海域水合物开采井-井周土-储层相互作用及致灾机理研究

As abundant and highly-efficient clean energy, gas hydrate is deemed as an important potential source of future energy in the energy strategy of many countries. The successful trial excavation in the South China Sea introduces the beginning of industrialized gas hydrate production in China meanwhile poses great engineering challenges, which call for in-depth researches into related fundamental theories. Centering complex oceanic reservoir conditions at the field scale and the well-soil-reservoir interaction during production, this proposed project explores the structure failure and malfunction mechanism of the production well. Major tasks include: 1) the implementation of a Thermo-Hydro-Mechanical-Chemical (THMC) coupled analysis module based on GEOS, a high-performance computing platform for geoscience; 2) the investigation into the interaction between production well, soil and reservoir under complex conditions along with the failure mechanism of the production well utilizing the THMC coupled numerical analysis; 3) the development of a new experimental apparatus for simulating sand production during gas hydrate production, and the probe into the dynamic process of sand production at both macro and micro scale for reaching the proper criterion of sand production. This study contributes to the optimization of gas hydrate production through profound understanding of failure mechanism of the hydrate production well. It carries great academic significance as well as application potential in terms of advancing gas hydrate industrial production progress and taking the world-leading position in gas hydrate production technology.

天然气水合物是资源量丰富的高效清洁能源，是未来全球能源发展的战略制高点。南海首次水合物试采获得成功，我国水合物开采产业化进程正拉开大幕。但是，水合物的安全开采面临诸多挑战，亟待夯实相关基础理论。本项目围绕现场尺度复杂海域储层条件和开采工况下水合物开采井与井周土/储层的相互作用机制，研究水合物开采井结构破坏及功能失效的致灾机理，主要研究内容包括：1）基于超大规模计算平台GEOS开发水合物开采热-流-力-化学（THMC）耦合数值分析模块；2）采用THMC耦合模块研究复杂条件下水合物开采井-井周土-储层相互作用以及开采井结构破坏机制；3）研制水合物开采条件下模拟井周出砂的室内实验装置，研究水合物开采过程中宏细观动态出砂规律和出砂定量预判方法。本研究有助于深刻认识水合物开采井致灾机理，对优化水合物开采方法和策略、推动我国水合物产业化进程、占领水合物开采技术的制高点具有深远的学术意义和应用价值。

天然气水合物是资源量丰富的高效清洁能源，是未来全球能源发展的战略制高点。南海首次水合物试采获得成功，我国水合物开采产业化进程正拉开大幕。但是，水合物的安全开采面临诸多挑战，亟待夯实相关基础理论。本项目围绕现场尺度复杂海域储层条件和开采工况下水合物开采井与井周土/储层的相互作用机制，研究水合物开采井结构破坏及功能失效的致灾机理，主要研究内容包括：1）基于超大规模计算平台GEOS开发水合物开采热-流-力-化学（THMC）耦合数值分析模块；2）采用THMC耦合模块研究复杂条件下水合物开采井-井周土-储层相互作用以及开采井结构破坏机制；3）研制水合物开采条件下模拟井周出砂的室内实验装置，研究水合物开采过程中宏细观动态出砂规律和出砂定量预判方法。.围绕上述研究内容，本项目的主要成果包括：1）基于超大规模计算平台GEOS开发了一套水合物开采THMC数值分析模块；2）研制了一套用于模拟水合物开采出砂的室内实验装置；3）基于精细化数值分析结果，揭示现场尺度开采全过程中开采井-井周土-储层相互作用规律；4）基于微观可视化物理模型实验，揭示水合物开采出砂微细观机制。研究成果有助于丰富水合物开采工程相关研究的试验手段和数值分析工具，可以推广到水合物开采工程问题的分析和模拟，对于深刻认识水合物开采井致灾机理具有学术意义，可为水合物开采井的结构设计与施工、开采方案优化和工程风险规避等工程实践提供理论参考。基于上述研究，培养研究生6名，发表/录用学术论文8篇，获软件著作权1项，申请发明专利1项。