中国石油大学学报（自然科学版）2025，Vol.49Issue(3)：37-50,14.DOI:10.3969/j.issn.1673-5005.2025.03.005
志靖-安塞地区长8段致密砂岩储层孔隙差异性演化及成因
Porosity differential evolution and genesis of Chang 8 Member tight sandstone reservoirs in Zhijing-Ansai Area
摘要
Abstract
The Chang 8 Member reservoirs in the Zhijing-Ansai area of the Ordos Basin have promising exploration potential;however,the dense nature of the sandstones and their strong heterogeneity hinder further oil and gas development.This study adopts an integrated approach,including thin-sections petrography,scanning electron microscopy,cathodoluminescence,flu-id inclusion analysis,and carbon and oxygen isotope analysis,to characterize the rock composition,diagenetic processes,pore types,and porosity evolution under the constraint of varying rock compositions.The results indicate that the Chang 8 reservoirs are dominated by lithic arkose,with common cements including calcite,quartz overgrowths,and chlorite.The pri-mary pore types are intergranular pores and feldspar dissolution pores.Based on differences in rock composition,the sand-stones are categorized into two types:plastic particle-rich tight reservoirs and rigid particle-rich tight reservoirs.Strong com-paction results in the loss of over 80%of original porosity,making compaction the main factor in densification in plastic parti-cle-rich reservoirs.Two stages of calcite and silica cementation are the dominant contributors to porosity reduction,with ce-mentation accounting for more than 50%porosity loss on average in rigid particle-rich reservoirs.Dissolution significantly im-proves the physical properties of the sandstone.making such reservoirs more favorable for exploration and development.关键词
岩石组分差异性/孔隙演化/致密砂岩/延长组/鄂尔多斯盆地Key words
differential rock composition/porosity evolution/tight sandstone reservoirs/Yanchang Formation/Ordos Basin分类
石油、天然气工程引用本文复制引用
葸克来,张泽涵,操应长,辛红刚,淡卫东,李驰..志靖-安塞地区长8段致密砂岩储层孔隙差异性演化及成因[J].中国石油大学学报（自然科学版）,2025,49(3):37-50,14.基金项目
国家自然科学基金项目(42072161) （42072161）
中央高校基本科研业务费专项(22CX07008A) （22CX07008A）
