Westerngeco L.l.p.

Schlumberger Technology Corporation

Other

James Edward Martin

Julian Edward Kragh

Everhard Johan Muyzert

John Richard Tulett

Arthur H Hartog

Nicolas Goujon

Robert Montgomery Laws

Ali Ozbek

Emmanuel Coste

Kambiz Iranpour

Colin Allan Wilson

Rune Sindre Voldsbekk

Johan Fredrik Naes

Bent Andreas Kjellesvig

Philip Andrew Felton Christie

Bence Papp

Johan Robertsson

Kambiz Iranpour Mobarekeh

Daniela Donno

Hiroshi Nomura

Benjamin Peter Jeffryes

Tsutomu Yamate

Ahmet Kemal Ozdemir

Andreas W Laake

Robert Hughes Jones

Andrew Curtis

Ali Özbek

Paul Steven Jaques

Johan Olaf Anders Robertsson

Will Wason

Sarah Ryan

Gwénola Claire Marie Michaud

Ahmet Kemal Özdemir

Svein Haheim

Tatsuki Endo

A technique includes spatially filtering a signal that is derived from a seismic acquisition. The filtering is associated with a filter length, and the filtering includes varying the filter length with frequency. The filtering may be used in connection with adaptive noise attenuation, which is applied to decomposed subbands. Furthermore, the filtering may be applied during the reconstruction of the signal from the subbands.

Removing noise from a seismic measurement

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

A marine cable for seismic surveys is described with a plurality of ceramic pressure sensors arranged in groups of at least two pressure sensors with a group output being representative of the vertical pressure gradient at the group location, and an inclinometric system including one or more transducers for determining the orientation of the sensors of the group in order to determine their true vertical separation.

Marine seismic acquisition system

A borehole seismic acquisition system is described with a plurality of sensors arranged so as to identify within the data measured by the pressure sensors P- and S-wave related signals converted at the boundary of the borehole into pressure waves, the sensors being best arranged in groups or clusters sensitive to pressure gradients in one or more directions.

Borehole seismic acquisition system

Methods and apparatus for generating borehole seismic surveys are disclosed. The methods and apparatus enable more accurate surveys than previous surveying systems. In some embodiments, firing of remote seismic sources is synchronized with data recording in a borehole. In some embodiments, the synchronization is based on a universal time standard. In some embodiments, GPS positioning technology is used to predict firing times and synchronize firing times with downhole and surface recording.

Methods and apparatus of source control for synchronized firing of air gun arrays with receivers in a well bore in borehole seismic

A sensor device () is adapted to be installed at a land-air interface. The sensor device () comprises a fluid-filled housing () and a sensor arrangement () supported within the housing () and coupled directly to the fluid so as to detect movement thereof. A seismic sensor installation comprises a sensor device () installed at a land-air boundary, wherein the sensor device comprises a fluid-filled housing () and a sensor arrangement () supported within the housing () and coupled directly to the fluid as to detect movement thereof.

Seismic sensor devices

Methods and apparatus for borehole seismic survey are disclosed comprising a first seismic source under water at a first location and a second seismic source at a second, deeper location. Seismic signals from the seismic sources are recorded with synchronized sensors located in a borehole and source signature data are obtained by combining the recorded seismic signals such that low and high frequency content of the combined source signature data is extended relative to the source signature of the first seismic source and the second seismic source.

Methods and apparatus of borehole seismic surveys

A marine cable for seismic surveys is described with a plurality of ceramic pressure sensors (-) arranged in groups of at least two pressure sensors with a group output being representative of the vertical pressure gradient at the group location, and an inclinometric system including one or more transducers for determining the orientation of the sensors of the group in order to determine their true vertical separation.

A method and apparatus is provided for acoustic ranging by application of linear period modulated sound. In one aspect of the instant invention, an apparatus is provided for acoustic ranging by application of linear period modulated sound. The apparatus includes at least one source adapted to generate at least one modulated Doppler invariant signal and at least one receiver deployed along a seismic sensing cable, wherein the receiver is adapted to receive at least one modulated Doppler invariant signal from the at least one source. The apparatus further includes a signal processing unit adapted to determine the propagation time delay between the source and the receiver using the modulated Doppler invariant signal and the received Doppler invariant signal.

Acoustic ranging by application of linear period modulated sound

An improved de-ghosting method and system that utilizes multi-component marine seismic data recorded in a fluid medium. The method makes use of two types of data: pressure data that represents the pressure in the fluid medium, such as sea water, at a number of locations; and vertical particle motion data that represents the vertical particle motion of the acoustic energy propagating in the fluid medium at a number of locations within the same spatial area as the pressure data. The vertical particle motion data can be in various forms, for example, velocity, pressure gradient, displacement, or acceleration. A spatial filter is designed so as to be effective at separating up and down propagating acoustic energy over substantially the entire range of non-horizontal incidence angles in the fluid medium. The spatial filter is applied to either the vertical particle motion data or to the pressure data, and then combined with the other data to generate pressure data that has its up and down propagating components separated.

Method and system for reducing effects of sea surface ghost contamination in seismic data

Methods and apparatus for controlling seismic source firings are disclosed. The methods and apparatus enable firing of seismic sources to increase pressure wave amplitude. Some methods and apparatus reduce ghosting and align first pressure peaks of multiple seismic sources. The multiple seismic sources may be fired sequentially according to active feedback mechanisms. Controlling the firing of the seismic source facilitates more accurate seismic data and a more consistent seismic source signature.

Methods and apparatus of source control for sequential firing of staggered air gun arrays in borehole seismic

A housing for a seismic sensing element () for use on the earth's surface comprises connecting means () for connecting the housing () to a support cable () so as to allow relative movement between the sensor housing () and the cable (). This de-couples the sensor housing from the support cable, and improves the fidelity of the sensor. The connecting means () preferably comprises resilient connecting elements, to prevent the transmission of vibrations between the support cable and the sensor housing. The sensor housing () preferably has a flat base (), so that there is good coupling between the sensor housing and the earth. Alternatively, the sensor housing can be fitted with a base member (() that has at least one flat face ().

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Cottenham, United Kingdom

James Edward Martin