Finite-difference modelling of anisotropic wave scattering in discrete fracture model

Journal of earth system science

A M Ekanem^1¹  Y Xu^2² 

[1] Department of Physics, Akwa Ibom State University, P.M.B. 1167, MkpatEnin, Nigeria.^1;School of Geosciences and Technology, Southwest Petroleum University, 8 Xindu Avenue, Chengdu 610500, P.R. China.^2

关键词: Finite difference;    standard-staggered grid;    fractures;    attenuation;    anisotropy;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

The presence of fractures in reservoir rocks causes scattering of seismic wave energy. In this paper, we utilize the finite-difference modelling technique to study these scattering effects to gain more insights into the effects and assess the validity of using anisotropic wave scattering energy as a diagnostic tool to characterize fractured hydrocarbon reservoirs. We use a simplified fractured reservoir model with four horizontal layers with a fractured-layer as the third layer. The fractures are represented by grid cells containing equivalent anisotropic medium by the use of the linear slip equivalent model. Our results showthat the scattered energy, quantified through estimates of the seismic quality factor (Q) is anisotropic, exhibiting a characteristic elliptical (cos 2θ) variations relative to the survey azimuth angle θ. The fracture normal is inferred from the minor axis of the Q ellipse. This direction correlates with the direction of maximum wave scattering. Minimum wave scattering occurs in the fracture strike direction inferredfrom the major axis of the Q ellipse. These results provide more complete insights into anisotropic wave scattering characteristics in fractured media and thus, validate the practical utility of using anisotropic attenuation attribute as an additional diagnostic tool for delineation of fracture properties from seismic

【 授权许可】

CC BY