Methodology and approach used to characterize micellization and adsorption related parameters for an individual corrosion inhibitor components; specifically, data for a homologous quaternary amine series.

Most composite repair installations take place with some amount of pressure in the pipe. The traditional design standards ASME PCC-2 4.1 and ISO 24817 each provide a design equation that includes consideration of installation pressure but the equations up to this point have been theoretical only and never tested. It is important to note that in the equations an increasing installation pressure acts to reduce the required composite repair thickness. This experimental test program studied the effects of internal pipe pressure during installation on composite reinforcement systems to verify if the performance of the repair was maintained when applied to simulated corrosion defects. The full-scale testing analyzed the effects on the burst pressure and the cyclic pressure fatigue life of a pipe with a 50% wall loss simulated corrosion defect. The installation pressures considered were varied from 0 up to 50% SMYS. The results of the test are presented and recommendations given for design use in future works.

The oil and gas industry utilize surfactant-type organic corrosion inhibitors as a way to mitigate internal pipeline corrosion. Changes in corrosion rates due to inhibitor addition have been related to adsorption isotherms as a function of the inhibitor concentration. However the question as to how a corrosion inhibitor affects the electrochemical reactions governing CO2 corrosion remains unclear. This research proposed to investigate the aforementioned question by using a systematic approach: four different corrosion inhibitors synthesized in-house were utilized to determine the effect of the tail length on the activation energy of the electrochemical process underlying the corrosion of an API 5L X65 steel in CO2 corrosion at pH 4. The corrosion inhibitors all contained the same head group (dimethyl-benzyl-ammonium) with four different alkyl tail lengths (C4 C8 C12 and C16). A theoretical description of the increase in the activation energy of the electrochemical process underlying CO2 corrosion due to the presence of the corrosion inhibitors was proposed. Such a description also led to the development of a modified Butler-Volmer equation that describes the retardation in charge transfer rates of the electrochemical reactions associated with the corrosion of mild steel. The model is based upon changes in activation energy calculated by an Arrhenius plot. The model was compared with experimental potentiodynamic sweeps for each corrosion inhibitor model compound. As a result the corrosion model predicts the corrosion rate and the open circuit potential in the presence of a corrosion inhibitor with reasonable accuracy.