Abstract
Corrosion inhibitors injected into production fluids can be an extremely effective method of mitigating corrosion in pipelines. In many cases, the use of expensive alloys can be avoided if the appropriate corrosion inhibitor is utilized, saving significant capital expenditure. In some cases however, corrosion control in the infrastructure may deteriorate over time. This is often the case when significant quantities of oily solids accumulate in the pipeline. This material, which is affectionately termed ‘schmoo’, has the potential to adsorb a significant quantity of inhibitor and forms a safe haven for bacteria. This makes it extremely difficult, if not impossible, for even the best corrosion inhibitor to be effective.
Through measuring oil-water interfacial tensions and contact angles, the work of adhesion of an oil drop on a submerged carbon steel surface has been calculated in the presence of a series of corrosion inhibitors. A novel multifunctional corrosion inhibitor formulation has been developed that is extremely effective at removing oily deposits from the internal surface of pipelines. The effectiveness has been demonstrated in a series of dynamic ‘schmoo’ removal studies. The formulation is also shown to be an extremely effective corrosion inhibitor.
Results from recent field evaluations with this new product corroborate laboratory findings. The new multifunctional inhibitor is seen to exhibit superior inhibition performance to existing high performance products. Additionally, the product is shown to both prevent the deposition of ‘schmoo’ in a pipeline and remove it from a previously fouled system. The removal resulted in a significant increase in water injection rates and an associated increase in oil production.
