中国地质2026，Vol.53Issue(2)：476-490,15.DOI:10.12029/gc20200710001
低孔低渗储层CO2封存迁移规律——以鄂尔多斯盆地为例
Migration law of CO2 storage in low-porosity and low-permeability reservoirs:Taking Ordos Basin as an example
摘要
Abstract
[Objective]To enrich the research on carbon storage in low-porosity and low-permeability depleted hydrocarbon reservoirs in the Ordos Basin,a carbon capture and storage(CCS)project with an annual capacity of 100,000 tons is planned.The project involves 21 injection wells,each with an average injection rate of 0.15 kg/s.[Methods]The Chang 6 oil layer of the Yanchang Formation in the Ordos Basin is selected as the target reservoir,characterized by an average porosity of 7％-12％and an average permeability of 0.1-5 mD.Based on the fundamental theories of percolation mechanics,multiphase fluid dynamics,and computational fluid dynamics,both homogeneous and heterogeneous conceptual geological models were constructed.Numerical simulations were employed to comparatively analyze the CO2 storage characteristics,fluid migration laws,and phase-transition mechanisms under different geological conditions.Furthermore,in combination with field practices,the study investigates the specific features of CO2 storage in low-porosity and low-permeability reservoirs,the behaviors of fluid migration and transport,and related physical phenomena.[Results]During supercritical CO2 injection,the initial formation pressure equilibrium is disrupted,leading to a rapid pressure increase around the injection wells.In the homogeneous model,the pressure diffuses uniformly in a radial pattern.Conversely,in the heterogeneous model,the pressure front exhibits significant anisotropy and"stepped"distribution characteristics due to permeability contrast.Following the cessation of injection,the formation pressure gradually stabilizes.In the homogeneous model,CO2 forms a"tongue-like"accumulation zone at the top of the reservoir,with its lateral distribution continuously expanding.In contrast,the heterogeneous model exhibits pronounced"viscous fingering"and jagged edge characteristics.[Conclusions]A comparison between the simulated average CO2 migration velocity during the injection period(0.0157 m/d)and the field-measured velocity following hydraulic fracturing(7.35 m/d)reveals that pre-treating the low-porosity and low-permeability reservoirs in the Ordos Basin with hydraulic fracturing significantly accelerates CO2 migration and enhances injection capacity.关键词
CO2/地质封存/低孔低渗/延长组/油气勘查工程/鄂尔多斯Key words
CO2/geological storage/low-porosity and low-permeability/Yanchang Formation/oil and gas exploration engineering/Ordos分类
天文与地球科学引用本文复制引用
汪锋,戴世鑫,朱伟,胡盼,宫玉菲..低孔低渗储层CO2封存迁移规律——以鄂尔多斯盆地为例[J].中国地质,2026,53(2):476-490,15.基金项目
国家重点研发计划项目(2018YFB0605503,2018YFC0807801)和国家自然科学基金项目(51804112)联合资助. Supported by National Key Research and Development Program of China(No.2018YFB0605503,No.2018YFC0807801),and National Natural Science Foundation of China(No.51804112). （2018YFB0605503,2018YFC0807801）
