Modeling of Multiphase Wax Deposition

1999 ◽  
Vol 121 (2) ◽  
pp. 81-85 ◽  
Author(s):  
G. M. Elphingstone ◽  
K. L. Greenhill ◽  
J. J. C. Hsu
Keyword(s):  
Single Phase ◽  
Scale Up ◽  
Wax Deposition ◽  
Flow Loop ◽  
Waxy Crude Oil ◽  
Multiphase Transport ◽  
Waxy Crude ◽  
Semi Empirical ◽  
Production Problems ◽  
Deposition Tendency

The environmental conditions typically encountered in deepwater petroleum operations lead to a number of production problems. The cold environment promotes particle formation and deposition of paraffinic compounds in a waxy crude system. These solids can build up inside flowlines and significantly decrease production rates. The wax deposition scale-up technique used for single phase has been applied to multiphase flow conditions. The resulting semi-empirical model is used to simulate multiphase transport of waxy crude oil through integration with a commercial steady-state pipeline simulation package. The wax model is a semi-empirical representation of the wax deposition phenomena. The model incorporates the effects of diffusion and shear through the wax deposition tendency. The key parameters are first measured in a laboratory flow loop.

Study of Wax Deposition Rate in Waxy Crude Oil Pipeline

2013 ◽  
Vol 401-403 ◽  
pp. 891-894 ◽  
Author(s):  
Qing Lin Cheng ◽  
Xu Xu Wang ◽  
Xian Li Li ◽  
Wei Sun ◽  
Ling De Meng
Keyword(s):  
Crude Oil ◽  
Deposition Rate ◽  
Normal Operation ◽  
Wax Deposition ◽  
Waxy Crude Oil ◽  
Waxy Crude ◽  
Oil Pipeline ◽  
Oil Transportation ◽  
Different Seasons ◽  
Deposition Tendency

In waxy crude oil transportation process, wax crystals start to precipitate as the oil temperature drops to wax appearance point, and then form a network structure gradually which attaches to the wall. The problem of wax deposition seriously affects the normal operation of pipeline. Based on the wax deposition tendency coefficient method, combined with experimental data, the parameters related to wax deposition tendency coefficient is fitted, and the wax deposition rate equation of crude oil is determined finally. The variation law of wax deposition rate along the pipeline is analyzed, and the influence of different seasons and different throughput the on wax deposition rate is discussed subsequently.

Effect of Thermal Treatment Temperature on the Flowability and Wax Deposition Characteristics of Changqing Waxy Crude Oil

2018 ◽  
Vol 32 (10) ◽  
pp. 10605-10615 ◽  
Author(s):  
Haoran Zhu ◽  
Chuanxian Li ◽  
Fei Yang ◽  
Hongye Liu ◽  
Dinghong Liu ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Crude Oil ◽  
Treatment Temperature ◽  
Wax Deposition ◽  
Waxy Crude Oil ◽  
Thermal Treatment Temperature ◽  
Waxy Crude

Wax deposition during production of waxy crude oil and its remediation

2017 ◽  
Vol 35 (18) ◽  
pp. 1831-1838 ◽  
Author(s):  
Ashish Dewangan ◽  
Ashok Kumar Yadav
Keyword(s):  
Crude Oil ◽  
Wax Deposition ◽  
Waxy Crude Oil ◽  
Waxy Crude

Influence of Hydrostatic Pressure on the Formation of Voids in Gelled Crude Oil

2021 ◽  
Author(s):  
Girma T. Chala ◽  
Shaharin A. Sulaiman ◽  
Azuraien Japper-Jaafar ◽  
Wan Ahmad Kamil Wan Abdullah
Keyword(s):  
Hydrostatic Pressure ◽  
Crude Oil ◽  
Vertical Pipe ◽  
Flow Loop ◽  
Waxy Crude Oil ◽  
Horizontal Pipe ◽  
Waxy Crude ◽  
Oil Transportation ◽  
Wax Content ◽  
Lower Temperature

Production of waxy crude oil from offshore fields has increased in the last decade. However, the operation is being challenged with the high wax content of crude oil that tends to precipitate at lower temperature. This paper presents the effects of hydrostatic pressure on the voids formed in waxy crude oil gel. A flow loop rig that simulates offshore waxy crude oil transportation was used to produce the gel. A Magnetic Resonance Imaging of 3-Tesla system was used to scan the gelled samples in horizontal and vertical pipes. The hydrostatic pressure effect was found to be most significant near the pipe wall as a change in percent voids volume of 0.53% was observed at that region. In particular, the voids volume reduction was more pronounced in the lower half side of the pipe. The total volume of voids in the vertical pipe was lower than that in the horizontal pipe, and this suggests that the gel in the vertical pipe became denser due to the effects from the hydrostatic pressure. Conversely, the voids volume around the pipe core in the vertical pipe was higher when compared to that in the horizontal pipe. The change in voids volume near the pipe core and wall shrunk to a minimum and converged to 0.18% voids volume at larger duration of the hydrostatic effect. Further, hydrostatic pressure was observed to have significant influences for higher duration making the void size to be distributed across and along the pipeline; however, it was found to have insignificant effects on voids size distribution for smaller duration. The findings of this study can help for better understanding of voids formation in vertical pipelines that would further assist in developing a model predicting restart pressure accurately.

Impacts of Cooling Rates on Voids in Waxy Crude Oil under Quiescent Cooling Mode

2015 ◽  
Vol 799-800 ◽  
pp. 62-66 ◽  
Author(s):  
Girma T. Chala ◽  
Shaharin Anwar Sulaiman ◽  
Azuraien Japper-Jaafar ◽  
Wan Ahmad Kamil Wan Abdullah
Keyword(s):  
Crude Oil ◽  
Cooling Rate ◽  
Pipe Wall ◽  
Flow Loop ◽  
Cooling Mode ◽  
Waxy Crude Oil ◽  
Cooling Rates ◽  
Waxy Crude ◽  
Offshore Oil Production ◽  
Offshore Oil

When waxy crude oil becomes a gel, predicting a restart pressure in pipelines has been a challenge. The formation of gas voids within the gel following sufficient cooling has an impact on the restarting pressure. This study is aimed at analyzing the effects of cooling rates on voids in waxy crude oil gel using Magnetic Resonace Imaging (MRI) technique. The flow loop rig simulating offshore oil production was designed. Waxy crude oil underwent cooling through the same temperature range to observe the effects of cooling rates on voids formed. Cooling rates were found to have different influence on the formation of voids. A maximum total voids volume of 6.96% was formed at cooling rate of 1.00°C/min. Cooling rate of 0.55°C/min produced a minimum voids volume of 5.74% near pipe wall. Higher cooling rates generally produced higher voids volume near pipe wall and in entire pipe. However, there was no definite trend observed for the voids around pipe core at which slower cooling rates were also observed forming higher voids volume.

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