热力法开采天然气水合物的模拟实验研究

Experimental Investigation of Production Behavior of Gas Hydrate under Thermal Stimulation

在天然气水合物一维开采模拟系统上进行了模拟热力法开采天然气水合物的实验研究.使用甲烷气体与NaCl溶液在一定温度和压力条件下形成水合物.通过以不同速率注入不同温度的热水,研究了热力法开采水合物过程中含水合物沉积物的温度分布以及甲烷气体、水生产规律.结果表明,在整个分解过程中,气体生产速率随时间增加而增加,直到达到最大值后开始下降,而水生产的速率几乎保持恒定.通过对实验结果的能量分析表明,热力开采的能量效率在0.38～2.59之间.注入热水的温度、速率以及沉积物中水合物的饱和度对热力法开采水合物的能量效率有重要影响.

The temperature distribution and flowing characteristics of the dissociated gas and water from hydrate bearing porous sediments were investigated by utilizing a one dimension experimental model setup. With the developed apparatus, the gas hydrate was formed by mixing methane gas with NaC1 solution at proper temperature and pressure condition. The experiments were run for the thermal stimulation method by injecting hot water at different temperatures and rates. The experimental results suggest that the gas production rate increases with time until it reaches a maximum and then it begins to decrease. However, the water production rate keeps nearly constant during the whole production process. The calculated energy ratio for all experimental runs is in the range of 0.38-2.59. The injection water temperature and rate as well as the hydrate content in the sediment all influence the energy ratio of thermal stimulation production.