Cggveritas Services S.a.

Compagnie Generale De Geophysique

Other

Cgg Services Sas

Institut Francais Du Pe'trole

Gaz De France

Institute Francais Du Petrole

Cgg Services Sa

Syntron, Inc.

Gaz De France-service National

Ifp Energies Nouvelles

Sercel Inc.

Gdf Suez

Julien Meunier

Thomas Bianchi

Frédéric Huguet

Frederic Huguet

Patrick Meynier

Robert Soubaras

Michael L Maples

Olivier Winter

Cécile Berron

Alan Sprain

Yves Delassis

Fabien Espeute

Methods and systems for deriving S-wave velocity information from the low-frequency content of ambient noise are described. The ambient noise can be collected on a dedicated record or on a production record associated with the receivers of a three-dimensional seismic survey. The methods and systems use one of a plurality of analysis models selected based on quality factors of the ambient noise data. The methods and systems analyze the data at a plurality of single frequencies then transform the velocity versus frequency data into velocity versus depth data.

Device and method for velocity function extraction from the phase of ambient noise

Methods for seismic exploration of a subsurface formation increase productivity by simultaneously actuating closely located vibratory sources. Individual vibrations generated by different sources actuated simultaneously are encoded to enable separation of seismic data corresponding to each of the individual vibrations.

Apparatus and method for seismic data acquisition with simultaneous activation of clustered vibrators

Apparatus, computer instructions and method for controlling an energy output of a source array to be used in a seismic survey for illuminating a subsurface. The method includes generating a model (&#x3b2;) based on up-going (U) and down-going (D) components of seismic waves generated by source elements that form the source array; calculating the amplitudes and phases of each source element based on the model (&#x3b2;); and driving the source array based on the calculated amplitudes and phases for the source elements so that a ghost generated by the source array is reduced at emission.

Method and apparatus for controlling output of an array of seismic sources

A system and method are described herein for generating a frequency sweep signal set for use in seismic data gathering. Low frequency sweep rate modifications are combined to compensate for vibrator limitations and vibrator far-field responses with high frequency sweep rate modifications to compensate for absorption, and then the frequency sweep signal set is generated based on the combination of high and low frequency sweep rate modifications.

Sweep design for seismic sources

Method and retrievable vertical hydrophone cable for collecting seismic data underground. The retrievable vertical hydrophone cable includes an envelope having a first end at which a connector mechanism is provided to close the envelope; plural hydrophones distributed inside the envelope at predetermined positions; and a fluid provided inside the envelope and around the plural hydrophones. The envelope increases its volume when the fluid is pressurized through the connector mechanism.

Retrievable vertical hydrophone cable and method

A method and a mechanized system for deploying plural geophones underground for collecting seismic data. The mechanized system includes a vehicle configured to travel above ground and having a storage area that stores the plural geophones; a digging mechanism attached to the vehicle and configured to dig a trench when in contact with the ground; and a damping mechanism attached to the vehicle and configured to hold a geophone behind the digging mechanism relative to a traveling direction (X) of the vehicle.

Method and device for mechanized geophone deployment

The invention concerns a method of acquiring vibroseismic data concerning a zone of the subsoil. This method comprises the following steps: &#x2014;operating a vibroseismic source so that it transmits a first vibroseismic signal having a first amplitude (), &#x2014;operating the source so that it transmits a second vibroseismic signal having a second amplitude different from the first amplitude (), &#x2014;recording first data corresponding to the first signal after propagation in the medium to be explored (), &#x2014;recording second data corresponding to the second signal after propagation in the medium to be explored (). The method supplies information for filtering the surface waves (ground roll).

Method of acquiring vibroseismic data concerning a zone of the subsoil, and seismic exploration method including such a method

The invention relates to a method for the acquisition of seismic data that uses sources operable to produce, when they are in a shooting station, seismic vibrations according to a sweep type shooting sequence, of predetermined duration and variable frequency. According to this method, the source and recording device clocks are synchronized, shooting is authorized for each of the sources at a series of predetermined shooting times tk,n, with k being an order number for a given source and n a source order number, between 1 and the number of sources Ns, and carried out on condition that the source is in a state to produce vibrations at such time tk,n, and the signals produced by the receivers are continuously recorded. The invention also relates to a system for seismic acquisition that implements this method.

Process and system for the acquisition of seismic data

The invention relates to a method for monitoring a subsoil zone, wherein a plurality of receivers are arranged on a surface of the soil or near said surface, straight above a geological zone to be monitored, comprising the following steps: generating a set of reference seismic data recording seismic data by means of said receivers; correlating the seismic data recorded () with the reference seismic data; comparing each trace of the correlated data, with correlated traces located in a vicinity of said trace, in order to evaluate a similarity of each correlated trace with the adjacent correlated traces, detecting a microseismic event occurring in the subsoil zone by analysing said similarity. This method enables real-time monitoring.

Method for monitoring a subsoil zone using a plurality of correlated traces, particularly during simulated fracturing operations

A method and device for monitoring a subsoil zone, wherein a plurality of receivers are arranged on a surface of the soil or near said surface, straight above a geological zone to be monitored, comprising the following steps: generating a set of reference seismic data; recording seismic data by means of said receivers; correlating the seismic data recorded with the reference seismic data; comparing each trace of the correlated data, with correlated traces located in a vicinity of said trace, in order to evaluate a similarity of each correlated trace with the adjacent correlated traces; and, detecting a microseismic event occurring in the subsoil zone by analysing said similarity. The method and device enables real-time monitoring.

Method for monitoring a subsoil zone, particularly during simulated fracturing operations

The invention relates to a method for seismic exploration, comprising the steps of controlling a plurality of sources so that they emit a plurality of seismic waves in a subsurface zone to be explored, each source successively occupying a plurality of emitter positions, producing for each emission a signal representative of the emission, and recording the position of the source and the instant at which the emission starts, continuously recording by means of seismic sensors the composite signals reflected by the medium in response to said emissions, and carrying out shot point migration, on the one hand, from a reflected wave field constituted of said composite signals and respective sensor positions, and on the other hand, from an incident wave field constituted of signals representative of the emissions, source positions and start emission instants, so as to obtain a seismic image.

Method for seismic exploration

A device for seismic emission in an underground formation comprising one or more vibrators of any type and method for implementing same. According to a preferred embodiment, each vibrator comprises at least one pillar () of sensitive elements (of piezoelectric type for example) between two end plates or slabs () and a signal generator for applying vibrational signals to the pillar. The pillar () is coated with a protective sheath () and the vibrator is positioned in a well or cavity (W) and embedded in a mass of a solid coupling material () in contact with protective sheath () and the two end plates () over at least part of each of the respective faces thereof, which provides coupling of the vibrator with the surrounding formation. The vibrators can be buried at intervals in relation to one another in a well. Sequential triggering thereof with selected delays allows reinforcement of the waves emitted by the device in a preferred direction. Applications include repetitive seismic monitoring of an underground reservoir during development for example.

Device for seismic emission in an underground formation and method for implementing same

This invention is a method of separating induced microseismicity signals from seismic signals acquired within active seismic monitoring operations carried out in underground zones under development which has application for monitoring of underground hydrocarbon or fluid storage reservoirs. Seismic records are formed from signals emitted by one or more seismic sources controlled by orthogonal signals. In this case, the signals are processed to separate the respective contributions of the at least one seismic source to the signals received and to reconstruct the seismograms equivalent to those that would be obtained by actuating the at least one seismic source separately. The induced microseismicity signals (passive seismic signals) are separated from the seismic signals coming from sources (active seismic signals) essentially by isolating the contribution thereof by comparison with a spectral reference model at the fundamental frequencies emitted and at the respective harmonics thereof, and by reconstructing in the time domain the induced microseismicity signals and the signals coming from the at least one seismic source.

Method for separating microseismic signals from seismic signals emitted by one or several sources

Method and system intended for seismic monitoring of an underground zone ( ), comprising simultaneously using several seismic vibrators. The system comprises for example several local units (LU) comprising each a vibrator ( ), a seismic pickup antenna ( ), a local acquisition and processing unit ( ), and a central control and synchronization unit ( ) for simultaneously controlling the various vibrators by means of orthogonal signals, local units ( ) being suited, by means of particular; processing, to isolate and to reconstitute the seismograms corresponding to the contributions of the various vibrators. Applications: monitoring of a hydrocarbon reservoir during production or of a reservoir used for gas storage for example.

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Paris, France

Julien Meunier