储层厚度和电阻率对海洋可控源电磁法的影响分析

随着海底油气资源勘探的进行，海洋可控源电磁法（CSEM）成为研究的热点。本文采用二维自适应有限元正演程序MARE2DCSEM，建立正演模型，模拟了不同厚度、电阻率对异常的影响。模拟结果表明：厚度一定时，MVO曲线和电阻率先成正比例，而在达到最大响应的收发距时则随之减少；电阻率相同时，厚度从小渐渐增大时，MVO曲线逐渐增大，在达到最大响应的收发距时则随之减小；储层厚度和电阻率变化是一个体积效应，当乘积相同时，归一化曲线差别很小，大约在2%左右，这为反演提供了理论依据。

The Analysis of Reservoir Thickness and Electrical resistivity Impact on Controlled-source Electromagnetic Method

With the oil and gas resources exploration, the application of controlled-source electromagnetic method (CSEM) toseafloor detection has become the study hotspot overseas. In this paper,We use the two-dimensional numerical simulation of forward model through adaptive finite element method, simulate different thickness and electrical resistivity for abnormal effects. The result show that when the thickness stay invariant, MVO curve increase with electrical resistivity increasing, but the proportional to the maximum in the response of the sending and receiving is reduced; when the electrical resistivity stay invariant, MVO curve increase with thickness increasing, but the proportional to the maximum in the response of the sending and receiving is reduced. Reservoir thickness and resistivity change is a volume effect, when the same product, the normalized difference curve is very small, at about 2%, which provides the theoretical basis for inversion.