Experimental and Numerical investigations on the erosion corrosion behavior of carbon steel in CO2 saturated environment

Erosion corrosion is considered to be one of the serious problems being faced by many industries. In a piping system, when the flow starts, an initial oxide film forms on the surface, which subsequently sows down further oxidation/corrosion reaction. However if this film is damaged/removed, corrosion rate will be increased significantly. The fluid flow rate and the, sand particles present in the fluid increase the corrosion rate. So the prediction of corrosion or erosion-corrosion with/without these oxide films is not easy. There are multiple factors such as, fluid type, nature of fluid flow, properties of erodent (sand particles) and material composition etc. must be considered while investigating the erosion corrosion behavior of materials. The contribution to erosion by corrosion or to corrosion by erosion is an important subject which requires extensive investigations. There have been a lot of work on the erosion corrosion issue, but still there arent any effective erosion corrosion correlations which can predict erosion-enhanced corrosion or corrosion-enhanced erosion in CO2 saturated environment. So in this proposed project, we plan to develop a reliable in-house erosion corrosion database based on both in-situ and ex-situ experimental investigations in a flow loop while simulating the real time situation in the piping systems. Such a database will be used to develop erosion corrosion correlations which will be used to develop erosion prediction model in this project and later erosion enhanced corrosion prediction model in a separate study. An in-house erosion corrosion testing facility is available (developed in our previous project), which has a state of the art stainless steel flow loop, an air-jet erosion tester and a rotating disk electrode. This facility with some modifications and additions for CO2 corrosion will enable the project team to accomplish this proposed research effectively in due time. The experiments will be conducted for different carbon steel grades (AISI 1030, API 65) under different fluid flow velocity, impingement angle, chloride concentration, with/without erodent particles and with/without CO2 saturated environment etc. Since the impact speeds of the solid particles that are entrained in the fluid are not necessarily the same as the fluid speed, the computational modelling of solid particles trajectories and the resulting erosion-enhanced corrosion will be achieved using numerical simulation of solid particle motion (using the Lagrangian particle-tracking technique) in the flow field. Thus local erosion-corrosion rates and pattern can be calculated for different flow velocities, impact angles considering solid particles of different sizes and hardness. The results of the computational model will be compared to the local measurements of the specimen material loss (thickness loss) to determine semi-empirical erosion-enhanced corrosion rate correlations. These correlations can then be used to predict new flow conditions that are encountered in various oil and gas fields. Prof. Shirazi from erosion corrosion research center of University of Tusla will be our consultant in this project, which requires a total budget of 298,000 SR for 24 months. The proposed research is of direct relevance to engineering applications especially in KSA oil and gas production facilities due to the presence of water, sand particles and corrosive agents (some of these are normally used in enhancing oil recovery) in the produced fluid. In addition, many KSA industries such as power plants, petrochemical industries and oil refineries, use sea water for cooling purposes resulting in serious erosion problems in almost all system components. So it is expected that outcomes of the proposed research will be very beneficial to the local industrial community