基于等效慢度的快速推进法求解三维地震波走时  

3D traveltime computation using the effective-slowness-based fast marching method

作　　者：赵忠华[1] 王成[1] 初海红[1] 张芝铭 杨凯 李正伟 ZHAO ZhongHua;WANG Cheng;CHU HaiHong;ZHANG ZhiMing;YANG Kai;LI ZhengWei(Exploration and Development Research Institute of Daqing Oilfield Company Ltd.,Daqing Heilongjiang 163712,China;Southern University of Science and Technology,Shenzhen Guangdong 518055,China)

机构地区：[1]大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712 [2]南方科技大学,广东深圳518055

出　　处：《地球物理学报》2024年第10期3904-3914,共11页Chinese Journal of Geophysics

基　　金：中国石油天然气股份公司重大科技专项“松北深层天然气富集规律、勘探技术研究与规模增储”(2016E-0203);国家自然科学基金项目(42104106)资助。

摘　　要：走时计算在地震学以及勘探地震学中具有广泛的应用.快速推进法是一种快速求解地震波走时的方法.但是,由于波前面在震源附近存在较大曲率,采用传统方法会产生较大误差.为了解决这个问题,我们提出了基于等效慢度的快速推进法求解地震波走时.该方法采用了“以直代曲”的思想,定义等效慢度为走时与点到源点直线距离的商.这种处理方式其实是把走时场的复杂度或曲率信息部分转移到具有解析解的距离项上,使得等效慢度具有更小的曲率半径,并且等效慢度场的分布更加光滑.使用差分格式对等效慢度进行离散求解代替传统方法对走时的离散求解,在得到等效慢度以后,用距离乘以等效慢度得到该点的走时,可以获得更高的精度.最后,通过数值算例的精度和效率分析,验证了算法的有效性.Traveltime calculation has wide applications in seismology and seismic exploration. The fast marching method is a technique used for rapidly calculating seismic traveltimes. However, Traditional methods can introduce significant errors due to the large curvature of the wavefront near the source. To solve this issue, we propose an effective-slowness-based fast marching method to calculate seismic traveltimes. This method adopts the idea of "straight-line-for-curved-line", defining the effective slowness as the quotient of traveltime and the straight-line distance from the point to the source. This approach effectively transfers the complexity of the traveltime or curvature partially to the distance term that has an analytical solution, resulting in smaller curvature and smoother distribution of equivalent slowness. We discretize the effective slowness using the differential operator, and then transform it into the traveltime to achieve higher accuracy. Finally, the effectiveness of this algorithm is validated through precision and efficiency analysis using numerical examples.

关 键 词：等效慢度 快速推进法 程函方程 走时 

分 类 号：P631[天文地球—地质矿产勘探]