Analysis of the Plastic Extension of Parking Cracks on Casing after Testing

Abstract:

To avoid the fatigue fracture of casing inside slips, the plastic extension of casing cracks near slips under inner pressure after taking RTTS packer out should be analyzed. The plastic zone size of instability extension of two/three-dimensional cracks on casing was derived based on the theory of fracture mechanics. Analysis results show that hoop stress caused by inner pressure of casing is a key factor to lead to the instability extension of casing radial cracks after testing. The plastic extension zone size of cracks on casing near slips increases with the inner pressure or hoop stress. And, the plastic extension of cracks on casing near slips reduces the burst strength of casing significantly. The materials of casing materials and the inner pressure should be appropriately controlled to control the propagation of cracks.

• Periodical: Applied Mechanics and Materials (Volumes 423-426)
• Pages: 1207-1210
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.423-426.1207
• Online since: September 2013
• Authors: Long Cang Huang*, Shao Kai Tong, Yin Ping Cao, Yi Hua Dou
• Keywords: Bitten Cracks, Casing, Plastic Extension, Plastic Zone Size, RTTS Packer, Slip

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