Study on Wax Removal During Pipeline-Pigging Operations
- Weidong Li (China Universiyu of Petroleum, Beijing) | Qiyu Huang (China Universiyu of Petroleum, Beijing) | Wenda Wang (China Huanqiu Contracting & Engineering Co., Ltd.) | Yijie Ren (China University of Petroleum, Beijing) | Xue Dong (China University of Petroleum, Beijing) | Qi Zhao (China University of Petroleum, Beijing) | Lei Hou (China University of Petroleum, Beijing)
- Document ID
- Society of Petroleum Engineers
- SPE Production & Operations
- Publication Date
- February 2019
- Document Type
- Journal Paper
- 216 - 231
- 2019.Society of Petroleum Engineers
- pigging, wax removal efficiency, wax breaking force, model development, nondimensional analysis
- 12 in the last 30 days
- 133 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 10.00|
|SPE Non-Member Price:||USD 30.00|
Widely used as it is, pipeline pigging still holds ambiguities in its mechanisms. In this paper we explore the nature of the wax removal process with a unique pigging facility. Solid wax content, yield stress, viscoelasticity, and microscopic characteristics of wax samples are thoroughly studied with differential-scanning-calorimetry (DSC) trials, rheological tests, and microscopic observations. We found that the relative solid wax content is approximately linearly dependent on temperature, and yield stress can be well-fitted with wax content in an exponential format. An investigation on wax-breaking force indicates that it increases with solid wax content. Wax removal efficiency increases with wax thickness and pipe-wall temperature, decreases with a wax-mixing ratio and solid wax content, and it varies irregularly vs. the scraping-element hardness in the pig. Furthermore, a prediction model of wax removal efficiency was developed on the basis of nondimensional analysis. The absolute average deviation of verification experiments against this model is 5.22%. This model might benefit in estimating the wax-scouring capacity of the wax-in-oil slurry and, therefore, helps to avoid wax blockage and to arrange the pigging program.
|File Size||1 MB||Number of Pages||16|
Alcazar-Vara, L. A. and Buenrostro-Gonzalez, E. 2011. Characterization of the Wax Precipitation in Mexican Crude Oils. Fuel Process. Technol. 92 (12): 2366–2374. https://doi.org/10.1016/j.fuproc.2011.08.012.
Al-Yaari, M. 2011. Paraffin Wax Deposition: Mitigation and Removal Techniques. Presented at the SPE Saudi Arabia Young Professionals Technical Symposium, Dhahran, Saudi Arabia, 14–16 March. SPE-155412-MS. https://doi.org/10.2118/155412-MS.
Aiyejina, A., Chakrabarti, D. P., Pilgrim, A. et al. 2011. Wax Formation in Oil Pipelines: A Critical Review. Int. J. Multiphase Flow 37 (7): 671–694. https://doi.org/10.1016/j.ijmultiphaseflow.2011.02.007.
Bai, C. 2013. Study on Some Fundamental Issues of Removing Wax Deposit in Crude Oil Pipelines. PhD dissertation, China University of Petroleum, Beijing (December 2016).
Chen, J., Zhang, J., and Li, H. 2004. Determining the Wax Content of Crude Oils by Using Differential Scanning Calorimetry. Thermochim. Acta 410 (1–2): 23–26. https://doi.org/10.1016/S0040-6031(03)00367-8.
Coutinho, J. A. P., Lopes da Silva, J. A., Ferreira, A. et al. 2003. Evidence for the Aging of Wax Depositor as in Crude Oils by Ostwald Ripening. Petro. Sci. Technol. 21 (3): 381–391. https://doi.org/10.1081/LFT-120018527.019.
Davidson, R. 2002. An Introduction to Pipeline Pigging. Presented at the Pigging Products and Services Association Seminar, Aberdeen, 6–7 November 2, 2018.
He, C., Ding, Y., Chen, J. et al. 2016. Influence of the Nano-Hybrid Pour Point Depressant on Flow Properties of Waxy Crude Oil. Fuel 167: 40–48. https://doi.org/10.1016/j.fuel.2015.11.031.
Hovden, L., Xu, Z., Ronningsen, H. P. et al. 2004. Pipeline Wax Deposition Models and Model for Removal of Wax by Pigging: Comparison Between Model Predictions and Operational Experience. Presented at the 4th North American Conference on Multiphase Technology, Banff, Canada, 3–4 June.
Jiang, Z., Hutchinson, J. M., and Imrie, C. T. 2001. Measurement of the Wax Appearance Temperatures of Crude Oils by Temperature Modulated Differential Scanning Calorimetry. Fuel 80 (3): 367–371. https://doi.org/10.1016/S0016-2361(00)00092-2.
Kang, P., Lee, D., and Lim, J. 2014. Status of Wax Mitigation Technologies in Offshore Oil Production. Presented at the Twenty-Fourth International Ocean and Polar Engineering Conference, Busan, Korea, 15–20 June. ISOPE-I-14-285. https://www.onepetro.org/conference-paper/ ISOPE-I-14-285.
Kleinhans, J. W., Niesen, V. G., and Brown, T. S. 2000. Pompano Paraffin Calibration Field Trials. Presented at the SPE Annual Technical Conference and Exhibition, Dallas, 1–4 October. SPE-62946-MS. https://doi.org/10.2118/62946-MS.
Lee, H. S., Sing, P., Thomason, W. H. et al. 2008. Waxy Oil Gel-Breaking Mechanisms: Adhesive vs. Cohesive Failure. Energy &. Fuels 22 (1): 480–487. https://doi.org/10.1021/ef700212v.
Li, H. and Zhang, J. 2003. A Generalized Model for Predicting Non-Newtonian Viscosity of Waxy Crudes as a Function of Temperature and Precipitated Wax. Fuel 82 (11): 1387–1397. https://doi.org/10.1016/S0016-2361(03)00035-8.
Li, H., Huang, Q., Zhang, F. et al. 2003. Determination of Wax Content in Crude Oil Using Differential Scanning Calorimetry. J. Univ. Petrol. China 27 (1): 60–62. (in Chinese) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=sydxxb200301018.
Masoudi, S., Sefti, M. V., Jafari, H. et al. 2010. The Hardening Process and Morphology of a Wax Deposit in a Pipe Flow. Petro. Sci. Technol. 28 (15): 1598–1610. https://doi.org/10.1080/10916466.2010.493910.
Mendes, S. P. R., Azevedo, L. F. A., Braga, A. M. B. et al. 1999. Resistive Force of Wax Deposits During Pigging Operation. J. Energ. Resour. Technol. 121 (3): 167–171. https://doi.org/10.1115/1.2795977.
Mokhatab, S. and Towler, B. 2009. Wax Prevention and Remediation in Subsea Pipelines and Flowlines. World Oil 230 (11): 55–58. https://www.worldoil.com/magazine/2009/november-2009/features.
Robustillo, M. D., Coto, B., Martos, C. et al. 2012. Assessment of Different Methods to Determine the Total Wax Content of Crude Oils. Energy & Fuels 26 (10): 6352–6357. https://doi.org/10.1021/ef301190s.
Sarica, C. and Panacharoensawad, E. 2012. Review of Paraffin Deposition Research Under Multiphase Flow Conditions. Energy & Fuels 26 (7): 3968–3978. https://doi.org/10.1021/ef300164q.
Silva, J. A. L. D. and Coutinho, J. A. P. 2004. Dynamic Rheological Analysis of the Gelation Behaviour of Waxy Crude Oils. Rheol. Acta 43 (5): 433–441. https://doi.org/10.1007/s00397-004-0367-6.
Soedarmo, A. A., Daraboina, N., and Sarica, C. 2016. Microscopic Study of Wax Deposition: Mass Transfer Boundary Layer and Deposit Morphology. Energy & Fuels 30 (4): 2674–2686. https://doi.org/10.1021/acs.energyfuels.5b02887.
Southgate, J. 2004. Wax Removal Using Pipeline Pigs. PhD dissertation, Durham University, UK (June 2004).
Tan, G. B., Wang, D. G., Liu, S. H. et al. 2014. Probing Tribological Properties of Waxy Oil in Pipeline Pigging With Fluorescence Technique. Tribol. Int. 71: 26–37. https://doi.org/10.1016/j.triboint.2013.10.020.
Tan, G., Liu, S., Wang, D. et al. 2015a. Tribological Behaviours of Wax-in-Oil Gel Deposition in Orthogonal Cleaning Process. Tribol. Lett. 57 (2): 16. https://doi.org/10.1007/s11249-015-0472-y.
Tan, G., Liu, S., Wang, D. et al. 2015b. Spatio-Temporal Structure in Wax-Oil Gel Scraping at a Soft Tribological Contact. Tribol. Int. 88: 236–251. https://doi.org/10.1016/j.triboint.2015.03.031.
Tiratsoo, J. 2013. Pipeline Pigging and Integrity Technology, fourth edition. London: Clarion Technical Publishers.
Valinejad, R. and Nazar, A. R. S. 2013. An Experimental Design Approach for Investigating the Effects of Operating Factors on the Wax Deposition in Pipelines. Fuel 106 (2): 843–850. https://doi.org/10.1016/j.fuel.2012.11.080.
Wang, Q., Sarica, C., and Chen, T. 2001. An Experimental Study on Mechanics of Wax Removal in Pipeline. Presented at the SPE Annual Technical Conference and Exhibition, New Orleans, 30 September–3 October. SPE-71544-MS. https://doi.org/10.2118/71544-MS.
Wang, Q., Sarica, C., and Volk, M. 2008. An Experimental Study on Wax Removal in Pipes With Oil Flow. J. Energ. Resour. Technol. 130 (4): 130–134. https://doi.org/10.1115/1.3000136.
Wang, Z., Yang, G., and Zhang, J. 2014. A New Coal Permeability Prediction Method Based on Experiment and Dimension Analysis. SPE J. 19 (3): 356–360. SPE-162940-PA. https://doi.org/10.2118/162940-PA.
Wang, W., Huang, Q., Liu, Y. et al. 2015. Experimental Study on Mechanisms of Wax Removal During Pipeline Pigging. Presented at the SPE Annual Technical Conference and Exhibition, Houston, 28–30 September. SPE-174827-MS. https://doi.org/10.2118/174827-MS.
Wang, W. 2016. Study on Wax Layer Removal and Transport Behaviors During Crude Oil Pipeline Pigging. PhD dissertation, China University of Petroleum, Beijing (June 2016).
Wettimuny, R. and Penumadu, D. 2003. Automated Digital Image Based Measurement of Boundary Fractal Dimension for Complex Nanoparticles. Part. Part. Syst. Char. 20 (1): 18–24. https://doi.org/10.1002/ppsc.200390001.
Yao, B., Li, X., Yang, F. et al. 2016. Structural Properties of Gelled Changqing Waxy Crude Oil Benefitted With Nanocomposite Pour Point Depressant. Fuel 184: 544–554. https://doi.org/10.1016/j.fuel.2016.07.056.
Zheng, S., Saidoun, M., Palermo, T. et al. 2017. Wax Deposition Modeling With Considerations of Non-Newtonian Characteristics: Application on Field-Scale Pipeline. Energy & Fuels 31 (5): 5011–5023. https://doi.org/10.1021/acs.energyfuels.7b00504.