海上空气枪点震源阵列的优化设计及应用

The optimal design of point source air-gun array inmarine and its application

常规海上气枪阵列震源激发的远场子波信号存在明显方向性差异,难以满足海上(或OBC)宽方位三维地震数据采集所需的点震源要求。基于地震波传播理论,本文探讨了无方向性差异点震源阵列的设计原理,并提出了理想点震源阵列设计方案。即通过非对称性分布的点震源阵列(如交错排列)优化设计,筛选出的优化子波模拟的远场子波信号适用于特定海洋勘探环境下宽方位地震数据采集。最终地震成像剖面显示:洼陷边界及内幕成像明显改善,洼陷底界波组连续性较好,洼陷内幕反射能量得到提高。

The far-field signature generated by conventional marine air-gun array varies with azimuth,which may not meet spatial omni-directional energy distribution for 3D wide-azimuth streamer or OBC acquisition.Based on seismic wave propagation theory,we discuss in the paper the design principle of non-directional difference point source,and propose a point source design.A point source design with asymmetric array distribution(such as staggered)is optimized to obtain optimized signature.Then this optimized signature is used to simulate far field signature,which is suitable for wide azimuth seismic acquisition under certain ocean environment.Applications of this kind of point source design show that reflection energy with good continuity from depressions is greatly improved and depression borders and insides are well imaged in seismic sections.