Objective In view of the problem of salt crystallization occurring in the near well area and wellbore during the development of the shale oil in Qianjiang Formation, the sodium ferrocyanide is used as a salt inhibitor, and the factors of salt crystallization formation are studied by single factor method.

Method The main components of salt crystals were analyzed by X-ray energy spectrometer, and the effects of temperature, pressure and flow rate on the quality of salt crystals in produced water were also investigated. In addition, the effects of salt inhibitor dosage and temperature on NaCl solubilization ability were studied, and the effects of salt inhibitor on core permeability and injection pressure were also studied by core flow experiment.

Result When the salt inhibitor dosage was 4%, the solubility of NaCl was 8.15%, the temperature resistance reached 150 ℃, the core permeability increased to 24.72×10⁻³ μm², the injection pressure decreased to 0.263 MPa, and the daily oil production of the well increased from 0.8 t to 5.7 t.

Conclusion The key factors of serious salt formation in shale oil reservoirs are identified, and salt crystallization can be effectively inhibited by adding appropriate salt inhibitors to the working fluid, which can provide a reference for inhibiting salt crystallization in high salinity oil and gas wells.