高含水油田优势流场识别调整研究

Study on Identification and Adjustment of Dominant Flow Field in High Water-Bearing Oil Field

针对砂岩油田高含水后期油层优势流场严重发育,制约水驱采收率进一步提高的难题,应用层次分析与模糊综合评价结合数值模拟方法,确定了油藏平面各优势流场影响因素的权重大小,得到了小层平面流场的模糊综合评价值及不同强度流场区域的油水井对分布状况。对优势流场区水井减注、调层及补孔治理,对弱流场区欠注水井增注调整。应用该方法对V油田某区块小层平面的优势流场判断,其中优势流场区井对7个,强优势流场区井对5个。对存在于优势流场区中的12个井组进行水井减注、封堵调层、补孔、油井合理配产、封堵等工艺。对部分欠注水井增注调整,全区综合含水率下降了1.1%,累积增产原油2.2×10^4 t,取得了较好的高含水期剩余油挖潜效果。

In the late stage of high water cut in sandstone oilfield,the dominant flow field is seriously developed,which restricts the further improvement of water drive recovery.In this paper,AHP and fuzzy comprehensive evaluation combined with numerical simulation method are used to determine the weight of the influencing factors of the dominant flow field in the reservoir plane.The fuzzy comprehensive evaluation index(FCI)of the advantaged flow channel is obtained by fuzzy calculation of the constructed matrix,and the production and injection well with the advantaged flow channel is determined by the FCI value.Basing on the study of the advantaged flow channel,water injection volume of ineffective circulating injection wells is reduced and injection layer is adjusted to enlarge the water-flooding area and to achieve the aim of further tapping the remaining oil with the idea of fine injection and production adjustment.This method is adopted to determine the advantaged flow channel of a block of V Oilfield.Among them,seven production and injection well pairs exist in advantaged flow channel area,five production and injection well pairs exist in much more advantaged flow channel areas.The comprehensive water cut in V Oilfield is reduced by 1.1%,the cumulative crude oil yield rises up to 2.2×10^4 t,achieving a good effect for taping reminding oil and controlling water cut by the deep profile and periodic water injection in injection well with the production well shutting off adjustment for 12 well groups which is in advantaged flow channel areas.