Effect of temperature on isothermal gelling properties for Qinghai crude oil

Key words:  waxy crude oil  isothermal gelling properties  static cooling  dynamic cooling  isothermal shearing  temperature

Abstract:

The effect of temperature on the isothermal gelling properties for waxy crude oil after three historical conditions were studied in detail. The ARG2 rheometer was used for small amplitude oscillatory shear mode. The results show that the storage modulus of waxy crude oil all increase with the decrease of temperature no matter what the historical condition is. The variation of loss angle shows significant difference. After static cooling, with the decrease of temperature, the loss angle becomes small. While after static cooling and isothermal shearing or after dynamic cooling, the loss angle decreases first and increases finally with the temperature decreasing. All the variation of storage modulus with time can be fitted well with one model and the correlation coefficients of the fitting curves are related to test temperature for the oils under the different histories. The correlation coefficients with the temperature changing are affected by the historical conditions before isothermal shearing.