Bp Corporation North America Inc.

Gerard Joseph Beaudoin

Raymond Lee Abma

Leon A Thomsen

Graham Openshaw

Ganyuan Xia

Richard L Crider

Scott T Michell

Zhiyong Jiang

Atle H Fyhn

Eivind W Berg

Nigel P Purnell

Raymond Abma

According to an embodiment of the instant invention there is provided a method for collecting a blended source seismic survey that utilizes new approach to determining a random time separation between successive shots. The random time separation may be drawn in some embodiments from a distribution of uniformly distributed numbers, with &#x3c4;&#x3e;1/(2 f), where &#x3c4; is the half-width of the uniform distribution and f is the lowest frequency of interest in the survey.

Shot scheduling limits for seismic acquisition with simultaneous source shooting

There is provided herein a system and method of seismic exploration that produces improved locations and timings for ocean bottom seismometers. The instant method utilizes linearized inversion in conjunction with a conventionally accurate clock to provide both time and positioning for each OBS unit with high accuracy as compared with the prior art approach. Inversion is one mathematical tool that effectively performs the requisite triangulation. Furthermore, the clock drift can be accounted for in the inversion scheme. The inversion not only determines the OBS position and shot timing errors, but also estimates the accuracy of the position and timing determination.

System and method for accurate determination of ocean bottom seismometer positioning and timing

This is a method of acquiring marine wide azimuth towed streamer seismic data. Preferably, a recording boat which tows a plurality of seismic streamers and at least one source may be accompanied by a plurality of source boats that each tow at least one source. The source boats may preferably activate their respective sources such that the subsurface reflections generated by each source interfere. The time separation between successive shots may preferably be a random variable related to the lowest frequency of interest in the data. Additionally, the source boats may preferably be alternatively fired from the head and tail of the recording streamers.

Method and apparatus for marine wide azimuth towed steamer seismic acquisition

A method and apparatus is disclosed for performing a seismic survey below the surface of a body of water and on the seabed. In one embodiment, a plurality of seismic data receivers are removably loaded in a carrier located above the surface of the water and the carrier is lowered into the water and placed at a depth relatively close to the seabed. Each of the receivers has a memory for recording the vibrations of the seabed and has a switch for activating the memory. A ROV is used to unload the receivers from the carrier and to deposit each receiver on the seabed and along a survey line. In one embodiment, the receivers comprise a frame, a pressure vessel for housing the memory and remotely activated controls, and a geophone that is separately planted into the seabed at a relatively short distance from the frame.

Geophysical method and apparatus

The instant invention is generally directed toward methods of using an AVO-type analysis on unstacked seismic data to identify subsurface exploration prospects. More particularly, a new method of identiflying and displaying converted mode seismic reflections is provided that has significant advantages over that in the prior art. Additionally, the instant invention can be used to attenuate or eliminate seismic reflections such as multiples that are not flattened by conventional velocity analysis. Further, a method is disclosed that provides for identification and display of only those seismic reflections deemed consistent with the usual or expected AVO behavior. Finally, another aspect of the instant invention involves the use of statistical goodness of fit measures, such as the Coefficient of Determination, to create a seismic display that is indicative of the degree to which each time slice in a gather conforms to a proposed AVO model.

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Houston, TX, United States of America

Gerard Joseph Beaudoin