海上全方位观测系统照明

全方位观测系统是目前海上一种可以实现连续环状采集的地震观测系统,它有效扩大目标层上面元的采集方位范围,能够更全面地反映地下构造信息,具有极高的生产效率.本文在波前构建法三维射线追踪技术的基础上,通过获得模拟偏移振幅强度作为照明量,来衡量目标层对不同观测系统的照明响应,为评价和优化不同观测系统提供指导依据.测试结果表明:与平行观测系统相比,全方位观测系统在目标层上的照明能量的连续性和均匀性最好,能够有效地改善平行观测系统下照明阴影区的照明效果,是一种理想的观测系统,可以广泛适用于海上复杂地质环境下的地震采集工作.

Illumination of marine full-azimuth survey

Full-azimuth survey is a new acquisition geometry that can run continuously linked circles with little or no nonproductive time. It can expand the acquisition azimuth range for the target strata, providing more complete illumination of the subsurface and having very high production efficiency. This work is based on 3D ray modeling by wavefront construction, and then numerically simulated migration amplitude (SMA).By treating the strength of SMA as illumination intensity, the seismic response of the target layer is measured. Further, we can obtain the level of contribution from different acquisition geometries in the target area. And this method can be used to estimate and optimize various acquisition geometries. The result of the numeric model test demonstrates that the illumination of the target strata collected by full azimuth survey has much better continuity and uniformity, improving the illumination intensity at the shadow area acquired by parallel geometries. So the full azimuth survey is a kind of ideal marine surveys, and can be widely used in complex geological environments in offshore exploration.