The Optimal Design of Point Source Air-gun Array in Marine and its Application

The far-field signature for conventional marine air-gun array varies with azimuth, which makes it difficult to meet spatial omni-directional energy distribution requirement of 3D wide-azimuth seismic acquisition with streamer or OBC. Based on the stacking principle of seismic energy in space, we analyze the quantitative relation between the far-field signature and spatial distribution of the air-gun units and individual volume elements. An azimuth-invariant point source array is proposed with symmetrically distributed air-gun units. On this basis, the optimal design for point source array with staggered asymmetric distribution is carried out and applied for actual wide-azimuth seismic acquisition in marine. The seismic profile shows that the reflected energy is significantly increased, reflected events are relatively continuous, the breakpoints of faults are clear, and the resolution is improved.