基于双孔模型的含流体各向异性介质地震波场数值模拟  

Seismic Wavefield Simulation of Fluid-saturated Anisotropic Media Based on Dual-porosity Model

作　　者：阮韵淇 李世凯[1,3] 李天[1,3] 文晓涛[1,3] RUAN Yun-qi LI Shi-kai LI Tian WEN Xiao-tao(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation College of Energy College of Geophysics , Chengdu University of Technology, Chengdu 610059 , P. R. China)

机构地区：[1]油气藏地质及开发工程国家重点实验室(成都理工大学),成都610059 [2]成都理工大学能源学院,成都610059 [3]成都理工大学地球物理学院,成都610059

出　　处：《科学技术与工程》2017年第2期155-160,共6页Science Technology and Engineering

基　　金：国家自然科学基金石油化工联合基金(U1562111);国家科技重大专项(2016ZX05002-004)资助

摘　　要：裂缝的存在是诱导地下介质产生各向异性的主要原因,而裂缝中的流体则能够对地震波产生十分明显的能量衰减。本文基于双重孔隙介质理论,对含流体各向异性介质的地震响应特征进行了数值模拟,发现双孔介质的各向异性与介质的渗透率、裂缝密度、有效压力和频率均有重要联系。基于衰减各向异性理论,推导了含流体各向异性介质二维三分量应力-应变关系,结合旋转交错网格有限差分法,通过数值模拟给出了双孔介质中地震波的传播规律,结果表明裂缝密度的增大能够显著地增强介质的各向异性,使得q P波和快慢q S波垂直或平行于裂缝面的波前面均更接近椭圆,且流体的存在能够对q P和q S波相速度造成较为显著的衰减。Anisotropy of subsurface media is induced by fractures,and the filled fluid can make remarkable attenuation to seismic energy. The seismic response characteristics of fluid-saturated anisotropic media is simulated based on dual-porosity media theory. It is discovered that the anisotropy of dual-porosity media is connected with the permeability,fracture porosity,effective pressure and frequency. With the attenuative anisotropy theory,the two-dimensional and three-component stress-strain relationship of fluid-saturated anisotropic media is derivated.Utilizing finite difference method of rotated staggered grid,the seismic wave propagation of dual-porosity media is simulated. The result demonstrates that the increasing of fracture porosity leads to remarkable increasing of anisotropy,making the wave-form of q P and q S wave closer to ellipse and the presence of fluid also make great influence on the attenuation of q P and q S wave phase velocity.

关 键 词：双孔模型 衰减各向异性 旋转交错网格 含流体介质 有限差分 

分 类 号：P631[天文地球—地质矿产勘探]