地层环境与CO2饱和度变化下深部咸水砂岩层化学-渗流-蠕变规律研究

项目名称： 地层环境与CO2饱和度变化下深部咸水砂岩层化学-渗流-蠕变规律研究

项目编号： No.41502302

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 地质学

项目作者： 郑虹

作者单位： 中国科学院武汉岩土力学研究所

项目金额： 22万元

中文摘要： 以咸水层矿化封存CO2机理及岩层力学、渗透性质演化规律为研究核心。采用一系列室内试验，揭示咸水层储层在不同地层压力、不同孔隙压力以及不同CO2饱和度的孔隙流体渗透条件下矿化封存CO2的机制及储层砂岩长期力学变形破坏机理、CO2不同运移模式与储集岩层渗透特性的协同控制关系。基于不同围压、不同轴压、不同孔隙压差与CO2浮力、重力场的组合模式条件下的试验结果，建立孔隙率-渗透率-有效应力系数模型以及深部储层砂岩的溶解-沉淀物理模型，分析储层砂岩固碳量随地层压力、孔隙压力分布和CO2运移分布的演化规律，提出CO2注入对储层长期力学强度的弱化评价指标，建立不同地层压力、不同孔隙压力以及不同CO2饱和度的孔隙流体渗透条件下储层砂岩化学-渗透-蠕变模型。研究成果为储层砂岩矿化封存CO2潜力的定量评价以及地层力学稳定性、长期变形控制和储层渗透范围预测分析提供重要的理论和技术支持。

中文关键词： 咸水层；多场耦合；岩石力学；CO2矿化封存；渗透演化

英文摘要： The project concentrates on the study of carbon sequestration by mineralization and the evolution of rock mechanics and permeability in saline aquifer. A series of experiments are conducted to reveal the mechanism of carbon sequestration by mineralization and the long-term deformation and failure of salt-water sandstone strata with different formation pressure and pore pressure under the see-page of pore fluid with different CO2 saturation, as well as the cooperative control relationship between the migration of CO2 and the permeability of reservoir stratum. On the base of test results under different confining pressure, different axial pressure and different composite mode of pore pressure difference, CO2 buoyancy and gravitation, the main objectives include the follows: develop a porosity-permeability-effective stress coefficient model and the dissolution/precipitation model of salt-water sandstone strata; analyze the evolution of fixed carbon content in salt-water sandstone strata with the changes of formation pressure, pore pressure and CO2 migration; propose the weakening envalution index of long-term mechanical strength of reservoir stratum after CO2 injection; develop the chemical-hydro-creep coupling model under the changes of stratum environment and CO2 saturation. The research findings of this project provide theory and technique supports for the quantitative assessment of potential carbon sequestration by mineralization in salt-water sandstone strata and the controlling of stratum long-term mechanical stability and deformation, as well as the predictive analytics of CO2 infiltration area range in reservoir.

英文关键词： saline aquifer ;multi-field coupling;rock mechanics;carbon sequestration by mineralization;permeability evolution