SSC Resistance of High Strength Low Alloy Steel OCTG in High Pressure H2S Environments

SSC resistance of 110ksi grade low alloy steel OCTG was evaluated in highly pressurized H2S environments assuming its application to High Pressure/High Temperature (HPHT) oil and gas fields.  DCB tests were conducted according to the basic procedures specified in NACE TM0177-2005 method D, with an exception that the test solutions saturated with highly pressurized H2S were used.  The H2S pressures were ranging from 1 to 15bar, and the testing temperatures were from 24 to 80 degree C.  Test results show that the measured KISSC values were strongly influenced by these testing variables.  The mechanism of the environmental effects on SSC susceptibility was discussed from viewpoints of corrosion reactions, corrosion products formed on the steel surface and atomic hydrogen absorption into the steel.