煤多孔介质水合物法存储CO2过程气-液-固多相场耦合机制

Adopting the similar chemical reaction mechanism to store CO2 in coal by the solid hydrate formation method which benefits for CO2 long-term solidifying sequestration. It not only can prevent the possible spill in the geological period if employing physical sequestration principle , but also will avoid the enormous economic risk from storage medium commonly happened in the hydrate-forming reacon. Previous experiments have illustrated the considerable storage capacity and the stable storage situation when applying hydrate formatioin technology to store CO2 in coal and verified the strong potential of engineering application. However, as a new geological storage method, it still exists plenty of scientific questions or problems need to be investigated in order to realize the maximum CO2 storage capacity in coal. This research proposal about the multi-phase fields coupling principle in the process of hydrate-forming when storing CO2 in the porous structure of coal is one of the key scientific topics. This proposal will carry out the research by principle analysis and theoretical modeling establishment. Through investigate the CO2 hydrate-forming experiments in the coal, establish the multi-phase field mathematical model coupling gas-water-solid, and simulation computing based on the experiments of coal dynamical porosity evolution in CO2 adsorption and hydrate-forming phases, controlling the boundary conditions, the theory and simulation model which can explain the CO2 hydrate-forming process in coal will be establish finally. Research will provide the theoretical and simulation solution for improving CO2 storage capacity in coal.

以固态水合物法储存CO2于煤层中，采用拟化学反应机制，更有利于CO2的长期固化封存，可较有效防止采用物理机制储存法潜在的地质时期泄漏事件，同时规避了水合物合成时所需储存媒介的巨大经济投入风险。前期实验展现了煤中CO2水合物可观的储气容量和稳定的储存状态，证实其可行性，表现出极大的工程应用潜力。然而，作为新的CO2地质储存方式，要实现储气量最大化，许多科学问题尚需深入研究。本课题拟开展的CO2在煤多孔介质中的水合物形成过程多相场耦合机制研究，正是关键问题之一。研究拟从机理分析和理论模型建立出发，开展CO2在煤多孔介质中的水合物合成实验；建立煤中CO2水合物合成前后气-液-固多相场耦合数学模型；基于煤中CO2吸附-水合物合成阶段煤受力动态孔隙率演化过程实验，控制边界条件进行数值计算；最终建立解释煤非均匀多孔介质中CO2水合物合成过程理论与数值模型，研究将为提高煤中CO2储量提供理论与数值解法。

以固态水合物法储存CO2于煤层中，采用拟化学反应机制，更有利于CO2的长期固化封存，可较有效防止采用物理机制储存法潜在的地质时期泄漏事件，同时规避了水合物合成时所需储存媒介的巨大经济投入风险。前期实验展现了煤中CO2水合物可观的储气容量和稳定的储存状态，证实其可行性，表现出极大的工程应用潜力。然而，作为新的CO2地质储存方式，要实现储气量最大化，许多科学问题尚需深入研究。为解决该关键问题，本课题开展了CO2在煤多孔介质中水合物形成过程的多相场耦合机制研究。研究从机理分析和理论模型建立出发，开展了CO2在煤多孔介质中的水合物合成实验；建立了煤中CO2水合物合成前后气-液-固多相场耦合数学模型；基于煤中CO2吸附-水合物合成阶段煤受力动态孔隙率演化过程实验，控制边界条件进行数值计算；最终建立了解释煤非均匀多孔介质中CO2水合物合成过程理论及数值模型，研究可为提高煤中CO2储量提供理论与数值解法。