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U.S. Department of Energy
Office of Scientific and Technical Information

Effects of environmental conditions on SSC resistance of C125 OCTG

Conference ·
OSTI ID:696967
;  [1]
  1. Nippon Steel Corp., Futtsushi, Chiba (Japan). Steel Research Labs.

Demand for high strength casing has increased to develop high pressure and/or deep wells. In order to cope with H{sub 2}S contained in produced fluid, the high strength casings are often required to be resistant to SSC (Sulfide Stress Cracking). Effects of environmental factors such as H{sub 2}S partial pressure and pH on SSC resistance of C125 grade OCTG were made clear using some types of SSC tests (tensile, V-notched 4-point bent beam, DC13 compact, tension, SSRT) and a hydrogen permeation test. For hydrogen entry into steel, one unit of pH decline is equivalent to a tenfold rise of H{sub 2}S partial pressure although the effect of pH becomes lower after long time. SSC resistance of C125 decreases with increasing pH{sub 2}S and decreasing pH and is very high at H{sub 2}S partial pressure of 0.001 MPa or lower and high at 0.01 MPa in case of higher pH.

OSTI ID:
696967
Report Number(s):
CONF-990401--
Country of Publication:
United States
Language:
English