Stability of Crude Oil Emulsion Characterized by Conductivity Difference between Upper and Lower Layers

doi:10.12422/j.issn.1006-396X.2023.03.003

Abstract

Abstract:

This paper studies the stability of crude oil emulsion characterized by conductivity difference between upper and lower layers. According to the changes of conductivity in the upper and lower layers of crude oil emulsion system, combined with optical microscope observation, the methods and conditions to characterize the stability of crude oil emulsion can be studied by the difference of conductivity between the upper and lower layers. Research finds that when the crude oil system is demulsified and phase separated, the composition, morphology and conductivity of the upper and lower emulsions will be different.Therefore, the conductivity difference between the upper and lower emulsions can be used as the characterization parameter of emulsion stability. By measuring the conductivity and the difference values of the upper and lower layers of the system at different electrical test signal frequencies (0.1,1.0,10.0,100.0 kHz), it is found that the conductivity values and the difference values at high frequency are greater than those at low frequency, and the sensitivity is higher. In addition,when the conductivity difference is greater than 15%, the system is unstable. The experimental results show that the method is also suitable for emulsion system containing anionic surfactant.

Key words: Crude oil emulsion, Stability, Difference between the upper and lower level, Conductivity, Electrical frequency

摘要：

建立了表征原油乳状液稳定性的上下层电导率差异法。根据原油乳状液上下层电导率的变化，结合光学显微镜观察，研究了利用原油乳状液上下层电导率差异值来表征原油乳状液稳定性的条件和方法。研究发现，当原油乳状液破乳分相时，上下层原油乳状液的组成、形态以及电导率出现差异，因而可利用上下层的电导率差异值作为原油乳状液稳定性的表征参数。通过测定不同电学频率（0.1、1.0、10.0、100.0 kHz）下的原油乳状液上下层电导率及其差异值，发现高电学频率时上下层原油乳状液电导率及差异值均大于低电学频率下的数值，且灵敏度更高；当上下层电导率差异值大于15%时，原油乳状液表现为不稳定。结果表明，该方法也同样适用于含阴离子型表面活性剂的原油乳状液。

关键词: 原油乳状液, 稳定性, 上下层差异, 电导率, 电学频率

CLC Number:

TQ014

Huan Sun, Lei Liu, Yuguo Liu, Tingyu Hu, Longli Zhang. Stability of Crude Oil Emulsion Characterized by Conductivity Difference between Upper and Lower Layers[J]. Journal of Petrochemical Universities, 2023, 36(3): 17-23.

孙桓, 刘磊, 刘玉国, 胡婷玉, 张龙力. 上下层电导率差异法表征原油乳状液稳定性[J]. 石油化工高等学校学报, 2023, 36(3): 17-23.

Figures/Tables 11

Fig.1 Diagram of the casing used in the experiment

Fig.2 The curve changes of the upper conductivity with time of crude oil emulsion at different electrical frequencies(without surfactant)

Fig.3 The curve changes of the layer conductivity with time of crude oil emulsion at different electrical frequencies(without surfactant)

Fig.4 The curve changes of conductivity difference with time of crude oil emulsion at different electrical frequencies(without surfactant)

Fig.5 Microscopic observation of crude oil emulsion

Fig.6 Particle size distribution of emulsion droplets

Fig.7 The curve changes of the upper conductivity with time of crude oil emulsion at different electrical frequencies(with SDBS)

Fig.8 The curve changes of the layer conductivity with time of crude oil emulsion at different frequencies(with SDBS)

Fig.9 The curve changes of conductivity difference with time of crude oil emulsion at different electrical frequencies(with SDBS)

Fig.10 Microscopic observation of crude oil emulsion after adding SDBS

Fig.11 Particle size distribution of emulsion droplets with SDBS

References 17

1	Rashid Z，Wilfred C D，Gnanasundaram N，et al.A comprehensive review on the recent advances on the petroleum asphaltene aggregation［J］.Journal of Petroleum Science and Engineering，2019，176：249⁃268.
2	李柏林，冯聪聪，杨凤艳，等.原油乳状液稳定性影响因素［J］.化学工程师，2013，27（11）：41⁃43.
	Li B L，Feng C C，Yang F Y，et al.Influencing factors of crude oil emulsion stability［J］.Chemical Engineer，2013，27（11）： 41⁃43.
3	Daaou M，Larbi A，Martinez B，et al.A comparative study of the chemical structure of asphaltenes from algerian petroleum collected at different stages of extraction and processing［J］.Journal of Petroleum Science and Engineering，2016，138：50⁃56.
4	Umar A A，Saaid I B M，Sulaimon A A，et al.A review of petroleum emulsions and recent progress on water⁃in⁃crude oil emulsions stabilized by natural surfactants and solids［J］.Journal of Petroleum Science and Engineering，2018，165：673⁃690.
5	赖南君，彭琴，叶仲斌，等.重质组分对稠油乳状液稳定性的影响［J］.西南石油大学学报（自然科学版），2014，36（1）： 145⁃149.
	Lai N J，Peng Q，Ye Z B，et al.Influence of heavy components on the heavy oil emulsion stability［J］.Journal of Southwest Petroleum University（Science & Technology Edition），2014，36（1）：145⁃149.
6	李明远，甄鹏，吴肇亮，等.原油乳状液稳定性研究Ⅵ.界面膜特性与原油乳状液稳定性［J］.石油学报（石油加工），1998，14（3）：1⁃5.
	Li M Y，Zhen P，Wu Z L，et al.Investigation of stability of water in crude oil emulsions Ⅵ.Properties of interfacial film and stability of crude oil emulsions［J］.Acta Petrolei Sinica （Petroleum Processing Section），1998，14（3）：1⁃5.
7	刘杨，王占胜，杨杰，等.影响水包油型乳化液稳定性的因素研究［J］.应用化工，2017，46（7）：1266⁃1269.
	Liu Y，Wang Z S，Yang J，et al.Study on the influence factors of oil in water emulsion stability［J］.Applied Chemical Industry，2017，46（7）：1266⁃1269.
8	孙琳，任梓寒，石彦，等.原油活性组分及相互作用对乳状液稳定性影响的研究进展［J］.油田化学，2022，39（2）：373⁃380.
	Sun L，Ren Z H，Shi Y，et al.Research progress of active components in crude oil and interaction on influence of emulsion stability［J］.Oilfield Chemistry，2022，39（2）：373⁃380.
9	Tian S J，Gao W，Liu Y J，et al.Study on the stability of heavy crude oil⁃in⁃water emulsions stabilized by two different hydrophobic amphiphilic polymers［J］.Colloids and Surfaces A：Physicochemical and Engineering Aspects，2019，572： 299⁃306.
10	徐明进，李明远，彭勃，等.Zeta电位和界面膜强度对水包油乳状液稳定性影响［J］.应用化学，2007，24（6）：623⁃627.
	Xu M J，Li M Y，Peng B，et al.Effects of strength of interfacial film and zeta potential on oil⁃in⁃water emulsion stability［J］.Chinese Journal of Applied Chemistry，2007，24（6）：623⁃627.
11	方洪波，林梅钦.阳离子聚合物对孤东原油乳状液的破乳研究［J］.石油化工高等学校学报，2018，31（4）：57⁃62.
	Fang H B，Lin M Q.Demulsification of Gudong crude oil emulsion by cationic functional polymers and the properties of oil⁃water interface［J］.Journal of Petrochemical Universities，2018，31（4）：57⁃62.
12	刘义刚，谢良波，赵鹏，等.渤海S油田聚合物驱采出液油水界面膜的稳定性分析［J］.油田化学，2020，37（1）：144⁃149.
	Liu Y G，Xie L B，Zhao P，et al.Stability analysis of polymer flooding produce fluid interface membrane in Bohai oilfield［J］.Oil Chemistry，2020，37（1）：144⁃149.
13	王志华，许云飞，戚向东，等.乳状液稳定性影响因素及其分子动力学模拟研究进展［J］.油田化学，2021，38（2）：360⁃367.
	Wang Z H，Xu Y F，Qi X D，et al.Research progress on influencing factors of emulsion stability with molecular dynamics simulation［J］.Oil Chemistry，2021，38（2）：360⁃367.
14	倪良，蒋文华，韩世钧.电导法研究硝基苯/水/十二烷基硫酸钠乳状液的稳定性［J］.化工学报，2001，52（12）：1104⁃1108.
	Ni L，Jiang W H，Han S J.Stability of emulsion composed of nitrobenzene/water/sodium dodecyl sulfate by conductance measurement［J］.Journal of Chemical Industry and Engineering（China），2001，52（12）：1104⁃1108.
15	张黎明，何利民，吕宇玲，等.油包水乳状液电导率与电破乳研究［J］.油田化学，2008，25（2）：158⁃161.
	Zhang L M，He L M，Lü Y L，et al.A study on electrical demulsification/dehydration and electric conductivity for W/O emulsions［J］.Oilfield Chemistry，2008，25（2）：158⁃161.
16	刘真，谯夫，海霞.界面张力对原油乳状液稳定性影响的探讨［J］.石油化工应用，2015，34（8）：123⁃124.
	Liu Z，Qiao F，Hai X.Discussion on the influence of interface tension on the stability of crude oil emulsion［J］.Petrochemical Industry Application，2015，34（8）：123⁃124.
17	李新学，林瑞森.油水界面行为对原油乳状液破乳的影响［J］.日用化学工业，2001，31（6）：14⁃15.
	Li X X，Lin R S.Effect of water/oil interfacial behavior on demulsification of crude oil emulsions［J］.China Surfactant Detergent & Cosmetics，2001，31（6）：14⁃15.

[1]	Ping FANG, Kangxin CHEN, Yuting LIN, Kaihao FAN, Chengyu SHAN, Xuesong LIU. The Regulation of MoO _x State and Its Effect on the Denitration Performance and Thermal Stability of VO _x /MoO _x ⁃TiO₂ Catalysts [J]. Journal of Petrochemical Universities, 2024, 37(4): 40-48.
[2]	Ao LUO, Xiaolin ZHANG, Na SUN, Haiyan WANG, Yujia WANG. Study on Improving the Light Stability of Paraffin [J]. Journal of Petrochemical Universities, 2023, 36(5): 24-30.
[3]	Xi Chen, Ying Jin, Ji Ma, Leilei Zhang, Zhaoyuan Song. Study on Cobalt Free Iron Base Like Perovskite as Cathode of SOFC [J]. Journal of Petrochemical Universities, 2023, 36(4): 69-74.
[4]	Jie Li, Zhiqiang Zhang, Yue Fu, Shujun Chen, Yao Xu, Haixu Fan. Numerical Simulation of Hydrogen Storage Process in MIL⁃101(Cr) with Different Thermal Conductivity [J]. Journal of Petrochemical Universities, 2023, 36(3): 31-36.
[5]	Xiang Wang, Jinhui Gu, Qing Liu, Zhaoyang Fei, Xian Chen, Mifen Cui, Xu Qiao. Study on Shaped Activated Carbon from Catechol Rectification Residue [J]. Journal of Petrochemical Universities, 2023, 36(3): 66-73.
[6]	Gaojun An, Zhenzhen Xue, Ximeng Xu, Yangfeng Xia, Yawen Liu, Changbo Lu, Zhe Zheng. Study on the Application Performance of Polyoxymethylene Dimethyl Ethers [J]. Journal of Petrochemical Universities, 2023, 36(1): 16-24.
[7]	Yingxi Liu, Jilin Wang, Lulu Wang, Zhiqiang Qu. Phytic Acid Framework⁃Based Alkaline Anion Exchange Membrane Construction for Fuel Cells [J]. Journal of Petrochemical Universities, 2023, 36(1): 74-80.
[8]	Wei Zhou, Jian Zhang, Wenqiang Qiao, Xi Sun, Yucai Qin, Lijuan Song. Effects of Acetylacetone Ligand on Catalytic Performance of SnCl₂/AC in Acetylene Hydrochlorination [J]. Journal of Petrochemical Universities, 2022, 35(2): 37-42.
[9]	Chenzhengzhe Yan, Lizhen Chen, Chuanhui Gao, Yumin Wu. Preparation and Characterization of Self⁃Healing Silicone Elastomers Based on Dynamic Imine Bonds [J]. Journal of Petrochemical Universities, 2021, 34(5): 9-15.
[10]	Yulong Li, Xing Sun, Xiaoling Li, Yuguo Wu, Guofu Wang. The Finite Element Analysis of the Influence of Arch Foot Displacement on Out⁃of⁃Plane Stability of Circular Arch Pipe [J]. Journal of Petrochemical Universities, 2021, 34(4): 72-77.
[11]	Wang Enbo， Xu Chunbi， Gao Feihong. Experimental Study on Acid Fracturing Conductivity of Carbonate Rocks in M5 Block [J]. Journal of Petrochemical Universities, 2021, 34(2): 60-65.
[12]	Zhang Jian, Sun Xi, Zhou Wei, Qiao Wenqiang, Qin Yucai, Song Lijuan. Effects of Bi and Cu Additives on Catalytic Performance of SnCl₄/AC for Acetylene Hydrochlorination [J]. Journal of Petrochemical Universities, 2020, 33(1): 7-11.
[13]	Hou Binbin，Dong Lina，Gao Lijun，Hou Wenge，Luo Yunxin，Tian Chuanchuan，Xu Lei. Evaluation of the Comprehensive Performance of the Environmentally⁃Friendly Acid System of FF⁃01 [J]. Journal of Petrochemical Universities, 2019, 32(5): 19-23.
[14]	Li Chuanxian，Li Tongyu，Yang Shuang，You Jia，Li Xiaoteng，Yang Fei，Sun Guangyu. Research of Solubility and Stability of Dissolved Gas Crude Oil Emulsion [J]. Journal of Petrochemical Universities, 2019, 32(5): 69-75.
[15]	Tian Zhongyuan，Lu Xiangguo，Cao Weijia，Chen Qing，Yan Dong. Experimental Study on Fracture Conductivity of Self Suspension and Ordinary Proppant [J]. Journal of Petrochemical Universities, 2019, 32(3): 33-38.