富油煤原位热解开发地下体系封闭方法探讨

我国富油煤资源丰富,采用地下原位热解“取油留碳”是富油煤资源绿色高效开发的主要趋势。富油煤地下原位热解开采尚处于技术研发阶段,需要围绕富油煤原位开发的关键技术开展攻关。地下体系封闭是保障富油煤原位热解开采能量高效利用和生态环保的关键技术之一,亟需研发并构建适于富油煤原位热解开发特点的地下体系封闭技术。根据目前地下体系封闭技术研究与应用现状,系统梳理总结了地下冻结、注浆帷幕、气驱止水、泡沫止水等各类地下体系封闭技术原理与优缺点,深入分析了各类技术的地层适应性。结合富油煤层埋深、层厚、区域构造等地质特点,以及热解开发工艺和规模,讨论了不同体系封闭技术在富油煤热解开发中的适用性。探讨了体系封闭技术研发的发展趋势,即创新现有技术原理、发展复合封闭技术。针对地下体系封闭技术的工程实施,围绕开发前精细设计、开发中严密监测和开发后安全恢复,提出了包括地下体系封闭设计-监测-修复和环境恢复的系统方法。通过整合富油煤原位热解、地下体系封闭、产物驱采、CO₂地质封存等关键技术,提出了富油煤地下原位热解开发及CO₂地质封存一体化技术构想,为我国富油煤地下原位热解开...

Discussion on underground system sealing methods in in-situ pyrolysis exploitation of tar-rich coal

China has abundant tar-rich coal resource, in-situ underground pyrolysis is the main trend of green and efficient development of tar-rich coal resources. However, the underground in-situ pyrolysis of tar-rich coal is still in the stage of technology research and development, and it is necessary to focus on the key technology of tar-rich coal to carry out research . Underground system sealing is one of the key technologies to ensure the efficient use of energy and ecological protection of tar-rich coal in-situ pyrolysis mining, and there is an urgent need to develop and construct underground system closure technology suitable for the characteristics of tar-rich coal in-situ pyrolysis development. Based on the current status of research and application of underground system sealing technology, the principles, advantages and disadvantages of various types of underground system sealing technologies such as underground artificial freezing, grouting curtain, water-stopping by gas flooding and foam water-stopping, etc. were systematically sorted out and summarized, and the stratigraphic adaptability of various technologies weas analyzed in depth. The applicability of different system sealing technologies in the development of tar-rich coal pyrolysis is analyzed in the context of geological characteristics such as burial depth, layer thickness and regional tectonics of tar-rich coal seam, as well as the pyrolysis development process and scale. Further, the development trend of system sealing technology is discussed, i.e., innovating of existing technical principles and development of composite sealing technology. For the engineering implementation of underground system sealing technology, a systematic approach including design-monitoring-repair and environment restoration of underground system sealing is proposed around the fine design before development, strict monitoring during development and safe restoration after development. Finally, an integrated technology concept of underground in-situ pyrolysis exploitation of tar-rich coal and CO₂ geological storage was proposed by integrating the key technologies such as in-situ pyrolysis, underground system sealing, product displacement and CO₂ geological storage, which provided references for the development and industrial application of in-situ pyrolysis exploitation technology of tar-rich coal in China.