平板填砂模型中天然气水合物注热与降压连续开采的实验研究

在平板模型中进行了天然气水合物的注热盐水与降压相结合的分解模拟实验,分析了分解过程中平面温度变化的情况、产气规律、产水规律及能量效率。实验结果表明:注入的热盐水并不能使模型内天然气水合物全部分解,有必要再进行降压分解;气体产出可明显地划分为注热分解产气和降压分解产气2个阶段;注热分解阶段产水速率略大于注水速率,降压分解产水速率很慢;注热与降压相结合的开采方式更加有利于天然气水合物的分解和产出,且能有效提高能量效率。

EXPERIMENTAL STUDY OF NATURAL GAS HYDRATE DISSOCIATION IN POROUS MEDIA WITH A 2D EXPERIMENTAL SYSTEM BY CONTINUOUS THERMAL STIMULATION AND DEPRESSURIZATION

Experimental study on NGH dissociation was carried out with a special designed 2D experimental system. The experiment was performed by injecting hot brine and decreasing pressure (thermal stimulation plus depressurization). The change of temperature, gas production rate, water production rate and energy efficiency were analyzed during the NGH dissociation. Experimental results demonstrate that the injecting hot brine water does not bring in the full dissociation of all of NGH in the model. So it is necessary to decrease pressure. Then the dissociated gas can be obviously divided into thermal dissociated gas and depressurized dissociation gas. Water production rate of the thermal stimulation is obviously greater than that of depressurization. Thermal stimulation together with depressurization can achieve higher energy efficiency and therefore is a better method for NGH dissociation and production.