Integrated Analysis of Optimizing Casing Materials Selection of Geothermal Well by Using a Model for Calculating Corrosion Rates

Abstract

The lifetime of geothermal well can be maintained as long as possible by performing the well casing design, particularly the selection of the appropriate production casing due to it was the only one casing which is in constant contact with the extracted geothermal fluid. Considering that the geothermal fluids often have a high salinity and contain many corrosive agents, it is not surprising that corrosion phenomena are a rather frequent occurrence in production casing resulting thinning that can lead to failure. This study presents a comprehensive methodology, as a pilot project of selecting production casing based on corrosion resistance in geothermal environment by using corrosion rate calculation resulted from Kurata et al experiments and pressure drop modelling. This study has been implemented for selecting materials casing in well conditions similar to well “A” in a geothermal field in Indonesia. Based on this study, it is known that the corrosion rate equation by Kurata et al cannot be applied in different geothermal environment directly due to the differences in data and observed area. Therefore, generation models have been made from the Kurata’s corrosion rate equation to the data field using analytical software SPSS to be more applicable regarding to particular condition. It is expected that the corrosion rate equation results of this study could be developed for conditions of geothermal wells in Indonesia and further research about corrosion study in wellbore could be growing.