Seismic data gathering method

Abstract

This specification discloses a method of seismic exploration and in particular a method of generating and gathering field seismic data. Paths or seismic lines are traversed across the earth or water layers overlying the earth and over subsurface earth formations thereunder, and seismic energy is generated and transmitted into the earth and a portion thereof is reflected from the subsurface formations back toward the surface of the earth where the reflected seismic energy is detected and recorded. In conducting the seismic survey, a long linear array of seismic sources is simultaneously activated to produce a seismic pulse that is focused essentially vertically into the earth, and seismic energy is reflected from subsurface formations thereof and is detected by a long array of seismic detectors and is recorded. At a separate but closely related time, the long linear array of seismic sources is activated, beginning at the end thereof farthest from the detectors and proceeding to the other end thereof with a preselected time delay between the activation of each next succeeding source to produce a seismic pulse which is focused downwardly into the earth at a designed angle with the vertical. At a still separate but closely related time, a point seismic source is activated to produce a nonfocused seismic pulse which is transmitted into the earth, and reflections from subsurface earth formations therefrom are recorded. The above-described operations are repeated at other locations or shotpoints in traversing the seismic lines, and seismic data are gathered from the earth's subsurface formations.

Dependencies are inferred from the claim text.