以CO2做垫层气的天然气地下储气库多源汇热质输运效应与调控研究

According to previous research on gas and CO2 permeation - diffusion combination displacement mechanism, theoretical and experimental methods have been employed to investigate the stability and reliability of utilizing CO2 as cushion gas in gas underground reservoirs, and under the effect of multi-source and multi-sink coupling, the influences of nohomogeneity of reservoirs and operational conditions on the movement of mixed zone have also been analyzed. Based on source /sink distributional theory, multi-source/sink, multi- ingredient and multi-phase coupled heat and mass transfer mathematical models under the complicated boundary conditions have been built and solved. Under the condition of ensuring normal operation of reservoirs, gas quality and dynamic stability of CO2 fingering displacement, by finding the analytical solution of optimized operational model, a dynamic regulation-control system and high efficient operational scheme of natural gas and cushion gas flow in the multi-well pattern..CO2 sequestration as cushion gas in the underground reservoirs, can not only save sedimentary funds, but also reduce greenhouse effect. The new introducing technical theory and method in the expansion and transport process of natural gas underground reservoirs, will create and perfect the multi-source/sink coupled permeation-diffusion theory in the fractal porous medium, and fill the blanks in the underground storage gas system theory, as well as provide theoretical reference for the development of natural gas industry and accomplishment of reducing the CO2 emission by 40%-50% in our country.

在已完成的天然气与CO2渗流扩散混合机理研究基础上，采用理论和实验相结合的方法，研究CO2作为地下储气库垫层气的稳定性与可靠性，分析多源汇耦合作用下，储层的地质条件和运行条件对混合带运移的影响，基于源汇分布理论，通过建立复杂边界条件下，多源汇多组分多相耦合的热质输运模型及求解方法，研究在保证储气库群扩容运行和采气质量、以及CO2指进驱替动力稳定性约束条件，通过优化运行模型的分析求解，提出储气库群多源汇井网天然气与垫层气的动态调控模式，以及经济高效运行方案。.CO2深埋作地下储气库的垫层气，既可节省沉积资金，又可实现碳隔离储存，减少温室效应,所提出的天然气地下储气库群扩容储运过程新技术理论、新方法，不仅创新和完善分形多孔介质内多源汇耦合渗流扩散理论、填补地下储气系统理论空白，而且能为我国天然气工业发展和实现CO2排放强度降低40-45%，提供理论依据。

采用理论和实验相结合的方法，测试了在实验室模拟运行压力下，储层岩心驱替过程的细部结构发育特征和混气渗流扩散的微观特征，研究了储层地质条件和运行条件对混合带运移的影响，以及多源汇耦合作用下，CO2作为地下储气库垫层气的稳定性与可靠性,以及储气库群注采运行过程，储层参数和物性参数的反演计算方法：基于源汇分布理论，通过建立复杂边界条件下，多源汇多组分多相耦合的热质输运模型及求解方法，提出多源汇，非均匀介质尺度效应下，天然气与CO2气气混合驱替时，参数相互影响及交互作用的规律：研究提出在保证储气库群扩容运行、以及CO2指进驱替动力稳定性约束条件下，储气库群注采的优化运行模型，基于实际算例，提出储气库群多源汇井网天然气与垫层气的动态调控模式和经济高效运行方案。 .CO2 深埋作地下储气库的垫层气，既可节省沉积资金，又可实现碳隔离储存，减少温室效应,所提出的天然气地下储气库群扩容储运过程新技术理论、新方法，不仅创新和完善分形多孔介质内多源汇耦合渗流扩散理论、填补地下储气系统理论空白，而且能为我国天然气工业发展和实现CO2 排放强度降低40-45%，提供理论依据。