地下储气库地层压力影响因素灰色关联分析

Grey relational analysis to influencing factors of formation pressure of underground gas storage

地下储气库注气过程中地层压力不断升高,过高的地层压力可能导致断层封闭性遭到破坏而发生天然气泄漏事故。需要分析各影响因素对地层压力的影响程度,得到影响地层压力的主要因素,为储气库安全运行提供参考。利用灰色系统理论的关联度分析法分析各影响因素与地层压力的关联度,通过关联度反映各影响因素对地层压力的影响程度。分析表明影响程度由大到小依次为注气速度、储层厚度、渗透率、孔隙度、井距、注采井到断层距离、运行井数。由关联度分析结果可知为保证储气库安全运行应合理选择注气速度和运行井数。

In the process of gas injection in underground gas storage, the formation pressure is rising continuously, and the high formation pressure may lead to the damage of fault sealing and the occurrence of natural gas leakage. It is necessary to analyze the influence degree of each influence factor on formation pressure, and get the main factors that affect formation pressure, so as to provide reference for safe operation of gas storage. The correlation degree of each influence factor and formation pressure is analyzed by the method of correlation analysis of grey system theory, and the influence degree of each influence factor on formation pressure is expressed by correlation degree. The analysis shows that the influence degree from large to small is gas injection velocity, reservoir thickness, permeability, porosity, well spacing, injection production well to fault distance, and operation well number. According to the correlation analysis, the gas injection rate and the number of operation wells should be selected reasonably in order to ensure the safe operation of the gas storage.