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

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.

Author(s):  
Liping Guo ◽  
Tao Feng ◽  
Yang Liu ◽  
Xu Chen ◽  
Wenbo Li ◽  
...  

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.


2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Mo Zhang ◽  
Ramin Dabirian ◽  
Ram S. Mohan ◽  
Ovadia Shoham

Oil–water dispersed flow occurs commonly in the petroleum industry during the production and transportation of crudes. Phase inversion occurs when the dispersed phase grows into the continuous phase and the continuous phase becomes the dispersed phase caused by changes in the composition, interfacial properties, and other factors. Production equipment, such as pumps and chokes, generates shear in oil–water mixture flow, which has a strong effect on phase inversion phenomena. The objective of this paper is to investigate the effects of shear intensity and water cut (WC) on the phase inversion region and also the droplet size distribution. A state-of-the-art closed-loop two phase (oil–water) flow facility including a multipass gear pump and a differential dielectric sensor (DDS) is used to identify the phase inversion region. Also, the facility utilizes an in-line droplet size analyzer (a high speed camera), to record real-time videos of oil–water emulsion to determine the droplet size distribution. The experimental data for phase inversion confirm that as shear intensity increases, the phase inversion occurs at relatively higher dispersed phase fractions. Also the data show that oil-in-water emulsion requires larger dispersed phase volumetric fraction for phase inversion as compared with that of water-in-oil emulsion under the same shear intensity conditions. Experiments for droplet size distribution confirm that larger droplets are obtained for the water continuous phase, and increasing the dispersed phase volume fraction leads to the creation of larger droplets.


2020 ◽  
Vol 5 (3) ◽  
pp. 050-058
Author(s):  
Nora Mamulaishvili ◽  
Gaioz Partskhaladze ◽  
Gocha Chavleshvili ◽  
Otar Janelidze ◽  
Nigar Salimova

The paper presents the results of the process of demulsification of crude oil, well No. 15 of the Supsa field. The reasons for the formation of persistent petroleum emulsion are considered, the component composition of crude oil is determined, including the content of the amount of formation water. The experiments were carried out at low (20-30)Hz and high (50-80) Hz frequencies of the magnetic field. The destruction of the oil-water emulsion was carried out without heat treatment under conditions of stabilization of the magnetic field and demulsifier Alkan 202. The technological scheme and parameters of crude oil dehydration are given. The influence of the magnetic field on the rate of destruction of the water-oil emulsion and the amount of released water is shown.


Author(s):  
Xinyu Lin ◽  
Zhihua Wang ◽  
Qingshan Feng ◽  
Lei Zhang ◽  
Yunfei Xu

Abstract Although the problem of wax deposition in multiphase transportation pipelines have been addressed and some related wax deposition models have been developed in recent years, the complex wax deposition paths derived from the potential variety of flow regimes in multiphase flow have not been well understood. This study presented a method for characterizing wax crystals aggregation behavior and developed a model for describing wax deposition path in oil/water two-phase flows. The impact of the emulsified water droplets on wax crystals aggregation in shearing flows was quantified using polarized light microscopy and image analysis method. The role of the emulsified water droplets in the wax deposition path reaching the upper side and lower side of pipeline wall was discussed by solving the developed model which involves the possible inclination angle of multiphase transportation pipeline. The availability of the mechanistic model was validated by the data and knowledge in the existing literature. The results indicated that wax crystals morphologies and structures tended to be regular with the enhancement of shearing effect, and their aggregation behavior were restrained. The circular degree and particle size of wax crystals showed a characteristic that it firstly increased and then decreased with the accumulation of emulsified water droplets in shearing flow, and this transition appeared to the phase inversion point of the oil/water two-phase. The velocity for wax crystals depositing to pipeline wall decreased and the time for wax crystals depositing to pipeline wall extended with the existence of emulsified water droplets. The wax deposition path became more complex in multiphase transportation, and such effect became remarkable when the dispersity of oil/water two-phase enhanced. Accordingly, the intractable wax deposition of waxy crude oil in cold environment transportation would be mitigated to some extent. This study contributes to comprehending the distinction of wax deposition mechanism in single-phase and multiphase transportation of waxy crude oil, and the proposed method and model are valuable for further predicting wax deposition in waxy crude oil emulsions pipelines. The findings in this study also point out an approach to conducting cost-effective flow assurance operations in crude oil production and transportation.


Author(s):  
Dongxu Sun ◽  
Zuoliang Zhu ◽  
Zhiyong Hu ◽  
Ming Wu

An experimental loop apparatus of heat insulated waxy crude oil pipeline was established to study the wax deposition behaviors. The effects of flow rate and ambient temperature on the thickness and wax content of deposition layer were investigated. A kinetic calculation model for the thickness and wax content of deposition layer in heat insulated crude oil pipeline was established based on the principle of molecular diffusion, aging and shear energy. The results calculated by the model are in good agreement with the experimental values. The wax deposition thickness of a heat insulated crude oil pipeline in different seasons and operation time in Northeast China was predicted according to the theoretical model, which was anticipated that can provide a scientific basis for formulating the wax removal cycle of the pipeline. The predicted results showed that the thickness of the wax deposition layer increases first and then decreases along the pipeline.


2018 ◽  
Vol 32 (10) ◽  
pp. 10605-10615 ◽  
Author(s):  
Haoran Zhu ◽  
Chuanxian Li ◽  
Fei Yang ◽  
Hongye Liu ◽  
Dinghong Liu ◽  
...  

2016 ◽  
Vol 9 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Jiaqiang Jing ◽  
Jiatong Tan ◽  
Haili Hu ◽  
Jie Sun ◽  
Peiyu Jing

Transparent model oils are commonly used to study the flow patterns and pressure gradient of crude oil-water flow in gathering pipes. However, there are many differences between the model oil and crude oils. The existing literatures focus on the flow pattern transition and pressure gradient calculation of model oils. This paper compares two most commonly used model oils (white mineral oil and silicon oil) with Xinjiang crude oil from the perspectives of rheological properties, oil-water interfacial tensions, emulsion photomicrographs and demulsification process. It indicates that both the white mineral oil and the crude oils are pseudo plastic fluids, while silicon oil is Newtonian fluid. The viscosity-temperature relationship of white mineral oil is similar to that of the diluted crude oil, while the silicon oil presents a less viscosity gradient with the increasing temperature. The oil-water interfacial tension can be used to evaluate the oil dispersing ability in the water phase, but not to evaluate the emulsion stability. According to the Turbiscan lab and the stability test, the model oil emulsion is less stable than that of crude oil, and easier to present water separation.


2017 ◽  
Vol 35 (18) ◽  
pp. 1831-1838 ◽  
Author(s):  
Ashish Dewangan ◽  
Ashok Kumar Yadav

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