Modeling of solid wax content in wax deposits

The problem of wax deposition in crude oil pipelines is one of the important concerns for flow assurance in recent 50 years. Herein, the solid wax content in wax deposit was modeled with the precipitation enthalpy and precipitation entropy based on the wax precipitation characteristics to characteri...

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Main Authors: Xun ZHANG, Qiyu HUANG, Xuedong GAO, Yu ZHANG, Xiangrui ZHU, Dongxu ZHANG
Format: Article
Language:zho
Published: Editorial Office of Oil & Gas Storage and Transportation 2022-03-01
Series:You-qi chuyun
Subjects:
Online Access:http://yqcy.xml-journal.net/cn/article/doi/10.6047/j.issn.1000-8241.2022.03.012
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author Xun ZHANG
Qiyu HUANG
Xuedong GAO
Yu ZHANG
Xiangrui ZHU
Dongxu ZHANG
author_facet Xun ZHANG
Qiyu HUANG
Xuedong GAO
Yu ZHANG
Xiangrui ZHU
Dongxu ZHANG
author_sort Xun ZHANG
collection DOAJ
description The problem of wax deposition in crude oil pipelines is one of the important concerns for flow assurance in recent 50 years. Herein, the solid wax content in wax deposit was modeled with the precipitation enthalpy and precipitation entropy based on the wax precipitation characteristics to characterize accurately and quantitatively the change of solid wax content with temperature. Meanwhile, the solid wax content model expressed by crystallization activation energy of wax deposits was further derived according to the van't Hoff equation, which is helpful to understanding the precipitation process of wax crystal. In addition, the model was validated by comparing the model's calculation results with the experimental results of field pipeline wax deposits and using the experimental wax deposits at different oil-wax ratios to fit the model. Moreover, the mechanism of different influencing factors acting on the precipitation process of wax crystal in wax deposits was investigated on the basis of the solid wax content model. The results show that both the cooling rate and the carbon number-based composition of wax deposits affect the precipitation process of n-alkanes in wax deposit by changing the free energy of crystallization. Generally, the model can well describe the change of solid wax content in wax deposit with temperature, thus laying a theoretical foundation for the study of the strength of wax deposits and having the value for application in the field of pigging technology for crude oil pipelines.
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spelling doaj.art-b686aafd83ef4a2ba7de22112302299e2024-04-13T02:28:13ZzhoEditorial Office of Oil & Gas Storage and TransportationYou-qi chuyun1000-82412022-03-0141333233810.6047/j.issn.1000-8241.2022.03.012yqcy-41-3-332Modeling of solid wax content in wax depositsXun ZHANG0Qiyu HUANG1Xuedong GAO2Yu ZHANG3Xiangrui ZHU4Dongxu ZHANG5College of Mechanical and Transportation Engineering, China University of Petroleum (Beijing)//Beijing Key Laboratory of Urban Oil and Gas Distribution TechnologyCollege of Mechanical and Transportation Engineering, China University of Petroleum (Beijing)//Beijing Key Laboratory of Urban Oil and Gas Distribution TechnologyCollege of Mechanical and Transportation Engineering, China University of Petroleum (Beijing)//Beijing Key Laboratory of Urban Oil and Gas Distribution TechnologyCollege of Mechanical and Transportation Engineering, China University of Petroleum (Beijing)//Beijing Key Laboratory of Urban Oil and Gas Distribution TechnologyCollege of Mechanical and Transportation Engineering, China University of Petroleum (Beijing)//Beijing Key Laboratory of Urban Oil and Gas Distribution TechnologyCollege of Mechanical and Transportation Engineering, China University of Petroleum (Beijing)//Beijing Key Laboratory of Urban Oil and Gas Distribution TechnologyThe problem of wax deposition in crude oil pipelines is one of the important concerns for flow assurance in recent 50 years. Herein, the solid wax content in wax deposit was modeled with the precipitation enthalpy and precipitation entropy based on the wax precipitation characteristics to characterize accurately and quantitatively the change of solid wax content with temperature. Meanwhile, the solid wax content model expressed by crystallization activation energy of wax deposits was further derived according to the van't Hoff equation, which is helpful to understanding the precipitation process of wax crystal. In addition, the model was validated by comparing the model's calculation results with the experimental results of field pipeline wax deposits and using the experimental wax deposits at different oil-wax ratios to fit the model. Moreover, the mechanism of different influencing factors acting on the precipitation process of wax crystal in wax deposits was investigated on the basis of the solid wax content model. The results show that both the cooling rate and the carbon number-based composition of wax deposits affect the precipitation process of n-alkanes in wax deposit by changing the free energy of crystallization. Generally, the model can well describe the change of solid wax content in wax deposit with temperature, thus laying a theoretical foundation for the study of the strength of wax deposits and having the value for application in the field of pigging technology for crude oil pipelines.http://yqcy.xml-journal.net/cn/article/doi/10.6047/j.issn.1000-8241.2022.03.012wax depositssolid wax content modelgibbs free energyprecipitation enthalpyfree energy of crystallization
spellingShingle Xun ZHANG
Qiyu HUANG
Xuedong GAO
Yu ZHANG
Xiangrui ZHU
Dongxu ZHANG
Modeling of solid wax content in wax deposits
You-qi chuyun
wax deposits
solid wax content model
gibbs free energy
precipitation enthalpy
free energy of crystallization
title Modeling of solid wax content in wax deposits
title_full Modeling of solid wax content in wax deposits
title_fullStr Modeling of solid wax content in wax deposits
title_full_unstemmed Modeling of solid wax content in wax deposits
title_short Modeling of solid wax content in wax deposits
title_sort modeling of solid wax content in wax deposits
topic wax deposits
solid wax content model
gibbs free energy
precipitation enthalpy
free energy of crystallization
url http://yqcy.xml-journal.net/cn/article/doi/10.6047/j.issn.1000-8241.2022.03.012
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AT xuedonggao modelingofsolidwaxcontentinwaxdeposits
AT yuzhang modelingofsolidwaxcontentinwaxdeposits
AT xiangruizhu modelingofsolidwaxcontentinwaxdeposits
AT dongxuzhang modelingofsolidwaxcontentinwaxdeposits