一体化多功能抗盐稠化剂的研制与应用

为满足高矿化度水配液区块压裂作业对液体速溶性、耐盐性、降阻、耐温耐剪切和助排一体化的需求，以丙烯酰胺和丙烯酸钠为聚合物主体结构，添加抗盐单体，通过反相乳液聚合制备出一体化多功能抗盐稠化剂。通过将该稠化剂配制成压裂液并开展室内性能评价实验。结果表明，该稠化剂在50 000～60 000 mg/L矿化度水中30 s黏度释放率达到85%以上，配制的压裂液在模拟现场施工排量10 m³/min条件下降阻率大于75%，在90℃、170 s^-1条件下剪切90 min后黏度保持在30 mPa·s以上；在不添加助排剂情况下，压裂液彻底破胶后，表面张力最低24.65 mN/m，界面张力最低1.06 mN/m，残渣含量低于30 mg/L。在新疆油田MH区块某井采用稀释的盐湖水配液进行稠化剂的现场应用，施工过程中切换方便，无需额外添加助排剂，液体性能稳定，满足施工要求。

The Development and Application of an Integrated Multifunctional Salt-Resistant Thickening Agent

An integrated multifunctional salt-resistant thickening agent was synthesized with acrylamide and sodium acrylate as the main raw materials to satisfy the needs of fracturing fluids, which are formulated in blocks where only high salinity salt waters are available, for integrated requirements such as instant capacity, salt-resistance, friction reducing, high temperature and shearing tolerance, as well as cleanup. In the inverse emulsion polymerization of the thickening agent, salt-resistant monomers were used to render the thickening agent salt-resistance. Laboratory test on a fracturing fluid treated with the synthesized thickening agent has shown that the viscosity developing rate of the thickening agent in waters of salinity between 50,000 mg/L and 60,000 mg/L in 30 s was at least 85%. The fracturing fluid formulated with this thickening agent had rate of friction reduction of at least 75% at a simulated flow rate of 10 m3/min generally used in field operations. After shearing at 170 s-1 and 90 ℃ for 90 min, the fracturing fluid still had viscosity of more than 30 mPa?s. Without using cleanup additives, after complete gel breaking, the fracturing fluid had surface tension of at least 24.65 mN/m, interfacial tension of at least 1.06 mN/m, and residue content of less than 30 mg/L. This thickening agent has been tried on a well in block MH in Xinjiang Oilfield, the fracturing fluid was formulated with diluted saltwater from a salt lake. The different jobs can be easily switched between each other, no cleanup additives were required, and the fluid had stable properties, satisfying the needs of the field operation.