Study on the Stability of Horizontal Gas Storage with Different Salt Cavern Shapes

ABSTRACT: The successful application of horizontal salt cavities is crucial for building gas storage in thin salt layers, but the technology is nascent. This study focuses on the stability of horizontal salt cavity structure. By establishing numerical models based on Russia's experiment, it analyzes the influence of cavity length, cross-sectional morphology and maximum diameter on stability. Results show that: 1) A longer horizontal cavity length leads to greater cavity roof deformation, a higher volume shrinkage rate, and weaker cavern stability; 2) Circular cross-sections result in the least cavity roof deformation and volume shrinkage rate; conical ones maximize the plastic zone and volume shrinkage rate, while arched ones minimize the plastic zone volume; 3) An increase in diameter raises cavity roof deformation, plastic zone volume, and volume shrinkage rate; 4) Diameter change affects stability more significantly than length and cross-sectional structure. It is recommended to set the horizontal salt cavern length at 425 m, choose a circular cross-section with a maximum diameter of 30 m. Given that actual cross-sections are mostly arched, the maximum cross-sectional diameter should be reasonably controlled. This study can provide guidance for designing salt cavern morphology in horizontal gas storage construction within thin salt layers.