海洋CSEM法探测高阻储层的勘探参数设计

对选定测区运用海洋CSEM法进行实际探测之前,需综合考虑影响高阻储层探测的主要勘探参数,以确保探测的可行性及有效性。设计通用的一维模型,针对不同的勘探参数进行正演模拟,利用快速汉克尔变换计算其电磁响应,通过分析电磁响应曲线及异常特征,探讨海洋CSEM法探测高阻储层的勘探参数设计。研究表明,根据趋肤深度的计算结果结合频率-收发距归一化振幅图,可确定出合适的发射频率范围,而收发距范围可以由频率-收发距归一化振幅图确定,发射天线离海底越近接收到的电磁信号越强,越有利于高阻储层的探测。研究结果可为实际勘探参数的设计提供参考。

PRELIMINARY STUDY OF PARAMETERS DESIGN FOR EXPLORATION OF HIGH RESISTIVITY RESERVOIR USING MARINE CSEM METHOD

To guarantee the feasibility and effectiveness of marine CSEM method, the main exploration parameters affecting resistive reservoir detection should be considered before actual exploration in target areas. After the design of a common 1D model, the electromagnetic response in different situations is calculated by forward modeling using fast Hankel transform with different exploration parameters. By studying the response curves and anomalous features, the problems about marine CSEM exploration parameters used in resistive reservoir detection can be researched to provide references of exploration parameters for actual exploration. Studies have shown that appropriate transmission frequency can be determined by skin depth and frequency-offset normalized amplitude. Frequency-offset normalized amplitude can also be used to determine the suitable offset range. The closer the transmitting antenna from the seabed, the stronger the electromagnetic response and the better the result of resistive reservoir detection. The results can provide references for actual design of exploration parameters.