石油地质与工程2026，Vol.40Issue(3)：72-79,8.DOI:10.26976/j.cnki.sydz.202603009
基于成岩—孔隙耦合的致密储层特征及成因机制
Tight reservoir characteristics and genetic mechanism based on diagenesis-porosity coupling:acase study of Chang 6 oil-bearing formation in X area,Ordos Basin
摘要
Abstract
The Chang 6 oil reservoirs of the Triassic Yanchang Formation in Block X,central Shaanxi Slope,Ordos Basin,is a typical tight reservoir with low porosity and low permeability.Based on core observation,thin section identification,scanning electron microscopy(SEM),X-ray diffraction(XRD)and mercury intrusion porosimetry,this paper systematically investigates the petrological characteristics,physical properties,pore structure and diagenesis of the Chang 6 reservoir.Research results show that the reservoir lithology is mainly feldspar sandstone,and the mineral composition is dominated by feldspar and quartz.Intergranular dissolved pores are the predominant pore type,and the pore-throat structure is characterized by small pores and fine throats.Quantitative evolution analysis of diagenesis-porosity system indicates that the original porosity(approximately 35%)was reduced by 19.1%due to compaction,with an additional loss of 4.3%caused by cementation.The final measured porosity is only 11.6%,among which the pore-increasing effect of dissolution raised the porosity by about 3.1%.Early compaction and cementation are the main factors for reservoir densification,while dissolution plays a key role in improving reservoir quality.This study reveals the formation mechanism of tight Chang 6 reservoirs,and is of great significance for the effectiveness evaluation of tight sandstone reservoirs and the selection of hydrocarbon exploration targets in the Ordos Basin.关键词
鄂尔多斯盆地/延长组/长6油层组/致密储层/孔隙结构/成岩作用Key words
Ordos Basin/Yanchang Formation/Chang 6 oil reservoirs/tight reservoir/pore structure/diagenesis分类
能源科技引用本文复制引用
李芙蓉,李爱荣,余志红,韦健,霍瑞麟,侯宾东,毛振宇..基于成岩—孔隙耦合的致密储层特征及成因机制[J].石油地质与工程,2026,40(3):72-79,8.基金项目
国家自然科学基金项目"鄂尔多斯盆地南部长6油层组地层水特征与油气富集规律研究"(41772140). （41772140）
