Development and evaluation of a novel high-density weighted fracturing fluid in ultra-deep reservoirs

Abstract

Abstract Ultra-deep reservoirs make the fracturing operations facing some inevitable problems, especially the higher surface treating pressure, which usually exceeds the limitation of existing fracturing equipment. Weighted fracturing fluid has become one of the most effective methods to deal with this challenge. In this study, a novel high-density weighted fracturing fluid was developed with self-synthesized new weighting agent and crosslinker through extensive laboratory experiments. The density of the new weighted fracturing fluid was up to 1.46 g/cm3. The crosslinking time can be controlled within 3.1∼10.2 mins, which helps in limiting the tubing friction. Performance evaluation results show that the fluid system has desired high temperature-stability and shearing resistance. Under 150 °C, 170 s–1, the final apparent viscosity still remains above 50 mPa·s after shearing for 60 mins. The maximum friction reduction rate of the based fluid reached 68.4 %, which is speculated lower than the wellsite application. The newly proposed weighted fracturing fluid is a good choice for ultra-deep and high-temperature reservoirs stimulation and hence improving the recovery.