Bp Corporation North America Inc.

Raymond Lee Abma

Allan A Ross

Gerard Joseph Beaudoin

Joseph Anthony Dellinger

Brian Edward Hornby

Kang Fu

Min Zhou

Kenneth Howell Matson

David John Howe

Zhiyong Jiang

John Naranjo

A method of seismic exploration above a region of the subsurface containing structural or stratigraphic features conducive to the presence, migration, or accumulation of hydrocarbons comprises accessing at least a portion of a blended seismic source survey, separating the at least two interfering seismic source excitations using inversion separation, producing one or more source gathers based on the separating, and using the one or more source gathers to explore for hydrocarbons within said region of the subsurface. The blended source seismic survey contains at least two interfering seismic source excitations therein, and the seismic source excitations can be produced by seismic source types having different signatures or frequency characteristics.

Separation of multiple seismic sources of different types by inversion

A method for use in vertical seismic profiling includes: independently and simultaneously shooting a plurality of seismic sources in a plurality of shooting areas to impart seismic signals into a water bottom: receiving reflections of the seismic signals from a subterranean formation beneath the water bottom at a plurality of seismic receivers; and recording the received reflections; wherein, one of the seismic sources and the seismic receivers are disposed in a wellbore in the water bottom.

Independent simultaneous shooting acquisition with vertical seismic profile recording

A method for use in marine seismic surveying includes: towing at least a portion of a marine seismic survey spread; imparting a composite swept seismic signal from the marine seismic survey spread, the composite swept seismic signal including a plurality of randomized subsweeps having different frequencies relative to one another and being emitted in parallel; and receiving a respective return for each of the subsweeps.

Coding of signals for efficient acquisition

According to an embodiment, there is provided a system and method of collecting seismic data using a predetermined pattern of source activations that is intended to control the properties of the resulting seismic signal. One embodiment utilizes a seismic source array (or, more generally, any collection of controllable sources) to create a series of spaced apart in time source activations, with the spacing and number of such activations being used to shape the resulting signal. In one method of building sweeps, the guns are fired at an increasing rate (decreasing time separation) as time goes by. Other patterns may be generated by decreasing the firing rate as time goes by, or some combination of the foregoing. In an embodiment, the rate of the increase or decrease in the firing rate will change from pattern to pattern.

Analytically generated shooting schedules for use with patterned and simultaneous source acquisition

So-called 'Popcorn shooting', and especially continuous Popcorn shooting, combined with simultaneous source shooting allows considerable flexibility in producing high-resolution data and in creating source arrays. Using a combination of simultaneous source de-blending and Popcorn reconstruction it is possible to construct using post acquisition processing arrays of any desired length by constructing a popcorn pattern that takes into account the vessel speed and physical arrangement of guns behind the towing vessel.

Spatial sampling improvements and the formation of arrays using popcorn and simultaneous source acquisition

The Monte-Carlo method of generating Popcorn shooting patterns starts with the number and sizes of the guns available and the length in time of the desired Popcorn pattern. The firing times and order of the guns will be randomly perturbed and a large number of Popcorn patterns built. Candidate Popcorn patterns will then be tested against a set of criteria to identify acceptable or the best patterns. These criteria may include limits on maximum peak strength, distinctiveness compared to the other patterns, and the size of the notches and peaks in the spectra.

Seismic source coding, activation, and acquisition

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

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

The maximum output of a seismic source array may be reduced by activating the individual seismic sources within these seismic source array in a pattern that is extended in time rather than by the presently employed conventional simultaneous activation of a large number of individual seismic sources. Methods are disclosed which take data shot with patterned sources and may use a sparse inversion method to create data with the about same image quality as that of conventional sources. In this manner the output of the maximum impulse of a seismic source array may be reduced by an amplitude factor of about 10 in the examples shown here, corresponding to a reduction of about 20 dB while maintaining virtually the same seismic image quality. The disclosed methods may be used in combination with any simultaneous sourcing technique. In addition, the disclosed methods may be used with a plurality of source arrays.

Seismic acquisition method and system

This is a method of separating simultaneous sources that uses an inversion-type approach. Each source will preferably activated at a random time with respect to the others. These random delays tend to make the interference between sources incoherent while the reflections create coherent events within a series of shots. The shot separation is performed via a numerical inversion process that utilizes the sweeps for each shot, the start times of each shot, and the coherence of reflection events between nearby shots. Implementation of this method will allow seismic surveys to be acquired faster and cheaper.

Method for separating independent simultaneous sources

This is a method of separating simultaneous sources that uses an inversion-type approach. Each source will preferably activated at a random time with respect to the others. These random delays tend to make the interference between sources incoherent while the reflections create coherent events within a series of shots. The shot separation is performed via a numerical inversion process that utilizes the sweeps for each shot, the start times of each shot, and the coherence of reflection events between nearby shots. This method will allow seismic surveys to be acquired faster and cheaper.

According to a preferred aspect of the instant invention, there is provided herein a system and method for Interpolation of seismic data with a POCS (projection onto convex sets) algorithm that can produce high quality interpolation results, at a reduced computational cost. In particular, optimizing the threshold calculations, allowing for aliased data, allowing the algorithm to skip unneeded Fourier transforms, and parallelization makes the method more practical and robust. Robust interpolation of aliased data may be done by limiting the calculations of the beginning iterations to the lowest temporal and spatial frequencies included in the data, then gradually allowing higher temporal and spatial frequencies into the following iterations.

Method of seismic data interpolation by projection on convex sets

According to a preferred aspect of the instant invention, there is provided herein a system and method for removing or attenuating multiples in datasets that is much more efficient than methods used heretofore. The increases in efficiency principally originate in two algorithmic advances. First, the instant inventors have improved the overall efficiency of the conventional SRME process by reordering the computations in a novel way. Second, the instant inventors have conceived and developed a faster method of computing the DMO transformation step that is often used as one component of the SMRE process, thereby increasing the efficiency of the multiple removal process even further.

Method of multiple attenuation

According to a preferred aspect of the instant invention, there is provided herein a system and method for improving the computational efficiency of the DMO transformation that has many uses in the seismic processing arts. More particularly, the instant inventor has conceived and invented a faster method of calculating a log-stretch DMO transformation that utilizes multiple independent time windows, each with its own starting and ending time. A particularly preferred usage of the improved DMO method is as an element of a multiple attenuation program such as SRME.

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Houston, TX, United States of America

Raymond Lee Abma