基于混合方程的裂隙介质地震波场数值模拟  

Numerical Simulation for Fracture Medium Seismic Wave Field Based on Mixed Equations

作　　者：杜正聪[1] 贺振华[2] 黄德济[2] 

机构地区：[1]攀枝花学院,四川攀枝花617000 [2]成都理工大学信息工程学院,四川成都610059

出　　处：《石油天然气学报》2005年第2期197-200,133,共4页Journal of Oil and Gas Technology

基　　金：国家自然科学基金资助项目(40174039);国家"973"项目(G1999043311)。

摘　　要：在Hudson理论的基础上推导出基于弹性声学近似的裂缝模型反射系数计算公式;用变参考慢度Rytov近似波场延拓算子对给定裂缝模型进行正演和偏移,并分析其波场特征。结果表明:①在当前地震分辨率下,不能识别单个裂缝,但可以探测裂缝发育带;②裂缝带达到一定的宽度和密度时,可以用地震方法检测裂缝的分布,潜山内幕反射波的范围与强弱,有利于研究裂缝发育带的宽度和密度;③裂缝带的低频复波反射,表明在裂缝发育带,地震波频率减低,这意味着用地震波的频率特征是可以检测裂缝的。Based on the Hudson theory, equation for calculating the reflectance of fracture model based on elastic-acoustic approximation are derived, the variational reference slowness Rytov approximation-wavefield extrapolation operator is used to forward and migrate and analyze the field features. The result shows that: ①when the resolution of seism decreases, the single fracture can not be recognized, but its growing belt can be detected; ②when the fracture is arrived at certain width and density, a seismic method can be used to check the distribution of fracture, the range and intensity of reflecting wave inside buried hill, which is beneficial for studying the fracture growing width and density; ③in the fracture belt, the low frequency composed-wave reflection indicates that in the fracture growing belt, the seismic wave frequency decreases, it indicates that the feature of seismic wave frequency can be used for fracture detection.

关 键 词：裂缝(岩石) 地震模型 裂缝带 裂缝宽度 地震勘探 慢度 正演 地震偏移 

分 类 号：P631.4[天文地球—地质矿产勘探]