scholarly journals Viscosity models for bitumen–solvent mixtures

2021 ◽  
Vol 11 (3) ◽  
pp. 1505-1520
Author(s):  
Olalekan S. Alade ◽  
Dhafer A. Al Shehri ◽  
Mohamed Mahmoud ◽  
Samuel Olusegun ◽  
Lateef Owolabi Lawal ◽  
...  

AbstractViscosity is the resistance of a material to continuous deformation exerted by shear force. High viscosity, which is sometimes greater than 1 million mPa s, at the initial reservoir conditions, is a major challenge to recovery, production, and transportation of bitumen. Addition of organic solvents or diluents with bitumen leads to significant viscosity reduction and forms the basis for the steam/solvent-assisted recovery methods of extra-heavy oil and bitumen. Therefore, modeling and predicting viscosity of bitumen–solvent mixture has become an important step in the development of solvent-assisted system. The aim of this article is to present a concise survey of the various viscosity models that have been proposed to predict the viscosity of bitumen–solvent mixtures, and make comparative discussion on their applicability. Available reports revealed that the accuracy of a model to predict the viscosity of bitumen–solvent mixtures depends on various factors including the type and concentration of solvents, and the properties of the bitumen. Thus, no model has been found to have absolute capability to predict the viscosity for all mixtures. Therefore, there is room for further improvement on the viscosity modeling of bitumen–solvent system for wider applications.

2012 ◽  
Vol 268-270 ◽  
pp. 547-550
Author(s):  
Qing Wang Liu ◽  
Xin Wang ◽  
Zhen Zhong Fan ◽  
Jiao Wang ◽  
Rui Gao ◽  
...  

Liaohe oil field block 58 for Huancai, the efficiency of production of thickened oil is low, and the efficiency of displacement is worse, likely to cause other issues. Researching and developing an type of Heavy Oil Viscosity Reducer for exploiting. The high viscosity of W/O emulsion changed into low viscosity O/W emulsion to facilitate recovery, enhanced oil recovery. Through the experiment determine the viscosity properties of Heavy Oil Viscosity Reducer. The oil/water interfacial tension is lower than 0.0031mN•m-1, salt-resisting is good. The efficiency of viscosity reduction is higher than 90%, and also good at 180°C.


SPE Journal ◽  
2020 ◽  
Vol 25 (05) ◽  
pp. 2648-2662
Author(s):  
Hossein Nourozieh ◽  
Ehsan Ranjbar ◽  
Anjani Kumar ◽  
Kevin Forrester ◽  
Mohsen Sadeghi

Summary Various solvent-based recovery processes for bitumen and heavy-oil reservoirs have gained much interest in recent years. In these processes, viscosity reduction is attained not only because of thermal effects, but also by dilution of bitumen with a solvent. Accurate characterization of the oil/solvent-mixture viscosity is critical for accurate prediction of recovery and effectiveness of such processes. There are varieties of models designed to predict and correlate the mixture viscosities. Among them, the linear log mixing (Arrhenius) model is the most commonly used method in the oil industry. This model, originally proposed for light oils, often show poor performance (40 to 60% error) when applied to highly viscous fluids such as heavy oil and bitumen. The modified Arrhenius model, called the nonlinear log mixing model, gives slightly better predictions compared with the original Arrhenius model. However, the predictions still might not be acceptable because of large deviations from measured experimental data. Calculated mixture-phase viscosity has a significant effect on flow calculations in commercial reservoir simulators. Underestimation of mixture viscosities leads to overprediction of oil-production rates. Using such mixing models in reservoir simulation can lead to inaccuracy in mixture viscosities and hence large uncertainty in model results. In the present study, different correlations and mixing rules available in the literature are evaluated against the mixture-viscosity data for a variety of bitumen/solvent systems. A new form (nonlinear) of the double-log mixing rule is proposed, which shows a significant improvement over the existing models on predicting viscosities of bitumen/solvent mixtures, especially at high temperatures.


2020 ◽  
Vol 17 (6) ◽  
pp. 1683-1698 ◽  
Author(s):  
Xiao-Fei Sun ◽  
Zhao-Yao Song ◽  
Lin-Feng Cai ◽  
Yan-Yu Zhang ◽  
Peng Li

AbstractA novel experimental procedure was proposed to investigate the phase behavior of a solvent mixture (SM) (64 mol% CH4, 8 mol% CO2, and 28 mol% C3H8) with heavy oil. Then, a theoretical methodology was employed to estimate the phase behavior of the heavy oil–solvent mixture (HO–SM) systems with various mole fractions of SM. The experimental results show that as the mole fraction of SM increases, the saturation pressures and swelling factors of the HO–SM systems considerably increase, and the viscosities and densities of the HO–SM systems decrease. The heavy oil is upgraded in situ via asphaltene precipitation and SM dissolution. Therefore, the solvent-enriched oil phase at the top layer of reservoirs can easily be produced from the reservoir. The aforementioned results indicate that the SM has promising application potential for enhanced heavy oil recovery via solvent-based processes. The theoretical methodology can accurately predict the saturation pressures, swelling factors, and densities of HO–SM systems with various mole fractions of SM, with average error percentages of 1.77% for saturation pressures, 0.07% for swelling factors, and 0.07% for densities.


1991 ◽  
Vol 69 (3) ◽  
pp. 509-517 ◽  
Author(s):  
Andrea Marchetti ◽  
Carlo Preti ◽  
Mara Tagliazucchi ◽  
Lorenzo Tassi ◽  
Giuseppe Tosi

Three empirical equations are proposed to fit the experimental values of the dissociation constant for picric acid, chosen as guide-solute working in the N, N-dimethylformamide/2-methoxyethanol solvent system. The work was performed operating at 19 temperatures ranging from − 10 to + 80 °C in the pure solvents and in their nine mixtures, identified by the mole fraction (X) of one component. This empirical treatment, which describes the dependence of the dissociation constant on temperature and composition of the solvent mixture, is represented by functions of the type K = K(T), K = K(X), and K = K(T, X). The K = K(T, X) equation in its complete form is composed of 20 terms, some of which can be eliminated because of small statistical weight; the number and type of these terms vary on passing from one solvent system to another and the best-fitting form is suggested. A comparison among various K = K(T, X) equations proposed in the present and in previous works has been made. Key words: dissociation equilibria, binary nonaqueous solvent mixtures, picric acid, N,N-dimethylformamide, 2-methoxyethanol.


2014 ◽  
Vol 981 ◽  
pp. 946-950
Author(s):  
Feng Wang ◽  
Chi Ai ◽  
Dan Dan Yuan ◽  
Shuang Liang ◽  
Guang Miao Qu

In this paper, alkyl polyglucoside (APG) and fatty alcohol polyoxyethylene ether (AEO3) were prepared to obtain a new type of soluble viscosity reducer which can change the rheological behavior of the crude oil and reduce its viscosity using method of emulsification viscosity reduction. The typical sample of heavy oil produced in Jilin oilfield was analyzed to figure out the key factors of influencing the viscosity of this heavy oil and the static evaluation experiments were carried out to investigate the reducing performance of the viscosity breaker. The viscosity breaker can lower the interfacial tension between oil and water to some extent, and the stability of emulsion between the oil and water is relatively good, in addition, it can provide high viscosity reduction rate and detergent factor of oil to produce a good viscosity reduction performance.


2011 ◽  
Vol 474-476 ◽  
pp. 893-897 ◽  
Author(s):  
Fa Jun Zhao ◽  
Yong Jian Liu ◽  
Yi Wu ◽  
Yong Si ◽  
Bo Zhang ◽  
...  

As an irreversible viscosity reduction way, catalytic aquathermolysis of heavy oil is given close attention by scholars at home and abroad, and a high content of asphaltene in heavy oil is the major cause for the high viscosity of heavy oil. Through the use of IR spectrum and TG-DTA, this paper analyzes the asphaltene structure and thermal analysis before and after the catalytic aquathermolysis reaction, and the result shows some changes in the heavy component structure in the asphaltene after the reaction, a reduction in some unsaturated structures, an increase in saturated structures, a reduction in long-chain structures, an increase in short-chain structures, and an increase in light components. Thermal analysis shows that part of the asphaltenes can be converted into alkane soluble substance. The catalyst acts on the heteroatoms in asphaltenes, which partly changes the asphaltene structure and makes it cracked to some extent, so as to lead to the lower viscosity of heavy oil.


SPE Journal ◽  
2016 ◽  
Vol 21 (01) ◽  
pp. 170-179 ◽  
Author(s):  
Songyan Li ◽  
Zhaomin Li

Summary Foamy-oil flow has been successfully demonstrated in laboratory experiments and site applications. On the basis of solution-gas-drive experiments with Orinoco belt heavy oil, the effects of temperature on foamy-oil recovery and gas/oil relative permeability were investigated. Oil-recovery efficiency increases and then decreases with temperature and attains a maximum value of 20.23% at 100°C. The Johnson-Bossler-Naumann (JBN) method has been proposed to interpret relative permeability characteristics from solution-gas-drive experiments with Orinoco belt heavy oil, neglecting the effect of capillary pressure. The gas relative permeability is lower than the oil relative permeability by two to four orders of magnitude. No intersection was identified on the oil and gas relative permeability curves. Because of an increase in temperature, the oil relative permeability changes slightly, and the gas relative permeability increases. Thermal recovery at an intermediate temperature is suitable for foamy oil, whereas a significantly higher temperature can reduce foamy behavior, which appears to counteract the positive effect of viscosity reduction. The main reason for the flow characteristics of foamy oil in porous media is the low gas mobility caused by the oil components and the high viscosity. High resin and asphaltene concentrations and the high viscosity of Orinoco belt heavy oil increase the stability of bubble films and prevent gas breakthrough in the oil phase, which forms a continuous gas, compared with the solution-gas drive of light oil. The increase in the gas relative permeability with temperature is caused by higher interfacial tensions and the bubble-coalescence rate at high temperatures. The experimental results can provide theoretical support for foamy-oil production.


2020 ◽  
pp. 1-23
Author(s):  
Xinqian Lu ◽  
Zeyu Lin ◽  
Xiang Zhou ◽  
Fanhua Zeng

Abstract Heavy oil resources, as a non-renewable energy resource, often requires extra enhanced oil recovery techniques such as solvent-based processes. Many kinds of solvents including pure and mixed solvent have been tested in the solvent-based applications. Compared with pure solvent, the solvent mixture has an advantage of relatively higher dew point pressure while maintaining desirable solubility in heavy oil. The characterization of foamy oil behavior in pure solvent system is different from the solvent mixture system despite their similarities. Thus, an additional numerical simulation study is necessary for solvent mixture system. This work conducted simulation studies to investigate foamy oil behavior in a heavy oil-mixture solvent (C1+C3) system from pressure depletion tests. A better understanding of foamy oil characterization and mechanism in a heavy oil-mixture solvent system is obtained. A reliable non-equilibrium model is developed to perform simulation studies. Since previous experiments suggest the behavior of foamy oil in the solvent mixture system share similarities with the heavy oil-methane system, this investigation first conducted simulation study with consideration of two reactions in the model and achieved good agreements between the simulated calculation results and experimentally measurement. Then four reactions are considered in the model for simulation study and obtained better history match results. The simulation results suggest methane has more impact on the foamy oil behaviors than propane in the heavy oil-mixture solvent system. This work also discussed effect of model parameters involved in the history matching process and conducted sensitivity analysis.


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