Numerical analysis of cathodic protection of a Q355ND frame in a shallow water subsea Christmas tree
Author:
Ju Shaodong1, Liu Yuming1, Yin Qishuai2, Wang Xing1, Wang Shiqiang1, Jiang Zitao3, Deng Siyao3
Affiliation:
1. CNOOC EnerTech-Drilling and Production Co , Tianjin , China 2. Department of Safety Engineering , 74537 China University of Petroleum Beijing , Changping-qu , China 3. China University of Petroleum Beijing , Changping-qu , China
Abstract
Abstract
This study develops a 3D model of a Christmas tree using cathodic protection technology and conducts numerical simulations on the Q355ND framework of a shallow Christmas tree. The boundary element method is employed for modeling, examining the distribution of protection potentials under varying corrosion layer breakage rates, anode numbers, and positions. The influence of sacrificial anode parameters on the cathodic protection effect of the Christmas tree is also investigated. The findings reveal that when the breakage rate of the anticorrosion layer reaches 35 % during Christmas tree operation, the sacrificial anode fails to provide complete protection. However, if the coating breakage rate is 10 %, reducing the number of anodes by six can still achieve a protection potential of −850 mV. Thus, it is imperative for Christmas trees to maintain a corrosion protection layer breakage rate below 35 %. Beyond this threshold, sacrificial anodes exhibit minimal effectiveness in preserving their integrity.
Funder
National Key Research and Development Program of China Ministry of Industry and Information Technology of the People’s Republic of China
Publisher
Walter de Gruyter GmbH
Reference13 articles.
1. N. Pang, et al.., “Dynamic Bayesian network-based reliability and safety assessment of the subsea Christmas tree,” Proc. Safety Environ. Prot., vol. 145, pp. 435–446, 2021, https://doi.org/10.1016/j.psep.2020.11.026. 2. Q. Yin, et al.., “Material qualification of a 13Cr-L80 casing for sour conditions,” Mater. Test., vol. 61, no. 9, pp. 833–841, 2019, https://doi.org/10.3139/120.111362. 3. P. W. Yu, et al.., “Research and application of cathodic protection of deep-sea horizontal Christmas trees,” Petrochem. Corr. Prot., vol. 37, no. 1, pp. 1–4, 2020, https://doi.org/10.3969/j.issn.1007-015X.2020.01.001. 4. C. Liu, A. Shankar, M. Orazem, and D. Riemer, “Numerical simulations for cathodic protection of pipelines,” in Underground Pipeline Corrosion, M. E. Orazem, Ed., United Kingdom, Elsevier, 2014, pp. 85–126. 5. K. Amaya and S. Aoki, “Effective boundary element methods in corrosion analysis,” Eng. Anal. Boundary Elem., vol. 27, no. 5, pp. 507–519, 2003, https://doi.org/10.1016/S0955-7997(02)00158-3.
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