Westerngeco L.l.p.

Reflection Marine Norge As

Schlumberger Technology Corporation

Geco Technology B.v.

Jon-Fredrik Hopperstad

Robert Montgomery Laws

Julian Edward Kragh

David Fraser Halliday

Aslaug Stroemmen Melboe

Johan O A Robertsson

Svein Arne Frivik

Henk Keers

Julian Edward (Ed) Kragh

Luren Yang

Morten Svendsen

Johan-Fredrik Synnevaag

Ali Ozbek

Emmanuel Coste

Johan Olof Anders Robertsson

Claudio Bagaini

Massimiliano Vassallo

Clement Kostov

John Richard Tulett

Philip Kitchenside

Pieter Leonard Vermeer

Aslaug Strømmen Melbø

Ahmet Kemal Ozdemir

Aslaug Strømmen Melboe

Karin Schalkwijk

Ed Kragh

Robert Laws

Anneli Soppi

Embodiments included herein are directed towards a marine seismic streamer. The seismic streamer may include an outer skin formed in a longitudinally extending tubular shape, an inner surface of the outer skin defining an internal volume containing a gel substance. The seismic streamer may also include a plurality of micro-electro-mechanical ('MEMS') sensors and a plurality of hydrophones associated with the outer skin, wherein the plurality of MEMS sensors are spaced non-uniformly in the seismic streamer along an axial direction of the streamer, such that not more than 100 MEMS sensors are located in the seismic streamer over a continuous 100 meter axial length of seismic streamer. The seismic streamer may further include an electronics system extending axially through an inside portion of the outer skin and a strength member core extending axially through an inside portion of the outer skin.

Compressive sensing marine streamer system

Marine seismic surveys, including ocean bottom surveys, utilizing marine vibrator arrays that are capable of being driven in anti-phase to produce a directional source gradient. Marine seismic surveys may include activating the vibrator array to emit a plurality of radiation patterns with at least a first radiation pattern that has a first notch at a take-off angle that is not dose to vertical. Some marine seismic surveys included emitting directive wavefields from two or more simultaneous seismic source arrays, where the two or more seismic source arrays have a phase that changes from shot-to-shot to allow simultaneous source separation of the directive wavefields.

Marine vibrator directive source survey

Marine seismic surveys, including ocean bottom surveys, utilizing marine vibrator arrays that are capable of being driven in anti-phase to produce a directional source gradient. Marine seismic surveys may include activating the vibrator array to emit a plurality of radiation patterns with at least a first radiation pattern that has a first notch at a take-off angle that is not close to vertical. Some marine seismic surveys includes emitting directive wavefields from two or more simultaneous seismic source arrays, where the two or more seismic source arrays have a phase that changes from shot-to-shot to allow simultaneous source separation of the directive wavefields.

A technique for reconstructing a seismic wavefield includes receiving data over one or more channels of a plurality of channels from a plurality of stations. The data is recorded by a plurality of seismic receivers and represent measurements of properties of the seismic wavefield. Each station includes a region in space including one or more seismic receivers. Each channel either measures a property of the seismic wavefield or a property of the seismic wavefield after the seismic wavefield has undergone a known transformation. At least one channel is derived as a function of one or more other channels. The technique includes using a processor based machine to process the data to model the seismic wavefield as a sum of basis functions; apply to the basis functions at least one forward transformation that describes the measurements received over the channel(s); and determine optimum basis functions based at least in part on the measurements.

Wavefield reconstruction

Marine seismic vibrators in a marine seismic vibrator array for use in a seismic survey are activated to produce a source gradient wavefield to survey a target structure. The seismic survey may comprise a marine seismic survey conducted in a body of water.

Wavefield generation using a seismic vibrator array

A method for selecting parameters of a seismic source array comprising a plurality of source elements each having a notional source spectrum is described, the method comprising calculating a ghost response function of the array; calculating directivity effects of the array; and adjusting the parameters of the array such that the directivity effects of the array are compensated by the ghost response to minimize angular variation of a far field response in a predetermined frequency range. A method for determining a phase center of a seismic source array is also related, the method comprising calculating a far field spectrum of the array at predetermined spherical angles, and minimizing the phase difference between the farfield spectra within a predetermined frequency range by adjusting a vertical reference position from which the spherical angles are defined.

Method and system for selecting parameters of a seismic source array

To acquire near-zero offset survey data, a survey source and a first streamer attached to the survey source are provided, where the first streamer has at least one survey receiver. A second streamer separate from the survey source and the first streamer includes survey receivers. Near-zero offset data is measured using the at least one survey receiver of the first streamer.

Acquiring near-zero offset survey data

A technique facilitates obtaining seismic data in a marine environment. An array of acoustic sources is deployed in a marine environment. The array can be utilized for creating acoustic pulses that facilitate the collection of data on subsea structures. The methodology enables optimization of acoustic source array performance to improve the collection of useful data during a seismic survey.

Method for optimizing acoustic source array performance

A technique provides a source design and method for increasing low frequency output of a marine source array. The approach comprises providing a plurality of airguns. At least some of the airguns are activated to generate an effective bubble energy. The effective bubble energy may be optimized through use, preparation and/or arrangement of the airguns.

Systems and methods for optimizing low frequency output from airgun source arrays

A method of processing seismic data acquired consequent to actuation of a seismic source is described. The method comprises taking the result of the following process into account when processing the seismic data where the process comprises estimating the effect of uncertainty in the position and/or orientation of the seismic source relative to the measuring receiver on processing the seismic data by estimating a source wavefield from data acquired by a near-field measuring receiver and from a first parameter set including at least one parameter indicative of the position and/or orientation of the seismic source relative to the measuring receiver, varying the value of at least one parameter of the first parameter set, estimating the source wavefield from the data acquired by the measuring receiver and from the varied first parameter set and obtaining information about the uncertainty in the estimate of the source wavefield.

Processing seismic data

A technique facilitates the acquisition of seismic data at a substantially reduced source volume. The methodology generally comprises conducting a seismic survey with seismic sources that have a reduced source volume to collect seismic data. The low frequency data which is lost due to the reduced source volume is replaced with data acquired from a complementary method, such as a receiver-side acquisition method. The two sets of data are combined to provide a comprehensive seismic survey image without requiring conventional seismic source volume.

Method for reducing marine source volume while maintaining image quality

Systems and methods for optimizing low frequency output of marine sources are described. The marine source arrangements and associated methods disclosed herein seek to fully frequency lock bubbles emitted by airguns in close proximity to one another. In this manner, larger effective bubble volumes can be achieved, thus increasing low frequency output.

A seismic source array includes a first source and a second source. The first source has a first spectral output and the second source has a second spectral output different than the first spectral output. The first source has a first total volume different than a second total volume of the second source.

Source acquisition with multiple frequency components

A method of obtaining information about the positions of sources in a marine seismic source array that has N seismic sources, including at least Ntypes of sources that are nominally non-identical to one another, where 1&#x2266;N&#x2266;N&#x2212;1. The method comprises measuring the pressure field at M independent locations of the N sources, where M&#x3e;N, and obtaining information about the positions of sources from the M pressure measurements and from the constraint that at least two of the sources are nominally identical to one another.

Position determination of a seismic source array

A method of obtaining information about the positions of sources in a marine seismic source array, comprises: determining respective notional signatures for m selected seismic sources, where m&#x3c;n, where n is the number of sources of the array actuated to generate an output; and obtaining information about the travel between one of the m selected seismic sources and one of the n&#x2212;m unselected seismic sources from the determined notional signatures. The m seismic sources are selected as sources whose positions, relative to one another, are expected to be close to their nominal positions. The effect of the n&#x2212;m unselected seismic sources is ignored in the calculation of the nominal signatures for the m sources, and this gives rise to anomalies in the nominal signatures for the m sources. The determined travel time may be converted to a distance, so that information about the positions of the n&#x2212;m unselected seismic sources may be obtained from the anomalies. Alternatively, the nominal signatures calculated for the m sources may be compared with notional signatures calculated for an estimate of the actual positions of the sources. The invention allows information about the actual geometry of the source array to be obtained from near-field measurements, so avoiding the need for a separate position-determining means.

Growing community of inventors

Cambridge, United Kingdom

Jon-Fredrik Hopperstad