南海双船地震勘探介绍

双船地震法包括ESP和SAP法是研究地壳深部结构和构造的有效方法.本文介绍了这两种方法资料处理的主要问题和步骤.预处理工作主要是解决在海洋动态环境下,两船和两套系统同时工作带来的一系列与定位、计时和地震系统有关的问题.着重介绍了用ESP的τ-p记录及x-t域记录进行速度分析的各种方法,它们大都不受反射波时距曲线是双曲线假设的限制.各种方法有各自的特点和限制,用户可根据实际工作的条件和需要选用.SAP的资料处理按四个子系统分别进行,处理方法与一般水平叠加剖面的常规处理相同,获得高质量剖面的关键是求准各层速度得到符合实际情况的叠加速度文件.仔细对比四个子剖面,反复进行处理,最后再有条件地将四个子剖面合成浅、中、深都清晰的合成排列剖面.在资料处理和解释过程中,两种方法相互配合、互为补充.

TWO-SHIP SEISMIC EXPERIMENTS IN SOUTH CHINA SEA

Two-ship seismic experiments include Expanded Spread Profile (ESP) and Synthetic Aperture Profile (SAP). The aim of ESP is to obtain a precise measurment of the Earth's velocity structure at a single point, and to depths much greater than can be achieved through CDP analysis of either single-ship or SAP data. SAP is very useful in the imagine the deep structure of the oceanic crust. This paper introduced some main problems and procedure in data processing of these methods and several methods of velocity analysis of ESP data that are not limited hyperbolic traveltime assumption. Generally, SAP and ESP are applied together and complementary to one another in data processing and interpretation.