Physical simulation of flow field and construction process of horizontal salt cavern for natural gas storage

Abstract

Underground salt caverns provide appropriate space for storing natural gas. However, salt caverns have to be constructed in bedded salt formations in China. The traditional construction method of salt cavern encounters serious problems in such formations. Instead, horizontal salt caverns are proposed as a possible alternative for gas storage. Horizontal caverns can be created by “multi-step retreating” (MSR) method. Two laboratory tests were conducted to understand the shape development and flow field of such cavern. In one test, we measured fluid velocity distribution in a simulated salt cavern environment by particle image velocimetry technology. In another test, the construction process of a salt cavern was simulated through MSR method. Results show that the flow field in horizontal cavern can be divided into five regions. The flow characteristics and rock salt dissolution properties in these regions are different. A semi-cylindrical cavern with similar cross section shape along the horizontal direction is obtained through the physical experiment. This study provides important guidance for analyzing the flow field and construction process of the horizontal salt cavern.