水淹衰竭型地下储气库的达容规律及影响因素

Rules and influencing factors on the capacity establishment of underground gas storage based on flooded depleted gas reservoirs

水淹衰竭型地下储气库库容动态变化过程中的驱水达容规律具有复杂性和普遍性,是研究地下储气库达到设计库容时间及最终能达到库容量的重要依据。为此,以大港地下储气库群5个投产运行多年的水淹衰竭型地下储气库为例,通过含水岩心气驱扩容室内实验,揭示了地下储气库的达容规律:①地下储气库库容量呈现逐渐增加的趋势,并最终趋于最大库容量;②地下储气库投产初期库容增速快,后期增速变缓;③地下储气库地下垫气量与工作气量呈正增长关系,但增长不同步。进而总结出了影响地下储气库达容的主要因素:地下储气库的构造特征、储层物性、注采能力、水体分布以及扩容方式。

The rules on water displacement and capacity establishment during the dynamic changing process of underground gas storage(UGS) based on flooded depleted gas reservoirs are of complexity and generality and are also an important basis in determining the final storage capacity and the time needed to achieve the designed storage capacity.Based on the existing 5 UGSs built on flooded depleted gas reservoirs operated by the Dagang Oilfield Company,this paper hereby reveals the capacity establishment rules by means of indoor experiments on gas-driving capacity expansion of water-bearing core.First,the storage capacity of UGS shows a gradually growing trend and will eventually reach the maximum storage capacity.Second,the capacity grows rapidly at the early stage and slows down at the late stage.Third,there exists a positive relationship between the UGS cushion gas volume and the working gas volume,but the growth is not synchronized.The paper also concludes that the main factors which impact the UGS capacity establishment process include the structural characteristics,reservoir petrophysical properties,injection and production capacity,water distribution,and capacity expansion means.