Effects of New Generation Drilling Fluids on Drilling Equipment Elastomers

ABSTRACT Environmentally safe drilling fluids have been the subject of considerable interest from governments, operators, oil companies and drilling fluid manufacturers. The use of these drilling fluids has been increasing, this has been especially true for offshore drilling operations. Drilling fluids can chemically alter the properties of elastomers used in drilling equipment, severely affecting life and function. The products affected include blowout preventers (BOPs), pulsation dampeners, downhole mud motors and drilling bits. This study centers on the effects of selected environmentally safe drilling fluids on BOP and pulsation dampener elastomers. The properties of these elastomers are presented before and after drilling fluid exposure. The property changes were evaluated with respect to equipment function and performance and exposure time. A wide variation was found in property changes which were dependent upon elastomer and drilling fluid composition. The performance of elastomers in drilling fluids is strongly dependent upon drilling fluid Chemistry, operating temperature and the type of elastomer chosen for service. Caution and testing were recommended when selecting environmentally safe drilling fluids and compatible elastomers.