Abstract
Generally, the most economical material for construction in oil and gas pipeline systems is carbon steel. Besides the safety and environmental issues, downtime caused by corrosion related failures and hydrate-induced blockages in pipelines can be costly to the operator. Asset integrity and flow assurance are, therefore, recognised to be critical issues in oil and gas production and transportation. Chemical inhibitors to protect pipelines from metal degradation and hydrate blockages are commonly utilised but compatible corrosion inhibitor (CI) and kinetic hydrate inhibitor (KHI) combinations are often difficult to formulate for sour gas applications. It is often found that either the KHI has an adverse affect on the CI function or vice versa. Before field deployment, extensive inhibitor testing and evaluation is conducted to ensure that the most appropriate products are selected. This paper presents data from a laboratory programme which was instigated to develop and assess new corrosion inhibitor formulations. Performance was evaluated in terms of the corrosion inhibition of the CI and its KHI compatibility and performance in supplementary secondary property tests under simulated sour gas pipeline operating conditions. From this work two CI/KHI combinations exhibiting excellent compatibility in terms of corrosion inhibition performance (both general corrosion inhibition as well as, more importantly, pitting corrosion inhibition), hydrate inhibition performance and high temperature injection performance have been developed.
