An experimental study on high-pressure water jets for paraffin scale removal in partially blocked production tubings

Yar’Adua, KH; John, IJ; Abbas, AJ; Lawal, KA; Kabir, A

Abstract

The common practice of using chemicals and solid-entrained liquids to remove soft scales in production tubings is associated with a high risk of contaminating the environment and eroding pipe internal surfaces. Due to the suspended solids, the current practices are also characterized by high pumping costs and are more problematic to rotating parts of machinery than freshwater. As a cheap and less risky alternative to these corrosive chemicals and liquids, this paper investigates the feasibility of utilizing multiple high-pressure (HP) water jets for the same objective. A total of 54 experimental trials were conducted to study the effects of four factors on the efficiency of scale removal with multiple flat-fan nozzles at an orientation of 25°. The factors investigated are (i) number of nozzles; (ii) spray injection pressure; (iii) stand-off distance between the spray nozzle and target scale; and (iv) condition of the production tubing: ambient and pressurized. Details of the experimental set-up, equipment and procedure are provided. The results of these controlled experiments show a positive correlation between descaling efficiency and spray injection pressure. The same set of experiments reveals a negative correlation between descaling efficiency and nozzle count, as well as between descaling efficiency and spray stand-off. However, for the scale samples and range of parameters investigated in this study, descaling efficiency did not exhibit significant dependency on the chamber conditions i.e. ambient vs. pressurized. The results of this study provide some insights into the feasibility of multiple HP water jets as a cleaner alternative to the use of corrosive chemicals and solid-entrained liquids to remove soft scales in production tubings in oil fields and other applications.

Citation

Yar’Adua, K., John, I., Abbas, A., Lawal, K., & Kabir, A. (2021). An experimental study on high-pressure water jets for paraffin scale removal in partially blocked production tubings. Journal of Petroleum Exploration and Production Technologies, 11(2), 973-988. https://doi.org/10.1007/s13202-020-01009-w

• Journal Article Type: Article
• Acceptance Date: Sep 19, 2020
• Online Publication Date: Oct 10, 2020
• Publication Date: Feb 1, 2021
• Deposit Date: Oct 15, 2020
• Publicly Available Date: Oct 15, 2020
• Journal: Journal of Petroleum Exploration and Production Technology
• Print ISSN: 2190-0558
• Electronic ISSN: 2190-0566
• Publisher: Springer Verlag
• Volume: 11
• Issue: 2
• Pages: 973-988
• DOI: https://doi.org/10.1007/s13202-020-01009-w
• Publisher URL: https://doi.org/10.1007/s13202-020-01009-w
• Related Public URLs: https://link.springer.com/journal/13202