考虑成岩固结作用的双重孔隙介质岩石物理模型及其应用  

A petrophysical model of dual-porosity medium considering diagenetic consolidation and its application

作　　者：高强 李红兵 潘豪杰 GAO Qiang;LI Hongbing;PAN Haojie(Department of Geophysical Exploration Technology,Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China;College of Geophysics and Petroleum Resources,Yangtze University,Wuhan,Hubei 430110,China)

机构地区：[1]中国石油勘探开发研究院油气地球物理研究所,北京100083 [2]长江大学地球物理与石油资源学院,湖北武汉430110

出　　处：《石油地球物理勘探》2022年第1期149-158,I0006,共11页Oil Geophysical Prospecting

基　　金：国家重点研发计划课题“盐下超深储层地球物理表征与油气预测技术”(2019YFC0605504);陆相深层超深层油气富集规律与勘探评价技术研究项目“四川盆地深层碎屑岩及火山岩天然气富集高产主控因素研究”(2021DJ0204)联合资助。

摘　　要：成岩固结作用和孔隙结构及类型是影响致密油气储层弹性性质的重要因素。然而,现有的岩石物理模型大多聚焦于单一孔隙类型或只考虑成岩作用,难以准确刻画致密油气储层低孔低渗、流体分布不均匀及孔隙结构和类型复杂等特征。为此,充分利用微分等效介质(DEM)理论和Pride模型导出考虑成岩固结作用的双重孔隙介质岩石物理模型,通过引入固结参数、软孔和硬孔纵横比、体积占比,实现对岩石成岩作用和微观孔隙结构的联合表征。利用该模型定量分析了孔隙度、固结参数、孔隙纵横比和软孔隙体积比对纵、横波速度和弹性模量的影响。基于不同压力下的砂泥岩实验数据和苏里格地区实验数据验证了该模型的有效性和适用性。最后,将该模型应用于苏里格致密气砂岩储层横波速度预测,结果表明由该模型预测的横波速度的误差小于其他岩石物理模型,即所提岩石物理模型在致密砂岩储层横波速度预测方面具有较高精度。Diagenetic consolidation,pore structure,and pore structure type are important factors affecting the elastic properties of tight oil and gas reservoirs.However,most of the existing petrophysical models,focusing on a single pore type or only considering diagenesis,fail to accurately describe the characteristics of tight oil and gas reservoirs such as low porosity and low permeability,uneven fluid distribution,and complex pore structures and pore structure types.Therefore,in this paper,the differential equivalent medium(DEM)theory and the Pride model are fully used to deduce a petrophysical model of a dual-porosity medium considering diagenetic consolidation.Consolidation parameters and the aspect ratios and volume percentages of soft and hard pores are introduced for the joint characterization of diagenesis and microscopic pore structures.The effects of porosity,consolidation parameters,pore aspect ratio,and volume ratio of soft pores on compressional wave velocity,shear wave velocity,and elastic modulus are quantitatively analyzed with this model.The validity and applicability of the model are verified by the experimental data of sandstone and mudstone under different pressures and the experimental data of the Sulige area.Finally,the model is applied to the prediction of shear wave velocity in Sulige tight sandstone gas reservoirs.Compared with the prediction results of other petrophysical models,the shear wave velocity predicted by this model has the smallest error,confirming that the proposed petrophysical model has high prediction accuracy of shear wave velocity in tight sandstone reservoirs.

关 键 词：横波速度预测 双重孔隙结构 岩石物理 DEM模型 Pride模型 

分 类 号：P631[天文地球—地质矿产勘探]