高温环境下气藏型储气库泥岩盖层密封性评价

为探究高温作用对泥岩盖层密封性的影响,从理论上剖析储气库盖层产生热应力的3种形式,在室内试验的基础上,分析泥岩在高温环境下力学损伤程度和盖层物性封闭评价指标随温度变化特征.结果表明:高温环境下泥岩整体结构性能降低,400℃左右是泥岩在周期热应力作用下损伤的阈值温度;高温作用会显著改变泥岩盖层物性封闭特征,400℃左右是...

Evaluation on sealing performance of mudstone caprocks of gas reservoir-type gas storage in high temperature environment

In order to explore influence of high temperature on sealing performance of mudstone caprocks,three forms of thermal stress generated by gas storage caprocks were theoretically analyzed.Then,based on laboratory tests,mechanical damage degree of mudstone and changes of caprock sealing assessment indicators in high temperature environment were analyzed.The results show that the overall structural performance of mudstone is reduced under high temperature,with 400℃being generally the threshold temperature for its damage under action of periodic thermal stress.High temperature will significantly change the physical sealing characteristics of mudstone caprocks,and when it is around 400℃,which is the threshold,sealing ability will be lost.According to empirical research and analysis results of caprocks in a gas reservoir type gas storage,temperature range of target caprock has not exceeded the threshold.It is believed that the mudstone caprock has good sealing performance,and evaluation result can reflect the true situation of mudstone capping.