Epoxy Resin Exhibits Long-Term Durability and Chemical Stability as a Well Sealant

The necessity to verify epoxy resin sealant's reliability for well applications is amplified as its use increases. Limited data exists to confirm resin's long-term durability or chemical stability under exposure to well fluids at temperature and pressure. This paper presents laboratory results illustrating durability and stability of epoxy resin exposed to a range of well fluids over a span of temperatures. Additionally, results of accelerated thermal degradation testing further quantify long-term thermal and chemical stability. Epoxy resins formulated for a range of remedial and abandonment applications were cured in fresh water, CaCl2 brine, and hydrocarbon at 170°F up to one year. Additional samples cured in fresh water and water containing CO2 and H2S at elevated temperatures (220°F to 320°F) for up to six weeks to produce accelerated degradation reactions allowed the assessment of resin degradation verses temperature. Thermal Gravimetric Analysis (TGA) evaluated chemical and mechanical degradation verses time at temperatures ranging from 200°C to 400°C. Arrhenius calculations were performed to forecast long term stability of resins across their intended temperature ranges. Resulting data were analyzed to develop an inclusive assessment of resin stability and durability in well environments. Results indicate properly formulated epoxy resin is a mechanically, chemically, and thermally durable sealant for well applications.