气驱协同型储气库建库不同阶段产能预测

气驱协同型储气库建库不同阶段生产气油比差异大,多个阶段存在油气水三相复杂流动,目前计算储气库的多相产能一般是将油折算为气体当量,误差较大。在三相渗流微分方程基础上,引入油气水三相拟压力,建立了考虑气体高速非达西渗流影响的三相流产能计算方法,得到气驱阶段、协同建库阶段和储气库阶段的油相产能方程、气相产能方程及流入动态曲线,并与生产数据进行对比。结果表明：三相流产能计算方法计算的产量在储气库建库3个阶段的误差小于6.16%;当生产压差较小时,传统折算方法与三相流产能计算方法的计算结果接近;但是随着储气库建库阶段的发展,误差越来越大。三相流产能计算方法计算简便,精度较高,易于理解,可对协同型储气库建库不同阶段产能预测提供一定借鉴。

Productivity Prediction in Different Stages of Collaborative Construction of Underground Gas Storage and Gas Flooding

In different stages of the collaborative construction of underground gas storage (UGS) and gas flooding, the produced gas-oil ratio (GOR) varies greatly, and the complex oil, gas and water three-phase flow occurs in several stages. Currently, the multiphase productivity of UGS is generally calculated by converting oil production to gas equivalent, which produces relatively large errors. On the basis of the three-phase flow differential equation, the three-phase pseudo pressures of oil, gas and water were introduced, and a three-phase flow productivity calculation method considering the influence of high-speed non-Darcy flow of gas was established. With the help of this method, the oil phase productivity equation, gas phase productivity equation, and inflow performance relationship (IPR) curve in gas flooding stage, collaborative construction stage, and UGS stage were obtained and then compared with production data. The results show that the productivity calculated by the three-phase flow productivity calculation method is less than 6.16% in each of the three stages. When the production pressure difference is small, the calculation results from the traditional conversion method and the three-phase flow productivity calculation method are close. However, with the progress of construction, the error of the traditional conversion method becomes larger. The three-phase flow productivity calculation method is simple, accurate, and operable. It is of guiding significance for predicting the productivities in different stages of collaborative construction of UGS and gas flooding.