【摘要】 针对河流相储层厚度薄、纵向叠置严重、横向变化快、常规确定性反演方法受地震频带限制难以准确刻画的特点,尝试应用基于MCMC算法的地质统计学方法进行反演,以提高分辨率和储层预测精度,并全程应用成岩储集相控制建模,以便从储层地质学的角度加强模型约束,促进概念模型向定量模型的转化,建立合理的反映地下实际情况的油藏物性模型。具体实现方法是,首先利用对岩性识别敏感的测井曲线重构拟声阻抗曲线,再以声阻抗为中间变量,对岩性、物性参数空间变异性进行双重变差函数分析,最后基于MCMC算法实现了成岩储集相控制的地质统计学反演。得到的三维岩性、阻抗及孔隙度模型,其纵向分辨率为1ms,既可以很好地展现不同期次砂体的叠置关系、隔夹层的分布以及沉积旋回纵、横向演变规律,又可以实现物性变异方向沿河道砂体弯曲方向变化的趋势,同时可对地震资料的多解性进行有效限制。更多还原

【Abstract】 The fluvial sandy reservoirs are usually quite thin in thickness and changing rapidly in both vertical and lateral directions in the Qinhuangdao Oilfield.It is difficult to identify those reservoirs with ordinary seismic inversion methods due to limited frequency bands.The geostatistical inversion method based on MCMC algorithm,however,is more powerful in improving resolution and accuracy for reservoir prediction,and the application of facies controlling method during the process may enhance the facies model constraints on reservoir identification to help developing aquantitative model from a conceptual model,and establishing the reasonable 3Dporosity,permeability and oil saturation models.The recommended workflow is,firstly,to reconstruct a pseudo p-wave impedance curve using the lower and higher frequency components of SP and deep resistivity logging for distinguishing the sandy and shaly layers more sensitively;then,to take the pseudo pwave impedance as intermediate variable and analyze the spatial variation of sand-shale lithology and physical properties using the double-variogram function;and finally,to make geostatistical inversion based on lithological facies controlling MCMC algorithm.The 3Dporosity model achieved with vertical resolution of 1-ms can not only reveal the superimposed relations of the sand-bodies in different stages,differentiate the distribution of intercalations in vertical sequences and define the spatial pattern of sedimentary cycles more precisely,but also can make it clear the variation in physical properties of the meandering channel sands,and reduce the multiple-solutions of seismic data effectively.更多还原