水驱油田含水上升规律和递减规律研究μ

Study on incremental law of water cut and decline law in water drive oilfield

含水上升规律和递减规律是水驱油田的主要规律,但目前对于两者的内在联系及含水上升规律的主要影响因素还未认识清楚。根据相对渗透率曲线和分流量方程,从理论上揭示了水驱油田含水上升率的变化规律及其影响因素,同时研究了在定产液量的条件下含水上升率和递减率的关系。结果表明:含水上升率通常随可采储量采出程度先凹形上升后转凸形上升,上升到峰值后开始下降,先凸形下降后转凹形下降,转折点的含水上升率及对应的可采储量采出程度和含水率由水油流度比、水相指数和油相指数3个参数确定;在定产液量的条件下,含水上升率和递减率的变化规律一致。认清含水上升规律和递减规律,可以更准确地预测水驱油田的开发指标。

Incremental law of water cut and production decline law are the major laws of water drive oilfield.At present,we are not fully aware of the internal relations between them,and there is no clear understanding of the factors that affect incremental law of water cut.According to relative permeability curve and fractional flow equation,change law of water cut increasing rate and its influence factors in water drive oilfield are revealed theoretically.The relationship between water cut increasing rate and decline rate is studied under constant liquid production.The results show that water cut increasing rate is usually rising up concavely with the recovery percent of recoverable reserves then convexly rising to the peak,then convexly declining and concavely decreasing,and water cut increasing rate at these inflection points and the corresponding recovery percent of recoverable reserves,and water cut are determined by parameters of water-oil mobility ratio,water index and oil index,and water cut increasing rate is proportional to decline rate under constant liquid production.We can more accurately predict the development indexes of water drive oil-field based on the laws above.