sides that confine the islands within the shield body.

Gain-corrected measurements

An electromagnetic measurement tool for making multi-frequency, full tensor, complex, electromagnetic measurements includes a triaxial transmitter and a triaxial receiver deployed on a tubular member. An electronic module is configured to obtain electromagnetic measurements at four or more distinct frequencies. The measurement tool may be used for various applications including obtaining a resistivity of sand layers in an alternating shale-sand formation; computing a dielectric permittivity, a conductivity anisotropy, and/or a permittivity anisotropy of a formation sample; and/or identifying formation mineralization including discriminating between pyrite and graphite inclusions and/or computing weight percent graphite and/or pyrite in the formation sample.

Multi-frequency electromagnetic tensor measurements

A method for calibrating an electromagnetic core analysis tool is disclosed. The method includes disposing a tilted test loop inside of or outside of a tool having more than one antenna. A uniform test pack, a layered test pack, and an effective media test pack are each disposed in the tool. A signal is induced in a receiver antenna in the tool when a second antenna is energized with a known current of a known frequency. The induced signal is measured and a calibration gain and offset is determined. A corrected signal is produced and compared with the determined signal based on a forward model.

Petrophysically-consistent calibration of full-tensor electromagnetic induction tools

An electromagnetic method for obtaining a dip azimuth angle from downhole electromagnetic measurements includes acquiring electromagnetic measurement data in a subterranean borehole from at least one measurement array. The electromagnetic measurement data is processed by a least squares method to obtain the dip azimuth angle. Related systems and apparatuses are also disclosed herein.

Electromagnetic method for obtaining dip azimuth angle

The apparatus employs the remote field eddy-current (RFEC) inspection technique to electromagnetically measure physical parameters of a metallic pipe. RFEC devices inserted into and displaced along a cylindrical pipes may be used to measure the ratio of pipe thickness to electromagnetic skin-depth and thus allow for the non-invasive detection of flaws or metal loss. Typically these RFEC thickness measurements exhibit a so-called double-indication of flaws, an undesired artifact due to a double-peaked geometrical sensitivity function of the device. The method describes a means by which this double indication artifact may be removed by an appropriate processing of RFEC measurements performed by an apparatus specifically designed for this purpose. The invention is particularly well designed for applications in the oilfield industry.

Method and apparatus for removal of the double indication of defects in remote eddy current inspection of pipes

The present disclosure relates to a method to produce an image of a subsurface formation using directional measurements. A downhole logging tool having one or more transmitters and one or more receivers, and being capable of making directional measurement, is used to measure the voltage in a particular receiver due to a particular transmitter for one or more transmitter/receiver pairs, at least one of those voltage measurements being a directional measurement. The complex (phasor) voltage recorded on a receiver coil is divided by the complex voltage recorded at another reference receiver coil. Alternatively, we can use the ratio of a receiver voltage at a particular rotation angle of the tool divided by the voltage on the same receiver when the tool has rotated by an angle of 180 degrees. The information in those ratios is combined to produce images of the resistivity of the subsurface formation surrounding the tool.

Imaging using directional resistivity measurements

A method for correcting formation properties due to effects of a borehole is disclosed. The method includes obtaining voltage measurements using a logging tool disposed in a borehole penetrating a subsurface formation. The method further includes using a processor to: determine a tensor for the formation using the voltage measurement. For a given set of parameters, the processor determines, based upon the voltage measurements, a parameter value for each parameter in a subset of the set of parameters. The method further uses the processor to compute a borehole-inclusive modeled tensor that includes the effects of the borehole using the parameter values, optimize the parameter values using the determined tensor and the borehole-inclusive tensor, compute an optimized tensor using the optimized parameter values, compute a borehole corrected tensor using the optimized tensor, and determine at least one borehole corrected formation property using at least one of the borehole corrected tensor or the optimized parameter values.

Determining borehole corrected formation properties

A downhole logging tool includes a tool body having a co-located set of antennas located on the tool body and first and second antennas formed from respective first and second pairs of coil windings having a closed-loop pattern. Both the first and second pair of coil windings are arranged on diametrically opposed antenna sections. A cylindrical shield is disposed over the co-located set of antennas and has a first set of vertical slots arranged interposed between each of the underlying antenna sections, a second set of vertical slots arranged over each of the underlying antenna sections, with each of the second set of vertical slots being perpendicular to a portion of the coil winding in the underlying antenna section, and a set of non-vertical slots arranged over each the underlying antenna sections. Each of non-vertical slots is perpendicular to a portion of the coil winding in the underlying antenna section.

Shielded antenna for a downhole logging tool

This disclosure relates to a downhole logging tool for acquiring data in an earth formation. In one embodiment, the downhole logging tool has a tool body with a longitudinal axis, a set of antennas located on the tool body and including coil windings forming a closed-loop pattern, and a shield disposed over the antennas and having an arrangement of slots with each slot being substantially perpendicular to a proximate portion of at least one of the underlying coil windings, wherein the path length around each slot is more than twice the length of the distance between the slot and a directly adjacent slot along an arc of the coil windings. The downhole logging tool may be a wireline or while-drilling tool, and it may be an induction or propagation tool.

A method to determine one or more borehole corrected formation properties using measurements made using a logging tool disposed in a borehole penetrating an earth formation is disclosed. The measurements are used to determine an apparent conductivity tensor for the formation and, for a set of parameters, a parameter value for each parameter in a subset of the set of parameters. A parameter value for each parameter in the set of parameters not in the subset is provided and a borehole-inclusive modeled conductivity tensor is computed. The apparent conductivity tensor and the borehole-inclusive modeled conductivity tensor are iteratively used to optimize the parameter values, and the optimized parameter values are used to compute an optimized conductivity tensor. A borehole corrected conductivity tensor is computed using the optimized conductivity tensor, and the borehole corrected formation properties are determined using the borehole corrected conductivity tensor and/or the optimized parameter values.

Determining borehole corrected formation on properties

The present disclosure relates to a method to determine the vertical resistivity of a subsurface formation. A downhole logging tool having a plurality of spaced antennas, at least one of which is a transverse antenna, at least two of which are tilted antennas, and at least two of which are axial antennas is provided. Measurements involving the transverse and/or the tilted antennas of the downhole logging tool are obtained. Voltage ratios are formed using the measurements, and conditioning factors are formed by raising the determined voltage ratios not involving the transverse antenna to some arbitrary power. The sum of the exponents of the conditioning factors preferably equals one. A voltage ratio involving the transverse antenna is multiplied by the conditioning factors, and the vertical resistivity of the subsurface formation is determined using the resulting ratio.

Determining anisotropic resistivity

The present invention relates to a downhole logging tool having on its tool body a set of co-located antennas, one or more additional antennas spaced longitudinally apart from the set of co-located antennas, an electromagnetically transparent shield circumferentially surrounding the set of co-located antennas, and an electromagnetically transparent shield circumferentially surrounding each of the one or more additional antennas. The downhole logging tool may be a wireline or while-drilling tool, and it may be an induction or propagation tool. The shields may have slots that are locally perpendicular to the windings of underlying coil antennas.

Logging tool having shielded triaxial antennas

The present disclosure relates to a method to produce an image of a subsurface formation using directional measurements. A downhole logging tool having one or more transmitters and one or more receivers, and being capable of making directional measurements, is used to measure the voltage in a particular receiver due to a particular transmitter for one or more transmitter/receiver pairs, at least one of those voltage measurements being a directional measurement. The complex (phasor) voltage recorded on a receiver coil is divided by the complex voltage recorded at another reference receiver coil. Alternatively, we can use the ratio of a receiver voltage at a particular rotation angle of the tool divided by the voltage on the same receiver when the tool has rotated by an angle of 180 degrees. The information in those ratios is combined to produce images of the resistivity of the subsurface formation surrounding the tool.

Growing community of inventors

Missouri City, TX, United States of America

Gerald N Minerbo