The preparation integrated suspension liquid system with high-temperature and shear-resistance by anhydrous pre-mixing with novel titanium crosslinking agent

To address the issue of low viscosity and poor high-temperature shear resistance of suspension liquid type fracturing fluids commonly used in continuous fracturing operations for high-temperature unconventional oil reservoirs with large displacement mineralized water, A novel titanium crosslinking agent has been prepared, which can significantly enhances the temperature resistance and shear resistance of the gel. In addition, a novel dialysis purification method is proposed, which allows the titanium crosslinker to be pre-mixed with anhydrous suspension, and overcomes the defect of uneven mixing due to high viscosity fluid when add crosslinker, which can’t be solved by boron or zirconium crosslinker. Here, the crosslinking agent was prepared by mixing butyl titanate, lactic acid, triethanolamine and water according to a certain molar ratio. Then, the resulting gel was obtained by pre-mixing with suspension fracturing fluid liquid, and can maintain the viscosity of 63.1mPa·s at a shear rate of 170 s⁻¹ and 150 °C, which is nearly twice that of the gel to bring with added externally crosslinking agents. The fracturing fluid can effectively increase fracturing efficiency, and has excellent application prospects in the context of High temperature deep well and large displacement fracturing.