Two of the key challenges currently encountered in operating geothermal wells using conventional steel casings are corrosion and scaling. These problems significantly reduce the lifespan of the steel casing systems, causing wellbore integrity issues, which could lead to major environmental contamination. Moreover, the corrosion leads to surface degradation of the casing, causing excessive pressure losses. To prevent major damage, costly workover operations are inevitable, becoming a substantial financial burden and may ultimately jeopardize project economics of steel based geothermal well designs.
Dynaflow Research Group (DRG) is partner in the GEOTHERMICA-funded GRE-GEO project, a multinational consortium of geothermal experts to solve these challenges through development of the new glass fiber reinforced epoxy (fiberglass) casing system for geothermal applications.
This paper covers a short overview of a number of studies that were carried out by DRG as part of the GRE-GEO project to investigate well integrity topics like electro static discharge (ESD), wear (erosion and abrasion) and chemical compatibility of the casing material with well fluids. A HAZID study has been carried out to identify potential risks associated with the application of fiberglass in geothermal wells and to offer mitigating actions to manage these risks.
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