克里格方法在大地电磁静校正中的应用

Application of Kriging method in magnetotelluric statics correction

(1． 同济大学海洋与地球科学学院，上海200092； 2. 中国石油化工集团公司江苏石油勘探局工程处,江苏扬州225009）

Ocean and Earth Science Institute, Tongji University, Shanghai 200092, China

大地电磁测深中,静校正处理直接影响到视电阻率的真实性以及反演、解释结果的可靠性。考虑到地学断面的空间结构横向上存在着一定的相关性,引入地质统计学的克里格(Kriging)方法以校正畸变的视电阻率断面和相位断面。克里格方法是根据待估样点或待估块段有限领域内已测定的样点数据,在认真考虑了样点的形状,大小和空间相互位置关系,它们与待估样点空间相互位置关系,以及变异函数提供的结构信息之后,对该待估样点值进行的一种线性无偏最优估计。根据这一思路,编制了大地电磁测深数据校正软件，并且进行了理论模型试验和实际资料的处理，取得良好的效果。

In magnetotelluric sounding, the statics directly affects the validity of apparent resistivity and the reliability of inversion and interpretation results. Considering the horizontal coherency of spatial structures in physiographic fractured surfaces, the Kriging method of geostatistics was introduced to correct the distorted sections of apparent resistivity and phase. The basic principles of Kriging method are as follows: Based on the measured sample data of points or block to be appraised, after considering the shape, size and spatial position relationship of sample points, the spatial position relationship of points to be evaluated and structure information offered by variant function, the sample points to be evaluated is linearly and optimally estimated without bias. According to this thinking, a magnetotelluric sounding data correction software was developed and used in theoretical model analysis and actual data processing, achieving a good effect.