深水区各向异性叠前深度偏移成像  

Anisotropic prestack depth migration imaging in deepwater area

作　　者：许自强[1] 但志伟[1] 王新领[1] 方中于[1] 李三福[1] 关伟龙[1] 

机构地区：[1]中海油能源发展股份有限公司钻采院地球物理所,广东湛江524057

出　　处：《石油地球物理勘探》2013年第A01期17-22,202+4-5,共6页Oil Geophysical Prospecting

摘　　要：深度偏移是解决深水区复杂海底问题最有效的手段,不仅能够恢复崎岖海底造成的下伏地层的扭曲变形,反映真实的地下构造,而且能解决时间偏移画弧问题。然而由于地下介质的各向异性,速度会随着入射角不同而改变,应用各向同性偏移深度结果往往与测井深度的差异较大,而且共反射成像道集远道不能拉平,因此改用各向异性叠前深度偏移方法。本文对南海深水区地震资料进行了各向异性叠前深度偏移处理,重点研究了初始速度场的建立方法、各向异性参数的确定,并对各向异性深度偏移在深水区的应用效果进行了详细分析。Prestack depth migration is the most effective method for deepwater complex seafloor.This method can restore contorts and distortion of the subsurface caused by rough ocean bottom,and show true structures.At the same time it can solve bow-tie-effects in prestack time migration.However,due to the anisotropy of medium,seismic velocity changes with different incident angles.The isotropic depth migration often results in large depth errors with well logs.And the common imaging gathers are not flattened at far offsets.Therefore,anisotropic prestack depth migration shall be applied in deepwater seismic data processing.In this paper anisotropic prestack depth migration is applies to seismic data in South China Sea.In this paper,we focus on initial velocity field building and anisotropic parameter analysis,and analyze results of the anisotropic depth migration in the deep water area.

关 键 词：深水区 VTI介质 外漂克里金 各向异性 叠前深度偏移 

分 类 号：P631[天文地球—地质矿产勘探]