【摘要】 裂缝发育导致的地震波场各向异性,是裂缝型油气藏的一个重要特征.然而针对该类油气藏的叠前弹性阻抗技术,一直没有通过各向异性弹性阻抗公式建立与裂缝参数的直接关系.本文在回顾封闭平行硬币状裂缝模型和线性滑动模型的基础上,将裂缝填充物性质、分布密度与围岩的横纵波速度比,引入裂缝型HTI介质弹性阻抗公式,并对相应的归一化弹性阻抗响应特征进行模拟分析.分析表明,弹性阻抗受以上三参数的影响规律存在明显差异,其中含气裂隙介质随裂缝密度的变化要明显高于对应的流体裂隙介质,流体填充裂隙介质随横、纵波速度比的变化幅度要高于对应的含气裂隙介.该结论初步为裂缝型油气藏流体识别工作提供了依据.更多还原

【Abstract】 Anisotropy is a very important property in fractured reservoirs and caused by crack development.However,explicit functional relations between anisotropic elastic impedance and crack parameters haven’t been built up in pre-stack elastic impedance inversion for these reservoirs.In this article,we review the isolated parallel penny-shaped cracks model and linear slip model,and introduce crack fillings,distribution density and the square of vs/vp of wall rocks into HTI elastic impedance equation.The numerical simulation results show that elastic impedance are influenced by these three parameters in obvious different ways: EI for the cracked gas-filled media changes more with the variations of crack density,while the cracked fluid-filled ones are more sensitive to the variations of vs/vp.The above conclusion may be beneficial to fracture reservoir fluid identification.更多还原