Development of Corrosion Inhibitors to Address under Deposit Corrosion in Oil and Gas Production Systems

Abstract

Abstract Whilst the phenomena of sand production, its erosional effects in high velocity systems, and the ability of chemicals to mitigate erosion have been well documented, little attention has been given to low velocity systems where sand settles to form deposits. Deposition of sand has reportedly resulted in partial or complete blockage of pipelines, trapping of pigs, or under deposit corrosion. This latter phenomena is of some concern to operators whose production rates dictate low flow conditions combined with the presence of solids - especially in relation to the effectiveness of chemicals to inhibit under deposits. The interaction of corrosion inhibitors with sand (solids) is of importance to better understand their likely efficacy in systems containing sand – particularly if settling is possible. Perhaps the two more important parameters include the affinity of the chemical for sand and the ability of a chemical to afford inhibition under settled sand. A dynamic adsorption test has been used to evaluate the ability of several corrosion inhibitor active components to penetrate sand beds. In addition, detail regarding the extent of adsorption of these chemicals to sand particles has been determined and discussed. Relationships between adsorption to sand and physicochemical parameters of the molecules are discussed. The relationship between adsorption studies and simulated corrosion experiments is also discussed.