Schlumberger Technology Corporation

Westerngeco L.l.p.

Electromagnetic Instruments, Inc.

Schlumberger Holdings Limited

Geco Technology B.v.

Edward Nichols

David Lee Alumbaugh

Jiuping Chen

Nestor Cuevas

Michael Wilt

Frank Morrison

Kevin Eyl

Ping Zhang

Richard A Rosthal

Luis Eduardo DePavia

Kamal Babour

Ugo Conti

Kambiz A Safinya

Hong Zhang

Christian Besson

Tarek M Habashy

Emmanuel Legendre

Aria Abubakar

H Frank Morrison

Philip Heelan

Stephen Allan Horne

Stephen A Horne

Brian Oliver Clark

Dean M Homan

Dzevat Omeragic

John R Lovell

Jean P Seydoux

Leendert Combee

Martin N Howlid

Cengiz Esmersoy

James P Brady

Gaelle Jannin

Jean-Luc Le Calvez

Christopher Bogath

Andrea Zerilli

Yuji Hosoda

Garrett Kramer

Rafael Vinit

Thor Johnsen

Vamsi Vytla

James J Kohring

Systems, apparatuses, and methods for measuring material thickness of multiple tubulars by placing a logging tool in a well with multiple conductive tubulars and generating an electromagnetic field that interacts with the tubulars. A logging tool obtains the measurements using one or more receivers. A monitoring system or the logging tool applies the measurements to a mathematical model that considers at least a transition zone and one or both of a near field zone and a remote field zone of the electromagnetic field that interacts with the multiple conductive tubulars. Furthermore, the monitoring system or the logging tool may ascertain a thickness of the one or more conductive tubulars using the mathematical model.

Electromagnetic assessment of multiple conductive tubulars

Methods and systems are provided to determine a property of an earth formation, comprising a mobile transmitter disposed at a predetermined elevated height above a surface of the earth formation, and one or more receivers moveably disposed in a wellbore penetrating the earth formation. Electromagnetic energy is transmitted from the mobile transmitter into the formation from a plurality of locations; and at the one or more receivers a signal is measured. Using the signal received by the one or more receivers, a property of the formation, such as resistivity, can be determined and mapped.

System and method for elevated source to borehole electromagnetic survey

Systems, methods, and devices for compensating for environmental conditions on electromagnetic measurements are provided. For example, a downhole logging tool may include a first transmitter coil, a second transmitter coil, and a first receiver coil. The first transmitter coil may provide a first magnetic signal in a wellbore having a conductive casing. The second transmitter coil may provide a second magnetic signal in the wellbore. The first receiver may obtain a first measurement relating to the first magnetic signal and a second measurement relating to the second magnetic signal. The first receiver coil may be near enough to the first transmitter coil and the second transmitter coil to obtain measurements predominantly in the near field eddy current regime. A ratio of the first measurement and the second measurement may cancel environmental dependencies of the first receiver coil.

Measurement compensation using multiple electromagnetic transmitters

Systems, apparatuses, and methods for measuring material thickness of one or more casings using a permeable core are presented. A magnetic field is generated using a permeable core and transmitted through one or more casings. Moreover, one or more receivers measure changes to the magnetic field.

Remote field testing using a permeable core

A method analyzes a subterranean formation. At least one property of a well casing in the subterranean formation is determined and a plurality of current source vectors at respective positions along a trajectory of the well casing are determined. The effect of the well casing is determined based upon the plurality of current source vectors and the at least one property of the well casing.

Analyzing subterranean formation with current source vectors

A disclosed example method involves receiving a first signal transmitted into a reservoir from a production installation in a formation at a wellsite, and determining an apparent resistance of the reservoir based on the first signal. A distance between a fluid extraction tool and a fluid distribution is determined based on the apparent resistance.

Methods and apparatus to detect fluid distributions

A drill string is disposed in the borehole having a BHA and a drill bit advancing the borehole. Among other BHA components, including a telemetry unit and a data acquisition unit, in a surface-to-borehole configuration a receiver (or receiver array) is positioned immediately proximate the drill bit in the borehole, while a source (or source array) is positioned at the Earth's surface. Alternatively, in a borehole-to-surface configuration the source may be positioned immediately proximate the drill bit in the borehole while a receiver (or receiver array) is positioned at the surface. The surface-to-borehole, or borehole-to-surface, system enables an electromagnetic look about while drilling operations are underway.

Systems and methods for electromagnetic detection of a formation anomaly from a near bit location while drilling

Methods and related systems are described for measuring naturally occurring electromagnetic fields both at the earth's surface as well as downhole. These fields originate from currents in the ionosphere above the earth, and are the same fields as employed by known magnetotelluric geophysical methods based on surface measurements. Some embodiments are especially useful in horizontal wells that are uncased at depth, although some embodiments are also useful in normal vertical wells that are both uncased or cased with a conductive liner. The method includes receiving downhole electromagnetic survey data of the naturally occurring electromagnetic fields obtained using a downhole receiver deployed at a first location in a borehole. A second set of electromagnetic survey data of the naturally occurring electromagnetic fields is also received that has been obtained using a receiver deployed at a second location. A transfer function is estimated between the first and second locations for portions of the electromagnetic fields based on the two sets of electromagnetic survey data.

Electromagnetic survey using naturally occurring electromagnetic fields as a source

A technique that is usable with a well includes providing a model so predict measurements that are received by receivers due to transmissions by sources based on estimated positions of the receivers relative to the sources. The estimated positions each have at least two dimensions. At least some of the receivers and the sources are located in the well. On a computer, the estimated positions are automatically refined based on a comparison of the predicted measurements and actual measurements that are obtained by the receivers.

Method and apparatus to automatically recover well geometry from low frequency electromagnetic signal measurements

The present disclosure relates to determining a property, such as resistivity, of an earth formation. A transmitter is disposed in a wellbore penetrating the formation, and a plurality of receivers are distributed on or near the earth's surface. The transmitter sends electromagnetic energy into the formation and the resulting signal, after passing through the formation, is detected by the array of receivers. The received signal is used to determine the property of the formation. This is often achieved using an inversion or numerical model of the formation being measured. The inversion takes into account changes in the background formation model due to transmitting from various locations. The measurements made on the formation can be performed while drilling the wellbore or subsequent to the drilling.

Electromagnetic logging between borehole and surface

Impedances of an electromagnetic (EM) coil positioned in a well lined with an electrically conductive liner are determined. The impedances correspond to plural frequencies of operation of the EM coil. Based on the impedances of the EM coil corresponding to the plural frequencies, an attenuation factor associated with the electrically conductive liner is determined.

Characterizing at least one property of a liner that lines a well

A survey module includes at least one sensing element to measure a first electromagnetic (EM) field along a first direction, and circuitry to derive a second EM field along a second, different direction based on the first EM field.

Deriving an electromagnetic field in one direction based on measurement data of one or more sensing elements for measuring an electromagnetic field in another direction

To synchronize units of a formation evaluation/drilling operation evaluation system, a time delay associated with a communications link between a master unit and a slave unit of the formation evaluation/drilling operation evaluation system is determined. The master unit has a master time clock that provides universal time. The time delay associated with the communications link is used to enable synchronization of time provided by a slave time clock in the slave unit to the universal time.

Time synchronization in units at different locations

To process measurement data representing a subterranean structure, a derivative of the measurement data collected by at least one survey receiver is computed, with respect to frequency. A response representing the subterranean structure is then computed based on the derivative of the measurement data, where the response contains an air-wave component that has been suppressed due to computing the derivative of the measurement data relative to at least another component that is sensitive to the subterranean structure.

Processing measurement data that involves computing a derivative of the measurement data that represents a subterranean structure

A system to perform a marine subterranean survey includes at least one vertical electromagnetic (EM) source and at least one EM receiver to measure a response of a subterranean structure that is responsive to EM signals produced by the vertical EM source. At least one tow cable is used to tow the EM source and EM receiver through a body of water.

Surveying using vertical electromagnetic sources that are towed along with survey receivers

Growing community of inventors

Berkeley, CA, United States of America

Edward Nichols