一种优化的过渡带三维观测系统

An optimized 3-D geometry for transitional zone seismic survey

（1.中国地质大学地球物理与信息技术学院，北京100083；2.中国石油东方地球物理勘探有限公司,河北涿州072751;3.中国石油天然气勘探开发公司,北京100034）

School of Geophysics and Technology Information, China University of Geosciences, Beijing 100083, China

过渡带地区三维地震资料采集所用的观测系统包括陆上和水上两种，涉及两种观测系统过渡的问题。通常陆上采用接收道数多激发炮点少的观测系统，水上则使用接收道数少激发炮点多的观测系统，理论上水上和陆上的观测系统可以实现无缝连接，实际上由于陆上放炮时，要求水上的排列数与陆上的相同而很难实现。为此，在理论设计的无缝连接观测系统基础上，根据炮检互换原理，提出了一种优化的适合过渡带施工特点的观测系统。应用实例表明，优化过渡带三维观测系统不仅解决了实际施工中水上排列不足而陆上排列闲置的问题，实现了陆上和水上观测系统的无缝隙连接，而且同时保证了水上和陆上地震资料属性分布的一致性。

The geometry applied in transitional zone seismic survey includes onshore geometry and offshore geometry, and the complicated transition between the two geometries is also involved. Generally, 3-D land seismic survey geometry uses more receiver channels with relatively fewer shot points. 3-D offshore seismic survey geometry utilizes more shot points with relatively fewer receiver channels. Geometries can be merged seamlessly in theoretical design, but the merging is very difficult to be realized because the spread for some specific land shots are required to be of the same channels as it extends from land to offshore water. Therefore, based on the above seamlessly geometry theoretical design, by adopting shot-receiver interchangeable principle, an optimized geometry suitable for the working characteristics in transitional zone was proposed. Actual application shows that the optimized 3-D seismic survey geometry in the transitional zone not only solves the problem of deficiency in offshore arranges and sufficiency in land arranges in actual work, realizes the seamless merging of offshore and land system, but also maintains the attributes distribution consistency of the onshore and offshore data.