Effect of Thermal Treatment Temperature on the Flowability and Wax Deposition Characteristics of Changqing Waxy Crude Oil

In waxy crude oil transportation process, wax crystals start to precipitate as the oil temperature drops to wax appearance point, and then form a network structure gradually which attaches to the wall. The problem of wax deposition seriously affects the normal operation of pipeline. Based on the wax deposition tendency coefficient method, combined with experimental data, the parameters related to wax deposition tendency coefficient is fitted, and the wax deposition rate equation of crude oil is determined finally. The variation law of wax deposition rate along the pipeline is analyzed, and the influence of different seasons and different throughput the on wax deposition rate is discussed subsequently.

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An Experimental Study on Wax Deposition of Water in Waxy Crude Oil Emulsions

Petroleum Science and Technology ◽

10.1080/10916460903096822 ◽

2010 ◽

Vol 28 (16) ◽

pp. 1653-1664 ◽

Cited By ~ 12

Author(s):

Y. Zhang ◽

J. Gong ◽

H. Wu

Keyword(s):

Experimental Study ◽

Crude Oil ◽

Wax Deposition ◽

Waxy Crude Oil ◽

Waxy Crude ◽

Oil Emulsions

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Review on the gelation of wax and pour point depressant in crude oil multiphase system

International Journal of Modern Physics B ◽

10.1142/s021797922130005x ◽

2021 ◽

Vol 35 (12) ◽

pp. 2130005

Author(s):

Hongmei Xu ◽

Yanpu Wang ◽

Kun Wang

Keyword(s):

Crude Oil ◽

Pour Point ◽

Molecular Design ◽

Research Progress ◽

Multiphase System ◽

Wax Deposition ◽

Pour Point Depressant ◽

Waxy Crude Oil ◽

Waxy Crude ◽

Point Depressant

The gelation of waxy crude oil multiphase system can result in the formation of network cementitious structure, which seriously impacts the safe and economic production of crude oil. This paper reviews current experimental, theoretical and numerical results on the gelation of wax in crude oil. For the experimental side, the most important problems are in situ measurement and measurement accuracy. On the theoretical side, the present methods own defects of low accuracy and limited application scope. Numerically, the models are of oversimplification, which are hardly applied to the real production. Besides, as a promising solution, the research progress of crude oil pour point depressant is also reviewed. The molecular design is a powerful approach to develop the optimized pour point depressant. The goals of this paper are to bridge the microscale atomic interactions and the macroscale physicochemical properties of waxy crude oil and pour point depressant, so as to lay a solid theoretical basis for preventing and controlling wax deposition in crude oil. These are beneficial to the future efficient, clean and safe energy production system.

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

ASME 2019 Asia Pacific Pipeline Conference ◽

10.1115/appc2019-7629 ◽

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.

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The Role of Emulsified Water in the Wax Deposition Path of a Waxy Crude Oil Multiphase Transportation Pipeline

ASME 2019 Asia Pacific Pipeline Conference ◽

10.1115/appc2019-7605 ◽

2019 ◽

Author(s):

Xinyu Lin ◽

Zhihua Wang ◽

Qingshan Feng ◽

Lei Zhang ◽

Yunfei Xu

Keyword(s):

Crude Oil ◽

Water Droplets ◽

Wax Deposition ◽

Waxy Crude Oil ◽

Two Phase ◽

Waxy Crude ◽

Oil Water ◽

Emulsified Water ◽

Pipeline Wall ◽

Wax Crystals

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.

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