川中磨溪—高石梯地区龙王庙组白云岩储层渗透率受岩溶作用的影响较大,现有渗透率计算模型的适用性较差.利用岩心照片、岩石薄片、高压压汞、核磁共振、物性分析、测井等资料,首先根据岩溶作用、储集空间、孔隙结构对储层进行分类,将非均质性极强的滩控岩溶型白云岩储层划分为溶洞型、溶孔型与基质孔隙型3种相对均质的储层类型,再运用全直径岩样与标准柱塞样物性分析结果,借助其表征尺度的差异,对各类型储层进行渗透率建模.全直径岩样表征尺度较大,用以建立溶洞型储层渗透率解释模型;标准柱塞样表征尺度较小,用以建立溶孔型与基质孔隙型储层渗透率解释模型.现场应用结果表明,相对于常规Timur公式与核磁Coates等模型,上述分储层类型计算的渗透率值与岩心分析结果更吻合,有效提高了碳酸盐岩滩控岩溶型白云岩储层渗透率计算结果的准确度.%Reservoir permeability is greatly affected by karstification,and the applicability of existing permeability models is poor in Cambrian dolomite reservoirs of Longwangmiao Formation,Moxi-Gaoshiti area,central Sichuan Basin.The core photos,rock slices,mercury injection capillary pressure,nuclear magnetic resonance and logging data were used to classify the reservoir types according to karstification,reservoir space and pore structure.The beach-controlled karst dolomite reservoirs with strong heterogeneity were divided into karst cave type,dissolved pore type and matrix pore type.Then,new permeability models were established with physical property analysis data of full diameter core and standard plunger core by the difference between their characterization scale.Full diameter core has larger scale of representation,so as to establish the permeability interpretation model of karst cave type;standard plunger core has smaller scale of representation,so as to establish permeability interpretation models of dissolved pore type and matrix pore type.Practical application results show that,compared with the conventional Timur formula and NMR Coates model,the permeability value calculated by classified statistic models is more consistent with core analysis.This method can effectively improve the accuracy of permeability calculation in beach-controlled karst reservoirs.
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