气藏改建储气库下限压力设计新方法

A new design method of minimum storage pressure of underground gas storage rebuilt from gas reservoir

储气库下限压力与工作气量、注采井数、补充垫气量等参数密切相关,将直接影响项目的经济性。现有方法以地质气藏认识为基础,采用定性半定量方法设计,其结果难以定量精确确定。在充分考虑储气库地质条件、水侵规律、气井产能、外输条件以及实现库容最大化的基础上,通过分析不同下限压力的有效库容形成与项目建设投资的内在关系,以项目经济性最优为目标函数,提出地质—经济一体化预测模型,建立气藏改建储气库下限压力设计新方法。在国内某储气库方案设计中的应用实践表明,该方法统筹了技术经济性,设计基础更加牢靠,结果更加科学。

The minimum storage pressure of underground gas storage,which is closely related to parameters such as working gas volume,injection-withdrawal well numbers,additional cushion gas volume etc.,will directly affect project economics.The existing methods are based on the understanding of geological conditions and are designed using qualitative and semi-quantitative methods.The results are difficult to determine quantitatively and accurately.By taking full consideration of the geological conditions of gas storage,water invasion,gas well productivity,gas transmission pressure,and the realization of maximum storage capacity,this paper analyzes the inherent relationship between effective storage capacity at different minimum pressures and project construction investment.With the project economic optimality as the objective function,a geological-economic integrated forecasting model is proposed,thus a new method for designing the minimum pressure of gas reservoir is established.Application practice in a domestic underground gas storage shows that this method takes overall technical and economic advantages into consideration and has a more solid design basis and more scientific results.It is of great importance for the minimum storage pressure design and optimization of subsequent underground gas storages rebuilt from gas reservoirs.