摘要:
常规油藏井网产能公式都是基于单相渗流或油水流度比为1、水驱油为活塞式驱的假设条件上建立的，这些假设条件在低渗透油藏水驱油实际过程中并不成立。本文根据联合面积布井注采单元的水驱油特征，将流动区域划分为三个区，运用等值渗流阻力理论，建立了考虑低渗透油藏油水两相渗流特征的注采井网产能公式的通式，并与常规注采井网产能公式进行对比，结果表明，当无因次采液指数随含水饱和度变化较小，趋近于1时，两者计算结果一致；而当无因次采液指数随含水饱和度变化较大，远小于1时，常规产能公式计算结果明显偏大，而且无因次采液指数越低，常规产能公式计算结果误差越大；本文建立的产能公式计算结果更加符合莫北低渗油藏注采井网油井的实际产能。
Productivity formulas of conventional reservoir’s well-net are based on single-phase flow or oil-water mobility ratio is 1 under the condition of piston water flooding. But this is not consistent with the actual process in low permeability reservoirs. According to the water driving characteristics of areal well pattern injection-production unit, the flow region is divided into three zones in this paper. Productivity formula is derived based on the equivalent flowing resistance method considering the low permeability reservoir charac-teristics of oil-water two-phase flow capacity of the flooding pattern. Compare the productivity formula with the conventional productivity formula. The results show that when the dimensionless liquid production index change little with water saturation, close to 1, the two calculated results are consistent; when the dimension-less liquid production index change great with water saturation, much less than 1, the results of conventional capacity formula are obvious big, and the error calculation is increasing with the decreases of the dimension-less liquid production index; The production formula established is more in line with Mobei low permeability reservoirs.