塔河油田断溶体油藏气驱井组注气量计算方法

塔河油田断溶体油藏注氮气提高采收率开发效果显著,但尚没有针对塔河油田断溶体油藏合理注气量的确定方法.根据生产数据分析法,通过流量重整压力和物质平衡时间曲线的拟合,得到了塔河油田断溶体油藏气驱井组总动用储量;考虑塔河油田断溶体油藏井网特征,得到了线状井网气驱平面波及系数计算方法;根据地震能量体属性缝洞体三维分布,得到了考...

A Method to Calculate Gas Injection Volume in Fault-Karst Carbonate Reservoirs of Tahe Oilfield

Good development effects of nitrogen injection EOR technology have been achieved in the fault karst reservoirs of Tahe oilfield,but there is no method to determine the reasonable gas injection volume especially for the reservoirs in the oilfield.Based on the production data analysis method and the matching of flow reforming pressure and material balance time curve,the total producing reserves of gas drive well groups in fault karst reservoirs of Tahe oilfield is obtained.Considering the well pattern characteristics in the fault karst reservoirs of Tahe oilfield,a method to calculate the plane sweep efficiency of gas drive in the linear well pattern is obtained.Based on the 3D fracture cave body distribution in the fault karst reservoirs,a method for calculating the vertical producing degree of gas drive in the fault karst res ervoirs is developed.Based on numerical simulation of the typical fault karst reservoir,the reasonable gas injection volume is determined to be 0.75 PV of the remaining reserves.Based on the obtained total producing reserves,cumulative oil production before gas injection,plane sweep efficiency,vertical producing degree and reasonable gas injection volume of the gas drive well groups in the fault karst reservoirs,a method to calculate the reasonable gas injection volume is established for the fault karst reservoirs of Tahe oilfield.The reasonable gas in jection volume obtained from the calculation method has been applied in the gas drive of the fault karst carbonate reservoirs in Tahe oil field and the oil production of the response producers can reach 2.5 times the production before gas injection.