关键词: 返排液, 快速回用, 冰点, 防冻压裂液

Abstract: In view of the low treatment speed and high cost of fracturing fluid flowback fluid in Sulige gas field, especially the instability of fluid performance and the difficulty of recovery and utilization caused by low temperature in winter, the overall recovery and utilization rate is low. In this paper, the polymer fracturing fluid system is added with high valence cation shielding agent to improve the salt resistance of the system, so that the on-site flowback fluid only needs to be simple and rapidly filtration treated to meet the water quality requirements. At the same time, the liquid additives susceptible to low temperature are added with antifreeze agent to reduce the freezing point below - 10 ℃ for inhibiting the effective content reduction caused by flocculation and crystallization at low temperature, so as to meet the requirements of construction in winter. The salt resistance of the formed fracturing fluid system which can be quickly reused is more than 45 000 mg /L, the core damage rate is 12. 22% , the temperature resistance, shear resistance and gel breaking performance are all good, and the construction process of rapid treatment and reuse of flowback fluid is established. Eight wells have been successfully applied in Sulige gas field. The overall recovery rate of flowback fluid is 73% , and the average open flow rate is 18.4 × 10⁴ m³ /d, which has achieved remarkable effects of reuse and stimulation.

Key words: backflow fluid, fast reuse, freezing point, antifreeze fracturing fluid