Applicability of Emulsion Viscosity Models to Crude Oil Emulsion

2012 ◽  
Vol 581-582 ◽  
pp. 50-53 ◽  
Author(s):  
Li Ping Guo ◽  
Lei Wang ◽  
Yi Min Zhang
Keyword(s):  
Experimental Data ◽  
Crude Oil ◽  
Apparent Viscosity ◽  
Least Square ◽  
Model Parameters ◽  
Average Absolute Deviation ◽  
Absolute Deviation ◽  
Oil Emulsion ◽  
Waxy Crude ◽  
Water Cut

The rheology behavior of waxy crude emulsion is an important basic information on safeguard research of crude oil-water flow. The non-newtonian characteristics of apparent viscosity of three kinds of waxy crude emulsions were studied experimentally around condensation point; three apparent viscosity forecasting models were evaluated by least-square regressions based on experimental data of shear balance and the average absolute deviation was taken as the measurement of fitness of a model to experimental data. It is concluded that the Pal-Rhodes model, whose relative deviation can be as high as 80%, is the worst forecasting model, but it need the least experiment data to obtain model parameters, only water cut was needed. Elgibaly model has the best forecasting results, the average absolute deviation of forecasting results of three waxy crude emulsions under the condition of different temperature, water cut and shear rate were all less than 15%, but compared with the other two models, Elgibaly model needs the most parameters.

Characterization of a Water-in-Waxy Crude Oil Emulsion by its Steady Apparent Viscosity

2019 ◽  
Author(s):  
Liping Guo ◽  
Tao Feng ◽  
Yang Liu ◽  
Xu Chen ◽  
Wenbo Li ◽  
...  
Keyword(s):  
Crude Oil ◽  
Viscous Flow ◽  
Apparent Viscosity ◽  
Rheological Parameters ◽  
Wax Deposition ◽  
Waxy Crude Oil ◽  
Oil Emulsion ◽  
Waxy Crude ◽  
Stirring Time ◽  
Water Cut

Abstract The rheological properties of water-in-waxy crude oil emulsion depend highly on its forming conditions. Among these, the steady apparent viscosity is capable of characterizing its degree of emulsification. Adopting waxy crude oil in the field, we examine the influence of the water cut, the stirring speed, and the stirring time on the steady apparent viscosity of the emulsions formed under various conditions in this study. A model based on the viscous flow entropy generated in emulsion preparation is applied to correlate the steady apparent viscosity with the key parameters. A regression model is constructed for the dependence of the steady apparent viscosity on the viscous flow entropy, the shear rate, the rheological parameters of blank crude oil, and the wax deposition volume.

Evaluation of Thixotropic Models of Waxy Crude

2012 ◽  
Vol 581-582 ◽  
pp. 85-88 ◽  
Author(s):  
Li Ping Guo ◽  
Lei Wang ◽  
Yi Min Zhang
Keyword(s):  
Shear Rate ◽  
Crude Oil ◽  
Least Square ◽  
Suitable Model ◽  
Cyclic Change ◽  
Hydraulic Characteristics ◽  
Average Absolute Deviation ◽  
Absolute Deviation ◽  
Oil Pipelines ◽  
Constant Shear Rate

Thixotropy, which is an important rheological behavior of waxy crudes, is very important to the hydraulic characteristics and safety of the restart process of crude oil pipelines. Thixotropic behaviors of four waxy crudes were studied experimentally under three kinds of loading conditions, which were constant shear rate, stepwise increase of shear rate and cyclic change of shear rate, namely hysteresis loop. Eight thixotropic models were evaluated by least-square regressions based on experimental data. The average absolute deviation was taken as the measurement of fitness of a model. It is concluded that the model, which was established on the basis of Houska model and Cheng’s idea that wax crude oil contains both complete and partial reversibility structures, is the most suitable model to describe the thixotropy of wax crude oil

Kinetic Study on a Commercial Amorphous Hydrocracking Catalyst by Weighted Lumping Strategy

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Sepehr Sadighi ◽  
Arshad Ahmad ◽  
Akbar Irandoukht
Keyword(s):  
Objective Function ◽  
Space Velocity ◽  
Reaction Rates ◽  
Pilot Scale ◽  
Least Square ◽  
Average Absolute Deviation ◽  
Absolute Deviation ◽  
Dual Functional ◽  
Hydrocracking Catalyst ◽  
Middle Distillates

Hydrocracking is an important upgrading process in the petroleum refinery, and it is generally used to process feedstocks ranging from vacuum gas oil (VGO) to vacuum residue. In this work, hydrocracking of VGO using a dual functional amorphous catalyst was carried out at a pilot scale unit under the following reaction conditions: liquid hourly space velocity (LHSV) from 1 to 1.5 hr-1 and reaction temperatures of 360-440°C at the constant pressure and hydrogen to oil, 156 bar and 1780 Nm3/m3, respectively. The effluent of the reactor was characterized to dry gas, naphtha, kerosene, diesel and unconverted VGO or residue. The pilot tests demonstrated that performing experiments beyond the temperature, recommended by catalyst vendor, lead the process to unstable hydrocracking. To describe the yield of hydrocracking products a five-lump discrete lumping approach with ten reactions was proposed. At first, the kinetic model contained twenty kinetic constants which were estimated by using the conventional objective function. The estimated parameters showed that the tendency of the catalyst to convert VGO to gas and naphtha was negligible whilst rate constants for hydrocracking of VGO to middle distillates were considerably high which was compatible with the nature of amorphous hydrocracking catalysts. After evaluating the magnitude of reaction rates and eliminating the ignorable constants, the network was reduced to six reactions in which only nine parameters were needed. The predictions indicated that the latter network could fit the yield of products more acceptable as if the average absolute deviation between experimental and calculated yields was descended from 16.25% to 12.6%. Then, to have a better prediction, a weighted objective function was used in which weight factors were calculated by a proposed weighted least square expression. The results confirmed that this approach could reduce average absolute deviation of model to 10.75%, and it created a fairly even distribution of deviation between hydrocracking products.

The Research of Demulsifiers's Influence on Oil Emulsion's Rheological Property

2013 ◽  
Vol 401-403 ◽  
pp. 404-408
Author(s):  
Wei Lin Cui ◽  
Shi Xu Li ◽  
Ling Jian Song ◽  
Yong Sheng Li
Keyword(s):  
Rheological Property ◽  
Crude Oil ◽  
Evaluation Index ◽  
Oil Emulsion ◽  
Field Development ◽  
Moisture Contents ◽  
Return Water ◽  
Water Cut

Abstract: During the transportation of the oil which is replaced from stratum by return water with demulsifier, the rheology of the water cut oil must have been affected. In order to study the influence rule of emulsion which contains hydrophilic demulsifier, we don this experiment which tests the different demulsifier using HAAKE Viscotester 550. The testing result showed that for crude oil emulsion, the effects of the factors on the rheological index and demulsifier evaluation index into corresponding relation, this provides the rheological field development significance; Demulsifier could move forward the emulsification diversion point, and the viscosity of the emulsion decreased effectively with different moisture contents. Different structure types of demulsifier have the different influence on viscosity. Finally, we conclude the influence rule of emulsion which provides the daterbase for crude oil heating airtight gathering and transportation technology .

Effects of the Dispersed Phase on Oil/Water Wax Deposition

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Pengyu Wang ◽  
Wei Wang ◽  
Jing Gong ◽  
Yuanxin Zhou ◽  
Wei Yang
Keyword(s):  
Particle Size ◽  
Crude Oil ◽  
Dispersed Phase ◽  
Wax Deposition ◽  
Waxy Crude Oil ◽  
Water Emulsion ◽  
Oil Emulsion ◽  
Wax Content ◽  
Oil Water ◽  
Water Cut

In the study of the foundation of the oil / water wax deposition experiment, the emulsification characteristics of crude oil emulsion with high wax content have gradually become the hot research area. In the current research of emulsification characteristics of oil/water emulsion, the attention has been focused on the study of the effects of water cut, stirring speed, particle size distribution on the viscosity of waxy crude oil emulsion in the experiment, in which heavy oil and simulated oil are adopted as the working fluids. In this study, the emulsion with different water cut and stirred by different speed was prepared under three different temperature conditions, the temperature above the wax appearance temperature (WAT), near the WAT, and below the WAT. The polarization microscope and rotary viscometer were applied to measure the effects of the particle size of the dispersed phase and waxy crystal distribution on the oil/water emulsion viscosity. The results suggest that preparing the temperature for crude oil emulsion with high wax content has an important influence on the emulsion microstructure. This study lays the foundation for further study of oil/water two phase dynamic wax deposition experiments.

Structural Behaviors of Waxy Crude Oil Emulsion Gels

2014 ◽  
Vol 28 (6) ◽  
pp. 3718-3729 ◽  
Author(s):  
Guangyu Sun ◽  
Jinjun Zhang ◽  
Hongying Li
Keyword(s):  
Crude Oil ◽  
Waxy Crude Oil ◽  
Oil Emulsion ◽  
Waxy Crude ◽  
Structural Behaviors

Waxy Crude Oil Emulsion Gel: Impact on Flow Assurance†

2010 ◽  
Vol 24 (4) ◽  
pp. 2287-2293 ◽  
Author(s):  
Márcia Cristina K. de Oliveira ◽  
Rogério M. Carvalho ◽  
Alexandre B. Carvalho ◽  
Bruno C. Couto ◽  
Fátima R. D. Faria ◽  
...  
Keyword(s):  
Crude Oil ◽  
Flow Assurance ◽  
Waxy Crude Oil ◽  
Oil Emulsion ◽  
Waxy Crude ◽  
Emulsion Gel

Study on structures and electronic properties of neutral and anionic TiSin(0,-1)(n = 1–8) clusters using G4 theory

2014 ◽  
Vol 13 (05) ◽  
pp. 1450038 ◽  
Author(s):  
Jun Lu ◽  
Jucai Yang ◽  
Zhifei Xing ◽  
Hongmei Ning
Keyword(s):  
Experimental Data ◽  
Ground State ◽  
Electronic Structures ◽  
Electron Affinities ◽  
Average Absolute Deviation ◽  
Absolute Deviation ◽  
Relative Stabilities ◽  
Dissociation Energies ◽  
Ground State Structures ◽  
Experimental Values

The geometries, electronic structures and energies of small TiSi n species (n = 1–8) and their anions were systematically investigated by G4 theory. The ground-state structures of these clusters are presented herein. For neutral TiSi n (n = 1–8), the spin multiplicities of the ground-state structures are singlet, with the exception of n = 2, which exists in a triplet state. For anionic TiSi n-, the spin multiplicities of the ground-state structures are doublet, with the exception of n = 2, which is quartet. The adiabatic electron affinities for TiSi n are estimated to be 1.31 eV ( TiSi ), 1.46 eV ( TiSi 2), 1.53 eV ( TiSi 3), 1.71 eV ( TiSi 4), 2.06 eV ( TiSi 5), 2.16 eV ( TiSi 6), 2.20 eV ( TiSi 7) and 2.39 eV ( TiSi 8). In comparison with the available experimental data, the calculated adiabatic electron affinities differ from experimental values by an average absolute deviation of only 0.03 eV. Additionally, the dissociation energies of Ti atoms from TiSi n, and Si atoms from TiSi n and Si n clusters are estimated to examine relative stabilities.

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