Study on polymer synthesis of temperature-resistant and salt-resistant slick water fracturing fluids

Slick water volume fracturing technology is one of the main technologies for the development of high temperature and compact carbonate reservoirs in Western China at present. Slick water complex acid is mainly used to form volume acid fracturing fractures to improve the stimulation effect. However, at the present stage of field construction in Western China, high salinity groundwater is used to distribute fluids, while formation temperature is high, the performance of conventional friction reducer is seriously reduced, so it is necessary to develop targeted high-performance polymer friction reducer. Through the optimization of fracturing fluid additives, free radical aqueous solution copolymerization was carried out by using one or more hydrophilic monomers and temperature/salt resistant monomers. In order to optimize the modified monomers and their dosage, infrared spectroscopy, nuclear magnetic resonance and differential scanning calorimetry are used to analyze the newly synthesized polymers. Finally a kind of modified monomers is developed, which has good temperature resistance, fast dissolution rate under high salinity conditions, excellent friction reduction, swelling properties, low formation damage, and the flowback treatment is simple. It can tolerate high temperature of 140 ℃, and rapidly dissolve under the salinity of 100, 000 mg/L, the resistance reduction rate is about 70%. A new type of temperature-resistant and salt-resistant slick water fracturing fluid system act as a theoretical foundation and technical support for the development of ultra-deep carbonate rocks.