Molecular dynamics simulation ongelation process of waxy crude oil

GUO Liping; XU Xiao; SUN Haiying; JIANG Yuzhuo

doi:10.6047/j.issn.1000-8241.2022.07.009

Oil & Gas Storage and Transportation > 2022 > 41(7): 819-825. > DOI: 10.6047/j.issn.1000-8241.2022.07.009

GUO Liping, XU Xiao, SUN Haiying, JIANG Yuzhuo. Molecular dynamics simulation ongelation process of waxy crude oil[J]. Oil & Gas Storage and Transportation, 2022, 41(7): 819-825. DOI: 10.6047/j.issn.1000-8241.2022.07.009

Citation:

PDF (3428 KB)

Molecular dynamics simulation ongelation process of waxy crude oil

1.
Northeast Petroleum University//MOE Key Laboratory of Enhanced Oil Recovery
2.
CNOOC (Tianjin) Pipeline Engineering Technology Co. Ltd.
3.
Daqing Oilfield Design Institute Co. Ltd.
4.
Pipeline Department, PetroChina Qinghai Oilfield Company

More Information

Received Date: January 02, 2021
Revised Date: April 06, 2022
Available Online: August 20, 2023

Graphical Abstract

Abstract

Abstract

Gelation of waxy crude oil is the source of its complex macroscopic rheological properties, while the rheological properties of waxy crude oil are the important basic data for pipeline transportation.Herein, two models of waxy crude oil system were established based on the macroscopic experimental data, and the molecular dynamics simulation was carried out using the Materials Studio software. In this way, the microscopic mechanism for gelation process of waxy crude oil was studied from the prospective of molecular dynamics. According to the results, the simulated condensation point value of crude oil is consistent with the experimental value through the judgment based on the density and diffusion coefficient. The sudden change of diffusion coefficient of wax crystal molecules and the deviation of mean square displacement are significantly reduced due to the formation of spatial network structure during crude oil gelation. By characterizing the change of microstructure of crude oil during gelationwith the radial distribution function, it is found that the peak value of radial distribution function between the same types of molecular increases gradually, and the largest degree of aggregation between wax crystals occurs at the condensation point. So, wax crystal molecule is the main factor that affects the condensation point of waxy crude oil. Generally, the research resultscouldprovide a basic theory for the acquisition of basic data concerning the pipeline transportation technology of waxy crude oil.
- waxy crude oil,
- molecular dynamics,
- gelation,
- condensation point,
- microscopic mechanism

FullText(HTML)

References (24)

References

[1]	于涛, 邓中华, 郭晔, 余川, 王谢, 董一凡. 石空—兰州含蜡原油管道运行方案优化[J]. 油气储运, 2014, 33(3): 332-334. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCY201403026.htm YU T, DENG Z H, GUO Y, YU C, WANG X, DONG Y F. Running scheme optimization of Shikong-Lanzhou Waxy Crude Oil Pipeline[J]. Oil & Gas Storage and Transportation, 2014, 33(3): 332-334. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCY201403026.htm
[2]	国丽萍, 徐秋仿, 刘扬. 胶凝含蜡原油的黏弹-触变特性[J]. 油气储运, 2020, 39(6): 645-649. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCY202006007.htm GUO L P, XU Q F, LIU Y. Viscoelastic-thixotropic properties of gelled waxy crude oil[J]. Oil & Gas Storage and Transportation, 2020, 39(6): 645-649. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCY202006007.htm
[3]	侯磊, 张劲军. 基于粘弹性分析的含蜡原油触变性研究[J]. 石油大学学报(自然科学版), 2005, 29(4): 84-86, 94. https://www.cnki.com.cn/Article/CJFDTOTAL-SYDX200504019.htm HOU L, ZHANG J J. Study on thixotropy of waxy crude based on viscoelasticity analysis[J]. Journal of the University of Petroleum, China (Edition of Natural Science), 2005, 29(4): 84-86, 94. https://www.cnki.com.cn/Article/CJFDTOTAL-SYDX200504019.htm
[4]	WAINWEIGHT T, ALDER B J. Molecular dynamics computations for the hard sphere system[J]. Il Nuovo Cimento (1955—1965), 1958, 9(1): 116-132.
[5]	陈雪娇, 侯磊, 李师瑶. 航空煤油冰点及黏温关系的分子动力学模拟[J]. 石油科学通报, 2016, 1(3): 493-502. https://www.cnki.com.cn/Article/CJFDTOTAL-SYKE201603020.htm CHEN X J, HOU L, LI S Y. Molecular dynamics simulation of freezing point and viscosity-temperature relationship of aviation kerosene[J]. Petroleum Science Bulletin, 2016, 1(3): 493-502. https://www.cnki.com.cn/Article/CJFDTOTAL-SYKE201603020.htm
[6]	苗杰, 龙军, 任强, 秦冰, 王振宇. 原油乳状液稳定机理的分子模拟研究[J]. 石油学报(石油加工), 2018, 34(1): 86-93. https://www.cnki.com.cn/Article/CJFDTOTAL-SXJG201801015.htm MIAO J, LONG J, REN Q, QIN B, WANG Z Y. Molecular simulation study on the stabilization mechanism of crude oil emulsion[J]. Acta Petrolei Sinica(Petroleum Processing Section), 2018, 34(1): 86-93. https://www.cnki.com.cn/Article/CJFDTOTAL-SXJG201801015.htm
[7]	王共元, 周勋, 万霞, 殷开梁. 分子动力学模拟几种生物柴油模拟系统的冷滤点[J]. 常州大学学报(自然科学版), 2012, 24(2): 88-92. https://www.cnki.com.cn/Article/CJFDTOTAL-JSSY201202019.htm WANG G Y, ZHOU X, WAN X, YIN K L. Molecular dynamics simulation on cold filter plugging point (CFPP) of several modeled biodiesel systems[J]. Journal of Changzhou University (Natural Science Edition), 2012, 24(2): 88-92. https://www.cnki.com.cn/Article/CJFDTOTAL-JSSY201202019.htm
[8]	崔青, 张长桥, 修建新, 许士明, 卢丽丽. 稠油沥青质胶质降粘机理的分子动力学模拟[J]. 山东大学学报(工学版), 2017, 47(2): 123-130. https://www.cnki.com.cn/Article/CJFDTOTAL-SDGY201702020.htm CUI Q, ZHANG C Q, XIU J X, XU S M, LU L L. Molecular dynamic simulation on the mechanism of viscosity reduction to asphaltene and resin in heavy oil[J]. Journal of Shandong University (Engineering Science), 2017, 47(2): 123-130. https://www.cnki.com.cn/Article/CJFDTOTAL-SDGY201702020.htm
[9]	刘刚, 付伟娜, 滕厚兴, 张国忠, 陈雷. 流变仪响应特性对含蜡原油屈服应力测试结果的影响[J]. 油气储运, 2017, 36(4): 403-408. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCY201704008.htm LIU G, FU W N, TENG H X, ZHANG G Z, CHEN L. The effects of rheometer response characteristics on yield stress test results of waxy crude oil[J]. Oil & Gas Storage and Transportation, 2017, 36(4): 403-408. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCY201704008.htm
[10]	贾邦龙, 张劲军. 含蜡原油触变性测试方法[J]. 油气储运, 2012, 31(4): 254-259. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCY201204008.htm JIA B L, ZHANG J J. Thixotropy test method of waxy crude oil[J]. Oil & Gas Storage and Transportation, 2012, 31(4): 254-259. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCY201204008.htm
[11]	GAO P, ZHANG J J, MA G X. Direct image-based fractal characterization of morphologies and structures of wax crystals in waxy crude oils[J]. Journal of Physics: Condensed Matter, 2006, 18(50): 11487.
[12]	李生华, 刘晨光, 梁文杰, 朱亚杰. 从石油溶液到碳质中间相——Ⅲ. 抑制生/结焦的物理化学[J]. 石油学报(石油加工), 1995, 11(2): 72-76. https://www.cnki.com.cn/Article/CJFDTOTAL-SXJG199502010.htm LI S H, LIU C G, LIANG W J, ZHU Y J. From petroleum solution to carbonaceous mesophase Ⅲ. Physicochemical approaches to coke suppression[J]. Acta Petrolei Sinica(Petroleum Processing Section), 1995, 11(2): 72-76. https://www.cnki.com.cn/Article/CJFDTOTAL-SXJG199502010.htm
[13]	BOUHADDA Y, BORMANN D, SHEU E, BENDEDOUCH D, KRALLAFA A, DAAOU M. Characterization of Algerian Hassi-Messaoud asphaltene structure using Raman spectrometry and X-ray diffraction[J]. Fuel, 2007, 86(12/13): 1855-1864.
[14]	张宏玉, 王艳艳, 陶国强, 桂彬, 殷长龙, 柴永明, 等. 石油化学粗粒化分子力学/分子动力学力场: Ⅰ. 烷烃的粗粒化模型[J]. 化学学报, 2011, 69(17): 2053-2062. https://www.cnki.com.cn/Article/CJFDTOTAL-HXXB201117017.htm ZHANG H Y, WANG Y Y, TAO G Q, GUI B, YIN C L, CHAI Y M, et al. Coarse grained molecular mechanics (MM)/molecular dynamics (MD) force field for petroleum chemistry: Ⅰ. Coarse grained model for alkanes in petroleum[J]. Acta Chimica Sinica, 2011, 69(17): 2053-2062. https://www.cnki.com.cn/Article/CJFDTOTAL-HXXB201117017.htm
[15]	殷开梁, 徐端钧, 夏庆, 叶雅静, 邬国英, 陈正隆. 正十六烷体系凝固过程的分子动力学模拟[J]. 物理化学学报, 2004, 20(3): 302-305. https://www.cnki.com.cn/Article/CJFDTOTAL-WLHX200403016.htm YIN K L, XU D J, XIA Q, YE Y J, WU G Y, CHEN Z L. Molecular dynamics simulation on solidification process of n-hexadecane systems[J]. Acta Physico-Chimica Sinica, 2004, 20(3): 302-305. https://www.cnki.com.cn/Article/CJFDTOTAL-WLHX200403016.htm
[16]	KOWALEWSKI I, VANDENBROUCKE M, HUC A Y, TAYLOR M J, FAULON J L. Preliminary results on molecular modeling of asphaltenes using structure elucidation programs in conjunction with molecular simulation programs[J]. Energy & Fuels, 1996, 10(1): 97-107.
[17]	孙炜, 黄素逸, 王存文, 池汝安. 超临界水密度和自扩散系数预测的分子动力学模拟[J]. 华中科技大学学报(自然科学版), 2008, 36(5): 103-105. https://www.cnki.com.cn/Article/CJFDTOTAL-HZLG200805037.htm SUN W, HUANG S Y, WANG C W, CHI R A. Numeral simulation of the densities and self-diffusion coefficients of supercritical water by molecular dynamics method[J]. Journal of Huazhong University of Science and Technology (Natural Science Edition), 2008, 36(5): 103-105. https://www.cnki.com.cn/Article/CJFDTOTAL-HZLG200805037.htm
[18]	RAPAPORT D C. Molecular dynamics simulation[J]. Computing in Science & Engineering, 1999, 1(1): 70-71.
[19]	KWON T W, LEE S H. Molecular dynamics simulation studies of mid-size liquid n-alkanes, C12－C160[J]. Bulletin of the Korean Chemical Society, 2015, 36(4): 1165-1171.
[20]	CHOI J, YU S, YANG S, CHO M. The glass transition and thermoelastic behavior of epoxy-based nanocomposites: a molecular dynamics study[J]. Polymer, 2011, 52(22): 5197-5203.
[21]	陈正隆, 徐为人, 汤立达. 分子模拟的理论与实践[M]. 北京: 化学工业出版社, 2007: 110-113. CHEN Z L, XU W R, TANG L D. The theory and practice of molecular dynamics[M]. Beijing: Chemical Industry Press, 2007: 110-113.
[22]	殷开梁, 闫朋克, 孙静, 周荣慧, 杨宝珠. 生物柴油分子系统凝固过程的分子动力学模拟[J]. 计算机与应用化学, 2011, 28(5): 602-606. https://www.cnki.com.cn/Article/CJFDTOTAL-JSYH201105024.htm YIN K L, YAN P K, SUN J, ZHOU R H, YANG B Z. Molecular dynamics simulation on solidification process of bio-diesel molecular systems[J]. Computers and Applied Chemistry, 2011, 28(5): 602-606. https://www.cnki.com.cn/Article/CJFDTOTAL-JSYH201105024.htm
[23]	赵晓非, 刘立新, 孟秋菊, 赵春雷, 张立新. 高蜡原油蜡晶形态及降凝剂的影响[J]. 大庆石油学院学报, 2005, 29(5): 55-57, 127. https://www.cnki.com.cn/Article/CJFDTOTAL-DQSY200505015.htm ZHAO X F, LIU L X, MENG Q J, ZHAO C L, ZHANG L X. Morphology of crystals of waxy crude oil and susceptibility to pour point depressant[J]. Journal of Daqing Petroleum Institute, 2005, 29(5): 55-57, 127. https://www.cnki.com.cn/Article/CJFDTOTAL-DQSY200505015.htm
[24]	LI M, LIU X Y, QIN J Q, GU Y. Molecular dynamics simulation on glass transition temperature of isomeric polyimide[J]. Express Polymer Letters, 2009, 3(10): 665-675.

Supplements (0)

Cited By

Get Citation

PDF

XML

Article views PDF downloads

Turn off MathJax

Article Contents

Abstract

References

Molecular dynamics simulation ongelation process of waxy crude oil

Abstract

References

Catalog

Export File

Citation

Format

Content