Westerngeco L.l.p.

Western Atlas International, Inc.

Sercel Inc.

Geokinetics Acquisition Company

Roy Malcolm Lansley

Gary Joseph Elkington

Ronald E Chambers

David Lee Nyland

Madjid Berraki

Jean-Charles Ferran

Nicholas John Battaglino, Iii

A system mechanically alters the geometry of the surface of the water by breaking the water surface with a mechanical device. The mechanical device may comprise a plurality of propellers, a plurality of aquafoils in the shape of plows, a wire whip, or other mechanical device to reduce the coefficient of reflectivity of the air-water interface.

System and method for reducing the effects of ghosts from the air-water interface in marine seismic exploration

A receiver point arrangement is deployed having one or more receiver lines, each receiver line having receivers with substantially uniform inline spacing. A seismic source is triggered at each source point in an arrangement of source points along one or more source lines, each source line having source points with substantially uniform crossline spacing. Seismic data traces are collected, each trace having an associated midpoint. A perturbation pattern is applied to at least one of the receiver point arrangement and the source point arrangement to distribute the midpoints evenly within a bin having dimensions of half the receiver inline spacing and half the source crossline spacing across multiple locations within that bin. The fractionation in the crossline and inline directions is determined by the interaction between the number of offset positions in the receiver point arrangement and number of offset positions in the source point arrangement, respectively; phase shifts of the perturbation pattern between adjacent receiver lines and between adjacent source lines, respectively; and crossline and inline fold, respectively, of a recording patch employed.

Three-dimensional seismic survey methods using a perturbation pattern to provide bin fractionation

A seismic survey area is divided into a number of &ldquo;bins&rdquo; of a convenient shape and size. The data from the suite of shot and receiver positions are analyzed and all shot-receiver pairs that have a common sort point (CSP) are assigned to the spatial bin in which the CSP is located. The CSP maybe a common mid-point (CMP). The data within each bin are analyzed to give a figure of merit of the adequacy of the sampling for each bin. These figures of merit are displayed in a color display that makes the inadequacies of the sampling apparent, making it possible to modify the planned acquisition geometry prior to the actual deployment of the receiver lines. Alternatively, a figure of merit is determined for the overall survey.

Method of determining merit of offset and azimuth distributions in seismic data acquisition

A method for performing a seismic survey with even fold. An inline direction and a crossline direction are selected. Seismic signals are generated at a plurality of source locations positioned along one or more source lines. The source locations are substantially equally spaced, and the source lines are substantially parallel to each other. Seismic signals are detected at a plurality of receiver locations positioned along a plurality of receiver paths having longitudinal axes parallel to the inline direction, and substantially equally spaced in each receiver path. Each receiver path is positioned along its axis, and extends in a regular pattern on both sides of the axis. The axes are substantially parallel to each other. A desired fold, F.sub.i, is determined in the inline direction, and a desired fold, F.sub.x, is determined in the crossline direction. A number of receiver channels, NC.sub.i, per receiver path in the inline direction, a spacing, RI.sub.i, between receiver locations in the inline direction, a number, NRL.sub.x, of receiver paths in the crossline direction, and a number, NS.sub.x, of source locations in the crossline direction are determined. Spacing, SI.sub.i, between source locations in the inline direction satisfying the expression F.sub.i =(NC.sub.i .times.RI.sub.i)/(2.times.SI.sub.i), and spacing, SI.sub.x between source locations in the crossline direction, and distance, R.sub.x, rolled in the crossline direction which satisfy the expression F.sub.x =(NRL.sub.x .times.NS.sub.x .times.SI.sub.x)/(2.times.R.sub.x) are selected.

Growing community of inventors

Bellville, TX, United States of America

Roy Malcolm Lansley