Elastomers are high quality rubber (or plastic) used when sealing is required. Primarily used as o-rings, seals and gaskets, elastomers are used in packers, completion equipment, liner hangers, plugs, BOP, wellhead equipment, stimulation and zonal isolation equipment, logging tools, sampling equipment, motors and alike. There is large variety of elastomers available today to match down-hole well conditions, when it comes to pressure, temperature, corrosion, H2S, impact of chemicals and a like. Yet, it is generally agreed that there is no product that will meet all the criteria, hence selection of the right elastomer is key in ensuring the longest life and reliability, at optimum cost. Wrongly selected elastomers can lead to problems in a well or overly expensive projects. Depending on the application, cost of elastomers may change up 5x, i.e. HP/HT and H2S content a higher grades of elastomers must be selected, from FFKM family.
Elastomers are not natural and is a produce of chemistry. The difference between natural rubber and elastomers is simple - the former is made of natural rubber (latex), whereas the latter is a synthetic rubber and made of a polymer that shows elastic properties, with up to 10 other components that may be included when manufacturing elastomers. There are various brands and sub-materials from various manufacturers with branded names and trademarks. Elastomers are also classified into elastomers, fluoroelastomers and perfluoroelastomers. The classification is very complex, but it is mainly around:
- NBR is a basic nitrile rubber
- HNBR has slightly better tolerance than standard nitrile
- EPDM is used for sealing water-based liquids when there is no oil contact
- FKM is the group of about 80% of fluoroelastomers. FKM fluoroelastomers are divided into different types (from 1 to 5). There are many manufactures of FKM globally.
- FEPM is a copolymer of tetrafluoroethylene (TFE) and propylene. These materials have better chemical and heat resistance characteristics
- FFKM is a perfluoro-elastomers with higher amount of fluoride than FKM which makes them more chemical and heat resistant
Although there are more manufactures globally, below is the list of major materials and producers used in the oil industry.
|Name||Class||Applications in Oil & Gas||Other Applications||Manufacturer|
|Hydrogenated Nitrile||HNBR||Slightly better tolerance than standard nitrile||Various|
PPE ( Precision Polymer Engineering)
|Tecnoflon®||FKM||Low to medium down-hole temperature||Solvay|