天然气水合物开采技术研究进展及思考

Discussion on natural gas hydrate production technologies

近年来,越来越多的国家开始关注储量极大的清洁能源天然气水合物矿藏。在大量调研国内外天然气水合物开采技术、专利等的基础上,对天然气水合物开采原理进行了介绍,并对传统的热激发法、降压法、化学抑制剂法及CO_2—CH_4置换法进行了详细的对比和分析,总结了各方法的优缺点;在此基础上,对目前几种主要的创新技术,包括双水平井热水注入法、单井热吞吐法、部分氧化法、电加热辅助降压法及CO_2置换辅助降压法的技术原理、创新点、优缺点进行了详细分析、对比和思考;分析认为,当前创新热点大多基于重油油砂等的热采技术移植,且主要集中于降压法与热激发法相结合、扩大储层热接触面积、提高热量利用效率上。

In the recent years, more and more counla＇ies have focused on natural gas hydrate （NGH）. In this paper, numerous NGH production technologies and patents at home and abroad were reviewed and the principles of NGH production were presented. Moreover, some conventional production technologies （e.g. thermal stimulation, depressurization, chemical inhibitor and CO2-CH4 exchange） were compared and analyzed for their advantages and disadvantages. Then, several innovative technologies （e.g. hot water injection with a pair of horizontal wells, hot water huff ＆ puff with single well, partial oxidation, electrical heating assisted depressurization, and CO2 swapping depressurization） were discussed in view of principles, innovations, advantages and disadvantages. It is concluded that most of the innovative technologies are based on the thermal production technologies for heavy oil and oil sand etc., and they are usually designed with the combination of depressurization and thermal stimulation to increase the thermal contact area in reservoir and to improve the heat utilization efficiency.