SAGD技术应用于陆域冻土天然气水合物开采中的理论研究

Theoretical Study on the Application of SAGD Technology in Exploitation of Natural Gas Hydrate in Land Permafrost Region

摘要:

天然气水合物被誉为最有研究价值和开采价值的清洁能源，已经成为当今世界能源研究的热点。但到目前为止还未形成成熟稳定的天然气水合物开采技术体系，仍处于研究和试采阶段。陆域冻土天然气水合物开采与海域天然气水合物开采相比相对比较容易，在钻进过程中能够形成较稳定的孔壁。天然气水合物开采的主要方法有热激法、降压法、置换法和化学抑制剂法。SAGD（Steam Assisted Gravity Drainage）技术也叫蒸汽辅助重力驱油技术，在重油、油砂开采中得到了迅速发展，取得了非常有效的成果，被认为是目前重油开采最有效的方法。对SAGD技术应用到陆域冻土天然气水合物开采中进行理论分析研究，经过分析发现将SAGD技术应用到天然气水合物开采中是可行的，但确定两口水平井之间的距离是关键，且在应用时要将上部井变为生产井，下部井变为注汽井。

Abstract:

Natural gas hydrate is regarded as clean energy with research and production value, which has become a hot research topic in the world. But so far, it is still in the research and production stage, no mature and stable gas hydrate production technology system has formed. The exploitation of natural gas hydrate in land permafrost region is relatively easy in contrast with the exploitation of natural gas hydrate in sea area, and the stable hole wall can form during the drilling process. The main natural gas hydrate exploitation methods are thermal stimulation method, depressurization method, displacement method and chemical inhibitor method. SAGD technology is also known as steam assisted gravity drainage, it has been rapidly developed in heavy oil and oil sands mining with very effective results, and is considered to be the most effective way of heavy oil exploitation. In this paper, the application of SAGD technology in natural gas hydrate exploitation in land permafrost region is analyzed, it is found that SAGD technology is feasible in the application of natural gas hydrate mining; however, it is very important to determine the distance between the 2 horizontal wells, and in the application, the upper well should be changed into a production well, while the lower one into the steam injection well.