海底沉积物中天然气水合物生成和分解规律研究进展

对国内外有关海底沉积物中天然气水合物生成和分解规律方面的研究进行了详细调研,得到如下结论:天然气水合物的生成和分解条件在海底沉积物中与在井筒、管道中有明显不同,其主要原因是多孔介质中流体与孔隙壁面间的界面效应对海底沉积物中天然气水合物的形成条件会产生明显影响;在海底沉积物中天然气水合物生成和分解条件的数值模拟技术研究方面,研究者大都假设以天然气水合物作为盖层的成藏类型,借助常规油气藏数值模拟技术进行模拟研究;影响海底沉积物中天然气水合物生成和分解条件的因素很多,因此海底沉积物中天然气水合物生成和分解规律研究必须借助试验模拟、数值模拟和现场测试相结合的综合方式进行。该调研成果可为今后天然气水合物经济有效开采技术方案选择和进行天然气水合物危害控制等提供参考。

Some advances in studying formation and dissociation of gas hydrate in submarine sediments

The literatures about the formation and dissociation process of gas hydrate in submarine sediments are widely surveyed at home and abroad,and several conclusions are drawn:(1) The conditions of gas-hydrate formation and dissociation are different in submarine sediments and in well bore and pipeline,mainly because the interface effect between fluid and pore wall in porous media may greatly influence the formation conditions of gas hydrate in submarine sediments.(2) For numerical simulation of formation and dissociation of gas hydrates in submarine sediments,most researchers applied an accumulation model with the gas hydrate as a seal,and made the simulation by means of the numerical simulation techniques for conventional hydrocarbon reservoir.(3) The experimental simulation,numerical simulation and field testing have to be combined to study the formation and dissociation process of gas hydrate in submarine sediments,because there are a lot of factors to control its formation and dissociation.These conclusions may provide useful references for selecting economic development plan of gas hydrate and controlling its hazards in the future.