Rheological Properties Of Heavy Oil Research Articles

Experimental study on the viscosity-temperature characteristics and rheological properties of offshore heavy oil

The viscosity-temperature characteristics and rheological properties of heavy oil were investigated experimentally. Experimental results indicate that viscosity is sensitive to temperature, and it is a binary function of temperature and shear rate meeting preferably Arrhenius equation. In addition, the semi-log curve of viscosity-temperature can be divided into three regions and there is no obvious turning point, which exhibits that the internal microstructure of heavy oil during the heating process changes gradually. Besides, activation energy of low temperature range is higher than that of high temperature range. Moreover, the heavy oil always behaves as Newtonian fluid when temperature is higher than crystallisation temperature. Furthermore, on condition that temperature is less than crystallisation temperature, the heavy oil behaves as pseudo-plastic fluid characterising shear thinning phenomenon when shear rate is less than critical shear rate, and it presents as Bingham fluid with yield stress when shear rate falls between 10 and 50 s−1. [Received: March 16, 2018; Accepted: October 24, 2018]

Experimental study on the viscosity-temperature characteristics and rheological properties of offshore heavy oil

The viscosity-temperature characteristics and rheological properties of heavy oil were investigated experimentally. Experimental results indicate that viscosity is sensitive to temperature, and it is a binary function of temperature and shear rate meeting preferably Arrhenius equation. In addition, the semi-log curve of viscosity-temperature can be divided into three regions and there is no obvious turning point, which exhibits that the internal microstructure of heavy oil during the heating process changes gradually. Besides, activation energy of low temperature range is higher than that of high temperature range. Moreover, the heavy oil always behaves as Newtonian fluid when temperature is higher than crystallisation temperature. Furthermore, on condition that temperature is less than crystallisation temperature, the heavy oil behaves as pseudo-plastic fluid characterising shear thinning phenomenon when shear rate is less than critical shear rate, and it presents as Bingham fluid with yield stress when shear rate falls between 10 and 50 s−1. [Received: March 16, 2018; Accepted: October 24, 2018]

Influence of Microwave Processing of Heavy Stock Oil on Oil Fluidity

The effect of heavy stock oil heating by ultra-high frequency (microwave) electromagnetic field on oil viscosity changes is investigated in the present work. The influence of the phase state of supramolecular formations on the rheological properties of heavy oil after the application of various dielectric heating schemes is studied. The energy of the intermolecular interaction of asphaltene nanoaggregates of various sizes is estimated based on rheometric studies of heavy oil treated with microwave energy. It has been established that for a stable asphaltene oil, the hybrid microwave processing scheme is most effective.

Modifying the Viscosity of Heavy Crude Oil Using Surfactants and Polymer Additives

A systematic study of the influence of surfactant and stabilizing polymer additives on the rheological properties of heavy oil was carried out. The aim was to optimize the recipe for the most effective reduction in the oil viscosity. A total of 41 versions of the emulsion were prepared using different protocols. Creation of the emulsions with different recipes and modes of mixing led to a regulation of their morphologies, which determined the rheological properties of the final products. In all cases, emulsification resulted in a transformation of the oil from Newtonian behavior to a viscoplastic medium with a blurred yield stress. Dependent upon the composition, the yield stress was decreased up to 0.6 Pa and the viscosity at high shear obtained a value up to 50 mPa s, which is lower than the viscosity of crude oil by 34 times. The efficiency of the viscosity reduction increased with a decreasing temperature.

Effect of water content and temperature on the rheological behavior of Caoqiao heavy oil

ABSTRACTDue to the high viscosity and the complex fluid characteristics of Caoqiao heavy oil, it is difficult for its exploitation and transportation. In order to effectively develop the Caoqiao heavy oil, the effect of temperature and water content on the rheological properties of heavy oil are experimentally studied. The results show that when the water content is in the range of 0 to 30%, the viscosity of heavy oil first changes little, then increases, and finally decreases with the increase of water content. The water content and temperature have a significant effect on the fluid type of Caoqiao heavy oil. There exists a Newtonian fluid transformation temperature point. When the temperature is higher than the point, the viscosity of heavy oil is basically not affected by the change of shear rate. The higher the water content, the lower the point there is. The temperature of the transformation point is the key factor to ensure the fluidity of Caoqiao heavy oil in the formation and wellbore. The experimental results can provide a directional guide for the efficient extraction and transportation of Caoqiao heavy oil.

Synthesis and physicochemical study of tetraaquatritetraphthalatodiiron(III)

An iron(III) complex of terephthalic acid of the general formula Fe2[C6H4(COO)2]3(H2O)4.was synthesized. The composition and structure of the complex were studied by X-ray phase analysis and IR spectroscopy. The thermal stability of the complex was studied in the range 20–900°C. It was shown that doping with a Fe2[C6H4(COO)2]3(H2O)4 reagent improves the rheological properties of heavy oil.

Rheological Properties of Heavy Oils and Heavy Oil Emulsions

In this study, we investigated the effects of a number of process variables such as shear rate, measurement temperature, pressure, the influence of pretreatment, and the role of various amounts of added water on the rheology of the resulting heavy oil or the emulsion. Rheological properties of heavy oils and the corresponding emulsions are important from transportation and processing standpoints.