PEEK encapsulated sensors for deep drilling

Edited by the Processingtalk editorial team Sep 7, 2007

Victrex PEEK polymer is a high performance thermoplastic, able to withstand extreme environments: it has been applied for complete encapsulation of a miniature sensor used in deep drilling equipment

The sensor, measuring 10mm long by 3mm in diameter, was developed and encapsulated in order to withstand the hostile environment of deep drilling operations.

Deep drilling equipment must be capable of operating under pressures of up to 1400 bars (20,300 psi) and have the ability to withstand the most extreme mechanical forces.

According to Robert Navo, Victrex Global Applications Manager for Oil and Gas, "Victrex PEEK polymer offers a unique combination of mechanical and tribological properties at the elevated temperatures found in deep drilling operations.

In that environment, its not unusual to encounter temperatures ranging between 180C (356F) and 200C (392F) in the presence of hydrogen sulphide, methane, carbon dioxide, salt water and crude oil.

Victrex PEEK polymer, which has a continuous use temperature up to 260C (500F), offers excellent chemical and hydrolysis resistance along with very stable electrical properties".

Additional characteristics of Victrex PEEK polymer include high rigidity and dimensional stability at high temperatures, UL94-VO fire classification with zero halogen content, and very low levels of out-gassing extractable ions and wear particles.

Due of its range of high performance characteristics, Victrex PEEK polymer is also being used as an insulating and encapsulating material for connector insulators, condenser housings, potentiometers and coil frames.

The material has been applied by micro moulder CG.TEC Injection, of Frasne in France, whose technical and engineering approach to the sensor application made it possible to define a functional and reliable design, guaranteeing perfect impermeability of the assembly, which could be industrialised without damaging the components to be duplicate moulded.

Once the sensor design was approved, CG.TEC developed the mould and regulated it at high temperatures to guarantee good crystallinity of the Victrex PEEK polymer.

The entire process of industrialising and starting production required 1200 hours of work and 330 hours of research and development.