A comparison of the ANSI/NACE MR0175/ISO 15156 regions of environmental severity for SSC at both NPT and 20,000 psig at 75°F. Calculations(3) at 20,000 psig were made based on the proposed CH2S-SSC scalability paradigm at 75°F (24°C). WGR = 10 bbl/MMscf: 0 mg/L Cl−with the nonaqueous phase containing 60 mol ppm H2S + 10 mol% CO2 + bal. CH4.