Abstract
Liquid corrosion inhibitor (CI) package injection is one of the most cost-effective solutions and commonly applied methods to control internal corrosion and prevent corrosion failures of carbon steel pipelines in the oil and gas industry. However, due to the amphiphilic nature of CIs, a significant fraction of the injected CI is lost into the oil phase through partitioning, dramatically decreasing the efficiency of CIs due to lowered CI concentration in the water phase. To enhance CI efficiency, a novel CI encapsulation technology was developed to bypass the oil phase and deliver inhibitors directly to the water phase.
In this study, commercial CI packages as well as custom CI blends were encapsulated with water soluble matrix materials into microsphere morphology via spray drying technique. The stability of the encapsulated CIs in crude oils as well as synthetic oil was evaluated via weight loss measurement and the payload of the encapsulated CIs was estimated via solubility study in polar solvents. Partitioning behavior of encapsulated CI in an oil/water two phase system was investigated using methyl orange CI residual measurement method. The corrosion inhibition performance of encapsulated CIs in sweet aqueous corrosion environment was evaluated and compared with conventional liquid CIs through electrochemical corrosion tests. Due to minimized CI loss in oil phase, encapsulated CIs demonstrated superior corrosion inhibition efficiency and performance to commercial liquid CIs in an oil/water two phase system.
