凝析气顶油藏油气产量的计算方法探讨

大港油田存在一些凝析气顶油藏(带油环的凝析气藏)，在降压开采过程中，由于气顶区和油区压降不平衡，会导致气窜或油窜现象，因此生产井采出的油、气中均可能出现原油、凝析油、气顶气和溶解气混合物。根据凝析气的特殊热力学性质，结合油气藏动态分析方法，导出了两种凝析气顶油藏产量的计算方法，实例证明两种方法都能准确计算出4种烃类的产量，对凝析气顶油藏的开发动态分析、剩余油气分布研究、开发调整和油气最终采收率及可采储量的确定具有指导作用。表3参2（余元洲摘）

An approach to the calculation of hydrocarbon output of condensate gas cap reservoirs

There are some large quantitative condensate gas cap reservoirs (gas condensate reservoirs with oil ring) in Dagang oil field. In the process of depletion recovery, gas breakthrough and oil breakthrough will exist, as a result of the unbalanced pressure fall between gas cap and oil areas. Accordingly, the hydrocarbon from producing well is likely to involve the mixture of crude oil, oil condensate and gas cap gas as well as solution gas. The authors put forward the two calculable methods of hydrocarbon output for condensate gas cap reservoirs, through the special thermodynamic property of condensate gas, combined with the method of reservoir performance analysis. The concrete instances show that 4 kinds of hydrocarbon output can be calculated accurately with the two methods. This will play a very important role for guiding the analysis of production performance, the research of remaining oil gas distribution, the development adjustment, determination of ultimate oil gas recovery factors as well as recoverable reserves of the condensate gas reservoirs.