High pressure full size prototype sulfide stress cracking (SSC) tests of C90, C100, and C110 casing were conducted in NACE TM0177 Method A SCC test enviornment followed by failure analysis. The NACE TM0177 Method A SCC test environment was also used to determine smooth tensile sample SSC threshold data for the materials. An alternate environment consisting of 10% H2S and 90% N2 was also used to conduct prototype tests. The Von Mises threshold stress determined from the prototype samples was consistently less than the threshold stress determined by using NACE TM0177 Method A. It is concluded that the NACE Method A test does not provide the lower bound of the threshold stress compared to prototype test samples.
Keywords: Hydrogen sulfide, casing, sour gas, corrosive, cracking, oil wells, gas wells