一种水驱油藏产油量递减率评价新方法

A New Method for Evaluating Oil Production Decline Rate in Water Drive Reservoirs

为客观、准确地评价水驱油藏递减率是否合理,科学制定油田未来调整挖潜、减缓递减的措施方向,从递减率定义出发,推导建立了水驱油藏产油量递减率与综合含水率、采油速度、含水上升率、产液量变化率4个影响因素之间的变化关系式,实现递减率影响因素的量化分析。引入"单位采油速度递减率"新评价指标,以渤海油田为例,统计不同类型油藏、不同含水阶段的分布规律,并以此为基础制定评价标准,形成了一种水驱油藏产油量递减率评价新方法。渤海油田大量实例应用结果表明,由于该新方法消除了"采油速度""综合含水率""油藏类型"对递减率指标的客观影响,其评价结果更加准确、可靠,具有较强的推广、应用价值。其他油田/油区只需根据本文方法、思路制定其各自评价标准即可。

In order to objectively and accurately evaluate the rationality of decline rate in water drive reservoirs, and to scientifically formulate measures for adjusting, tapping and slowing down the decline of oil fields in the future, based on the definition of decline rate, the relationship between the decline rate of oil production and the four influencing factors of comprehensive water cut, oil recovery rate, water cut rise rate and liquid production rate was deduced and established, and the quantitative analysis of the influencing factors of decline rate was realized. Taking Bohai oilfield as an example, this paper introduces a new evaluation index named“unit oil production rate decline rate”. The distribution law of different reservoir types and different water-cut stages was statistically analyzed, based on which the evaluation criteria are formulated. And a new method for evaluating oil production decline rate of water drive reservoirs was formed. The application results of a large number of examples in Bohai oilfield show that the new method eliminates the objective influence of“oil recovery rate”,“comprehensive water cut”,“reservoir type”on the decline rate index, so the evaluation result is more accurate and reliable, which has a strong popularization and application value. Using the methods and the ideas in this paper, the respective evaluation criteria of any other oilfields could be formulated.