辽河特高孔渗“双特高期”油藏聚合物+表面活性剂复合驱开发效果分析评价

Analysis and Evaluation of the Polymer-Surfactant Combination Flooding Performance for the Ultra-High Porosity-Permeability Reservoir within “Dual Ultra-High Stage”,Liaohe Oilfield

辽河欢喜岭油田锦16区块处于特高含水、特高采出程度"双特高期"开发阶段,水驱已临近经济极限,2011年开展了25注37采大规模聚合物+表面活性剂复合驱工业化试验。通过数值模拟、物理模拟、密闭取心测试、与驱替效果较好同类油田类比等手段建立开发效果评价方法,系统总结聚合物+表面活性剂复合驱前置段塞、主段塞前期、主段塞低含水期等不同开发阶段含水率、产出能力、注入能力、动用状况、采出流体、含油饱和度、驱油效率等生产参数特征,对现场试验开发规律进行对比分析,对见效规律不明显井通过提高聚合物浓度,分注、有利时机增加采油井点等措施进行全过程跟踪调整,试验区高峰日产油达353t/d,是转驱前的6倍,综合含水最低为81.7%,较转驱前降低15个百分点,阶段累计产油量为59.7×10~4t,复合驱提高采收率19个百分点,最终采收率可达70%,投入产出比为1.00∶2.42。研究成果可为复合驱全程跟踪调整技术提供理论支持,也可为同类型油藏复合驱开发评价和跟踪调整提供借鉴。

The Block Jin16 of Liaohe Huanxiling Oilfield has stepped into the"dual ultra-high stage"with ultrahigh water-cut and recovery factor,and the waterflooding has approximated the economic limit.In 2011,a largescale polymer-surfactant combination flooding industrialization test was carried out for 25 injections and 37 productions.A set of development performance valuation methods is established by reservoir numerical simulation,laboratory physical simulation,sealed coring test,analogy with similar oilfield,etc.A series of production parameters were systematically summarized for the polymer-surfactant combination flooding,including the water-cut,production capacity,injection capacity,producing level,production fluid,oil saturation,oil saturation and displacement efficiency in different development stages,such as pre-slug,major slug and the low water-cut period of major slug.It also provides a comparative analysis of the field test development performance.Increasing polymer concentration,separate injection and favorable timing to infill production well points and other measures were implemented for the less-responding wells.The peak daily oil production rate of the field test block is up to 353t/d,which is 5 times higher than before.The minimum comprehensive water-cut is 81.7%,which is 15 percentages lower than before.The periodic cumulative oil production is 59.7×10^4t.The oil recovery factor has been enhanced by 19 percentages,the ultimate oil recovery factor can reach 70%,and the input-output ratio is 1.00 ∶2.42.This research could provide certain technical basis for the comprehensive tracking and adjustment of combination flooding,and could also supply certain reference for the development and adjustment of similar reservoirs.