Schlumberger Technology Corporation

Services Petroliers Schlumberger

Schlumberger Holdings Limited

Prad Research and Development Limited

Prad Research Development Limited

Andrei Davydychev

William B Vandermeer

Bulent Finci

John F Hunka

Scott S Chesser

Richard Dan Ward

Dzevat Omeragic

Thomas D Barber

Gerald N Minerbo

Michael Thiel

Jingjing (Karen) Sun

Yi-Qiao Song

Tarek M Habashy

Dean M Homan

Edward Harrigan

Jean P Seydoux

Anthony Louis Collins

Denis Heliot

Srinand Sreedharan Karuppoor

Andrew John Carnegie

Mark A Fredette

Henry N Bachman

Keli Sun

Steve F Crary

Yves Barriol

Tim Hopper

Bennett N Nicholas

Denis Lebreton

Jingjing Karen Sun

Jean Seydoux

Inversion-based workflows are provided for real-time interpretation of the electromagnetic (EM) look-around and look-ahead measurements. The profile of a look-around zone is determined by interpreting EM measurements of a look-around zone. The profile of the look-around zone characterizes formation dip as well as vertical resistivity or resistivity anisotropy of one or more formation layers of the look-around zone. The profile of a look-ahead zone is determined by interpreting EM measurements of the look-ahead zone. The profile of the look-ahead zone characterizes formation dip as well as horizontal resistivity, vertical resistivity or anisotropy of one or more formation layers of the look-ahead zone. The workflows can also involve interpretation of look-around resistivity measurements to aid in the characterization of the look-around zone.

Methods and systems employing look-around and look-ahead inversion of downhole measurements

An inversion based calibration method for downhole electromagnetic tools includes processing an inversion of a formation model using acquired electromagnetic measurement data to obtain formation parameters and calibration parameters for at least one measurement array.

Inversion-based calibration of downhole electromagnetic tools

A method and system for producing look-ahead profiles measurements includes positioning an energy transmitter, such as a transmitting antenna, proximate to a borehole assembly tool. One or more energy receivers, such as receiving antennas, are positioned along a length of the borehole assembly. Next, energy is transmitted to produce look-ahead scans relative to the borehole assembly tool. Look-ahead graph data with an x-axis being a function of a time relative to the position of the borehole assembly tool is generated. The look-ahead graph is produced and displayed on a display device. The look-ahead graph may track estimated formation values based on earth models. The estimated formation values are displayed below a tool position history line that is part of the look-ahead graph. The estimated formation values in the look-ahead graph may be based on inversions of resistivity data from the look-ahead scans.

System and method for producing look-ahead profile measurements in a drilling operation

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

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

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

A method for correcting induction conductivity well log measurements for conductivity of a wellbore and a formation proximate the wellbore includes estimating an effective formation conductivity for the formation proximate the wellbore from measurements made by an induction receiver proximate an induction transmitter. The effective formation conductivity is used to correct apparent conductivity measurements made by at least one induction receiver on the instrument.

Method for determining an effective formation conductivity for induction log borehole correction

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

Sugar Land, TX, United States of America

Andrei Davydychev