The Dynamic Simulation of Underground Gas Storage by Computer

Nowadays, the world demand for natural gas as a source of energy has been increased. Since gas production is constant during the year and its consumption is almost seasonal, underground gas storage (USG) is a common activity in countries with major transport and distribution gas pipeline infrastructures, which allows to efficiently resolve demand seasonality problem. In this paper, UGS was studied on a gas driving depleted reservoir through numerical simulation. A mass conservation equation based 3-D single-phase gas flow and a PVT equation were improved to construct the USG simulator equipped with the functions for calculating physical phenomena: 1) cyclic gas injection and continuous gas injection, 2) the average pressure change of the formation, 3) the gas storing capacity of the UGS, 4) the distribution of saturation after the gas injection. In addition, the Forchheimer equation was introduced to modify the Darcy equation, which included the influence of inertial force and made the simulation more accurate and available.