裂缝诱导各向异性双乳隙介质波场传播特征  

Wavefield propagation characteristics in the fracture-induced anisotropic double-porosity medium

作　　者：杜启振[1] 孔丽云[2] 韩世春[3] 

机构地区：[1]中国石油大学(华东)地球资源与信息学院,山东东营257061 [2]清华大学工程力学系,北京100084 [3]胜利油田分公司物探研究院,山东东营257022

出　　处：《地球物理学报》2009年第4期1049-1058,共10页Chinese Journal of Geophysics

基　　金：新世纪优秀人才支持计划(NCET-07-0845);国家高技术研究发展计划(2006AA06A202);国家973项目(2007CB209505);中国石油物探重点实验室开放基金(GPKL0802);中国石油天然气集团公司创新基金(05E7028)资助

摘　　要：基于裂缝诱导各向异性和双相介质理论,对裂缝诱导的具有水平对称轴的横向各向同性(HTI)双孔隙介质的本构关系进行了研究,与等效连续介质模型相结合,综合考虑裂缝系统和基质孔隙系统的两种孔隙度和两种渗透率参数,得到裂缝诱导HTI双孔隙介质的等效孔隙度和等效渗透率,进而得到介质的运动平衡方程;并进一步推导出介质的一阶速度-应力方程.采用交错网格高阶有限差分法对模型进行了数值模拟,结果揭示了介质中两套系统的存在对其波场传播特征的影响,为进一步研究实际地球介质的波场特征奠定了基础.A fracture-induced horizontal transverse isotropic（HTI） double-porosity medium is studied in this paper. Based on theories of fracture-induced anisotropic media and two-phase media, constitutive equations are derived. Using the concept of continuous percolation, combining two sets of porosity and permeability, the equivalent porosity and equivalent permeability are given, then we obtain the motion equations. Furthermore, first-order velocity- stress equations are derived. Numerical simulations of elastic wave propagation are performed by the 2D high-order staggered-grid finite-difference, and the results show the effects caused by the double porosity systems of the medium on the wavefield propagation characteristics, which will lay a foundation of further studies on seismic wave propagation in actual earth media.

关 键 词：裂缝诱导 各向异性 双孔隙 交错网格 波场特征 

分 类 号：P631[天文地球—地质矿产勘探]