Cgg Services Sas

Cggveritas Services S.a.

Cgg Services Sa

Yuan Ni

Gordon Poole

Risto Siliqi

Thierry Payen

Ziqin Yu

Chris Davison

Cheikh Niang

Behzad Vahida

A method for estimating a time variant signal representing a seismic source obtains seismic data recorded by at least one receiver and generated by the seismic source, the recorded seismic data comprising direct arrivals and derives the time variant signal using an operator that relates the time variant signal to the acquired seismic data, the operator constrained such that the time variant signal is sparse in time.

Estimating a time variant signal representing a seismic source

In order to use near-field measurements to obtain signature of a signal penetrating seafloor in a shallow water surveyed area, the water-bottom reflections' effect is removed. The removal is performed by obtaining first a far-field initial estimate from stacked primary pulses in the near-field measurements, and then estimating water-bottom reflection portions for different depths using differences between the near-field measurements and the far-field initial estimate. The signature of the air-gun for each shot is then deblended from the near-field measurement for the shot using the one of the water-bottom reflection portions according to a water-bottom depth associated with the shot location.

Method and apparatus for estimating source signature in shallow water

Marine seismic sources for exploring formations under the seafloor using reflection seismology include ghost attenuators for reducing or eliminating ghost signals. Such a ghost attenuator is located in the water above an individual source element and 5 water surface and is configured to dissipate energy of up-going signals and/or to redirect the up-going signals.

Method and ghost attenuator for mitigating ghost effect

A method for detecting faults of individual wave sources in a marine source array includes acquiring near-field data using sensors, the sensors being located near the individual wave sources. The method further includes generating an index for each of the individual wave sources based on (A) the near-field data and (B) information on the geometry of the marine source array that enables localizing the individual wave sources and respective sensors relative to one another. The method also includes comparing the index for each of the individual wave sources with a corresponding reference index for determining whether a fault has occurred.

Method and device for detecting faults in a marine source array

A method controls a delay of an air-gun in an aquatic seismic source. The method includes a step of receiving an attribute of the air-gun during the aquatic seismic survey; a step of calculating, based on a time-delay algorithm that uses the attribute, the asynchronization time of the air-gun; a step of determining whether the asynchronization time is smaller than a given time threshold; a step of instructing a controller to (1) wait for a predetermined time before calculating again the asynchronization time of the air-gun if the asynchronization time is smaller than the given time threshold, or (2) calculate an updated asynchronization time for the air-gun based on the attribute if the asynchronization time is larger than the given time threshold; and a step of sending the updated asynchronization time to a gun controller of the air-gun for adjusting a delay time for firing the air-gun.

Method and device for dynamic control of delays in gun controller

A method and a catenary seismic source steering gear for towing seismic sources underwater. The catenary gear includes plural seismic sources configured to generate seismic waves underwater; a main rope configured to span between first and second vessels; and a connecting system configured to connect the plural seismic sources to the main rope. The main rope takes a substantially catenary shape when towed by the first and second vessels underwater.

Catenary source steering gear and method

A marine source sub-array and method for generating a pressure wave in a body of water. The marine source sub-array includes a float configured to float in the body of water; base plates connected to the float through cables; plural individual source elements connected to the base plates and configured to generate pressure waves underwater; and a coverage plate located between the plural individual source elements and the float. The coverage plate has a surface area larger than a surface area of the float.

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Paris, France

Yuan Ni