裂缝诱导双相HTI介质地震波场错格伪谱法模拟与波场特征分析  

Seismic wavefield simulation and feature analysis for a fracture-induced two-phase HTI medium based on the staggered-grid pseudo-spectral method

作　　者：刘财[1,2] 迟唤昭[2] 高炜[1] 鹿琪[1] 兰慧田[3] 

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026 [2]吉林大学地球科学学院,长春130061 [3]大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712

出　　处：《地球物理学报》2016年第5期1776-1789,共14页Chinese Journal of Geophysics

基　　金：国家重点基础研究发展计划(2013CB429805);国家自然科学基金项目(41430322;41340039)共同资助

摘　　要：裂缝诱导的双相具有水平对称轴的横向各向同性(HTI)介质模型是由一组平行排列的垂直裂缝嵌入到统计各向同性的流体饱和多孔隙岩石中而组成的,它综合考虑了裂缝型储层岩石的各向异性和孔隙性.高精度的地震波场数值模拟技术是研究该介质中地震波传播规律的主要方法.本文结合错格伪谱法和时间分裂法,求解描述该介质中地震波传播的一阶速度-应力方程.模拟了单层和双层模型中的地震波场,并对其进行了特征分析.研究结果表明:错格伪谱法能有效消除标准网格伪谱法波场模拟结果中出现的数值伪影现象,与时间分裂法结合能够获得稳定的、高精度的模拟结果;裂缝诱导双相HTI介质中的地震波场兼具裂缝各向异性介质和双相介质中传播的地震波的波场特征.A model for a fracture-induced horizontal transverse isotropic（HTI）double-porosity medium has been established by embedding a set of vertical fractures into the isotropic porous background rock in previous work,which considers the fractured reservoir rock anisotropy and porosity.High-precision seismic wavefield simulation is the main technique for the investigation of waves propagating in this media.In this paper,seismic wavefield is simulated using a singlelayer model and two-layer model by solving the one-order velocity-stress equations describing seismic wave propagation in this medium by combining staggered-grid pseudo-spectral method and time-splitting method.Then the wavefield features are analyzed.The results of numericalsimulation indicate that the artifacts in the wavefield simulation results by the standard-grid pseudo-spectral method can be removed by the staggered-grid pseudo-spectral method,and the stable and high-precision simulations results can be obtained by combining it with the timesplitting method.The seismic wavefield in the fractured-induced two-phase HTI medium has the characteristics of wavefield of seismic waves propagating in a fracture anisotropic medium and two-phase medium.

关 键 词：裂缝诱导 双相HTI介质 错格伪谱法 时间分裂法 波场特征 

分 类 号：P631[天文地球—地质矿产勘探]