几种裂缝模型的波场传播特征比较  

Comparison of wave field characteristics among the fracture rock models

作　　者：镇晶晶[1,2] 刘洋[1,2] 李敏[1,2] 

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京昌平102249 [2]中国石油大学(北京)CNPC物探重点实验室,北京102249

出　　处：《石油地球物理勘探》2012年第6期908-917,950,共11页Oil Geophysical Prospecting

基　　金：国家科技重大专项课题(2011ZX05019-008);国家自然科学基金课题(40839901)联合资助

摘　　要：本文总结了Hudson一阶模型、Hudson二阶模型、Schoenberg模型、Kachanov模型和Eshelby-Cheng模型等五种裂缝模型的弹性参数表达式。针对具有不同裂缝密度、裂缝纵横比的干裂缝和充水裂缝,采用弹性波波动方程数值模拟方法,模拟了波在五种裂缝模型介质中的传播。对模拟得到的波场快照和横波分裂现象进行分析,得出如下结论:裂缝密度影响纵波和横波的各向异性特征;裂缝充填物影响介质的各向异性;裂缝纵横比和裂缝充填物影响横波的传播特征;横波分裂现象随裂缝密度的增大而变明显;裂缝纵横比和裂缝充填物对横波分裂现象的影响很小。This article focuses on comparing among the first-order accuracy Hudson model,the second-order accuracy Hudson model,the Schoenberg model,the Kachanov model and the Eshelby-Cheng model.The paper summarizes the expressions of elasticity coefficient of the different models.Elastic wave equation numerical simulation is used to simulate propagation characteristics of waves in these fracture models respectively for dry fracture and water-filled fracture with different fracture density and fracture aspect ratio.And wave field snapshots and the phenomenon of shear-wave splitting from the simulation are analyzed.The following observations are obtained from the study: The fracture density affects the anisotropy feature of the P-and S-waves and the fracture fillings influence the anisotropy of the medium;while the fracture aspect ratio and the fracture fillings impact on the propagation characteristics of shear waves.Shear-wave splitting changes significantly with the increasing crack density,but the fracture aspect ratio and the fracture fillings have little effect on shear-wave splitting.

关 键 词：裂缝密度 裂缝纵横比 波场快照 横波分裂 

分 类 号：P631[天文地球—地质矿产勘探]