Karan field is Saudi Aramco's first offshore nonassociated gas field, which started production in mid-2011. The gas is sour (2% hydrogen sulfide (H2S) and 8% carbon dioxide (CO2)) and lean with no hydrocarbon condensate. The gas is predicted to produce 2 bbl/MMscf of condensed water with 750 ppm of organic acids. Water condensation throughout the trunk line creates a high risk of both corrosion and gas hydrates during winter.
The use of a Kinetic Hydrate Inhibitor (KHI) was selected for hydrate inhibition. Through rigorous qualification testing, it was realized that qualifying a compatible KHI — in the presence of a corrosion inhibitor (CI) for a sour predominantly structure I hydrate system — is very challenging. This paper describes the extensive work that has been exhausted to qualify a suitable KHI for the Karan field. The paper also presents a review of strategies for hydrate management, focusing on novel KHIs developed solely to meet this field's conditions. The work involves evaluating various mixtures of KHI and CI at different concentrations, using traditional and novel testing methods.