Application of Fluorinated Rubber in Oilfield

Oil field is an extremely harsh environment for rubber materials. Due to the high temperature and chemical mixture in the oil field, it is required that the rubber used can resist the harsh environment and provide safe and reliable services. Viton can be used in this harsh environment. The products made of fluororubber for oil field and petrochemical industry are various, including O-ring, packers, Drill seal, valve seal, pulsation dampeners，etc. Oil is extracted from the depths of the earth and then made into gasoline and chemicals to drive our lives. These seals and components are extremely important to ensure the normal operation, safety and reliability of oil extraction equipment every day.

Selection of materials

Each class of elastomers has a characteristic set of advantages and disadvantages when compared to other elastomer types. In sealing solutions, there is a wide range of properties that must be carefully considered when selecting the elastomer. Among the most important considerations are the chemical and heat resistance of the elastomer. Environments consisting of oil, aromatic hydrocarbons, aqueous environments with corrosion inhibitors, steam, and hydrogen sulfide are likely to be encountered in the oilfield. Long-term heat resistance in excess of 180°C may be necessary in deep wells. Additionally, low temperature flexibility and the ability to maintain a dynamic seal at temperatures below 0°C, an environment found in deepwater and northern sea floors, may also be a seal design factor.

Bisphenol cured FKMs has excellent aromatic hydrocarbon and oil resistance but poor resistance to bases high temperature water, and hydrogen sulfide. Compared with bisphenol cured FKM elastomer, peroxide cured FKM elastomer has improved chemical resistance, steam resistance, limited hydrogen sulfide resistance and improved base resistance.

AFLAS based FEPM elastomers serve in many oilfield applications. However, AFLAS elastomers are not resistant to aromatic hydrocarbons and exhibit extreme volume swell in aromatic containing fluids. The low temperature performance of AFLAS elastomers may not be suitable for many low temperature applications as the Tg is above 0°C. FEPM elastomers exhibit good resistance to hydrogen sulfide.

Perfluoroelastomer is very chemically and high temperature resistant. Perfluoroelastomer can be used in almost all fluid environments found in oil fields, including those containing hydrogen sulfide. The universal use of FFKM as a sealing material is possible but there can be the risk of over-engineering a part and consequently adding needless cost. The low temperature performance of FFKM, like that of AFLAS based elastomers may not be suitable for all applications.

Since there are many material choices for each individual application, the difficulty for the seal designer is to use a material that will be useful in as many applications as possible and provide the best value. Each oilfield has its own fluid composition and environment, and usually requires customized elastic components. Elastomer customization increases the cost of equipment and limits the use of parts designed for one field at another field with different environmental conditions. The use of a new type of FKM broadly defined as a FKM type 5, specifically known as Tecnoflon BR 9151, is gaining acceptance as an elastomer that bridges the properties of FKM, FEPM, and FFKM in oilfield applications.