根据水驱开发油田合理油水井数比和注采比的准确定义,由极值原理,详细推导了油水井地层压力相同和不同时油田合理油水井教比的计算公式.该公式不仅适用于注采平衡条件下油田合理油水井数比的计算,亦适合干非注采平衡条件及低渗透油田合理油水井数比计算.以往采用的算法均存在缺陷:"吸水、产液指数法"建立在注采平衡基础之上,"吸水、产液指数及注采比法"忽略了原油性质的影响,"吸水,产液指数比及注采压差法"不具有理论和实际意义.将提出的方法在大庆外围朝阳沟油田进行了实际应用和验证,结果表明,朝阳沟油田目前阶段的合理油水井数比为3.28,此时产液量可达到最高,为5155.8 t/d,图1表1参16%According to the accurate definition of the reasonable production-injection well ratio and injection-production ratio for waterflooding oilfields, the formula of the reasonable production-injection well ratio under the same or different formation pressures between oil well and injection well is derived based on the principle of extreme value. The formula can be used in the balanced or unbalanced injection-production system such as reservoirs in high water cut stage or lowpermeability reservoirs. All the previous formulas have flaws: the method of “injectivity, productivity indexes” is based on balanced injection-production system; the method of “injectivity, productivity indexes and injection-production ratio”ignores the influences of crude oil properties; and there is no theoretical and practical significance in the method of “injectivity index to liquid productivity index ratio and injection-production pressure difference”. The method presented in this paper is applied and verified in the Chaoyanggou Oilfield of Daqing. The daily fluid rate of the oilfield can reach the maximum value of 5 155.8 t at the reasonable production-injection well ratio of 3.28.
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