碳酸盐岩孔隙结构影响分析和等效孔隙结构参数计算

碳酸盐岩孔隙形状的差异导致了应用地震波速度及相关属性预测碳酸盐岩储层的多解性。在假设孔隙流体压缩系数远大于岩石基质压缩系数的前提下，将Eshelby-Walsh岩石骨架参数模型引入到Gassmann方程中，分析孔隙度和孔隙结构对碳酸盐岩体积模量的影响，结果表明，后者对碳酸盐岩体积模量的影响较孔隙度对其影响大，推导和建立了从测井数据计算碳酸盐岩等效孔隙结构参数的计算式。实际资料的应用验证了由此获得的碳酸盐岩基质压缩系数和等效孔隙结构参数是合理的，展示了等效孔隙结构参数不仅能够合理地解释碳酸盐岩的孔隙度与纵波速度之间相关性差的原因，而且在等效孔隙结构参数控制下能够提高由纵波速度估算孔隙度的精确度，为利用纵波速度或纵波阻抗数据计算高精度的孔隙度提供了一种新思路。

Different pore shapes of carbonate lead to ambiguity of carbonate reservoir prediction using seismic wave velocity and relevant attributes.By assuming fluid compressibility is much larger than rock matrix compressibility,we introduced Eshelby-Walsh matrix rock parameter model into Gassmann equation to analyze the influence of porosity and pore structure on the bulk modulus of carbonate.Meanwhile,the equivalent pore structure parameter estimation equation of carbonate from well-logging data is established.Mathematical analysis showed that the effect of pore structure on the bulk modulus of carbonate larger than that of porosity.The real data application of this method proved that the estimated rock matrix compressibility and equivalent pore structure parameter are reasonable,and showed equivalent pore structure parameter can not only reasonably explain the low correlation between porosity and P-wave velocity of carbonate,but also provided a new idea for accurately estimating porosity from P-wave velocity or P-wave impedance data by equivalent pore structure parameter controling.