Article
Thermodynamics
Hang Dong, Nan Guo, Lianjie Zhang, Jian Zhao
Summary: This study investigates the effects of heating tube with different diameters, locations, and inclination angles on the temperature field, flow field, and melting law of gelled crude oil through numerical simulation. The results show that the location of the heating tube has the most significant impact on the average temperature and temperature variance, while the inclination angle has the most significant impact on the synergy angle. The findings of this study provide theoretical guidance for the optimization design of tubular heater structure.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Hang Dong, RunZe Ma, Jian Zhao, Xiangrui Xi, Zhihua Wang
Summary: This paper applies rheo-optic in situ measurement technology to study the rheological characteristics of waxy crude oil for the first time, and investigates its response to thermal history, shear-thinning, and wax crystal dynamics. It is found that two types of wax crystals can be formed under certain thermal historical conditions, and their proportion change is the root cause of the fluency of waxed crude oil. The crack of the flocculation structure plays a leading role at shear rates below 5 s(-1), while the deformation of the wax crystal comes into effect when the shear rate exceeds 5 s(-1).
Article
Energy & Fuels
Qian Huang, Hongying Li, Yu Zhuang, Yifei Ding, Chenbo Ma, Chaohui Chen, Yiwei Xie, Huaqing Liang, Shanpeng Han, Jinjun Zhang
Summary: The application of an electric field perpendicular to the flow direction can achieve viscosity reduction in waxy crude oil, similar to that obtained with an electric field parallel to the flow direction. Additionally, higher electric field strength and lower oil temperature result in more significant viscosity reduction, with viscosity recovering gradually after the electric field is removed.
Article
Energy & Fuels
Jian Zhao, Xiangrui Xi, Hang Dong, Zhihua Wang, Zewen Zhuo
Summary: This study conducted Rheo-microscopy synchronous measurement to investigate the shear thinning behaviors of waxy crude oil. Results showed that with the increase in shear rate, the number of wax crystals decreased, dispersion degree increased, and the alignment of wax crystals along the flow field became more pronounced. The correlation between wax crystal behaviors and viscosity was strongest at specific temperatures, highlighting the importance of crystal dynamics on overall rheological properties.
Article
Thermodynamics
Yiwei Xie, Hongying Li, Miaomiao Xu, Yang Su, Chaoyue Zhang, Shanpeng Han, Jinjun Zhang
Summary: The application of high-voltage electric field can reduce the viscosity of waxy oil near the pour point, and the viscosity recovers gradually after the electric field is removed. The impact of shear on the durability of viscosity reduction has not been adequately studied. This study evaluated the effect of shear on the viscosity and impedance of waxy crude oils subjected to electric fields of different strengths. The results showed that shear had contrasting effects on the viscosity of electrically-treated oils with different properties.
Article
Energy & Fuels
Hongying Li, Chaohui Chen, Qian Huang, Yifei Ding, Yu Zhuang, Yiwei Xie, Miaomiao Xu, Shanpeng Han, Jinjun Zhang
Summary: Treatment with pour point depressant (PPD) can reduce the impedance changes caused by wax precipitation, making waxy crude oil easier to transport. Addition of PPD leads to increased capacitance and decreased resistance of wax particles, with a positive correlation between the viscosity reduction and the decrease in resistance. This study provides new insights into the functional mechanism of PPD in improving the flowability of waxy crude oil.
Article
Energy & Fuels
Lomesh Tikariha, Aniruddha Sanyal, Lalit Kumar
Summary: The precipitation of paraffin wax during crude oil transportation in low ambient temperature poses technological challenges in the petroleum industry. This study investigates the gelation process in a shutdown pipeline and subsequent non-isothermal flow start-up operation. The findings reveal that a pipeline filled with heterogeneous gel, with a weaker gel in the core, restarts faster than when it is filled with gel of equivalent average temperature.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Liping Guo, Xue Han, Tao Feng, Yang Liu, Baojun Liu
Summary: This study investigated the shearing rate of water-in-waxy crude oil emulsion under constant shear stress loading conditions and developed a prediction method to estimate the thixotropy of the emulsion. The method only requires thixotropy data of three water content emulsions and dehydrated crude oil, making it applicable for any volume of water content in the oil-water-waxy crude oil emulsion.
PETROLEUM SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Chemical
Haizatul Hafizah Hussain, Shaharin Anwar Sulaiman, Girma Tadesse Chala, Hazlina Husin
Summary: Transportation of waxy crude oil often faces flow assurance issues, such as wax deposition, which leads to operational complexity during pipeline restart after shutdown. This study investigates the effect of crude oil and nitrogen gas flow rates on the time taken for crude oil flow initiation. Results show that the presence of nitrogen gas improved pipeline restart phase by reducing both restart pressure and flow initiation time.
Article
Mechanics
Qian Huang, Hongying Li, Yiwei Xie, Yifei Ding, Yu Zhuang, Chaohui Chen, Shanpeng Han, Jinjun Zhang
Summary: It has been found in this study that applying an electric field to waxy crude oil gel can significantly weaken its structure, including reducing yield stress, moduli, and viscosity, and can transition from brittle-like to ductile-like fracture. A stronger structure weakening effect can be obtained at a higher field strength and lower temperature, and the effect induced by the electric field can be maintained for a certain period of time after removal.
JOURNAL OF RHEOLOGY
(2021)
Article
Engineering, Petroleum
Biswadeep Pal, Tarun Kumar Naiya, Gautam Sarkhel
Summary: This paper focuses on the application of a natural extract from Amla fruit in Indian waxy crude oil to improve flow behavior and wax deposition rate. The result shows that the Amla extract is more effective compared to commercial additives and is more environmentally friendly.
Article
Geosciences, Multidisciplinary
Aizimaiti Maimaiti, Qi Wang, Fang Hao, Xianzhang Yang, Haizu Zhang, Jinqiang Tian
Summary: This study conducted experiments on the thermal stability of liquid hydrocarbons in carbonate reservoirs through gold-tube experiments. The results showed that temperature and inorganic minerals play important roles in oil cracking. Dolomite and calcite were found to inhibit the generation of methane and increase the thermal stability of crude oil. The presence of carbonate minerals is significant in analyzing the potential of gas generation, the evolution of carbon isotope composition, and the prediction of hydrocarbon phase behavior during crude oil cracking.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Energy & Fuels
Chaoyue Zhang, Jinjun Zhang, Jiabao Kang, Yiwei Xie, Shanpeng Han, Hongying Li
Summary: Electrical treatment is an emerging method to improve the cold flowability of waxy crude oil. This study investigates the effect of AC electric fields on the oil's viscosity and yield stress. The results show that AC electric fields can also improve the cold flowability, but to a lesser extent compared to DC fields. The frequency and waveform of the AC field have an impact on its electrorheological effect.
Article
Microbiology
Raja Noor Zaliha Raja Abd Rahman, Wahhida Latip, Nur Aina Adlan, Suriana Sabri, Mohd Shukuri Mohamad Ali
Summary: Waxy crude oil is a concern in the oil and gas industry due to wax deposition in pipelines. Traditional chemical solutions are not environmentally friendly, so the biodegradation approach is explored as an alternative. A study on 11 thermophilic bacteria showed high hydrocarbon degradation ability, but it is believed that multiple species are needed for the degradation of paraffin wax. Five consortia were developed based on the efficiency of these bacteria, with Consortium 3 showing the highest degradation and dominance of Geobacillus, Parageobacillus, and Anoxybacillus genera.
ARCHIVES OF MICROBIOLOGY
(2022)
Article
Energy & Fuels
Bing-Fan Li, Man-Ping Yang, Gang Liu, Li-Ming Zheng, Chao Yang
Summary: This study comprehensively investigated the influence of dissolved methane gas on wax crystals and the rheology of crude oil. Experimental results showed that the behavior of crude oil varied depending on the type of crude oil and the pressure of dissolved CH4.