The Preparation of Suspension Liquid System with High-Temperature and Shear-Resistance by Anhydrous Pre-Mixing with New Titanium Crosslinking Agent

Abstract

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 preprared, which can significantly enhances the temperature resistance and shear resistance of the gel. Firstly, a new dialysis purification method is proposed to address the issue that the crosslinking agent and anhydrous suspension cannot be mixed in advance, overcoming the defect of uneven mixing of the external added crosslinking agent caused by high viscosity fluid. Here, the crosslinking agent is prepared by reacting titanium butylate, lactic acid, triethanolamine, and water at the molar ratio of 1:3:3.5:98 at 80°C under mixing for 7 hours. Then, the resulting gel was obtained by pre-mixing with suspension fracturing fluid liquid, and can maintain the viscosity of 63.1 mPa·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. This fracturing fluid can effectively increase fracturing efficiency, and has excellent application prospects in the context of High temperature deep well and large displacement fracturing.

Keywords: continuous mixing of fracturing fluid, organic titanium crosslinking agent, integrated suspension fracturing fluid, high-temperature fracturing