石油实验地质2025，Vol.47Issue(3)：490-503,14.DOI:10.11781/sysydz2025030490
鄂尔多斯盆地庆阳古隆起下古生界储层发育主控因素及成因模式
Main controlling factors and genesis models of reservoir development in Lower Paleozoic of Qingyang paleo-uplift,Ordos Basin
摘要
Abstract
In recent years,significant progress has been made in exploring the Lower Paleozoic deep natural gas of the Qingyang paleo-uplift in the southwestern Ordos Basin.However,the reservoirs in this region are generally tight,and the formation mechanisms of high-quality reservoirs are complex,making sweet spot prediction difficult.Based on drilling,logging,and seismic data,as well as experimental test data,this study analyzed the reservoir development types and main controlling factors of the gas-bearing layers,including the Cambrian Zhangxia Forma-tion and Sanshanzi Formation,and the second and fourth members of the Ordovician Majiagou Formation(Ma 2 and Ma 4).A genesis model of the Lower Paleozoic reservoirs in the Qingyang paleo-uplift was established.Four types of reservoirs were developed in the region:dolomite reservoirs,shoal reservoirs,karst reservoirs(super-gene karst and fault-karst reservoirs),and structural micro-fracture reservoirs.Among them,the Sanshanzi Forma-tion as well as the Ma 2 and Ma 4 members mainly featured dolomite reservoirs,while shoal reservoirs dominated the Zhangxia Formation.Karst reservoirs and structural micro-fracture reservoirs were developed across all layers.The controlling effect of sedimentary facies belts,weathered crusts,and faults on the development of Lower Paleozoic reservoirs in the Qingyang paleo-uplift was significant.Sedimentary facies belts controlled the development of intergranular(dissolution)pores in shoals and intercrystalline(dissolution)pores in dolomite.Two phases of weathered crusts controlled the development of supergene karst reservoirs,with the weathered crusts at the top of the Ordovician being the most influential.Karst residual hills controlled the planar distribution of strong dissolu-tion areas.The vertical dissolution intensity and gas content of reservoirs were closely related to their distance from the top of the weathered crust.Faults controlled the distribution of fault-karst reservoirs,and their associated micro-fractures effectively improved the reservoir properties.Based on these findings,four reservoir genesis models,including shoal-fault type,residual hill-fault type,dolomite-karst type,and dolomite-fault type,were estab-lished,providing insights into the exploration of the Lower Paleozoic natural gas in the Qingyang paleo-uplift.关键词
储层类型/储层成因模式/下古生界/庆阳古隆起/鄂尔多斯盆地Key words
reservoir types/reservoir genesis models/Lower Paleozoic/Qingyang paleo-uplift/Ordos Basin分类
石油、天然气工程引用本文复制引用
陈朝兵,庞天翊,郝泽坤,宋微,杨克荣,孟凤鸣,高建荣,段晨阳..鄂尔多斯盆地庆阳古隆起下古生界储层发育主控因素及成因模式[J].石油实验地质,2025,47(3):490-503,14.基金项目
国家科技重大专项(2011ZX05044)和西安石油大学研究生创新与实践能力培养计划(YCS23114115)联合资助. （2011ZX05044）
