SURFACE DIFFUSION ALLOYED SDA STEEL FOR OILFIELD TUBULARS

SURFACE DIFFUSION ALLOYED (SDA) STEEL FOR OILFIELD TUBULARS CORROSION TEST PROGRAM SAGE of AMERICA Sage of America 7907 Old Lee Highway Collegedale, Tennessee 37315

CORROSION TEST PROGRAM • Effect of p. H, Chloride, and Temperature – Pitting, crevice and general corrosion – Application limits – Comparison with CRAs • Effect of H 2 S – Pitting and general corrosion – Sulfide Stress Cracking – Hydrogen penetration

CORROSION TEST RESULTS • Cr diffusion alloyed 1018 and 4140 steel – Competes with 13 Cr and 2205 duplex CRA • Corrosion advantage over 420 stainless steel – p. H 3. 4 to 250, 000 ppm chloride at 95°C – p. H 2. 8 to 150, 000 ppm chloride at 95°C – Factor of 5 to 10 lower corrosion rate – Confirmed by 28 day test at 1, 000 ppm Cl¯

Corrosion Rate at p. H 3. 4 Weight loss corrosion rate for 1, 000 ppm Cl¯ T = 85°C, 28 days total exposure

Corrosion Rate at p. H 3. 4 Weight loss corrosion rate for 1, 000 to 250, 000 ppm Cl¯ T = 95°C, 374 hours total exposure

Corrosion Rate at p. H 3. 4 LPR corrosion rate for 1, 000 to 50, 000 ppm Cl¯ T = 95°C, 374 hours total exposure

Corrosion Rate at p. H 2. 8 Weight loss corrosion rate for 1, 000 to 150, 000 ppm Cl¯ T = 95°C, 336 hours total exposure

Effect of p. H on LPR Corrosion Rate LPR corrosion rate for 10, 000 ppm Cl¯ at T = 95°C

ADDITIONAL CORROSION TESTING • Long term tests at 85°C and p. H 3. 4 – Exposure time to 30 days – 1, 000 ppm Cl¯ (complete) – 150, 000 ppm Cl¯ • Sulfide stress cracking resistance at 25°C – NACE TM 0177 bent beam – ASTM G 146 hydrogen penetration • Full scale tests at temperatures to 150°C

Full Scale Test

Full Scale Test