压裂强化水合物分段降压开采模拟研究

Simulation Study on Hydrate Production Using Step-wise Depressurizatio Enhanced by Fracturing Method

水合物储层低渗透性诱发的天然气采收率过低是限制天然气水合物商业化开采的重要影响因素之一,通过压裂技术提高低渗透油气藏的渗透率已十分成熟,目前也逐步应用于水合物开采中。本文建立一个二维轴对称水合物开采模型进行了压裂辅助提高天然气水合物分段降压开采效率的模拟研究,通过分析岩心内部压力、饱和度分布以及产气和产水的变化,对比不同压裂工况下水合物开采效率,得到了压裂能够加快水合物分解速度,缩短开采时间,提高开采效率和经济性的结论。

The low natural gas recovery rate induced by low permeability of hydrate reservoirs is one of the important factors limiting the commercial exploitation of natural gas hydrates.Improving the permeability of low-permeability oil and gas reservoirs using fracturing technology has become very mature and is gradually applied in hydrate exploitation.A two-dimensional axisymmetric hydrate production model is established to simulate the efficiency of step-wise depressurization production of nature gas hydrate enhanced by fracturing.By analyzing the pressure and saturation distribution of the core and the changes of gas and water production,the hydrate production efficiency under different fracturing conditions is compared,it is concluded that fracturing can accelerate the hydrate decomposition rate,shorten the production time,and improve the production efficiency and economy.