Geometry inversion model for sediment zones of salt cavern used for natural gas storage

Abstract

The utilization of sediment pore space for gas storage is an effective measure to solve the problem of high-impurity bedded salt rock gas storage construction in China. However, the existing detection methods cannot obtain the cavern geometry at the sediment zones within the gas storage, which brings significant uncertainties to the debrining process. In response to this issue, this paper innovatively establishes a model that considers sediment porous media flow for the inversion of cavern geometry and applies the model to analyze the factors that influence the debrining parameters. The results show that the average error obtained from the model inversion calculations is less than 2 % for the cavern diameter, while for predicting the depth of the gas-brine interface, the average error is less than 2.5 %. Moreover, the research indicates that the cavern geometry, the sediment surface position, the debrining rate, and the permeability of the sediments influence the debrining process. The specific change patterns of debrining parameters are mainly influenced by the sediment surface position and the cavern geometry. This paper can provide theoretical support for the utilization of sediment pores for debrining and gas storage.