渤海小气顶油藏油气界面下移规律及应用

为了有效防止油气区的原油、天然气相互窜流,以渤海B油田小气顶油藏(气顶指数小于0.5)为例,基于数值模拟和油藏工程方法研究了小气顶油藏的油气界面下移规律。在此基础上,绘制出不同工作制度的油气界面下移规律图版,综合考虑油田的生产压差,筛选合理的工作制度。研究结果表明:采油速度、注采比等是影响油气界面下移的主控因素;小气顶油藏应在投产初期开始注水补充地层能量,并根据图版及时调整注采比、采油速度,以防止油井气侵。研究结果有效地指导了小气顶油藏的开发,改善了油田开发指标,对其他小气顶油藏的开发具有一定的意义。

The law of oil-gas interface moving down in small gas cap reservoir in Bohai Sea and its application

In order to prevent oil and natural gas from flowing into each other effectively,taking the gas cap reservoir(gas cap index is less than 0.5)of Bohai B oilfield as an example,the law of oil-gas interface moving down in small gas cap reservoir is summarized based on numerical simulation and reservoir engineering method.On this basis,the theory chart of oil-gas interface moving down rule under different working systems is drawn,and the reasonable working system is selected by considering the production pressure difference comprehensively.The results show that factors such as oil production rate and injection-production ratio are the main controlling factors that affect the oil-gas interface moving down.In small gas cap reservoir,water injection should be started at the beginning of production to replenish formation energy,and injection-production ratio and production rate should be adjusted in time according to the chart to prevent gas channeling.The research results effectively guide the development of small gas cap reservoirs,make the development index better,and have certain significance for the development of other small and medium gas cap reservoirs.