DY-Ⅱ调剖剂的研制及在大庆杏北区块的应用

Development of Profile Control Agent DY-Ⅱ and Its Application in Xingbei Block of Daqing Oilfield

大庆油田已进入特高含水开发阶段,层间、平面矛盾突出,浅调剖可作为分层注水技术的重要补充,但目前常用的调剖剂体系存在成本高、毒性大、现场调控难度大等问题,为此,研制了DY-Ⅱ浅调剖剂。该调剖剂聚合物使用浓度为2000~3000mg/L,聚交比为30∶1~40∶1。用TA公司2000EX流变仪,对该体系黏度、储能模量进行评价,发现该体系成胶黏度在17000mPa·s以上,储能模量在10Pa以上,属强凝胶体系。将该体系成胶后的样品在45℃下放置180d,黏度损失率在10%以内,长期热稳定性良好。5次岩心剪切后,该体系黏度和储能模量均没有太大变化,对岩心进行水驱,其突破压力达9.2MPa,后续水驱10PV后压力仍能稳定在7.5MPa,残余阻力系数可达500,具有较好的耐剪切和耐冲刷性能。与常规酚醛浅调剖剂体系相比,DY-Ⅱ浅调剖剂体系综合成本可降低30%。DY-Ⅱ浅调剖剂在大庆杏北油田现场应用68口井,平均单井启动压力升高1.70MPa,平均单井视吸水指数下降10.37m3/（d·MPa）。

Daqing oilfield has entered extra-high water cut period,and interlayer and plane contradiction is obvious.Shallow profile control may be the additional technology of separated layer water flooding.But common used profile control system has the problems of high cost,toxic excess and great difficulty on field control.So shallow profile control agent DY-Ⅱ is developed.The polymer concentration of the profile control agent DYⅡ is 2000-3000mg/L,and the ratio of polymer concentration and crosslinker concentration is 30 ∶1-40 ∶1.Rheometer 2000EX made by TA company is applied to assess of the system performance indexes,such as viscosity and storage modulus.The gelling viscosity of the system is more than 17000mPa·s,and the elastictiy（storage modulus） is more than 10Pa,which proves it a strong gel system.After the gelled sample of the system placed 180 days at 45℃,its viscosity losses is within 10%,which shows long-term thermal stability well.After 5 times of displacement and shearing process,the viscosity and elasticity of the system was not changed much,and the breakthrough pressure was up to 9.2MPa after water flooding on cores.After the follow-up 10PV water flooding,the pressure can be stable at 7.5MPa,and the residual resistance coefficient was 500.It means the system has excellent resistance to shear and abrasion.Compared with normal shallow profile control agent of phenolics,overall cost of the DY-Ⅱmay drop by 30%.After the application of the system in 68 wells of Xingbei oilfield in Daqing,the average start pressure of the single well increased by 1.70MPa,and the average apparent water injectivity index of the single well drop by 10.37m3/（d·MPa）.