蒸汽驱间歇注汽数值模拟研究

STUDY ON NUMERICAL MODELLING OF INTERMITTENT STEAM INJECTION OF STEAM FLOODING

针对中—厚互层状稠油油藏的蒸汽驱井组，用数值模拟研究了蒸汽驱过程中间歇注汽对开采效果的影响，优选出最佳停注时机为蒸汽突破到生产井时，停注间隔不宜超过60d，在此条件下间歇注汽的效果要好于连续汽驱，采收率提高0．36％。并探讨了提高采收率的机理，认为间歇注汽提高了油层纵向上的波及效率和驱油效率。现场实际资料基本与数值模拟结果一致。

For steam flooding well group of medium-thick interbedded reservoir bearing heavy oil, the effect of intermittent steam injection on production result during steamflooding period is studied by means of numerical modelling. After optimization, it is thoughtthat to stop steam injection by the time of steam breakthrough to producing well is best. Thetime interval of stopping injection should not exceed 60 days. By doing so, the result of intermittent steam injection is better than continuous steam flooding, and the recovery efficiency raises 0.36%. This paper also discusses the mechanism of enhancing recovery efficiency,and supposes that intermlttent steam injection can vertically improve sweep efficiency and oildisplacement efficiency of reservoir. Practical data is essentially consistent with the result ofnumerical modelling.