Preparation and Evaluation of Acid Gel Fracturing Fluid with Temperature Resistance

Carbonate reservoir takes large proportion of oil reservoirs in the world. Acid fracturing, as an effective stimulation method, has been widely used in carbonate and sandstone reservoir, and the results of acid fracturing largely depend on the quality of fracturing fluid. Acid gel fracturing fluids combine the advantage of matrix acidizing and hydrofracture. Acid gel carries proppants and forms fracture, which has longer distance and higher conductivity. A sort of acid gel fracturing fluid with good temperature resistance (130 °C) is developed. The gelling time could be adjusted by the composition and dosage of crosslinking liquid. The rheometer was used to study the temperature resistance, shearing tolerance. The retarding ability, suspended sand property, and gel breaking property had also been investigated. The viscosity of the acid gel is over 150 mPa s in 130 °C. The viscosity is reduced and less than 15 mPa s after gel breaking. This acid gel had the advantaged of crosslinking time controllable, strong suspended sand property, and perfect temperature resistance. This system is suitable for 130 °C carbonate reservoir acid fracturing.