正演模拟验证叠前弹性阻抗反演在碳酸盐储层预测中的应用

叠前弹性阻抗反演能够得到不同角度的弹性波阻抗体,对地下储层岩性及含流体性质的判别能力相对较强,但仍存在多解性问题。从实际的地质及地震资料出发,在测井资料约束下建立符合地下实际的缝洞型储层地震地质模型,首先从正演的角度分析目标储层的地震波场特征,然后对正演模拟结果及实际地震资料分别进行叠前弹性阻抗反演。正演模拟与实际资料弹性阻抗反演结果相互印证,综合判识缝洞型储层的岩性和含流体特性,提高了储层预测的精度。

With prestack elastic impedance inversion,we can get elastic wave impedance with different incidence angles,and it can better distinguish lithology of underground reservoir and fluid properties but fails to solve multi-solution problem.In this paper,we combine actual seismic data with drilling,logging and geological data,and build a fracture-cavity type reservoir seismic-geological model,which coincides with the actual underground condtions.In terms of forward modeling we analyze seismic wave field characteristics of target reservoir.On the basis of the above research,we apply prestack elastic impedance inversion on the result of forward modeling and actual seismic data.The effective combination of forward modeling and elastic inversion helps to recognize the lithology and fluid characteristics of fracture-cavity type reservoir and improve the accuracy of reservoir prediction.