LAUSR

Abstract The study aims to investigate the effect of heat treatment of the P110 downhole tubular steel on its resistance to sulfide stress cracking (SSC), with an aim of producing P110 steel with higher strength which in turn reduces the cost via the reduction of the tubular wall thickness. The reduction of the tubular wall thickness maximizes the diameter of the wellbore, which increase the production rate per well. The susceptibility of P110 downhole tubular steel to SSC has been investigated using small circumferential notch tensile (CNT) specimens. The P110 steel was tested with and without heat treatment in a deaerated 3.5% NaCl solution containing 0.01 M Na2S2O3 (as a source for H2S) at room temperature. The experimental results show the heat-treated P110 steel to be susceptible to SSC whereas the un-heat-treated steel was not susceptible to SSC. Scanning electron microscopy suggested intergranular propagation of stress corrosion cracks.