孔隙内天然气水合物分解纳米气泡演化规律及其对二次生成影响机制

天然气水合物是未来全球能源发展的战略制高点，我国储量巨大，其资源开采是我国重大战略需求。但天然气水合物开采仍存在产气效率低、持续性差的瓶颈。分解过程多相多组分运移规律及水合物二次生成机制是突破这一瓶颈必须解决的关键科学问题。分解液内纳米气泡富集，制约气水运移并控制水合物二次生成。然而，孔隙内纳米气泡演化规律不清，其对水合物二次生成的影响机制不明。项目聚焦天然气水合物分解及二次生成过程，探究CH4/水/固体体系润湿性变化规律及其微观控制机制，阐明润湿性、水合物分解液特性对纳米气泡演化的影响规律，建立孔隙内纳米气泡演化模型，追踪CH4分子“纳米气泡-水溶液-水合物”及水分子“水溶液-水合物”相态转变历程，在分子尺度解析水合物二次生成成核及生长路径，阐明纳米气泡演化对水合物二次生成的影响机制，开发基于纳米气泡控制的抑制水合物二次生成技术，探索解决水合物开采产气效率低、持续性差难题的有效方法。

Natural gas hydrate is the strategic point of global energy development in the future. China has huge reserves, and its resource exploitation is a major strategic demand of China. However, there are still bottlenecks of low gas production efficiency and poor sustainability in the exploitation of natural gas hydrate. The migration law of multiphase and multicomponent in decomposition process and the mechanism of hydrate secondary generation are the key scientific problems that must be solved to break through this bottleneck. The enrichment of nanobubbles in the decomposition solution restricts the gas-water migration and controls the secondary formation of hydrate. However, the evolution law of nanobubbles in pores is not clear, and the mechanism of its influence on hydrate secondary formation is open to questions. In the project, we focus on the decomposition and secondary generation process of natural gas hydrate, explore the variation of CH4/water/solid system wettability and its micro control mechanism, clarify the influence of wettability and hydrate decomposition solution characteristics on the evolution of nanobubbles, establish the evolution model of nanobubbles in pores, track the process of phase transition as CH4 molecule "nanobubbles-water solution-hydrate" and water molecule "water solution-hydrate", analyze the nucleation and growth path of hydrate secondary generation at molecular scale, clarify the influence mechanism of nanobubbles evolution on hydrate secondary generation, develop the technology of hydrate secondary generation inhibition based on the control of nanobubbles, and explore an effective method to solve the problem of low efficiency and poor sustainability of hydrate production.