叠前深度偏移速度建模方法分析  

Strategy of velocity model building in prestack depth migration

作　　者：马彦彦[1] 李国发[1] 张星宇 田纳新[3] 祝文亮[4] 翟桐立[4] 

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中海石油南海东部公司,广东广州510240 [3]中国石化勘探开发研究院,北京100083 [4]中国石油大港油田分公司,天津300280

出　　处：《石油地球物理勘探》2014年第4期687-693,3,共7页Oil Geophysical Prospecting

基　　金：国家自然科学基金课题(41174117);国家重大科技专项(2011ZX05031-001)联合资助

摘　　要：基于层位的层析反演和基于网格的层析反演是实际地震资料叠前深度偏移的两种主要速度建模方法。根据歧口凹陷典型地质模型及其正演模拟的地震波场,对两种速度建模方法进行了实验分析。实验结果表明:基于层位的层析反演方法具有较高的稳定性,但只能得到速度模型的低频分量;基于网格的层析反演方法可以获得速度场的高频分量,但受初始模型的影响较大,不容易收敛到实际速度模型。为此联合应用两种方法,即先利用基于层位的层析反演方法获得速度场的低频分量,再利用基于网格的层析反演方法获得速度场的高频分量,这样能够提高速度模型精度,改善叠前深度偏移的成像质量。Horizon-based tomography and grid-based tomography are two main model building methods for prestack depth migration in real seismic data processing.Using the typical geological model in Qikou Sag and its simulated wave fields,we analyze experimentally the imaging abilities of these two methods.Observations concludes that horizon-based tomography method is relatively robust,nevertheless,only the low frequency components can be inverted.On the other hand,the high frequency components can be inverted by grid-based tomography method.However,it is difficult to converge to the real velocity model.Therefore combined application of the two methods is proposed.First the low-frequency component of velocity model is inverted by horizon-based method,then the high-frequency is inverted by grid-based method.This joint approach is able to improve the reliability of the velocity model,as well as the imaging quality of prestack depth migration.

关 键 词：层位层析 网格层析 速度模型 叠前深度偏移 

分 类 号：P631[天文地球—地质矿产勘探]