Method for determining the reasonable wellhead pressure of gas storage production wells: A case study of the Liuzhuang gas storage reservoir, China

For the Liuzhuang gas storage reservoir with edge and bottom water, excessively high bottomhole pressure of production wells can cause edge and bottom water breakthrough, which reduces the effective storage capacity; whereas excessively low bottomhole pressure makes it difficult to achieve the gas production targets. Therefore, determining the reasonable wellhead pressure of production wells is of great significance for the efficient operation of gas storage reservoir. In this study, a comparison of seven critical liquid-carrying flow rate models, including the droplet inversion model and the liquid film inversion model, was made. The Belfroid critical liquid-carrying model was identified as the most accurate for evaluating liquid loading in the Liuzhuang gas storage reservoir. On this basis and in combination with nodal analysis, the relationship curves between gas production rate and critical liquid-carrying flow rate under different reservoir permeabilities and skin factors were obtained, leading to the development of wellhead pressure charts indicating the risk of liquid loading in gas wells of the Liuzhuang gas storage reservoir. This study provides technical support for field operations in diagnosing liquid loading in production wells.