水驱油藏特高含水阶段提高采收率可行性研究及技术对策  

Feasibility and technologies for improving recovery at extra-high water cut development stage in waterflooding reservoirs

作　　者：吕晓光 李伟[2] Lü Xiaoguang;LI Wei(C&C Reservoirs,Beijing City,100102,China;Development Department,Daqing Oilfield Co.,Ltd.,CNPC,Daqing City,Heilongjiang Province,163712,China)

机构地区：[1]C&CReservoirs,北京100102 [2]中国石油大庆油田有限责任公司开发事业部,黑龙江大庆163712

出　　处：《油气地质与采收率》2022年第6期130-137,共8页Petroleum Geology and Recovery Efficiency

摘　　要：常规砂岩油田注水开发最终采收率多为35%~50%。基于大量室内实验、应用实例和中外油田案例类比,分析了特高含水开发阶段进一步提高水驱油藏驱油效率的可行性。讨论了水驱油藏在周期注水、关停老井侧钻、多油层逐层上返或沿断层面钻加密井等扩大注水波及体积基础上,长期高孔隙体积倍数注水、低矿化度水驱等经济可行的提高驱油效率思路和方法。室内研究和矿场实践结果表明,长期注水开发砂岩油藏润湿性由偏亲油性向偏亲水性转化,残余油饱和度降低,有利于提高驱油效率。依据成熟开发油田大量类比实例,在油层和流体性质较为有利的条件下,强天然水驱油藏依靠天然能量开采,或弱天然能量油藏通过注水开发最终采收率可达70%。采用自流水注水、低矿化度水驱、同井注采工艺等技术已证实是经济可行的。特高含水开发阶段老油田已有的大量开发井和配套设施为进一步提高采收率提供了基础。应用经济可行的长期高孔隙体积倍数注水思路有望将水驱开发油田采收率进一步提高至50%~70%。The ultimate recovery of the conventional waterflooding sandstone reservoir ranges from 35%to 50%.This paper illustrates the feasibility of further improving the displacement efficiency of waterflooding reservoirs at the extra-high water cut development stage based on previous laboratory experiments,field applications,and global oilfield development cases.The economically feasible ideas and methods including long-term and large pore volume(PV)waterflooding and low salini⁃ty waterflooding etc.for improving the displacement efficiency are discussed in waterflooding reservoirs after improving sweep efficiency measures,such as the cyclic waterflooding,shut-in old well sidetracking,upward and layered waterflood⁃ing in multiple layers,or new infill wells along fault planes.Laboratory experiments and field applications reveal that the wettability of sandstone reservoirs changes from the oil-wet to the water-wet,and the saturation of residual oil reduces after long-term waterflooding,which can improve the displacement efficiency.Mature oilfield development cases indicate that with favorable reservoir and fluid properties,the ultimate recovery can reach 70%when reservoirs with strong natural water⁃flooding are developed by natural energy,or that with weak natural energy are developed by waterflooding.It has been prov⁃en that technologies such as dump flooding,low salinity waterflooding,and injecting and producing through one well are ec⁃onomically feasible.A large number of developed wells and existing facilities in mature field provide a basis for improving the recovery at the extra-high water cut development stage.The application of long-term and large PV waterflooding that is economically feasible is expected to increase the ultimate recovery to 50%-70%.

关 键 词：水驱开发 特高含水阶段 驱油效率 提高采收率 自流水注水 同井注采 低矿化度水驱 

分 类 号：TE341[石油与天然气工程—油气田开发工程]