CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Shikun Tong,Kele Yan,Jianbo Zhang,Zhiyuan Wang
Hydrate and wax phase transitions are typical flow risks during oil and gas development. The wax on hydrate formation was systematically studied based on dual-scale experimental platform. The sensitivity analysis on hydrate growth illustrates that the wax inhibits hydrate growth and the maximum reduction of hydrate growth rate is 79.6 % in waxy emulsions, and the wax on hydrate conversion ratio decreased the most by 27.2 %. The promoting effect of water content, subcooling, and stirring rate on hydrate growth increased by more than 10 times, 2 times, and 7 times, respectively. The droplet size first decreases and then increases as the wax concentration increases in emulsions. The mechanism of hydrate growth in waxy emulsions considers bidirectional growth and pores renewal of hydrate particles, and the mean error of the prediction model is 8.4 %. This work provides data basis and theoretical foundation for flow assurance management in oil and gas filed.
研究领域:
石油工程
·
化学工程
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2022
·
IF 4.654
Yijie Wang,Qiyu Huang,Dongxu Zhang,Kun Wang,Xun Zhang,Yu Zhang,Zhenkang Xu,WenChen Liu
The formation of hydrate increases the uncertainty of the flow system in subsea multiphase transportation pipelines. Waxes and asphaltenes have been found to influence hydrate formation, but the detailed mechanism of their interaction remains unclear. A lab-scale high-pressure stirring reactor was used to analyze the influence of asphaltenes on CO2 hydrate evolution behavior in waxy water-in-oil (W/O) emulsions. Results demonstrated that waxes inhibited CO2 hydrate nucleation. The addition of asphaltenes promoted the inhibition effect of waxes, and the enhancement effect was nonmonotonic with the asphaltene contents increased. Based on microscopic observation and wax precipitation characteristics, this behavior could be interpreted as the competitive effect of increased adsorption of wax crystals on the surface of the droplets and reduced amount of wax precipitation. Moreover, asphaltenes were found to facilitate the decomposition process of CO2 hydrates in waxy systems by decreasing the wax precipitation amount and stabilizing the emulsion. This work can provide potential engineering guidance for flow assurance applications.
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2018
·
IF 3.024
Dongfang Liu,Yuxin Suo,Jihe Zhao,Peiyao Zhu,Jiang Tan,Baogang Wang,Hongsheng Lu
Acidic substances (naphthenic acids) were found in crude oil, which provides favorable conditions for the formation of surfactants. N,N-Dimethylcyclohexylamine (DMCHA) can activate the naphthenic acid in the crude oil to form the surfactant by noncovalent bonding. This process has an unusual meaning for the crude oil pipelines transportation by the method of forming a low-viscosity oil-in-water emulsion. At the same time, CO2 can be used as a demulsifier to separate crude oil and water at the end of pipeline transportation because the surfactant has a CO2 stimulus response characteristic. In our study, it was found that crude oil-in-water emulsion can be formed and has very good stability. CO2 has a high demulsification efficiency in emulsions with lower crude oil content. For high oil content conditions, the emulsion cannot be demulsified completely by CO2. Since sulfuric acid, hydrochloric acid, and the like are liquid and corrosive, this is not conducive to its application as a demulsifier in crude oil pipeline transportation. Organic acids in this area have a stronger advantage obviously, so citric acid, oxalic acid, acetic acid, and lactic acid were used as demulsifiers in this article; all of them have good demulsification performance in high crude oil content emulsions, especially citric acid. Meanwhile, DMCHA can be recycled and reused by adding NaOH to the lower aqueous solution after demulsification.
研究领域:
化学工程
·
石油工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2020
·
IF 3.99
Jingjing Jiang,Yongfan Tang,Lihua Huang,Xi Yuan,Yue Wang,Ganghua Huang,Gang Xiong,Li Zhang
Deposition in natural gas pipelines is an issue of enormous economic and security consequences. In the past, corrosion products, elemental sulfur, hydrates and sand were common deposits in these pipelines. This study demonstrates for the first time the emulsion gel-like structure of deposit collected from Long Gang gas field in Sichuan, China. Rheological testing, thermal stability analysis, oil-water-solid three-phase ratio analysis, microscopic observations, and oil composition analysis were used for further investigation of the microstructure and macro-properties. The results suggest that the deposit has a water-in-oil emulsion structure with a high internal phase. It is extremely stable at room temperature but quickly separates into the water (79.1 wt%), oil (20.3 wt%), and solid (0.6 wt%) fractions at 80 °C. Resins and asphaltenes are two major components of the oil fraction, and they play an important role in deposit formation by strengthening the interfacial film between the oil and water phases. We speculate that the accumulation of deposits in pipelines is attributed to the emulsification of oilfield chemicals with water, hydrocarbons, natural minerals, and other gas well products under the influence of high temperature, pressure, and flow rate, among others. Finally, we provide a possible solution to deal with the deposit. The results reported in this study are expected to be useful in the development of pipeline cleaning techniques and in minimizing deposit formation.
研究领域:
石油工程
·
材料科学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Dongxu Zhang,Xin Wang,Cheng Liu,Lechun Song,Huiyuan Li,Qiyu Huang,Jianfeng Zhang
Hydrate formation is one of the major flow assurance issues for the subsea multiphase pipelines. The effects of the interaction between heavy fractions of crude oil components on hydrate behaviors are still not well understood. In this study, the effects of resins on hydrate formation behaviors in asphaltene-containing emulsions were investigated using a high-pressure reactor apparatus. The results indicated that both resins and asphaltenes inhibited hydrate nucleation and increased the induction time. Furthermore, considerable synergistic effects of asphaltenes and resins on the hydrate formation behaviors were discovered in the water-in-oil emulsions, depending on the aggregation state of asphaltenes. The addition of resins was observed to disperse the asphaltene aggregates significantly and enhance the inhibitory effect of asphaltenes on hydrate nucleation. Additionally, the calculated results of gas consumption showed that the presence of resins can decrease the growth rate of hydrates in the asphaltene-containing emulsions. A potential mechanism was presented to illustrate how resins affect hydrate formation in an emulsion with varying asphaltene aggregation states. These findings offer a better knowledge of the synergistic effects between the heavy components of resins and asphaltenes and have potential application in the hydrate management of crude oil pipelines.
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Shikun Tong,Pengfei Li,Fengjun Lv,Zhiyuan Wang,Weiqi Fu,Jianbo Zhang,Litao Chen,Xuerui Wang
Clarifying the effect of wax on hydrate formation and dissociation are important for the safe and high-efficient development of deep-water oil and gas fields. In this study, a series of experiments on the effect of wax on hydrate formation and dissociation in water-in-oil emulsions were systematically studied based on the variation analysis of temperature, pressure, torque, oil–water interface area morphology and water droplet size in emulsions. Microscopic images reveal that wax crystals form shell barriers on the oil–water interface, which increases transfer resistance, and the particle focused beam reflectance illustrates that the wax crystals decrease the water droplet size, which increases the oil–water interface area in emulsions. With increasing wax concentration, the hydrate induction time and growth rate show a bimodal shape because of the dual regulation of wax in emulsions, involving the inhibition effect of the transfer barrier layer and the promotion effect of the increasing water–oil interface area. The inhibition effect on hydrate formation was dominant when the wax concentration exceeds 6 wt%, resulting in a rapid decrease in both the growth rate and conversion ratio with increasing wax concentration. Compared with the bimodal shape of hydrate formation, the inhibition effect of wax on hydrate dissociation is the dominant regulation factor. The duration of complete hydrate dissociation by depressurization increased linearly with the increasing wax concentration, which increased the operation difficulty of hydrate plug removal. These experimental results provide valuable references for hydrate risk assessment and optimization of the project design of flow assurance for deep-water oil and gas fields.
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2025
·Vol. 18
·期 3
·630
·
IF 3.2
Yan Peng,Xiangyu Zhang,Lihua Cheng,Hong Zhang,Jieyun Tang,Hong Chen,Qinzhen Fan,Xinping Ouyang
The presence of asphaltene, especially in heavy crude oil, causes difficulties in the de-watering/desalting process, which is the initial step of crude oil pretreatment. This study investigates the effect of asphaltenes on the stability of crude oil emulsions using a simulated oil system composed of toluene and n-heptane. It was found that asphaltenes behave like conventional surfactants, adsorbing at the oil–water interface and reducing interfacial tension. The critical aggregation concentration (CAC) of W/O emulsions formed from a toluene and n-heptane mixture (7:3 volume ratio) was found to be 0.05 g/L. When the asphaltene concentration was greater than CAC, the asphaltene aggregated into clusters, forming a viscoelastic interface film that enhanced the strength of the emulsion droplets. At an asphaltene concentration of 0.01 g/L, the storage modulus (G′) and loss modulus (G″) were 1.12 Pa·s and 8.94 Pa·s, respectively. The storage modulus G′ was less than the loss modulus G″, indicating that the viscoelastic nature of the emulsion, and both the G′ and G″ of the emulsions increased with the increasing asphaltene concentration. When the concentration reached 11 g/L, G′ and G″ were 1033 Pa·s and 416 Pa·s, respectively, with G′ exceeding G″, indicating that the emulsion became more stable. Moreover, increasing the solvent aromaticity led to a rise in the CAC of asphaltene, which was favorable for breaking emulsions. The findings imply that reducing the asphaltene content at the interfaces of oil–water by adding an aromatic solvent or blending with light crude oil is a feasible way to break the emulsion and further dewater and desalt.
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Foods
·
2021
·Vol. 10
·期 8
·1868
·
IF 4.35
Huanhuan Cui,Qihang Liu,David Julian McClements,Bin Li,Shilin Liu,Yan Li
Protein-stabilized emulsions tend to be susceptible to droplet aggregation in the presence of high ionic strengths or when exposed to acidic gastric conditions due to a reduction of the electrostatic repulsion between the protein-coated droplets. Previously, we found that incorporating cinnamaldehyde into the oil phase improved the resistance of whey protein isolate (WPI)-stabilized emulsions against aggregation induced by NaCl, KCl and CaCl2. In the current study, we aimed to establish the impact of cinnamaldehyde on the tolerance of WPI-stabilized emulsions to high salt levels during food processing and to gastric conditions. In the absence of cinnamaldehyde, the addition of high levels of monovalent ions (NaCl and KCl) to WPI-emulsions cause appreciable droplet aggregation, with the particle sizes increasing from 150 nm to 413 nm and 906 nm in the presence of NaCl and KCl, respectively. In contrast, in the presence of 30% cinnamaldehyde in the oil phase, the WPI-emulsions remained stable to aggregation and the particle size of emulsions kept within 200 nm over a wide range of salt concentrations (0–2000 mM). Divalent counter-ions promoted droplet aggregation at lower concentrations (≤20 mM) than monovalent ones, which was attributed to ion-binding and ion-bridging effects, but the salt stability of the WPI emulsions was still improved after cinnamaldehyde addition. The incorporation of cinnamaldehyde into the oil phase also improved the resistance of the WPI-coated oil droplets to aggregation in simulated gastric fluids (pH 3.1–3.3). This study provides a novel way of improving the resistance of whey-protein-stabilized emulsions to aggregation at high ionic strengths or under gastric conditions.Keywords:whey protein;stability;ionic strength;gastric digestion;emulsions
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2021
·
IF 3.512
Chunhong Nie,Guoqiang Han,Jiawen Ni,Shuxia Guan,Huan Du,Yupeng Zhang,Heting Wang
The relationship model between the droplet lifetime and interface properties is established to characterize the stability of oil droplets, and then, the influence of the alkali–surfactant–polymer (ASP) concentration on the lifetime is analyzed by theoretical calculations. The stability dynamic characteristics of oil-in-water (O/W) emulsions from ASP flooding were evaluated using the emulsion stability model (Civan model) based on two-phase separation. The effect of ASP on dynamic characteristics of the emulsion was explored by analyzing film strength qualitatively and measuring interfacial tension and ζ potential. The results showed that the Civan model was suitable to evaluate the stability of the O/W emulsion and to obtain the corresponding dynamic characteristics. The O/W emulsions became more stable with the increasing alkali concentration first at a low alkali concentration (cNaOH < 200 mg/L) and then became less stable with the increasing alkali concentration at a high alkali concentration (cNaOH > 200 mg/L). The stabilities of O/W emulsions were improved with the increasing concentrations of the surfactant and polymer. The mechanism of stabilization of the O/W emulsion by ASP is as follows. The surface-active substances formed by the reaction of alkali and acidic substances in the oil phase, together with surfactants, adsorb at the oil–water interface, reducing the interfacial tension and increasing the strength of the oil–water interface film. The polymer only increases the strength of the interface film by increasing the viscoelasticity of the oil–water interface film.
研究领域:
石油工程
·
化学工程
·
胶体与表面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2024
·
IF 1.9
Feng Jiang,Xinchuan Huang,Shishi Pang,Wanfen Pu
The presence of natural lipophilic emulsifiers, such as asphaltenes (A), resin (R) and petroleum acids (PA) in crude oil, plays a crucial role in stabilizing the W/O emulsions. This study primarily focuses on elucidating the influence of their interactions on the interfacial properties of the water/model oil system, as well as its emulsion stability. First, equilibrium interfacial tension (IFT), interfacial dilational modulus (IDM) and phase angle are measured. Then, emulsion stability experiments are performed. Finally, microscopic images of the emulsions were captured to evaluate droplet size and dispersity. Results show that the addition of petroleum acid to both asphaltene-only and resin-only system reduces IFT and dilational modulus, weakening the strength of the interfacial film. The inhibitory effect of petroleum acid on resins’ adsorption at the interface is more pronounced compared to asphaltenes’. A low proportion of resin and petroleum acid (A/R ≥ 5, A/PA ≥ 7) enhances emulsion stability by co-adsorbing with asphaltenes at the oil–water interface. Conversely, a high proportion of resin and petroleum acid leads to a decrease in IDM and emulsion stability. For asphaltene/petroleum acid–water system, when A/PA ≤ 5, the presence of petroleum acid decreases the droplet size but enhances droplet dispersion while decreasing emulsion stability. It can be inferred that the presence of petroleum acids contributes more to the formation rather than stabilization of emulsions. This work deepens insights into the emulsion behavior of natural surfactants, providing theoretical guidance for the formation of stable emulsions underground and efficient demulsification above ground.
研究领域:
石油工程
·
表面化学
·
胶体科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Qi Li,Xiao-Dong Wang,Qiu-Ye Li,Jian-Jun Yang,Zhi-Jun Zhang
A new amphiphilic polymer was synthesized by allowing polyethylenimine to react with benzyl bromide, and it was used as an emulsifier for the viscosity reduction of Shengli extra heavy crude oil. The hydrophilicity/hydrophobicity of the polymer can be easily regulated by changing the number of grated benzyl on the polymer. The formation of a stable oil-in-water (O/W) emulsion depends on the hydrophilicity of the polymer, the oil-to-water mass ratio, the emulsifier concentration, and temperature. The polymers with higher hydrophile–lipophile balance values can induce forming stable Shengli heavy oil-in-water emulsions with low viscosities of less than 100 mPa·s at 50 °C. The addition of the required amount of emulsifier can greatly decrease the oil–water interfacial tension and form small O/W droplets, thereby leading to the viscosity reduction of the oil.
研究领域:
化学工程
·
材料科学
·
石油工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Changxiao Cao,Shaohua Gu,Zhaojie Song,Zehui Xie,Xuya Chang,Pingping Shen
Formation of water-in-oil (W/O) emulsion seriously limits heavy oil production, and the interfacial adsorption of heavy components of oil is the key to clarify the emulsification of crude oil and formation water. In this study, the viscosifying behavior of W/O emulsion was correlated with the interfacial adsorption of heavy components using two typical heavy oil samples, i.e., high-resins oil and high-asphaltenes oil. Results showed that the resins, instead of the asphaltenes , contributed to the pseudoplastic behavior of W/O emulsion. The interfacial adsorption of resins presented the lower interfacial tension (IFT), the higher interfacial viscosity and the stronger film stability. However, when more asphaltenes was adsorbed on the interface, the film of oil-water interface changed from viscous to brittle and breakable. According to the composition analysis, the interfacial activity of resins was much stronger than asphaltenes. Besides, the W/O emulsion formed using model oil with resins performed the better stability compared with that formed using model oil with asphaltenes. This study provided that the interfacial adsorption of resins enhanced the emulsifying ability of crude oil and the film stability of W/O emulsion, which heavily aggravated the viscosifying behavior.
研究领域:
石油工程
·
界面化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）