Abstract: A method comprising determining coordinates of a first point rigidly attached to a rigid body floating on the sea surface in a desired coordinate reference frame; measuring orientation parameters of the rigid floating body to determine 3D offset in the coordinate reference frame of the first point to any point on or rigidly attached to the body; applying a 3D coordinate shift from the first point to a second point rigidly attached to the body, thus determining coordinates of the second point in the desired reference frame; determining a distance from the second point to one or more devices that are components of a seismic acquisition spread, by comparing transmission times of a signal to recording times of transmitted signals and multiplying by a signal propagation rate; and determining relative positions of components of the spread to each other and to devices rigidly attached to the rigid body.
Abstract: An example of a cable positioning mechanism for directing a cable into a seismic sensor housing for connection with the seismic sensor includes a member sized to connect with a seismic sensor housing, the cable passing through the member at opposing anchor points for operational connection to the seismic sensor between the anchor points, wherein the cable is oriented through the member at an angle that is not perpendicular to a vertical axis of the sensor housing.
Type:
Grant
Filed:
July 28, 2008
Date of Patent:
August 16, 2011
Assignee:
WesternGeco L.L.C.
Inventors:
Jean-Michel Hache, Harvey Ray Grimes, Gunnar A. Lindeman, Jon Mangus Soerli, Kenneth Pedersen, Anders Falke Roeraas, Roar Stenhaug, Raymond R. Ness, Jr., Francis Maissant
Abstract: A sensor cable for surveying. The sensor cable may comprise at least one pair of current sensor electrodes and an amplifier. The current sensor electrodes may be disposed along opposite sides of the sensor cable. The current sensor electrodes may be configured to detect current in an electromagnetic field transverse to an inline direction of the sensor cable. The amplifier may be configured to amplify the current in the electromagnetic field for detection by the electrode pair.
Type:
Grant
Filed:
June 3, 2008
Date of Patent:
August 16, 2011
Assignee:
WesternGeco L.L.C.
Inventors:
Kamal Babour, Leendert Combee, James P. Brady, Martin Howlid
Abstract: An embodiment according to one or more aspects of the present disclosure for conducting a marine survey includes towing a survey spread comprising a plurality of receivers and an energy source along a selected course; emitting a signal from an energy source; receiving data from the plurality of receivers; detecting a cetacean from the received data; positioning the detected cetacean; limiting contact with the detected cetacean; and conducting a marine survey.
Abstract: A technique includes operating a seismic vibrator, including driving the seismic vibrator at different frequencies and driving forces. The technique includes monitoring a parameter affected by the operation of the seismic vibrator during the frequency sweep and based at least in part on the monitored parameter, determining a maximum driving force profile for the seismic vibrator.
Type:
Grant
Filed:
March 21, 2008
Date of Patent:
July 5, 2011
Assignee:
WesternGeco L.L.C.
Inventors:
Claudio Bagaini, John Quigley, Robert Vincent
Abstract: Methods, systems, and software for representing seismic shot or receiver data as a superposition of a plurality of diplets are disclosed. The method includes decomposing one or more prestack shot or receiver records into a set of diplets, migrating the diplets using one or more velocity models, and synthesizing one or more migrated diplets into a migrated seismic volume, wherein each diplet comprises information about spatial location, orientation, amplitude, an associated wavelet, acquisition configuration, and coherency.
Abstract: A method for managing a fracturing operation. In one implementation, the method may include positioning a seismic source and at least one seismic receiver near a hydrocarbon reservoir; pumping a fracturing fluid into a well bore of the hydrocarbon reservoir; performing a seismic survey with the seismic source and the at least one seismic receiver during the fracturing operation; and identifying locations of the fracturing fluid within subsurface formations in which the hydrocarbon reservoir is located.
Abstract: A method and apparatus for acquiring seismic signals from beneath a salt region in the earth. In one embodiment, the method includes tuning an air gun array to a first bubble oscillation; towing the air gun array in the water at a depth of at least 10 meters, in which the air gun array has a total volume in a range of about 6780 cubic inches to about 10,170 cubic inches; directing acoustic signals with the air gun array down through the water into the earth beneath the salt region; towing one or more seismic streamers in the water at one or more depths, in which at least one of the depths is at least 10 meters, in which each streamer comprises a plurality of hydrophones disposed therealong; and recording with the hydrophones seismic signals reflected from strata in the earth beneath the salt region.
Type:
Grant
Filed:
June 16, 2004
Date of Patent:
June 14, 2011
Assignee:
WesternGeco L.L.C.
Inventors:
Nicolae Moldoveanu, Philip A. F. Christie, Mark Egan
Abstract: A technique includes obtaining seismic data acquired by at least one seismic sensor. The technique includes processing the seismic data to determine a value that is indicative of a three-dimensional directional propagation attribute of a seismic event based on the seismic data.
Type:
Grant
Filed:
March 21, 2008
Date of Patent:
June 14, 2011
Assignee:
WesternGeco L.L.C.
Inventors:
Johan Robertsson, Dirk-Jan Van Manen, Susanne Rentsch
Abstract: A seismic survey system having a source array (11) coupled to a deflector device (15) that controls the position of the source array. A positioning system unit (16) is mounted on the source array to provide a signal to a controller, informing the controller of the current position of the source array so that the controller can control the position of the deflector device (15) and the coupled source array. A seismic source (14) on the source array may be triggered when the source array is at a desired location as measured by the positioning system unit. The deflector device (15) comprises one or more wings (18) in a generally vertical or, alternatively, in a generally horizontal arrangement disposed adjacent to a central body (19). The streamlined central body has connection points that allow the deflector device (15) to be connected to a tow cable (13) from the tow vessel (12) and to the source array (11).
Abstract: A method and apparatus for acquiring seismic data. In one embodiment, the method includes: moving a first air gun array in the water at a first depth and a second air gun array in the water at a second depth greater than the first depth, in which the total volume of the first air gun array is less than the total volume of the second air gun array, in which the first air gun array is separated from the second air gun array by a distance substantially equal to a shot point interval, firing seismic energy through the first and second air gun arrays through the water into the earth, and recording seismic signals reflected from strata in the earth beneath the water.
Abstract: To process subterranean survey data, measurement data is collected by a receiver positioned in deep water, where the collected measurement data is responsive to signals emitted by at least one signal source located at or near an air-water interface of the body of water. The measurement data is processed to reduce a predetermined signal component.
Type:
Grant
Filed:
November 21, 2007
Date of Patent:
May 24, 2011
Assignee:
WesternGeco L.L.C.
Inventors:
David Alumbaugh, Jiuping Chen, Kevin Eyl, Stephen Allan Horne, Edward Nichols
Abstract: Methods, systems, and software for generating a multi-dimensional volume are disclosed. The methods include decomposing one or more original volumes into a collection of diplets, wherein each diplet includes information about spatial location, orientation, amplitude, wavelet, acquisition configuration, and coherency. The methods further include migrating the collection of diplets using one or more of a velocity model or an anisotropic velocity model, and synthesizing one or more of the migrated diplets to an output multi-dimensional seismic volume.
Abstract: A technique includes performing at least one intervening towed seismic survey after a prior towed seismic survey and before a future towed seismic survey. The prior towed seismic survey has associated first streamer positions, and the future towed seismic survey has associated second streamer positions that do not coincide with the first streamer positions. The technique includes using measurements that are acquired in the intervening towed seismic survey(s) to link the prior towed seismic survey to the future towed seismic survey for time lapse analysis involving the prior and future towed seismic surveys.
Type:
Grant
Filed:
April 30, 2008
Date of Patent:
April 26, 2011
Assignee:
WesternGeco L.L.C.
Inventors:
Ralf Ferber, Stephen Pickering, Robin Charles Walker
Abstract: A subsurface imaging cable includes a plurality of sensor modules, wherein the plurality of the sensor modules are flexible and each of the plurality of the sensor modules is spaced apart on the subsurface imaging cable at a selected distance; and a flexible medium connecting the plurality of the sensor modules, wherein the subsurface imaging cable is flexible and adapted to be wound on a reel. A method for subsurface images includes acquiring direct-current measurements at a plurality of sites in a survey area; acquiring a first set of electric and magnetic measurements from natural electromagnetic fields at the plurality of sites; acquiring a second set of electric and magnetic measurements using controlled electric and magnetic sources at the plurality of sites; and determining a subsurface conductivity distribution from the direct-current measurements and the first set and the second set of electric and magnetic measurements.
Abstract: An electrical cable having a polymeric inner layer enclosing a cable core, and a polymeric outer layer enclosing the cable core and the inner layer. The outer layer operable to maintain integrity of the cable within a predetermined temperature range.
Type:
Grant
Filed:
June 6, 2008
Date of Patent:
March 29, 2011
Assignee:
WesternGeco L.L.C.
Inventors:
Joseph Varkey, Byong Un Kim, Jushik Yun, Willem A. Wijnberg, Montie W. Morrison
Abstract: A technique includes determining at least one parameter that characterizes a seismic survey in which multiple interfering seismic sources are fired and seismic sensors sense energy that is produced by the seismic sources. The determination of the parameter(s) includes optimizing the seismic survey for separation of the sensed energy according to the seismic sources.
Type:
Grant
Filed:
July 16, 2008
Date of Patent:
March 29, 2011
Assignee:
WesternGeco L.L.C.
Inventors:
Craig J. Beasley, William Henry Dragoset, Jr., Ian Moore
Abstract: Seismic data collected by a group of seismic receivers is received, and properties of coherent noise for plural modes of the coherent noise based on the received seismic data are computed to produce a model of the coherent noise for the plural modes. Using the model, the coherent noise is simulated to generate a synthetic noise.
Abstract: Various technologies for a seismic acquisition system, which may include an acquisition central system configured to determine a desired start time for a sweep cycle in one or more vibrators and a recorder source system controller in communication with the acquisition central system. The recorder source system controller may be configured to receive the desired start time from the acquisition central system. The seismic acquisition system may further include one or more vibrator units in communication with the recorder source system controller. Each vibrator unit may be configured to start a sweep cycle in a vibrator at the desired start time.