Performance of Electrostatic Field in Continuous Demulsification of Simulated Crude Oil Emulsion

2015 ◽  
Vol 74 (7) ◽  
Author(s):  
Norasikin Othman ◽  
Tan Kah Sin ◽  
Norul Fatiha Mohamed Noah ◽  
Ooi Zing Yi ◽  
Norela Jusoh ◽  
...  

Water-in-oil (W/O) emulsion is always formed in crude oil production. In most cases, the presence of water droplets in crude oil is undesirable because they can cause several problems such as corrosion of process equipment and a decrease in crude oil quality, as well as its market price. In this research, a simulated W/O emulsion that consists of kerosene as a continuous oil phase, water as a dispersed phase and SPAN 80 as an emulsifier has been formulated. The feasibility of using Span 80 for W/O emulsion formation and emulsion stability has been investigated. Stability test proved that the emulsions with 2 w/v % of Span 80 were stable and no separation was observed for the first 48 hours of gravitational settling. Besides, this research also aimed to study the effects of several parameters such as frequency, emulsion flow rate, voltage, water content in emulsion, and emulsifier concentration on the demulsification performance under high voltage electric field. The results showed that the best demulsification performance was 90% using electrical method at 1000 Hz of frequency, 10kV of voltage, 0.4 mL/s of emulsion flow rate, 2 w/v % of emulsifier, and 30 % of water portion of simulated crude oil.

Author(s):  
Abed Saad ◽  
Nour Abdurahman ◽  
Rosli Mohd Yunus

: In this study, the Sany-glass test was used to evaluate the performance of a new surfactant prepared from corn oil as a demulsifier for crude oil emulsions. Central composite design (CCD), based on the response surface methodology (RSM), was used to investigate the effect of four variables, including demulsifier dosage, water content, temperature, and pH, on the efficiency of water removal from the emulsion. As well, analysis of variance was applied to examine the precision of the CCD mathematical model. The results indicate that demulsifier dose and emulsion pH are two significant parameters determining demulsification. The maximum separation efficiency of 96% was attained at an alkaline pH and with 3500 ppm demulsifier. According to the RSM analysis, the optimal values for the input variables are 40% water content, 3500 ppm demulsifier, 60 °C, and pH 8.


Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4325
Author(s):  
Zhihua Wang ◽  
Yunfei Xu ◽  
Yi Zhao ◽  
Zhimin Li ◽  
Yang Liu ◽  
...  

Wax deposition during crude oil transmission can cause a series of negative effects and lead to problems associated with pipeline safety. A considerable number of previous works have investigated the wax deposition mechanism, inhibition technology, and remediation methods. However, studies on the shearing mechanism of wax deposition have focused largely on the characterization of this phenomena. The role of the shearing mechanism on wax deposition has not been completely clarified. This mechanism can be divided into the shearing dispersion effect caused by radial migration of wax particles and the shearing stripping effect caused by hydrodynamic scouring. From the perspective of energy analysis, a novel wax deposition model was proposed that considered the flow parameters of waxy crude oil in pipelines instead of its rheological parameters. Considering the two effects of shearing dispersion and shearing stripping coexist, with either one of them being the dominant mechanism, a shearing dispersion flux model and a shearing stripping model were established. Furthermore, a quantitative method to distinguish between the roles of shearing dispersion and shearing stripping in wax deposition was developed. The results indicated that the shearing mechanism can contribute an average of approximately 10% and a maximum of nearly 30% to the wax deposition process. With an increase in the oil flow rate, the effect of the shearing mechanism on wax deposition is enhanced, and its contribution was demonstrated to be negative; shear stripping was observed to be the dominant mechanism. A critical flow rate was observed when the dominant effect changes. When the oil flow rate is lower than the critical flow rate, the shearing dispersion effect is the dominant effect; its contribution rate increases with an increase in the oil flow temperature. When the oil flow rate is higher than the critical flow rate, the shearing stripping effect is the dominant effect; its contribution rate increases with an increase in the oil flow temperature. This understanding can be used to design operational parameters of the actual crude oil pipelines and address the potential flow assurance problems. The results of this study are of great significance for understanding the wax deposition theory of crude oil and accelerating the development of petroleum industry pipelines.


2016 ◽  
Vol 148 ◽  
pp. 1149-1155 ◽  
Author(s):  
Tajnor Suriya Taju Ariffin ◽  
Effah Yahya ◽  
Hazlina Husin

Author(s):  
Yuanyuan Chen ◽  
Jing Gong ◽  
Xiaoping Li ◽  
Nan Zhang ◽  
Shaojun He ◽  
...  

Pipeline commissioning, which is a key link from engineering construction to production operation, is aim to fill an empty pipe by injecting water or oil to push air out of it. For a large-slope crude oil pipeline with great elevation differences, air is fairly easy to entrap at downward inclined parts. The entrapped air, which is also called air pocket, will cause considerable damage on pumps and pipes. The presence of it may also bring difficulties in tracking the location of the liquid head or the interface between oil and water. It is the accumulated air that needed to be exhausted in time during commissioning. This paper focuses on the simulation of liquid-gas replacement in commissioning process that only liquid flow rate exists while gas stays stagnant in the pipe and is demanded to be replaced by liquid. Few previous researches have been found yet in this area. Consequently, the flow in a V-section pipeline consisted of a downhill segment and a subsequent uphill one is used here for studying both the formation and exhaustion behaviors of the intake air. The existing two-fluid model and simplified non-pressure wave model for gas-liquid stratified flow are applied to performance the gas formation and accumulation. The exhausting process is deemed to be a period in which the elongated bubble (Taylor bubble) is fragmented into dispersed small bubbles. A mathematical model to account for gas entrainment into liquid slug is proposed, implemented and incorporated in a computational procedure. By taking into account the comprehensive effects of liquid flow rate, fluid properties, surface tension, and inclination angle, the characteristics of the air section such as the length, pressure and mass can be calculated accurately. The model was found to show satisfactory predictions when tested in a pipeline. The simulation studies can provide theoretical support and guidance for field engineering application, which are meanwhile capable of helping detect changes in parameters of gas section. Thus corresponding control measures can be adopted timely and appropriately in commissioning process.


Author(s):  
Jean-Louis Salager ◽  
Ronald Marquez ◽  
Jose G. Delgado-Linares ◽  
Miguel Rondon ◽  
Ana Forgiarini
Keyword(s):  

SPE Journal ◽  
2021 ◽  
pp. 1-18
Author(s):  
Jianjun Zhu ◽  
Hanjun Zhao ◽  
Guangqiang Cao ◽  
Hattan Banjar ◽  
Haiwen Zhu ◽  
...  

Summary As the second most widely used artificial lift method in the petroleum industry, electrical submersible pumps (ESPs) maintain or increase flow rates by converting the kinetic energy to hydraulic pressure. As oilfields age, water is invariably produced with crude oil. The increase of water cut generates oil-water emulsions due to the high-shearing effects inside a rotating ESP. Emulsions can be stabilized by natural surfactants or fine solids existing in the reservoir fluids. The formation of emulsions during oil production creates a high viscous mixture, resulting in costly problems and flow assurance issues, such as increasing pressure drop and reducing production rates. This paper, for the first time, proposes a new rheology model to predict the oil-water emulsion effective viscosities and establishes a link of fluid rheology and its effect with the stage pressure increment of ESPs. Based on Brinkman's (1952) correlation, a new rheology model, accounting for ESP rotational speed, stage number, fluid properties, and so on, is developed, which can also predict the phase inversion in oil-water emulsions. For the new mechanistic model to calculate ESP boosting pressure, a conceptual best-match flow rate (QBM) is introduced. QBM corresponds to the flow rate whose direction at the ESP impeller outlet matches the designed flow direction. Induced by the liquid flow rates changing, various pressure losses can be derived from QBM, including recirculation losses, and losses due to friction, leakage, sudden change of flow directions, and so on. Incorporating the new rheology model into the mechanistic model, the ESP boosting pressure under oil-water emulsion flow can be calculated. To validate the proposed model, the experimental data from two different types of ESPs were compared with the model predictions in terms of ESP boosting pressure. Under both high-viscositysingle-phase fluid flow and oil-water emulsion flow, the model predicted ESP pressure increment matches the experimental measurements well. From medium to high flow rates with varying oil viscosities and water cuts, the prediction error is less than 15%.


2017 ◽  
Vol 35 (11) ◽  
pp. 1180-1187 ◽  
Author(s):  
Wanli Kang ◽  
Jiatong Jiang ◽  
Yao Lu ◽  
Derong Xu ◽  
Hairong Wu ◽  
...  

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