摘要
储气库在建造和运行时,一方面溶腔内气体通过自然对流与周围盐层进行热交换,与周围盐层壁面形成不稳态导热温度场;另一方面连续注采循环,使腔内气体压力、温度发生变化,特别是在连续采气时,降压的焦耳—汤姆逊效应极易使井口气体压力和温度进入生成水化物的危险范围,因此动态确定盐穴储气库注采天然气时的热工特性变化十分必要。为此,根据热力学、传热学和流体力学理论,针对注采过程天然气在井筒流动和溶腔内传热过程的特点,将井筒、溶腔和周围盐层视为一个系统,提出了描述注采动态工程相互耦合的数学模型及其求解方法,并开发了相应的数值计算软件。该软件可预测盐穴地下储气库在连续注采气过程中,溶腔内及井筒顶、底部气体的压力和温度,并判断水化物形成的危险范围等。研究成果能对盐穴地下储气库的建造和技术特性做出预测分析,对其运行工况给予指导,并对注采气地面系统的优化设计提供理论分析依据。
Building underground gas storages with salt caverns are one of the most economic and reasonable ways to solve the imbalances of short-term gas consumption in cities essentially. During building and operation of gas storages, the gas in the solved chambers makes thermal exchange with the surrounding salt formation by natural inter-flow, and the transient thermo-conducting temperature field is formed with the surrounding walls of salt caverns. In the other hand, the continuous injection/recovery cycle makes the pressure and temperature of the chambers change. Especially during continuous gas recovery, the well-head pressure and temperature easily enter the dangerous range to generate hydrate since the Joule-Thomson effect of pressure drop. So it is very necessary to determine the injection/recovery thermo-dynamic performance for underground gas storages with salt caverns. According to the theories of thermodynamics, transfer calorific and hydrodynamics, aiming at the characteristics of gas flowing in the borehole and thermo-transferring process in the solved chambers during gas injection/recovery process, and regarding the borehole, solved chambers and surrounding salt formation as one integral system, the coupling mathematical models and solution methods are developed to describe the injection/recovery performance. Also, the corresponding numeral calculating software is developed. The software can predict the pressures and temperatures in the solved chambers and the top/bottom of the bore-hole for underground gas storages with salt caverns during continuous injection/recovery process, and identify the dangerous range to generate hydrate etc. The study is helpful to predict and analyze the construction and features of underground gas storages with salt caverns; guide the operation conditions and provide the theoretical ground for the optimized design of surface injection/recovery system.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2005年第8期103-105,共3页
Natural Gas Industry
基金
中国博士后基金项目(20040350161)的资助~~
