Schlumberger Technology Corporation

York Limited

Bp Exploration Operating Company Limited

Sensor Highway Limited

York Sensors Limited

National Research Development Corporation

Onesubsea IP UK Limited

Mossgas (pty) Limited

Schlumberger Canada Limited

Services Petroliers Schlumberger

Schlumberger Holdings Limited

Prad Research and Development Limited

Arthur H Hartog

Dominic Joseph Brady

Douglas E Miller

Gareth P Lees

Ashley Bernard Johnson

Paul Simon Hammond

J Ernest Brown

John Mervyn Cook

Yuehua Chen

Andrew Strong

Jonathan James Elphick

Peter C Wait

Richard Timothy Coates

Francois M Auzerais

Maxwell Richard Hadley

Kamal Kader

Colin A Wilson

Henry Menkiti

Theo Cuny

Rogerio Tadeu Ramos

Everhard Johan Muyzert

Colin Allan Wilson

James Edward Martin

George Albert Brown

Johan Robertsson

Glynn R Williams

Kevin J Forbes

Christian Koeniger

Dylan H Davies

Paul Frederick Cilgrim Dickenson

Benjamin Peter Jeffryes

Philippe Gambier

Martin E Poitzsch

Tsutomu Yamate

Robert J Schroeder

David Randolph Smith

Simon James

Cheng-Gang Xie

Gary Martin Oddie

Hubertus V Thomeer

David Neil Payne

Xu Wu

Vladimir Vaynshteyn

Andrew Meredith

Pierre Vigneaux

Ian Atkinson

Jeffrey A Tarvin

William Brian Underhill

Ian Bradford

Ian David Richard Bradford

Roger Hampson

Bernard Frignet

Ed Kragh

Graeme Hilton

Daniela Donno

Bence Papp

Franck Monmont

Robert Greenaway

Franck Bruno Jean Monmont

Ernest Brown

Alexis Constantinou

James McInnes

Kevin Williams

Duncan Mackie

Timothy Dean

François Auzerais

Stephen Mullens

Dimitri Cadere

Kamal Kadar

Timothy Jeffreys

Marc J Middendorp

Jakob J Hamman

Kevin Forbes

Dillwyn P David

Adrian P Leach

Martin P Gold

Simon Severance

Samantha Rist

Florian Englich

Michael Clark

Dominic Brady

David R Smith

Ashley Johnson

Paul Hammond

Jonathan Elphick

James Ernest Brown

Robert Schroeder

Jeffrey Tarvin

Rogerio Ramos

Francois Auzerais

A distributed measurement system includes a first distributed optical sensing fiber deployed along a first desired measurement path and a second distributed optical sensing fiber deployed along a second desired measurement path. The system further includes an interrogation system coupled to the first distributed optical sensing fiber and to the second distributed optical sensing fiber. The system also includes a first distributed measuring instrument launch a first interrogating probe pulse set comprising a first pulse having a first frequency and a second pulse having a second frequency. The interrogation system is designed to direct the first pulse to the first distributed optical sensing fiber and the second pulse to the second distributed optical sensing fiber.

Simultaneous distributed measurement monitoring over multiple fibers

A sensor assembly for passive detections of downhole well features. Embodiments include a casing collar locator assembly that utilizes fiber optics in combination with a magneto-responsive sensor to detect casing collars and provide real-time location information in a well. The sensor may be configured to work with a poled monolithic structure that is dimensionally responsive to voltage in a way that substantially eliminates noise during detections. Additionally, the sensor may be intentionally imbalanced, utilizing multiple fibers of different lengths and multiple wavelength monitoring so as to provide enhanced directional information as well as allow operators to decipher and address circumstances of polarization fade.

Fiber optic magneto-responsive sensor assembly

An optical-fiber-containing sensor wire with at least one hermetically sealed optical fiber are provided. An optical-fiber-containing sensor wire may be installed in a cable that can be placed downhole in a wellbore. The optical-fiber-containing sensor wire may include a first optical fiber hermetically sealed within a metallic structure of the optical-fiber-containing sensor wire.

Sensor construction for distributed pressure sensing

Monitoring one or more items of equipment associated with a borehole or other conduit. A sensor system includes a vibration sensor for sensing vibrations at one or more sensor locations associated with one or more items of the equipment and/or the borehole or other conduit. A processing system processes the sensor information to determine a characteristic of the operation of the one or more items of equipment and/or the borehole or other conduit.

Monitoring of equipment associated with a borehole/conduit

A technique facilitates the use and application of a distributed vibration sensing system in, for example, a well application. The technique enables selection of a desired gauge length to achieve an optimum trade-off between the spatial resolution of a distributed vibration sensing/distributed acoustic sensing system and signal-to-noise ratio. The optimum gauge length can vary according to specific factors, e.g. depth within a well, and the present technique can be used to account for such factors in selecting an optimal gauge length which facilitates accurate collection of data on dynamic strain.

Gauge length optimization in distributed vibration sensing

Using hDVS techniques to detect a disturbance in a coherent Rayleigh backscatter caused by the presence of another optical signal in the fiber. The interaction can be caused by a pump pulse travelling shortly after a probe pulse and at a frequency close to that of the probe plus or minus a Brillouin frequency shift. This results in gain or attenuation of the backscatter signal. The Brillouin shift is a function of temperature and strain.

Non-linear interactions with backscattered light

A fiber optic distributed vibration system for detecting seismic signals in an earth formation is provided. The system includes a fiber optic cable deployed in a borehole that extends into the earth formation and which is configured to react along its length to a seismic wave incident on the fiber optic cable from outside the borehole. An optical source launches an optical signal into the fiber optic cable while the seismic wave is incident thereon. A receiver detects coherent Rayleigh noise (CRN) produced in response to the optical signal. A processing circuit processes the detected CRN signal to determine characteristics of the earth formation.

Detection of seismic signals using fiber optic distributed sensors

A system and method for simultaneously addressing multiple parallel distributed fiber optic sensors using a single interrogation instrument is disclosed. One or more of the fiber optic sensors are provided with a non-reflective delay element to prevent an overlap in time between backscatter returns from the distributed fiber optic sensors, thereby allowing the backscatter returns from each sensor to be distinguished based on round-trip transit time.

Multifiber interrogation with reflectometry techniques

Methods for determining separate velocity components of an acoustic wavefield that are incident on a distributed fiber optic sensor are disclosed. A fiber optic sensor includes fiber that is spatially distributed in non-parallel planes of a three-dimensional volume having three orthogonal axes. The fiber includes a first fiber pattern that is spatially distributed within a first plane of the three-dimensional volume, and a second fiber pattern that is spatially distributed within a second plane of the volume. The fiber patterns are interrogated separately by a distributed fiber optic interrogation system. The individual responses from each pattern are combined and processed to determine separate velocity components of the acoustic wavefield relative to the orthogonal axes of the three-dimensional volume.

Fiber optic distributed vibration sensing with directional sensitivity

An apparatus and method for correcting the wavenumber sensitivity of a distributed fiber optic sensor are disclosed. The distributed fiber optic sensor is deployed in a region of interest to measure a characteristic of an incident acoustic wavefield. A composite response of the distributed sensor is determined based on backscatter optical signals generated by the sensor, where the composite response is indicative of a characteristic of an incident acoustic wavefield. The composite response includes at least a first response having a first wavenumber sensitivity and a second response having a second wavenumber sensitivity. The second wavenumber sensitivity is selected so that wavenumber notches of the first and second responses do not overlap.

Fiber optic distributed vibration sensing with wavenumber sensitivity correction

Disclosed are a system, apparatus, and method for optical fiber well deployment in seismic optical surveying. Embodiments of this disclosure may include methods of deploying a spooled optical fiber distributed sensor into the wellbore integrated in a ballast or weight for a seismic optic tool, to achieve deployment of a lightweight disposable fiber optic cable against the wellbore walls via gravity. The method may further include unspooling the spooled optical fiber distributed sensor and using the optical fiber as a distributed seismic receiver. Once the fiber optic distributed sensor is deployed according to methods of the present disclosure, surveys may be obtained and processed by various methods.

Optical fiber well deployment for seismic surveying

An optical fiber sensor system and method for monitoring a condition of a linear structure such as a pipeline is provided which is capable of providing continuous monitoring in the event of a break in the sensing optical fiber or fibers. The system includes at least one sensing fiber provided along the length of the linear structure, and first and second interrogation and laser pumping sub-systems disposed at opposite ends of the sensing fiber, each of which includes a reflectometer. The reflectometer of the first interrogation and laser pumping sub-system is connected to one end of the sensing fiber. The reflectometer of the second interrogation and laser pumping sub-system is coupled to either (i) an end of a second sensing fiber provided along the length of the linear structure which is opposite from the one end of the first sensing fiber, or (ii) the opposite end of the first sensing fiber. Before any break of the sensing fiber or fibers occurs, each reflectometer redundantly monitors the condition of the linear structure over its entire length. After any such break occurs, each reflectometer will continue to receive signals up to the point of the break from opposite ends of the structure.

Redundant optical fiber system and method for remotely monitoring the condition of a pipeline

Apparatus and a method for monitoring of a pipe inspection tool in a pipeline, the apparatus comprising at least one sensor carrier apparatus being locatable along and in close proximity to a pipeline, a plurality of acoustic sensors being locatable on the sensor carrier apparatus, a pipeline inspection tool which is moveable through the pipeline being detectable by means of the acoustic sensors, and the location of the pipeline inspection tool being able to be determined by means of the acoustic sensors.

Monitoring of the position of a pipe inspection tool in a pipeline

A distributed acoustic wave detection system and method is provided. The system may include a fiber optic cable deployed in a well and configured to react to pressure changes resulting from a propagating acoustic wave and an optical source configured to launch interrogating pulses into the fiber optic cable. In addition, the system may include a receiver configured to detect coherent Rayleigh noise produced in response to the interrogating pulses. The CRN signal may be used to track the propagation of the acoustic waves in the well. Such capability allows the location of the cement sheath, as well as measuring the bonding of cement to at least a casing string at least partially surrounded by a cement sheath.

Methods for locating a cement sheath in a cased wellbore

A fiber optic distributed vibration sensor provides a highly sensitive measurement of a measurand with a high degree of linearity. The distributed vibration sensor includes subsections configured to have a high sensitivity to a measurand of interest interspaced in an alternating manner with subsections having a low sensitivity to the measurand. The distributed vibration sensor is interrogated such that a phase difference between the backscattered signals generated in low sensitivity subsections surrounding a high sensitivity subsection can be determined. Characteristics of the measurand may then be determined based on the phase difference.

Precision measurements in a fiber optic distributed sensor system

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Winchester, United Kingdom

Arthur H Hartog