各向同性介质长偏移距动校正方法精度对比  

Comparing the accuracy of normal moveout methods in isotropic media

作　　者：赵洋洋[1,2] 石浩 李永洲 

机构地区：[1]长安大学地质调查研究院,西安710054 [2]长安大学地质测量与测绘学院,西安710054 [3]中煤科工集团西安研究院有限公司,西安710077 [4]中石油煤层气有限责任公司勘探开发研究院,北京100028

出　　处：《物探化探计算技术》2016年第5期626-630,共5页Computing Techniques For Geophysical and Geochemical Exploration

摘　　要：常规地震勘探的动校正处理方法是利用Dix双曲线公式拉平同相轴,但是Dix双曲线公式只适用于较小的最大偏移距与目标层深度比。然而在实际勘探中,为了识别高速层地质目标(玄武岩等),检波器排列通常会超过10km以上,这时只适用于小偏移距的常规动校正方法会带来很大的误差,而高阶项动校正公式能提高长偏移动校正的精度。这里针对各向同性介质,对长偏移距地震资料动校正方法进行分析对比,由分析结果可知,多项式展开的高阶项系数是影响各向同性介质中长偏移距动校正精度的关键因素,高阶非双曲动校正方程的精度相对于传统方法均有所改善。Conventional approximations of the normal moveout（NMO）functions are based on the assumption of small offset-depth ratio to flatten the seismic gathers.However,offset used in seismic data acquisition is common in excess of 10 km in order to distinguish the high-velocity geologic target,for example,the sub-basalt.Therefore,traditional NMO methods have a large bias,whilst high-order NMO could improve the accuracy of long offset.In this paper,we compare several wellknown NMO functions in isotropic media.The consequence shows that high-order coefficients of polynomial expansion are the keys to influence the accuracy of long offset NMO in isotropic media.Compared to conventional methods,high-order nonhyperbolic NMO functions have improvements on accuracy.

关 键 词：各向同性介质 长偏移距 动校正 Dix公式 

分 类 号：P631.4[天文地球—地质矿产勘探]