Schlumberger Technology Corporation

Services Petroliers Schlumberger

Schlumberger Holdings Limited

Prad Research and Development Limited

Mark A Fredette

Mark T Frey

James Stephen Hall

Alan James Sallwasser

Julien Toniolo

Peter Wells

Dominique Dion

Qiming Li

Wade D DuPree

Scott Ritter

Reza Taherian

Yi-Qiao Song

Dean M Homan

Martin E Poitzsch

John R Lovell

Edward Harrigan

Richard A Rosthal

Jean P Seydoux

Emmanuel Legendre

Anthony Louis Collins

Jian Yang

Srinand Sreedharan Karuppoor

Fernando Garcia-Osuna

Andrew John Carnegie

Henry N Bachman

Gary A Hazen

Andrei Davydychev

Miguel F Pabon

William B Vandermeer

Yves Barriol

Libo Yang

Erik Rhein-Knudsen

Amanda Olivio

Tim Hopper

Michael C Sakach

Robert Monroe Lowe, Jr

Tao Xu

Mark Kuchenbecker

Ricardo Y Torres

Mia Pommier

Arturo Mejia

Jason Guernsey

Andrei I Davydychev

Andrew J Carnegie

A downhole borehole imaging tool and methods for determining a borehole size includes a magnetoresistive system and a hub moveably coupled to a fixed tool string. The hub includes a magnet. The magnetoresistive system includes magnetoresistive sensors disposed within the fixed tool string and segregated from the magnet. During operation, a routine scan of all sensors measures, for example, the output voltage V, angle &#x3b8; of magnetic field, and temperature. Measurements from each sensor may then be characterized to account for temperature and input voltages variation of the sensors. The most accurate measurement can be used to derive the position of the hubusing the previous baseline parameters stored in the tool.

Apparatus and method for determining borehole size with a borehole imaging tool

An imaging tool that includes an array of pads. The array of pads are in communication with a hot terminal of a single phase electrical alternating current power source in communication with the array of pads. The single phase electrical alternating current power source includes two return electrodes. One of the return electrodes is located above the array of pads, and the other return terminal is located below the array of pads.

Methods and apparatus for performing a well survey

A tool for use in a borehole in a geological formation may include a chassis, a drill collar surrounding the chassis, a port plug coupled between the drill collar and the chassis, RF antennas carried by the drill collar, and a multi-chip module (MCM) electronics package(s). The electronics package(s) may include a hermetically sealed electronics housing positioned between the chassis and the drill collar, a substrate within the electronics housing, RF transmitter circuitry on the substrate to cooperate with at least one first RF antenna to transmit RF signals into the geological formation, and RF receiver circuitry on the substrate to cooperate with at least one second RF antenna to receive RF signals from the geological formation. Furthermore, an electronics housing mount may couple the electronics housing with the port plug, and the electronics housing mount may have a passageway extending therethrough for receiving the port plug.

Downhole tool and electronics packaging configuration therefor

A downhole tool includes a logging tool. The logging tool includes a spring integral with a sensor. The spring applies the sensor to a formation wall. Additionally, the spring includes a groove formed along a neutral axis thereof. In addition, a wire is located within the groove and is operatively connected with the sensor and at least one other component of the logging tool.

Spring with integral borehole wall applied sensor

The present disclosure relates to a method to determine the phase of a signal when transmitter and receiver circuits use separate clocks. A discrepancy between the separate clocks is determined, as is a correction factor between the separate clocks. The phase is determined using a measured time of arrival of the signal, the determined discrepancy, and the determined correction factor. A drift factor and an expected start time of a pulse sequence may be used to determine the discrepancy. A start time of a pulse within the pulse sequence is determined and used to determine the correction factor. The method works by either absolute synchronization of the separate clocks, or by making the measurements independent of clock synchronization.

Measuring the phase of received signals

Subsurface formation evaluation comprising, for example, sealing a portion of a wall of a wellbore penetrating the formation, forming a hole through the sealed portion of the wellbore wall, injecting an injection fluid into the formation through the hole, and determining a saturation of the injection fluid in the formation by measuring a property of the formation proximate the hole while maintaining the sealed portion of the wellbore wall.

Formation evaluation instrument and method

A combined resistivity tool incorporating both induction/propagation antennas and lateral resistivity antennas disposed in recesses of downhole tubulars, in which a lateral resistivity antenna includes an insulating base layer disposed in the recess; a toroidal antenna disposed over the insulating base layer; and a shield disposed over the recess.

Combined propagation and lateral resistivity downhole tool

Resistivity logging tool and method for building the resistivity logging tool

An apparatus for logging a formation traversed by a borehole includes a plurality of logging tools adapted for conveyance inside the borehole. The plurality of logging tools includes a tool body, a sensing pad responsive to a density property of the formation coupled to the tool body, a current emitting measure electrode responsive to a lateral resistivity property of the formation incorporated on the sensing pad, a mechanism for urging the sensing pad in contact with a side of the borehole coupled to the tool body, and a pair of mass isolation bands disposed about the tool body to isolate a mass of the tool body adjacent the measure electrode.

Highly integrated logging tool

A borehole caliper tool includes a tool body and an arm coupled to the tool body. The arm is deflectable relative to the tool body. The caliper tool further includes a cam coupled to the arm such that a position of the cam changes as the arm deflects. The caliper tool further includes a proximity sensor for sensing the position of the cam, wherein the position of the cam provides an indication of the deflection of the arm relative to the tool body.

Borehole caliper tool

A borehole caliper tool includes a tool body, a bow spring flexibly coupled to the tool body, a target coupled to the bow spring, and an ultrasonic transducer coupled to the tool body, wherein in operation the ultrasonic transducer transmits an acoustic pulse to the target and receives an echo of the acoustic pulse from the target.

Borehole caliper tool using ultrasonic transducer

A method is disclosed for compressing a frame of data representing parameter values, a time at which each parameter value was recorded, and an orientation of a sensor at the time each parameter value was recorded. Generally the method includes performing a two-dimensional transform on the data in the orientation domain and in a domain related to the recording time. In one embodiment, the method includes calculating a logarithm of each parameter value. In one embodiment, the 2-D transform includes generating a Fourier transform of the logarithm of the parameter values in the azimuthal domain, generating a discrete cosine transform of the transform coefficients in the time domain. This embodiment includes quantizing the coefficients of the Fourier transform and the discrete cosine transform. One embodiment of the method is adapted to transmit resistivity measurements made by an LWD instrument in pressure modulation telemetry so that while-drilling images of a wellbore can be generated. The one embodiment includes encoding the quantized coefficients, error encoding the encoded coefficients, and applying the error encoded coefficients to the pressure modulation telemetry.

Data compression method for use in wellbore and formation characterization

The present invention describes a method and apparatus to control the effect of contact impedance on a formation resistivity measurement during a logging-while-drilling operation. The control of contact impedance is accomplished by maintaining a substantially zero difference in potential between two monitor electrodes positioned on the resistivity logging tool near a current electrode. The tool can employ a ring electrode configuration and/or a button electrode, configuration. The ring electrode configuration incorporates two pairs of ring monitor electrodes on each side of a ring current electrode. The button electrode configuration incorporates. a monitor electrode, surrounded by a current electrode, surrounded by a second monitor electrode. Insulation gaps are positioned between each electrode to separate the electrodes. A variable current is supplied to the current electrode in each configuration to maintain the same potential at each monitor electrode. The effect of contact impedance is controlled through maintaining the same potential at each monitor electrode.

Method and apparatus for controlling the effect of contact impedance on a galvanic tool in a logging-while-drilling application

Method and apparatus for fishing for and/or communicating with subsurface apparatus. In a preferred embodiment, a subsurface logging-while-drilling (LWD) or measuring-while-drilling (MWD) apparatus is placed in tandem with a drill string near the bottom of a borehole. The LWD apparatus includes a surface retrievable component such as a nuclear source carrier with a fishing head facing upwardly. The carrier is releasably secured within the LWD apparatus with means such as a shear pin. A wireline conveyed tool having a downwardly facing latching mechanism includes a downhole powered latch for telescopically extending beyond the fishing head, forcing a latching lug radially inwardly below the fishing head, and moving axially upward to latch the fishing head. Further upward latch movement causes the fishing head to move upwardly until the shear pin shears which releases the carrier from the subsurface apparatus. The wireline tool with the attached carrier is then brought to surface with the wireline cable. In a preferred embodiment, the subsurface apparatus includes a secondary coil within its tubular housing. A primary coil is provided on the wireline tool such that upon the wireline tool landing within the subsurface apparatus, the primary coil is nested within the secondary coil. As a result, a bi-directional communication link is established from surface instrumentation to the subsurface apparatus via the wireline cable and the nested coils.

Apparatus and method for retrieving and/or communicating with downhole

Growing community of inventors

Houston, TX, United States of America

Mark A Fredette