天然气水合物藏注热水开采敏感因素试验研究  

Experimental study on influencing factors for hydrate dissociation in a hot brine injection process

作　　者：李淑霞[1,2] 李杰[1] 徐新华 李小森[2] 

机构地区：[1]中国石油大学石油工程学院,山东青岛266580 [2]中国科学院可再生能源与天然气水合物重点实验室,广东广州510640

出　　处：《中国石油大学学报（自然科学版）》2014年第2期99-102,共4页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金项目(51274227;51374232);中国科学院可再生能源与天然气水合物重点实验室项目(y207k2)

摘　　要：采用自制的一维天然气水合物(NGH)开采模拟试验装置,模拟海洋地质条件,在填砂模型(填砂管直径8 cm,长80 cm)中生成天然气水合物,并通过注入热盐水进行热力开采的物理模拟试验,分析水合物藏地质因素和注热参数对注热水开采能量效率(水合物分解所得甲烷气的热量与注入热量之比)的影响。结果表明:影响能量效率的因素由大到小依次为注热水温度、水合物饱和度、初始温度、注热水时间、注热水速度;在水合物藏地质因素中,水合物饱和度越大,初始温度越高,注热水开采能量效率越高;在注热参数中,注热温度越高,能量效率越低;在注热开采时需要合理优化注热水温度、注热水时间和注热水速度;试验条件下,注热水开采能量效率最高的试验组合为水合物饱和度48%,初始温度5℃,注热水温度40℃,注热水时间350 min,注热水速度12 mL/min,最高能量效率为6.74。The formation and dissociation of natural gas hydrate（ NGH） was studied using a specially designed one-dimensional experimental set-up to simulate the hydrate bearing sediment below the seabed. NGH was formed in a sandpack model（ with a diameter of 8 cm and lengh of 80 cm）,and then hot brine was injected into the sandpack to dissociate the gas hydrate. The important factors that influencing the energy efficiency for hydrate dissociation were investigated,including the temperature of the injected hot brine,the saturation and initial temperature of hydrate formed,and the injection time and rate of the hot brine. The energy efficiency was defined as the ratio of the heat of the methane gas released to the injection heat. The experimental results show that,the order from big to small of factors that influencing the energy efficiency for hydrate dissociation is temperature of the injected hot brine,the saturation,initial temperature,the injection time and rate of the hot brine. The higher hydrate saturation and initial temperature,the higher energy efficiency,while the higher the hot-brine temperature,the lower the energy efficiency. The temperature,injection time and injection rate of hot-brine can be optimized in order to achieve a high thermal efficiency in the process of the hydrate dissociation. Under the experimental conditions,a maximum energy efficiency of 6. 74 is achieved during the dissociation of hydrate formed at 5 ℃ with a saturation of 48%,when hot-brine of 40 ℃ is injected at a rate of 12 mL / min for 350 min.

关 键 词：天然气水合物 注热盐水 水合物分解 能量效率 

分 类 号：TE375[石油与天然气工程—油气田开发工程]