孔隙介质弹性波叠前逆时偏移方法  

Prestack reverse-time migration of elastic waves in porous media

作　　者：刘欣欣[1] 印兴耀[1] 刘百红[2] 

机构地区：[1]中国石油大学(华东)地球科学与技术学院,青岛266580 [2]中国石化石油物探技术研究院,南京211130

出　　处：《地球物理学进展》2013年第6期3165-3173,共9页Progress in Geophysics

基　　金：国家973计划课题(2013CB228604);国家科技重大专项(2011ZX05030-004-002;2011ZX05019-003);国家自然科学基金项目(41004050)共同资助

摘　　要：常规的弹性波叠前逆时偏移是基于单相介质理论进行的,不能充分考虑地层中的孔隙和流体对弹性波场的影响,而实际储层是含流体的孔隙介质.考虑到固体基质和孔隙流体共同对弹性波传播产生影响,本文对孔隙介质弹性波叠前逆时偏移方法进行了初步探索.基于Biot理论弹性波方程,使用高阶有限差分方法,推导了孔隙介质中弹性波正时和逆时传播算子,讨论了人工边界条件及差分格式的稳定性条件,建立了基于PML边界的弹性波正演系统;使用互相关成像条件对正时传播和逆时传播的波场进行成像;使用Laplace滤波方法去除偏移噪声,得到了孔隙介质弹性波逆时偏移剖面.最后对模型进行逆时偏移试算并获得了成功,但由于所需物性参数难以获取等问题,本文方法的实际应用还有待进一步研究.Conventional prestack elastic wave reverse-time migration method is based on single-phase media theory, couldn＇t take full account of the influence of fluid in pores on elastic wave field. But actual underground reservoirs are two-phase media. We should take full account of fluid properties in underground formation to better understand the relationship between seismic information and reservoir properties. In this paper, we conducted a preliminary exploration of prestack reverse-time migration method for two-phase porous media. First, derived the forward and reverse-time propagation operator of elastic wave in porous media using high-order finite-difference equations, discussed the artificial boundary condition and stability conditions, built the elastic wave forward modeling system with PML boundary condition; then used cross-correlation imaging condition to the forward and reverse-time wave field, carried out Laplace filtering and obtained the reverse-time migration profile of the porous media. Finally, applied the method to designed models successfully. However, due to problems such as required physical parameters are difficult to obtain, etc, the practical application of this method needs to be further studied.

关 键 词：孔隙介质 弹性波 BIOT理论 有限差分方程 逆时偏移 

分 类 号：P631[天文地球—地质矿产勘探]