Research on the Influencing Factors of the Void Volume of Insoluble Sediment in Salt Cavern Gas Storage

Abstract

Utilizing voids of insoluble sediment (IS) to store gas is an effective way to improve the efficiency of salt cavern gas storage (SCGS) in China. In this study, a suitable method for predicting the void volume of insoluble sediments (VVISs) is established. This study explores three key factors affecting the VVISs through laboratory experiments. Firstly, in order to make the experimental results more in line with production realities, an analysis of the characteristics of IS in X SCGS was conducted to provide a basis for setting parameters for subsequent experiments. Secondly, experimental setups and methods for measuring the VVISs were designed. Finally, the experimental results were used to predict the VVISs in on-site cavity wells. The results indicate that the higher the proportion of quartz, illite, and large-grain particles in IS, the larger the VVISs. Under different parameters, the VVISs can account for approximately 10–40% of the IS accumulation volume. Different particle sizes can cause a variation of approximately 5–30% in the VVISs, while different mineral compositions can result in a difference of 6–23% in the VVISs. With increasing compaction pressure, the VVISs can decrease by around 5–80%. The prediction of the VVISs in on-site cavity wells shows a high degree of fit with empirical algorithms. This study can provide a reference basis for the utilization of the void space of IS in SCGS.