Effect of Acidizing Process on the Stress Corrosion Cracking of HP-13Cr Stainless Steel in the Ultra-depth Well Environment

Abstract

The effect of acidizing process on the stress corrosion cracking of HP-13Cr stainless steel in the ultra-depth well environment was studied by the slow strain rate test, the electrochemical measurement, the microstructure observation, and the finite element modeling. The results indicated that the acidizing process significantly increased the stress corrosion cracking susceptibility of HP-13Cr stainless steel and induced the fracture mode to the brittle characteristic in the high temperature and CO2 pressure environment. The stress corrosion cracking susceptibility also increased with the increase of temperature and CO2 pressure. There were dense defects including pits and cracks in the fracture section from the transverse view. After the acidizing process, under tensile stress condition, the increasing roughness will cause the stress concentration and promote the local anodic dissolution, which induces the initiation of stress corrosion cracking.

Damage evaluation of carbon fiber reinforced composites under corrosion condition of sour gas well

“…The corrosion media faced include H 2 S‐CO 2 , high salinity formation water, acidizing fluids, and dissolved oxygen (in water or nitrogen injection). [ 22,23 ] To assess the suitability of the three composite materials for corrosive conditions in oil and gas wellbore, a comprehensive corrosion evaluation test plan was developed to simulate the harsh service environment of typical wellbores, as shown in Table 1. The composition of formation water is shown in Table 2, and the acidizing fluid formulation consists of 20% hydrochloric acid, 0.8% thickening agent, 4% corrosion inhibitor, 1% demulsifier, 1% iron ion stabilizer, 2% crosslinker, and 0.02% defoamer.…”