论文详情
许多实际测井资料中缺失横波速度数据,给叠前地震资料反演、脆性因子计算、应力分析和储层预测等带来不利影响。关于碎屑岩和碳酸盐岩的横波速度预测方法已日趋成熟,而关于富有机质泥页岩的横波速度预测方法的研究相对较少。基于Keys-Xu干岩石模型,引入Gassmann方程和Brown-Korringa固体替代等岩石物理理论,构建了一种包含多矿物、复杂孔隙和有机质含量的富有机质泥页岩岩石物理横波速度预测方法。该方法将富有机质泥页岩等效为由岩石基质矿物、有机质和含流体孔隙组成的混合物,将岩石中复杂的孔隙结构等效为球形孔隙与裂缝状孔隙组合的结构;利用纵波速度计算球形孔隙与裂缝状孔隙的体积分数,进而预测横波速度。将该方法应用于实验室测试数据和建南构造侏罗系下统自流井组东岳庙段富有机质泥页岩实际测井资料,预测的横波速度与实测的横波速度吻合度较高,表明该方法在预测富有机质泥页岩横波速度时适用且有效。
The absence of shear-wave velocity in various logging data adversely affects pre-stack seismic inversion,brittleness index calculation,stress analysis,and reservoir prediction.Shear wave-velocity estimation methods for clastic and carbonate rocks have reached a more mature stage than those for organic-enriched shale.Based on the Keys-Xu dry rock physics model,combined with the Gassmann equation and Brown-Korringa solid substitution theory,a method is proposed to estimate the shear-wave velocity for organic-enriched shale containing multi-minerals,complex pore types,and organic matter content.In this method,the organic-enriched shale is equivalent to a mixture of rock-matrix minerals,organic matter,and pore fluid,while the complex pore structure of the rock is equivalent to a combination of stiff pores and compliant fractures.Based on this model,the volume fractions of stiff pores and compliant fractures is inverted using conventional logging data with the constraint of the P-wave velocity.Next,the volume fractions of stiff pores and compliant fractures is employed to calculate the S-wave velocity.This method is applied to lab data and actual logging data from the organic-enriched shale,and the results show that the estimated S-wave velocity has good agreement with the measured data,demonstrating the validity and applicability of the method.
中央高校基本科研业务费专项资金资助项目“群集智能优化含油气页岩岩石物理速度预测系统研究(300102268103)”、国家科技重大专项“鄂北深层岩溶储层地震预测技术”(2017ZX05005-004-009)和中国石油化工股份有限公司科技部项目“鄂北奥陶系风化壳储层及含气性地震预测技术”(P16066)共同资助。