天然气水合物一维注热开采影响因素实验研究

Experimental Study on Influencing Factors of One-dimension Thermal Recovery of Natural Gas Hydrate

水合物热采实验中,注热水的速度与温度影响分解进程和水合物层的温度、压力分布。为了探究不同因素对水合物一维注热开采的影响,实验采用间歇注气的方法增量合成水合物,合成饱和度为40.2%的水合物,可保证水合物均一分布在一维填砂管的多孔介质中,使注热水过程中热水均匀推进。模拟注热开采实验结果表明,为了加快开采速度,在技术可行与安全生产范围内,可适当增大注热水的速度;升高注热温度也可加快分解进程,但也会降低能量利用率,因此应在一定范围内选择合适的注水温度;另一方面,相比于不同温度,不同速度下平均分解前缘移动速率变化幅度更大,即相比于热传导,对流换热对前缘移动速率的影响较大。

In the thermal recovery experiment of hydrate,the injection rate and temperature of hot water affect the decomposition process of hydrate and the temperature and pressure distribution of hydrate layer.In order to discuss the influence factors of one-dimension thermal recovery of hydrate,the hydrate with saturation of 40.2%is synthesized by the incremental hydrate synthesis method under intermittent flow condition,which can ensure that the hydrate is uniformly distributed in the porous medium of one-dimensional sand filling pipe,and make the hot water advance evenly in the process of hot water injection.The experimental results show that in order to speed up the recovery rate of hydrate,the injection rate of hot water can be appropriately increased within the range of technical feasibility and safe production;increasing the injection temperature of hot water can also speed up the decomposition process of hydrate,but it will also reduce the energy utilization rate,so the appropriate water injection temperature should be selected within a certain range.Compared with changing the injection temperature,changing the injection rate of hot water makes the average moving rate of the decomposition front of hydrate change more greatly,that is to say,compared with heat conduction,the influence of convective heat transfer on the moving rate of the decomposition front is greater.