海洋CSEM的共中心点域快速反演

Fast marine CSEM inversion in the CMP domain

海洋可控源电磁法(CSEM)对海底高阻体的反映比较灵敏,可用于天然气水合物探测资料的定性解释和反演研究.海洋CSEM资料的共中心点(CMP)域转换方式,可在横向上较好地分辨高阻储层.本文提出在CMP域实现一维频率域海洋可控源电磁资料高斯-牛顿反演算法.鉴于一维反演是解释地球物理资料的基础,较于二维和三维反演方法有着更高的计算效率和更低的硬件要求,将二维模型的响应在CMP域单元内表达为一维模型的响应,进而运用一维高斯-牛顿反演解释二维海洋CSEM资料.模型数据试算表明,海洋CSEM的CMP域反演速度较快,能够实现二维CSEM资料的反演解释.

The marine controlled-source electromagnetic （CSEM） method has been recently established as a technique for hydrocarbon exploration, primarily due to its high sensitivity to thin resistive layers. In this paper, we present a converting method, which could invert data into the common mid-point （CMP） as a set of 1D model that correspond to their respective CMP cells. The inverted CMP data could resolve the horizontal distribution of the hydrate layer. It is commonly known that one-dimensional inversion is the foundation of geophysical data interpretation, and the algorithms of 2D and 3D inversion require complex implementation and high computational costs. The inversion method presented in this paper could invert data into CMP domain and interpret 2D data by using 1D Gauss-Newton inversion for each CMP cells. The inversion results show that CMP inversion is a fast inversion method of interpreting 2D CSEM data set.