大地电磁与地震联合反演技术在西亚某区的综合应用

The application of joint inversion of magnetotelluric and seismic data in Western Asia,

1. 中国科学院地质与地球物理研究所,北京 100029;2. 中国石化胜利伊朗项目部,山东东营 257000;3. 同济大学海洋地质教育部重点实验室,上海 200092

Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029, China

西亚某区山前复杂带勘探程度低,且地震勘探难度大,反射品质差。为此,开展了大地电磁与地震联合反演技术的研究。对反演所采用的模拟退火算法进行了探讨和改进,给出了联合反演的处理流程;讨论了反演的约束条件类型以及建立速度模型和电性模型的方法;利用实际采集的大地电磁连续阵列剖面法(CEMP)资料和地震数据进行了模拟退火约束同步联合反演处理,确定了各地层的电阻率和速度,并根据研究区的物性研究结果建立了基本物理-地质模型;利用重磁资料进行了顺序联合反演,确定了各地层的密度和磁化率,并得到了磁性体的位置;利用各种物探资料反演的结果进行了综合解释,划分了有利构造区带。在该区某构造带上钻探的一口井获得了高产油气流。

Constraint joint inversion of magnetotelluric and seismic data versus simulated annealing algorithm is used in Western Asia. The studied area was difficult to seismic prospecting, construction and the reflection quality was not good especially in the complicated piedmont structural are-a. Therefore, joint inversion technique was carried out u-sing CEMP data, seismic data and gravity & magnetic data as well to solve the distribution of deep target and basic structural features. Basic physical-geological models of the studied area were built in accordance with physical properties study. Then the constraint synchronous joint inversion technique of magnetotelluric and seismic data versus simulated annealing algorithm and the sequent joint inversion using gravity & magnetic data and the final integrated interpretation were put forward, the velocity, electrical, density and magnetic structures of the studied area were determined, which provided reliable bases for geological structure studies. The beneficial structural zones were also illustrated with the geology materials. The application of joint inversion was proved effective using different geophysical data.