压裂返排液弱凝胶深部调驱技术

Deep Profile Control and Weak Gel Displacement Technology of Fracture Flowback Fluids

针对压裂返排液的特点,以聚丙烯酰胺为主剂,引入糠醛合成糠醛树脂交联剂,加入杀菌剂,在一定条件下形成弱凝胶体系,用于注水井调驱。考察了该压裂返排液弱凝胶体系性能:室内研究确定最佳的弱凝胶体系配方,进行了热稳定性及耐盐稳定性评价。进行了压裂返排液弱凝胶体系岩心封堵性能评价,凝胶体系在30~80℃具有较好的热稳定性,岩心封堵率大于80%,突破压力达到2.7 MPa,压裂返排液弱凝胶体系对储层具有较好的封堵性能。现场应用10井次,应用压裂返排液配置弱凝胶体系3.5万m^3,投入产出比1:1.25,压裂返排液重复利用,取得较好的环保效益及经济效益。

According to the characteristics of the fracturing fluid,adding furfural resin synthesized by cross-linking agent polyacrylamide as the main agent and furfural and with fungicides,weak gel system was formed to deep profile control of water injection well under certain conditions.The performance of the weak gel system of the fracturing fluid was studied.The optimum formulation of weak gel system was studied,and the thermal stability and salt resistance stability were evaluated.The evaluation of the sealing performance of the weak gel system of the fracturing fluid was carried out.The gel system had good thermal stability at 30 to 80 ℃,and the core plugging rate was more than 80%.The breakthrough pressure reached 2.7 MPa.and the weak gel system of fracturing fluid had good sealing performance.The weak gel system was prepared as the amount of 35 000 m^3 and applied in 10 wells The ratio of output to input was 1:1.25 and the fracturing fluid could be recycled,achieving good environmental benefits and economic benefits.