Method for determining source and receiver statics in marine seismic exploration

Claim 1

A method for seismic exploration at a marine exploration site having an anomalous near surface low velocity layer below the water bottom, comprising the steps of: (a) deploying a marine seismic detector cable along a seismic exploration line for which seismic reflection signals traveling to said seismic detector cable pass through a near surface low velocity layer, (d) deploying a marine seismic monitor at a distance remote from said seismic detector cable such that the first energy received at said monitor consists of seismic refraction signals which have passed through said near surface low velocity layer, and (c) generating first seismic energy at an offset distance from said seismic detector cable so as to produce a first seismic signal which travels downward into the earth, is refracted through the earth, and travels upward through said near surface low velocity layer to intersect said seismic detector cable in a generally orthogonal direction, whereby said first seismic signal, as received by said detector cable, includes a receiver statics component attributable to said near surface low velocity layer, (d) generating second seismic energy so as to produce a second seismic signal which travels downward through said near surface low velocity layer into the earth, is (i) refracted through the earth and detected by said remote seismic monitor, said refracted second seismic signal including a source statics component attributable to said near surface low velocity layer and (ii) reflected from the earth and detected by said seismic detector cable at the same time said refracted second seismic signal is detected by said remote seismic monitor.

Claim 2

A method for seismic exploration at a marine exploration site having an anomalous near surface low velocity layer below the water bottom, comprising the steps of: (a) deploying a marine seismic detector cable along a seismic exploration line for which seismic reflection signals traveling to said seismic detector cable pass through a near surface low velocity layer, (d) deploying a marine seismic monitor at a distance remote from said seismic detector cable such that the first energy received at said monitor consists of seismic refraction signals which have passed through said near surface low velocity layer, and (c) generating first seismic energy at an offset distance from said seismic detector cable so as to produce a first seismic signal which travels downward into the earth, is refracted through the earth, and travels upward through said near surface low velocity layer to intersect said seismic detector cable in a generally orthogonal direction, whereby said first seismic signal, as received by said detector cable, includes a receiver statics component attributable to said near surface low velocity layer, (d) generating second seismic energy so as to produce a second seismic signal which travels downward through said near surface low velocity layer into the earth, is (i) refracted through the earth and detected by said remote seismic monitor, said refracted second seismic signal including a source statics component attributable to said near surface low velocity layer and (ii) reflected from the earth and detected by said seismic detector cable at the same time said refracted second seismic signal is detected by said remote seismic monitor.