合成源MCSEM高阻薄层识别

对于浅水区海洋可控源电磁法（MCSEM）来说,由于来自海—空界面的空气波与来自海底地层的有效信号耦合,增大了提取有效信号的难度,降低了该方法对高阻油气藏的识别能力,阻碍了其在浅水区的应用。利用雷达领域合成孔径思想的合成源处理方法能够突出储层的电阻率异常响应,从而更好地识别高阻油气藏。本文讨论了MCSEM电磁场合成源干涉法,计算并对比了一维层状模型合成源的归一化振幅、有效异常和可探测度对高阻油气藏的识别能力。然后计算对比了浅水区二维和三维海洋地电模型合成源的可探测度;最后对某区域的实际数据进行处理,结果表明利用可探测度可以提高海洋可控源电磁合成源干涉法对储层的识别能力。

High resistivity reservoir identification based on synthetic-sources marine controlled-source electromagnetic data

In shallow water areas,the marine controlled-source electromagnetic (CSEM) method faces challenges because the air wave from the air-sea interface interacts with signals from the seabed and dominates the electromagnetic responses,which makes it difficult to acquire signals and improve the ability to identify resistance reservoirs.The synthetic-source processing based on radar field synthetic aperture can be used to highlight high resistivity anomaly of thin beds and identify high resistivity reservoirs.In this paper,we discuss the source-interference method of marine CSEM field.We first calculate normalized amplitude,effective anomaly,and detectivity for 1D model,and compare their identification of high resistivity reservoirs.Then we calculate the normalized amplitude,effective anomaly,detectivity for 2D marine model,and the detectivity of synthetic sources for 3D model.Finally,we apply the proposed method to real data.The examples show that the detectivity can improve high-resistivity reservoir identification on synthetic-source marine CSEM data.