可分面元三维观测系统设计研究

Design of bin-divisible 3-D seismic layout.

在常规三维观测系统中 ,接收线间距是震源间距的倍数 ,震源线间距是接收器间距的倍数 ,这使得在震源线和接收线的每个交点处震源和接收器是重合的。这种布置理论上使得所有 CMP点都在每个面元的中心。可分面元观测系统排列的几何结构简单 ,便于野外施工。震源线的间距为道间距的非整数倍 ,接收线间距也不是炮点距的整数倍。接收线间距与震源线间距之比的余数决定了接收线方向和震源方向所期望的次反射面元。CMP点均匀分布在一个共反射面元内 ,面元具有可分性 ,地震处理人员可根据不同的地质任务选择面元大小 ,增加了资料处理和解释的可选性。由于在共反射面元内增加了来自不同共中心点的地震资料信息 。

In ordinary field 3-D layout, receiving-line spacing is n-times the seismic source gap, and source-line spacing is n-times the receiver interval; as a result, at each intersecting point of source line and receiving line, source position superposes receiver position. Theoretically, such layout makes each CMP lie at the center of corresponding reflection bin. Bin-divisible field layout is simple in its geometry structure, and favours field operation. The source-line spacing is the non-integral times of group interval, and the receiving-line spacing is not the integral times of source gap. The remainder after the ratio of receiving-line spacing to source-line spacing determines the expected sub-bins in directions of receiving line or source line. Common-mid points lie uniformly in a common reflection bin, which is divisible. Seismic data processors may choose proper bin size according to different geology tasks, increasing the options in seismic data processing and interpretation. Common reflection bin contains more seismic informations coming from different common-mid points, therefore both the variation and local anomaly of subsurface geological structure may be highlighted very obviously.