Article Article
Finite Element Analysis of 3D Defect Characterization in Coiled Tubing in Weak Magnetic Field

In this paper, signal characterization of arbitrary three-dimensional (3D) defects with weak magnetic field signals from coiled tubing inspections is investigated. A detection model based on weak magnetic fields using the geomagnetic field is established using the finite element method, with different-shape 3D defects on the surface of coiled tubing, typically cylindrical, conical, spherical, rectangular, and crack-like defects. The weak magnetic signal characteristic response from each of these defects has been simulated in this research. This paper acquires the characteristics of the three components of self-leakage magnetic signal and illustrates the characteristics of five typical 3D defects using self-leakage magnetic signal, and the shapes and sizes of different defects are presented as 3D images. The focus of the investigation is to identify and estimate the size and shape of surface 3D defects on the basis of their weak magnetic signal features.


Aharoni, A., 2000, Introduction to the Theory of Ferromagnetism, Clarendon Press, Oxford, United Kingdom.

Al-Naemi, F.I., J.P. Hall, and A.J. Moses, 2006, “FEM Modelling Tech-niques of Magnetic Flux Leakage-Type NDT for Ferromagnetic Plate Inspections,” Journal of Magnetism and Magnetic Materials, Vol. 304, No. 2, pp. e790–e793. 

ANSYS Inc., 2010, “ANSYS Maxwell 3D v15.0 User’sGuide,” ANSOFT Maxwell / ANSYS Maxwell Documentation, ANSYS Inc., Canonsburg, PA; available at

Breidenthal, W.C., G. Larin, S.M. Tipton, and R.K. Stanley, 2006, “The Use of Finite-Element-Calculated MFL Signals to Study Characterization of Defects in Steel Coiled Tubing,” SPE/ICoTA Coiled Tubing Confer-ence & Exhibition, 4–5 April, The Woodlands, TX.

Breidenthal, W.C., G.E. Larin, S.M. Tipton, and R.K. Stanley, 2009, “The Use of Finite-Element-Calculated Magnetic-Flux-Leakage Signals to Study the Characterization of Defects in Steel Coiled Tubing,” SPE Journal,  Vol. 14, No. 1, pp. 120–127.

Dutta, S.M., F.H. Ghorbel, and R.K. Stanley, 2009, “Simulation and Analysis of 3-D Magnetic Flux Leakage,” IEEE Transactions on Magnetics, Vol. 45, No. 4, pp. 1966–1972.

Katoh, M., N. Masumoto, K. Nishio, and T. Yamaguchi, 2003, “Modeling of the Yoke-Magnetization in MFL-Testing by Finite Elements,” NDT & E International, Vol. 36, No. 7, pp. 479–486.

Li, Y., J. Wilson, and G.Y. Tian, 2007, “Experiment and Simulation Study of 3D Magnetic Field Sensing for Magnetic Flux Leakage Defect Characteri-sation,” NDT & E International, Vol. 40, No. 2, pp. 179–184.

Liu, B., Y. Cao, H. Zhang, Y.R. Lin, W.R. Sun, and B. Xu, 2015, “Weak Magnetic Flux Leakage: A Possible Method for Studying Pipeline Defects Located Either Inside or Outside the Structures,” NDT & E International, Vol. 74, pp. 81–86.

Liu, Z., G. Minerbo, and A. Zheng, 2014, “Steel Coiled Tubing Defect Evaluation Using Magnetic Flux Leakage Signals,” SPE/ICoTA Coiled Tubing and Well Intervention Conference and Exhibition, 25–26 March, The Woodlands, TX.

Liu, Z., A. Zheng, O.O.R. Diaz, and L. Haugland, 2015, “A Novel Fatigue Assessment of CT with Defects Based on Magnetic Flux Leakage,” SPE/ICoTA Coiled Tubing & Well Intervention Conference & Exhibition, 24–25 March, Houston, TX.

Lian, Zhanghua, Hao Yu, Tiejun Lin, and Jianhua Guo, 2015, “A Study on Casing Deformation Failure during Multi-Stage Hydraulic Fracturing for the Stimulated Reservoir Volume of Horizontal Shale Wells,” Journal of Natural Gas Science and Engineering, Vol. 23, pp. 538–546.

Newman, K.R., and J. Lovell, 2003, “A New Approach to Ultrasonic Coiled Tubing Inspection,” SPE/ICoTA Coiled Tubing Conference and Exhibi-tion, 8–9 April, Houston, TX.

Ravan, M., R.K. Amineh, S. Koziel, N.K. Nikolova, and J.P. Reilly, 2010, “Sizing of 3-D Arbitrary Defects Using Magnetic Flux Leakage Measure-ments,” IEEE Transactions on Magnetics, Vol. 46, No. 4, pp. 1024–1033.

Roberts, T.C., 2003, Finite Element Analysis of Magnetic Flux Leakage in Coiled Tubing, University of Tulsa, Tulsa, OK.

Stanley, R.K., 2011, “Results of a New Coiled-Tubing Assessment Tool,” SPE/ICoTA Coiled Tubing & Well Intervention Conference and Exhibition, 5–6 April, The Woodlands, TX. 

Stanley, R.K., and S. Papadimitriou, 1994, “NDE Inspection of Used Coiled Tubing,” ASNT 1994 Fall Conference and Quality Testing Show, 19–23 September, Atlanta, GA, pp. 126–129.

van Adrichem, W.P., and H.A Larsen, 2002, “Coiled Tubing Failure Statis-tics Used to Develop CT Performance Indicators,” SPE Drilling & Comple-tion, Vol. 17, No. 3, pp. 159–163.

Yu, R., B. Hu, H. Zou, W. Xiao, Q. Cheng, W. Xu, and J. Xin, 2014, “Micro-magnetic Technology for Detection of Carbon Impurity in Crystalline Silicon,” NDT & E International, Vol. 62, pp. 1–5.

Zhaoming, Z., S. Taihe, Y. Runqiao, L. Zhangua, and W. Fu, 2014, “Metal Magnetic Memory-Based Fluxgate Sensor for Imaging Detection of Coiled Tubing,” Insight – Non-Destructive Testing and Condition Monitoring, Vol. 56, No. 12, pp. 691–696.

Zatsepin, N.N., and V.E. Shcherbinin, 1966, “On Calculation of the Magnetostatic Field of Surface Defects,” Defektoskopiya, Vol. 5, pp. 50–59.

Zuoying, H., Q. Peiwen, and C. Liang, 2006, “3D FEM Analysis in Magnetic Flux Leakage Method,” NDT & E International, Vol. 39, No. 1, pp. 61–66.

Usage Shares
Total Views
116 Page Views
Total Shares
0 Tweets
0 PDF Downloads
0 Facebook Shares
Total Usage