Corrosion Cracking Causes in 13Cr-110 Tubing in Oil and Gas Extraction and Transportation

With the continuous development of oil and gas fields, the demand for corrosion-resistant tubing is increasing, which is important for the safe exploitation of oil and gas energy. Due to its excellent CO2 corrosion resistance, 13Cr-110 martensitic stainless steel is widely used in sour gas-containing oil fields in western China. This paper describes a case of stress corrosion cracking (SCC) in a 13Cr-110 serviced in an ultra-deep gas well. The failure mode of the tubing is brittle along the lattice fracture, and the cracks are generated because of nitrogen gas-lift production-enhancement activities during the service of the tubing, leading to corrosion damage zones and cracks in the 13Cr-110 material under the synergistic effect of oxygen and chloric acid-containing environments. During subsequent production, the tubing is subjected to tensile stresses and cracks expanded at the 13Cr-110 lattice boundaries due to reduced structural strength in the corrosion region. To address the corrosion sensitivity of 13Cr-110 in an oxygen environment, it is recommended that the oxygen content in the wellbore be strictly controlled and that antioxidant corrosion inhibitors be added.