高含水、高采出程度阶段油田剩余油定量表征及其综合评价

Residual Oil Quantitative Characterization and Comprehensive Evaluation at High Water-cut and High Recovery Stage

河南X油田目前综合含水94.2%,采出程度38.6%,属于高含水、高采出程度(简称"双高")开发的油田。如何进一步发展"双高"开发单元提高采收率的方法,已成为目前的研究重点。建立X油田数值模拟模型,对其进行历史拟合。满足历史拟合要求后,针对"双高"阶段剩余油分布特点给出不同水淹级别划分标准。着重分析不同水淹级别下剩余油饱和度、剩余地质储量、平面和层间剩余油分布特征。建立了剩余油挖潜综合评价方法,将评价指标划分为4类,按照同一油组不同水淹级别对剩余油潜力区进行精细刻画,进而找出剩余油主要集中在Ⅲ、Ⅳ类潜力区。并针对不同潜力区提出不同挖潜策略,为X油田下一步剩余油精细挖潜提供依据,该方法对国内类似"双高"油田有借鉴意义。

Current water cut was 94.2% and recovery percent was 38.6% in X Oilfield of Henan Area,which was a 'double high ratio' oilfield,that was high water-cut and high recovery percent.How to further develop the high water-cut and high recovery units and enhance oil recovery was the key point of current researches.A numerical simulation model was established for X Oilfield for history matching.According to the distribution of remaining oil at the 'double high ratio stage' after history matching,the criterion of different flooding levels was given according to the features of residual oil.The remaining oil saturation,its geological reserves and its distribution features were emphatically analyzed.A synthesis evaluation method was established for tapping the potential of remaining oil,the evaluation indexes were divided into four categories.According to the different flooding areas,it gives a method to precisely determine the potential of remaining oil.It is determined that remaining oil is mainly concentrated in Ⅲ,Ⅳ potential areas.And according the different potential areas,different development strategies are put forward,it provides reference for tapping the potential of remaining oil in X Oilfield.