Failure Analysis of Ф73.02 mm × 5.51 mm S13Cr 110 Tubing Collapse in an Oil Field

Abstract

The field service conditions of a well’s collapse tubing were investigated, and the physical and chemical properties of metal materials (chemical composition analysis, mechanical property test, metallographic structure analysis of tubing materials), hydrogen sulfide stress corrosion cracking test of tubing materials, and scanning electron microscopy analysis of tubing cracks and fracture surfaces were tested in this paper. The results show that the major cause of tubing collapse is that the tubing material is super 13Cr (S13Cr). When it is used in the environment containing hydrogen sulfide, plenty of longitudinal stress corrosion cracks is generated on the inner wall, which greatly reduces the actual anti extrusion ability of the tubing. During the gas lift of the well in the later stage, the upper part of the oil pipe was blocked and the oil jacket was in series, and the gas lift pressure was transmitted into the oil jacket annulus, so that the pressure difference between the inner and outer parts of the oil pipe exceeded its actual anti extrusion capacity and collapse failure occurred.