碳酸盐岩储层孔隙度预测方法研究及其在南海某区的应用

Porosity prediction method research for carbonate reservoir and its application in South China Sea

大量研究结果表明,岩石的弹性性质和声学特性受孔隙结构的影响非常大,孔隙结构是影响孔隙度预测的重要因素。基于Gassmann方程并结合表征孔隙结构的综合岩石骨架模型,推导出了基于综合孔隙结构的地震孔隙度计算表达式。将考虑了孔隙结构影响的孔隙度预测方法应用于南海某区碳酸盐岩储层的孔隙度预测,首先由从测井数据计算得到单井参数,通过交会拟合方法,仅利用纵波速度计算了孔隙度;然后通过三维叠前地震反演参数横向拓展,得到了整个工区的孔隙度预测三维数据体。测井数据试算和实际地震资料应用结果表明,孔隙度预测效果很好,能适用于碳酸盐岩储层孔隙度的预测。

Lots of experiments has showed that pore structure has great influence to rock elastic properties and acoustic property, thus it is important of pore structure to predict porosity. In this work, we deduce a porosity calculating expression contained pore structure parameter based on the Gassmann＇s equation combined with composite rock skeleton models. The porosity prediction method considered the effect of pore structure is applied to predict porosity of carbonate reservoir in South China Sea. Firstly we calculate the parameters of single by logging data and only use the velocity of P-wave through cross plotting. Then we can get the whole survey＇s porosity by the 3D prestack seismic inversion data according to the porosity calculating expression. The result shows that the method is suitable for predicting the porosity for carbonate reservoirs with high accuracy.