Method for sorting seismic data

Abstract

An improved method for gathering traces in a 3-D seismic survey is disclosed. In one configuration, receiver lines having equally spaced geophone receivers stations are run in one direction, and lines of equally spaced shotpoint stations run orthogonal to the receiver station lines. The station spacing in each shotpoint and receiver lines is selected to produce a desired spatial resolution, and the individual lines are spaced apart by a distance equal to at least two times the station intervals. In this method, a series of common mid point gathers centered about source/receiver line intersection, referred to as 'hybrid gathers' is made, where each hybrid gather includes traces from a designated number of shots in the shotpoint line of the selected intersection that are directed into a designated number of geophone receivers in the receiver line of the selected intersection. Full survey data from the crossed-arrayed shotpoint/receiver geometry can be assembled from the series of hybrid gathers, however, an advantage of the hybrid gather is that each hybrid gather can be individually processed and imaged using techniques that depend upon adequate spatial sampling, such as velocity filtering, which techniques are normally reserved for full common midpoint summed gathers. Other shotpoint/receiver layout configurations used with hybrid gathers are also disclosed.