Failure Pressure Estimation of Corroded Pipeline with Different Depths of Interacting Defects Subjected to Internal Pressure

Abstract:

Pipelines are one of the most reliable and safest ways to transport oil and gas from one location to another. However, if not handled and maintained properly, they will cause major destruction should one of these pipelines burst. A pipeline which has oil or gas flowing through it will be subjected to internal pressure due to the flow of the oil or gas. Furthermore, the chemical composition of the oil and gas acts as a corrosive agent towards the pipeline. The corrosion eventually becomes defects thus compromising the pipeline integrity. In addition, if two defects are close enough, they are treated as interacting defects. In this work, the pipeline integrity was first calculated using DNV RP-101 codes. After calculating the maximum operating pressure for the pipeline using the codes, Finite Element Analyses using ANSYS were carried out to simulate and model the pipeline with the interacting defects. The maximum operating pressure given by the FEA was then compared to the DNV codes. We found that despite consistency between DNV codes, the FEA analysis showed that geometry plays an important part in determining the values of failure pressure. The FEA analysis showed that by increasing the ratio of depth between the interacting defects, the failure pressure decreases. This was likely because defects of larger depths are more likely to fail at lower pressures. This contradicts the results obtained from DNV codes where the failure pressure is constant for the same effective defect depth over thickness, (d₁₂/t)*.

• Periodical: Applied Mechanics and Materials (Volume 393)
• Pages: 1005-1010
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.393.1005
• Online since: September 2013
• Authors: Ariz Ahmad Azmy, Saravanan Karuppanan, Azmi Abdul Wahab
• Keywords: DNV RP-101 Code, Failure Pressure, Interacting Defects, Pipeline Assessment

References

[1] J.B. Choi, B.K. Goo, J.C. Kim, Y.J. Kim and W.S. Kim, Development of limit load solutions for corroded gas pipelines, The Int. J. of Pressure Vessels and Piping, 80(2) (2003) 121-128.

DOI: 10.1016/s0308-0161(03)00005-x

[2] W.K. Muhlbauer, Pipeline Risk Management Manual: Ideas, Techniques, and Resources, 3rd edition, Gulf Professional Publishing, Oxford, (2004).

[3] C.E. Jaske, J.A. Beavers and B.A. Harle, Effect of Stress Corrosion Cracking on Integrity and Remaining Life of Natural Gas Pipelines, Paper No. 255, Corrosion 96, NACE International, Houston, (1996).

[4] R. Nyborg, Controlling Internal Corrosion in Oil and Gas Pipelines, Business Briefing: Exploration & Production, The Oil & Gas Review, Issue 2, (2005).

[5] Y.K. Lee, Y.P. Kim, M.W. Moon, W.H. Bang, K.H. Oh and W.S. Kim, The prediction of failure pressure of gas pipeline with multi corroded region, Mater. Sci. Forum, 479 (2005) 3323-3326.

DOI: 10.4028/www.scientific.net/msf.475-479.3323

[6] R.C. C Silva, J.N. C Guerreiro and A.F. D Loula, A Study Of Pipe Interacting Corrosion Defects Using The FEM And Neural Networks, Adv. Eng. Softw., 38 (2007) 868-875.

DOI: 10.1016/j.advengsoft.2006.08.047

[7] S. Karuppanan, A. S. Aminudin and A. A. Wahab, Burst Pressure Estimation of Corroded Pipeline with Interacting Defects using Finite Element Analysis, J. of Applied Sciences, 12 (2002) 2626-2630.

DOI: 10.3923/jas.2012.2626.2630

[8] DNV, Recommended practice DNV-RP-F101 for corroded pipelines, Det Norske Veritas, Norway, (2004).

DOI: 10.3940/rina.mre.2010.01

[9] C. T. Belachew, M. C. Ismail and S. Karuppanan, Capacity assessment of corroded pipelines using available cades, NACE Asia Pacific, Kuala Lumpur, (2009).

[10] O.H. Bjornoy, G. Sigurdsson and M.J. Marley, Background and Development of DNV-RP-F101 Corroded Pipelines, Proceedings of the Eleventh International Offshore and Polar Engineering Conference, Norway, (2001).

DOI: 10.1115/ipc2004-0424