In this study, the effects of wax deposition on submarine multiphase pipelines are investigated. In order to understand the mechanism of wax deposition in submarine multiphase pipelines, a wax deposition model in a submarine pipeline was established using the OLGA wax deposition module, and key factors influencing this phenomenon were analyzed. Additionally, a multifactor impact analysis of wax deposition was performed via the orthogonal test method. The results indicated the relative influence of five factors on oil-gas-water three-phase wax deposition, namely, oil flow rate, water content, inlet temperature, gas-oil ratio, and outlet pressure. Then, the main influencing factors of wax deposition in a multiphase pipeline flow were extracted, and the wax deposition prediction model was established. The wax deposition rate under different operating conditions was simulated using the OLGA wax deposition simulation module. The SPSS software was used to perform nonlinear regression analysis under different working conditions. In this manner, the constant terms in the wax deposition prediction model for a submarine multiphase pipeline were obtained. The prediction model could be used to programmatically predict wax deposition along a multiphase pipeline by programming the initial waxing conditions. By using this method, the wax deposition prediction model of an M − N submarine multiphase pipeline was obtained under different working conditions. After comparing the predicted and the OLGA simulation results, it was concluded that the established wax deposition model can be used to accurately calculate the wax deposition in a submarine multiphase pipeline within an allowable error range. If the physical properties and operating parameters of the conveying medium in a multiphase pipeline are given, the developed oil-gas-water three-phase wax deposition model can be used to predict the distribution of wax deposition in submarine multiphase pipelines without laboratory experiments. The results of this study can help production units understand the waxing situation of pipelines in time in order to scientifically formulate a pigging plan and avoid pipeline blockages and shutdowns.
Author statements
All persons who have made substantial contributions to the work reported in the manuscript:
Conception or design of the Manuscript: Ying Xie;
Draft work, Writing review and editing: Jin Meng;
The acquisition, analysis, or interpretation of data for the Manuscript: Diwen Chen.
Declaration of competing interests
We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted.
| [1] |
J.M. Duan, J. Gong, Y. Zhang, et al., Research progress of wax deposition in multiphase mixed transmission pipeline, Oil Gas Storage Transp. 30 (4) (2011) 241e248 (in Chinese).
|
| [2] |
S.M. Pang, New type joint of subsea flexible pipes, Pet. Eng. Constr. 38 (4) (2012) 14e17 (in Chinese).
|
| [3] |
C. Liu,Route Selecting and Pipeline Laying during Subsea Pipeline Route Modification and Reconnection Technique, PhD Thesis, Tianjin University, Tianjin China, 2008 (in Chinese).
|
| [4] |
H.H. Wang, G.H. Liu, Statistics and analysis of subsea pipeline accidents of CNOOC, China Offshore Oil Gas 29 (5) (2017) 157e160 (in Chinese).
|
| [5] |
Z.X. Zhang,Low-throughput Operation Characteristics Analysis and Safe Assurance Technology Research of Waxy Crude Oil Pipeline, PhD Thesis, Northeast Petroleum University, Daqing China, 2016 (in Chinese).
|
| [6] |
B. Ye, X.C. Yu, W. Peng, Wax deposition prediction and pigging simulation in waxy crude oil tieback deepwater pipelines, Journal of China University of Petroleum (Natural Science Edition) 43 (3) (2019) 159e166 (in Chinese).
|
| [7] |
M.Y. Zhu, T. Cheng, B. Kong, Research progress in flow assurance technology for submarine oil and gas pipelines, Contemporary Chemical 8 (2019) 1755e1758 (in Chinese).
|
| [8] |
Y. Wang, Q.L. Cheng, X.L. Li, X. Yi, Determination of occurrence grades for factors affecting congelation failure on basis of fuzzy comprehensive assessment method, in: Advanced Materials Research vol. 753, Trans Tech Publications Ltd, 2013, pp. 2916-2919.
|
| [9] |
Z. Tian, et al., Development and computational analysis of the safe and economic pigging frequency model for waxy crude oil pipelines, China Offshore Oil Gas 27 (2) (2015) 120e126 (in Chinese).
|
| [10] |
J.D. Jiang, Q.Y. Huang, X.D. Gao, Experimental study on the wax deposition law in subsea crude oil pipeline of LH16-2 oilfield, China Offshore Oil Gas 32 (3) (2020) 175-180 (in Chinese).
|
| [11] |
Y.H. Yu, X.J. Zhang, Experimental facility of multiphase flow waxing and measurement technique, Natural gas and oil 37 (3) (2019) 18e24 (in Chinese).
|
| [12] |
Y. Xie, D.W. Chen, F.R. Mai, Economic pigging cycles for low-throughput pipelines, Adv. Mech. Eng. 10 (11) (2018) 1-10.
|
| [13] |
S.A. Sulaiman, B.K. Biga, G.T. Chala, Injection of non-reacting gas into production pipelines to ease restart pumping of waxy crude oil, J. Petrol. Sci. Eng. 152 (2017) 549-554.
|
| [14] |
Q. Quan,Experimental Study on Wax Deposition in Oil Gas Water Three Phase, PhD Thesis, China University of Petroleum (Beijing), Beijing China, 2016 (in Chinese).
|
| [15] |
R. Hoffmann, L. Amundsen, Z.Y. Huang, S. Zheng, H.S. Fogler, Wax deposition in stratified oil/water flow, Energy Fuels 26 (6) (2012) 3416-3423.
|
| [16] |
Y. Liu, X.L. Zhuge, Z.H. Wang, et al., Effect of emulsification mechanism on morphology and aggregation behavior of wax crystals in waxy crude oil, Oil Gas Storage Transp. 38 (8) (2019) 877-884. (in Chinese)
|
| [17] |
X.H. Ning,Simulation Researches about Multiphase Wax Deposition in Pipelines with OLGA, PhD Thesis, China University of Petroleum (Beijing), Beijing China, 2016 (in Chinese).
|
| [18] |
H. Shasha, H. Qiyu, Research on wax deposition in the pipeline without pigging for a long time, Petrol. Sci. Technol. 32 (3) (2014) 316-323.
|
| [19] |
Q. Miao, J. Liang, B. Jiang, Optimizing the Pigging Frequency through Prediction of Wax Deposition of Pipeline, American Society of Mechanical Engineers Digital Collection, International Pipeline Conference, 2006, January, pp. 729-739.
|
| [20] |
H.G. Hou, Y.M. Wang, Orthogonal Experiment, Jilin People’s Publishing Press, China, 1985 (in Chinese).
|
| [21] |
Y.J. Wang, Research on “L” Shaped Porous Buffered Oil Feeding Process, PhD Thesis, Southwest Petroleum University, Chengdu China, 2015 (in Chinese).
|
| [22] |
W.Q. Liu, Experiment Design, Hunan University Press, Beijing China, 2005 (in Chinese).
|
| [23] |
C. Cai, S. Quan, W. Yadong, Y. Zhifeng,Analysis of Key Influencing Factors of Equipment Battlefield Damage Test Design, IEEE, Chinese Control and Decision Conference (CCDC), 2019, June, pp. 3894-3898.
|
| [24] |
C.Z. He, H. Luo, Applied Statistics, Hunan University Press, Changsha China, 2005 (in Chinese).
|
| [25] |
Q.Y. Huang, Y.X. Li, J.J. Zhang, Unified wax deposition model, Acta Pet. Sin. 29 (3) (2008) 459-462.
|
| [26] |
H. Ding,Study on Wax Deposition Rule of Qingha Oil Pipeline under the Condition of Qing-Russia Oil Mixed Transportatio, PhD Thesis, Northeast Petroleum University, Daqing China, 2018 (in Chinese).
|
| [27] |
W. Wenda, H. Qiyu, H. Jun, P. Quan, F. Jun, W. Fenghui, Study of paraffin wax deposition in seasonally pigged pipelines, Chem. Technol. Fuels Oils 50 (1) (2014) 39-50.
|
| [28] |
Q.Y. Huang, J.J. Zhang, X.F. Gao, Z.H. Zhang, Study on wax deposition of Daqing crude oil, Acta Pet. Sin. 27 (4) (2006) 125-129.
|
| [29] |
X. Gao, Q. Huang, X. Zhang, W. Li, Y. Ren, J. Wang, Study on wax precipitation characteristics of wax deposit in pipes, Can. J. Chem. Eng. (2020) 1202-1210.
|
| [30] |
M.J. Jalalnezhad, V. Kamali, Development of an intelligent model for wax deposition in oil pipeline, J. Petroleum Exploration Production Technol. 6 (1) (2016) 129-133.
|