液压自封不漏失抽油泵在聚合物驱的应用

The Application of Hydraulic Self-sealing Pump with No Leakage in Polymer Flooding Block

针对常规柱塞泵在大庆油田聚驱采油过程中存在易磨损、漏失量大的问题,研制并应用了液压自封不漏失抽油(HSP)泵。该技术采用液压自封原理,上行程过程中,柱塞上游动阀关闭,泵筒下端的固定阀开启,柱塞腔内高压,柱塞下的泵筒腔内低压,柱塞内外形成压差,推动密封环压在泵筒内壁上,形成零间隙密封,保证不漏失;下行程过程中,柱塞游动阀开启,泵筒下端的固定阀关闭,柱塞内外压力趋于相等,柱塞和泵筒之间产生间隙,使下行阻力趋近于零,减少下行阻力。另外,设计选用耐磨材料作为密封环,提高柱塞耐磨性能,延长泵的使用寿命。该技术解决了含聚、出砂、低产复杂条件高效抽油的难题。现场应用表明,该泵可以最大限度降低偏磨的发生几率,改善泵的运行状况。聚驱阶段应用HSP泵,平均系统效率提高2%以上,平均泵效提高8%以上,检泵井平均检泵周期为503d,运行井最长运行周期超过700d,远高于常规泵井的检泵周期。

Aiming at the problems of easy wearing and large leakage of the common plunger pump during polymer flooding,hydraulic self-sealing pump with no leakage（HSP） has been developed and applied in Daqing oilfield.The principles of the technique is self-sealing at hydraulic pressure.In the process of upstroke,the up traveling valve of the plunger closes,but in the meantime the static valve of the pump opens.Thus it has high pressure inside the plunger,but adversely,it has low pressure inside the pump barrel.So the sealing ring of the plunger is pushed by the pressure differential tightly on the internal wall of the barrel,and zero clearance sealing is realized with no leakage.In the process of down stroke,the up traveling valve of the plunger opens,but in the meantime the static valve of the pump closes,so no pressure differential occurs.There is clearance between the plunger and the barrel,which makes the running resistance to be as less as zero and the overall running resistance decreased.Additionally,anti-abrasive material is applied in the sealing rings,and the wearability of plunger is promoted and the pump life is prolonged.And the problems of polymer bearing,sand production,low productivity of well,complex pump running conditions are resolved as well.The onsite application indicates that eccentric wear occurs lesser at large scale and operating situation of the pump is improved.After HSP pump is applied in polymer flooding,the pump efficiency and pump system efficiency are promoted more than 8% and 2% respectively.Average pump inspection cycle of the well is 503d.Maximum run duration is more than 700d,which is much longer than that of common pump well.