Westerngeco L.l.p.

Schlumberger Technology Corporation

Geco Technology B.v.

Julian Edward Kragh

Everhard Johan Muyzert

James Edward Martin

David Fraser Halliday

Jon-Fredrik Hopperstad

Pascal Guillaume Edme

Robert Montgomery Laws

Johan O A Robertsson

Clement Kostov

Philip A F Christie

Ying Ji

Nicolas Goujon

Kenneth E Welker

Emmanuel Coste

Johan Olof Anders Robertsson

Lasse Amundsen

Ali Özbek

Morten Svendsen

Tage Rosten

Johan Robertsson

Ali Ozbek

Kambiz Iranpour

Leendert Combee

Claudio Bagaini

Svein Arne Frivik

Martin N Howlid

Oeyvind Teigen

Toru Ikegami

Everhard Johan Muijzert

Ottar Kristiansen

Henk Keers

Marwan Charara

Philippe Caprioli

Qinglin Liu

Aslaug Stroemmen Melboe

Luren Yang

Daniel Ronnow

Jon Magnus Soerli

Johan Olaf Anders Robertsson

Dirk-Jan Van Manen

Gwénola Claire Marie Michaud

David Neser

Filippo Broggini

Anthony Curtis

Gabriele Busanello

Everhard Muyzert

Pascal Edme

Gwenola Claire Michaud

Philip Andrew Felton Christie

Methods of acquiring and processing seismic data using derivative sensors, such as strain sensors, that facilitate ground roll noise attenuation with seismic interferometry are disclosed. The methods use both seismic data and their spatial derivatives in computing ground-roll noises which are removed from processed seismic data.

Seismic interferometry for grand roll and noise attenuation

Seismic surveying techniques are described in which seismic receivers in a seismic array are used as seismic sources. These receiver-sources may be used to determine the near-surface structures of the Earth, geometric properties of the survey array, receiver locations and operations of the survey array. The receiver-sources may be driven by drive sequences to produce amplified receiver-source signals, plane waves, surface waves converging towards a point inside the seismic array, surface waves sweeping through the seismic array and/or the like. The receiver-sources may comprise geophones, hydrophones, accelerometers and/or the like. A driver may be used to drive the receiver-sources and the driver may be controlled by a processor. By encoding drive sequences, seismic data generated by the receiver-sources may be separated from seismic data generated by another seismic source in the seismic array. Similarly, seismic data can be separated by controlling the frequency of seismic signals produced by the receiver-sources.

Seismic receivers as seismic sources

A tool is described for seismic data collection which may have sensors mounted along its entire length to sample both geophysical signal and noise including at least one of acoustic noise, system noise, and noise resulting from the interaction between the two. Systems and methods for acquiring borehole seismic data are also described. In contrast to conventional systems which attempt to avoid introducing noise into the collected data stream, the present systems include a sufficient type, number, and spacing of sensors to intentionally sample at least one source of noise. The methods include operating a borehole seismic acquisition system to sample both a target signal and at least one source of noise and using a processor with machine-readable instructions for separating the noise from the signal.

Borehole seismic acquisition tools, systems and methods

Methods and apparatuses for land seismic survey are provided. The methods and apparatuses utilize spatial derivatives of a seismic wavefield to interpolate, regularize or extrapolate seismic data. The methods and apparatuses may considerably reduce land seismic field efforts and/or compensate data gaps.

Methods and systems for land seismic surveying

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

Methods and apparatuses for processing seismic data to generate images or determine properties of an interior section of the Earth. The seismic data is processed to filter coherent noise such as ground roll noise from seismic survey data. The noise is attenuated using 3D and/or 2D fan filters, which may have combined low-pass and band-pass filters derived from signal decomposition. The filters are designed with selected operator length, velocity bands of signals and noises and frequency range for a primary trace and adjacent traces within the operator length. The data is decomposed with the filters into signals and noises, and the noises are then filtered from the decomposed data. The process may be repeated for various frequencies and traces within the seismic data. The methods may be used for surveys that have either regular or irregular seismic receiver or seismic source positions.

Coherent noise attenuation

The present disclosure generally relates to the use of a self-propelled underwater vehicle for seismic data acquisition. The self-propelled underwater vehicle is adapted to gather seismic data from the seafloor and transmit such data to a control vessel. The self-propelled underwater vehicle may be redeployed to several seafloor locations during a seismic survey. Methods for real-time modeling of a target zone and redeployment of the self-propelled underwater vehicle based on the modeling are also described.

Seismic data acquisition using self-propelled underwater vehicles

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 seismic land vibrator, comprising a baseplate comprising a substantially flat, rigid member; at least one driven member that is connected with the baseplate and extends in a direction that is substantially perpendicular to baseplate; a rotation sensor that is coupled to the baseplate and adapted to provide a signal that is indicative of rotational movement of at least a portion of the baseplate.

Seismic vibrator device and method with rotation sensor

A technique facilitates the use of seismic data. The technique utilizes an autonomous underwater vehicle to obtain data on water column characteristics in a seismic survey area. The data can be used to adjust aspects of the seismic survey data and/or the seismic survey technique.

System and method of using autonomous underwater vehicle to facilitate seismic data acquisition

Embodiments of the invention provide a method of processing marine seismic data, the data having been acquired using a 'dense over/sparse under' streamer array having N over streamers disposed at a first depth and M under streamers disposed at a second depth greater than the first depth, where 0&#x3c;M&#x3c;N. The method comprises: a) processing seismic data for one of the over streamer target locations and seismic data for one of the under streamer target locations; b) processing seismic data for another of the over streamer target locations; and c) combining the result of (a) and the result of (b). The one of the over streamer target locations and the one of the under streamer target locations may lie in a vertical plane.

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

Generating an image of an interior of the Earth from a seismic survey using multiple sources. The multiple sources may be fired simultaneously and the data received by seismic sensors in the seismic survey may be decomposed so that seismic data generated by each of the multiple sources may be determined. Decomposing of the received data may be performed using frequency diverse basis functions and converting the data separation problem into an optimization problem, which can be a one-norm or zero-norm optimization problem in frequency-space domain. The decomposed data may be used to generate the image of the Earth's interior.

Separation of simultaneous source data

Neutrally-buoyant tools for seismic data collection are provided that may range from several hundred meters to several kilometers in length and have integrated sensors which move along with the borehole fluid in response to a passing seismic wave. The disclosure also provides methods of deploying neutrally-buoyant tools, which includes using a tractor, adding a weight or both to the tool in order to overcome the difficulty of lowering a neutrally buoyant tool into a borehole, and optionally occasionally clamping the tool to the borehole to alleviate tension in the tool. This disclosure also provides methods of acquiring seismic data, which involves positioning a neutrally-buoyant tool in a borehole such that the tool is able to move relatively freely along with the borehole fluid in response to a seismic wave passing through the fluid, firing a seismic source, and using the sensors to collect seismic data generated thereby.

Neutrally-buoyant borehole investigation tools and methods

Described are methods for obtaining seismic signals representative of properties of the earth's interior, including the steps of obtaining near-field acoustic signals recorded in the vicinity of a seismic source (), muting from the near-field acoustic signals at least partly signals representing direct arrivals from the seismic source (), and using a remaining part of the obtained signals as estimate of a zero-offset data set. The zero-off set data set can then be used to interpolate data from conventional acquisition location, such as streamers (), to locations closer to the source ().

Zero-offset seismic trace construction

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Finchingfield, United Kingdom

Julian Edward Kragh