甲烷水合物的CO_2置换效率强化方法研究进展

Research Progress in Enhancement Methods on Replacement of CH_4 from Methane Hydrate with CO_2

总结了强化CO_2置换甲烷水合物过程的研究,包括调节外界温压、使用添加剂、改变CO_2注入形态以及结合几种天然气开采方法等方面对CO_2-CH_4置换过程的影响。研究表明:一定范围内,置换效率随温度和压力的升高而增大,其中温度较压力的影响更为显著;适当的添加剂对置换效果有促进作用;对于纯质CO_2,置换效率乳液状CO_2>液态CO_2>气态CO_2,混合气体(N_2和CO_2)的置换效率较纯质CO_2气体大;CO_2置换法与传统开采方法的结合也大大增加了置换效率。最后,在论述目前强化CO_2置换开采法研究现状的基础上,指出了现存研究方法的一些不足,并对今后的研究工作进行了展望。

This paper summarized recent overseas and domestic researches in enhancement methods on replacement of CH_4 from methane hydrate with CO_2,including adjusting temperature and pressure,using additives,changing injection states of CO_2 and combining with the other recovery methods. It indicated that: replacement efficiency increased with the rise of temperature and pressure,and the impact of temperature was more significant than pressure; in the meantime,appropriate surfactants and injection states of CO_2 made for better displacement performances. As for pure CO_2,the replacement order was shown as follows: CO_2 emulsion > CO_2 liquid > CO_2 gas,and the replacement reaction was promoted by mixture of N_2/CO_2. In addition,combining injection CO_2 with other exploitation techniques could also strengthen the replacement processes prominently. Finally,based on the discussions from many researchers obtained about enhancement ways on replacement of CH_4 from hydrate with CO_2,some potential problems and development direction were put forward.