High Temperature Resistance and Low-Cost Fracturing Fluid System

Abstract

With the increasing of the number of the “three ultra” wells, reservoir stimulation is needed for more than 90% of the wells. As described in this paper, taking the reservoirs under high temperature and high pressure as the background, aiming at the existing problem of the weighted fracturing fluid, through weighting agent optimization, thickening agent development, crosslinking agent and gel-breaking technology development, a high temperature resistance and low cost weighted fracturing fluid system is obtained taking calcium chloride as the weighting agent. Its weighted density is as high as 1.35 g/cm³ and temperature resistance as high as 180 ℃ Comprehensive evaluation on the performance of the system is carried out. The base fluid of the system has low viscosity and it is easy to be prepared. It has the temperature control crosslinking features. As the temperature increases, the cross-link intensity is increased and the friction resistance is reduced during pumping. At 180 ℃, the shear rate is 100 s⁻¹ for 120 min and the viscosity is greater than 100 mPa·s, which meet the performance requirements of fracturing fluids. Using the new type of gel breaker, gel-breaking can be completely in 2 h and the viscosity of the gel breaker is less than 10 mPa·s. The fracturing fluid has a wide application prospect in the fracturing stimulation of reservoirs in high temperature and deep wells which can hardly be fractured.