Review of Performance of Oil and Gas Facilities in Sour Conditions

As part of a strategic review for future oil field developments, the historic performance of oil & gas production facilities of a number of sour fields in Oman have been re-assessed. The fields are all characterised as high CO₂ and H₂S (typically 2 to 16 mol% CO₂ and 1 to 10 mol% H₂S), high gas-oil ratio (100 to 800 sm³/m³) but very low water content (0.05 to 2%).

conditions.Different material selection strategies had been adopted over several years for the different fields despite the very similar operating conditions. In one field high nickel corrosion resistant alloys (CRAs) were used extensively; in another the bulk of the facilities were fabricated from carbon steel, and in the most recent development a mixture of CRAs, carbon steel and corrosion inhibition has been used. 

The paper will present a review of corrosion performance of carbon steel in these conditions, based on corrosion monitoring and corrosion inspection.  The actual performance of carbon steel components in the different fields will be compared to the predicted corrosion rates using industry standard models. 

Based on the practical experience and recent laboratory test data a new material selection strategy has been established for future developments