Corrosion Testing in Moderate and Ultra High Shear Production Environments

Abstract

Selection of effective corrosion for use in high wall shear conditions is of increasing importance in oilfield production. Development of new oil and gas fields often requires the use of more sophisticated downhole equipment. As a result these production conditions can result in exceptionally high wall shear stress, for example in-flow control devices (ICDs) can reach shear stresses up to 10,000 Pa. To accommodate this, there is need for more representative high shear tests for material and production chemical selection. A jet impingement test procedure is shown that allows for the evaluation of products under such environments. Further to this the shear stresses generated in standard laboratory tests have been compared with a high flow pilot rig and comparative Computational Fluid Dynamics (CFD) modelling. A test system has been developed that allows routine laboratory evaluation of corrosion processes at moderate to high shear stresses using jet impingement methodology. A series of tests have been conducted to determine the extent of corrosion under moderate to high shear conditions. Static tests and low shear rotating cylinder electrode (RCE) tests have been carried out using the same brine system to allow comparison of results from the different methods. Ultimately, high flow (moderate to high shear) pilot rig tests have also been used to verify the results. The results show that the jet impingement approach is effective in generating field representative conditions, which in turn can support material or chemical selection. The work presented is supported by case studies which will be illustrated. In order to test effectively, the flow regimes experienced in the field must be replicated. Using CFD models we demonstrate that the observed field conditions can be reproduced using these laboratory flow regimes and produce results that correlate well.