地质约束下的深水绕射多次波衰减技术

Geology constrained diffraction multiple attenuation technology

随着海洋勘探开发的深入,对深水地震资料品质要求越来越高.崎岖海底绕射多次波的压制和去除已成为当前深水陡坡带和复杂海底地震资料处理的重点和难点.当前海上单-窄方位采集观测方式下,由于崎岖海底产生的绕射多次波传播路径复杂、方向异变,二次反射源在自由表面的下行反射点位置常常位于排列方位之外,导致SRME技术无法准确有效预测和衰减崎岖海底下的绕射多次波.本文借鉴地表一致性处理思想,提出了一种基于地质统计约束下的绕射多次波衰减技术(GCDMA),通过地质信号的统计和建模分解实现对残余绕射多次波的判定和衰减,经实际资料测试处理取得了明显的应用效果,较好解决了深水陆坡崎岖海底下的绕射多次波衰减难题,极大提高了中深层地震资料品质.

With the development of offshore seismic exploration,the requirement of seismic data becomes higher. Diffraction multiple suppression under the irregular deep water bottom has become the key point in deep water seismic data processing,which contains slope-break zone and the irregular deep water bottom. For the marine narrow azimuth acquisition geometry,due to the diversity and mutation of diffraction multiple wave propagation path which caused by the irregular deep water bottom. The position of the secondary reflection source under the sea surface always located out of the geometry, In this situation, SRME technology can not accurately predict and attenuate diffraction multiple of the irregular deep water bottom. In this paper,Based on the surface-consistence processing theory,putting forward a geology constrained diffraction multiple attenuation technique（ GCDMA）. By Statistics of geological signals and modeling decomposition to realize residual diffraction multiples prediction and attenuation,and through the actual data testing and processing, it has obtained the obvious application effect,which solves the problem of multiple diffraction attenuation of the irregular deep water bottom,and greatly improved in quality of deep water seismic data.