Research and Application of Low Temperature Rapid Gel Breaking Fracturing Fluid System in Tight Gas Reservoir of Jidong Oilfield

Fracturing fluid is an important part of fracturing technology, and the breaking property of fracturing fluid directly affects the effect of fracturing construction. In the case of low temperature gas reservoir, conventional gel breaker has some problems, such as not timely breaking and incomplete backflow. In this paper, through in-depth research on the concentration of the fracturing liquid system thickening agent, high efficiency breaking agent accelerator, waterproof locking agent and other functional additives, forming a low-temperature rapid gel breaking fracturing fluid formula, which reduces the difficulty of fracturing fluid breaking, reduces the residue content of breaking fluid, and reduces reservoir damage caused by wellbore fluids. The system has been successfully applied in 9 Wells in Jidong Oilfield, achieving a technical breakthrough in tight gas reservoir fracturing fluid system, and forming a low temperature and rapid gel breaking fracturing fluid technology system suitable for this region. Large-scale fracturing is one of the efficient ways to explore and develop tight gas reservoirs in Jidong Oilfield [1–5].The average reservoir temperature of Jidong tight gas reservoir ranges from 40℃ to 80℃,and the geothermal gradient is 2.24℃ to 2.82℃/100 m. The reservoir temperature of Shiqianfeng Formation is the lowest, reaching 45℃ (the well test temperature of Qian5 Member is 45.2℃).At present, Jidong Oilfield mainly uses low concentration hydroxypropyl guanidine gum fracturing liquid system [2–6],the concentration of hydroxypropyl guanidine gum is 0.35–0.45%,and the operating temperature is 110℃-140℃.The system is difficult to break rubber under 70℃,with high concentration of breaker and incomplete break rubber. In order to meet the system requirements of tight gas development in Jidong oilfield, such as fast break rubber, fast flow back, low residue and low cost [6–8], the research on fracturing fluid of guanidine gum system with low temperature fast break rubber was carried out on this basis.