The use of Non-Metallics Materials (elastomers, thermoplastics and thermosets, including composites) as either free standing engineering materials or barrier layers for protection of low alloy carbon steels is highly desirable. Their many attributes include high strength to weight ratio and excellent resistance to corrosive aqueous environments.
However, they may be permeable to, and absorb, gases and liquids; be vulnerable to physical and chemical change in contact with produced fluids and treatment chemicals, which might render their short term properties inadequate; be limited by the long term effects of time, temperature and applied load (creep) and subject to long term ageing effects by thermal oxidation and hydrolysis etc.
In order to best utilise their desirable characteristics, it is necessary to understand the strength and weaknesses of the non-metallic material solution offered. It is essential to understand the interactions between each material and the in-service environment, to identify the risks and mechanisms for failure and the threshold values for properties critical to successful performance. The parameters identified shall be thoroughly tested in a programme to qualify the system for service. By defining the limiting service conditions and the operating envelope the risk of premature failure may be mitigated.
The paper will consider the different approaches available to test and qualify non-metallic materials for oilfield service, including accelerated testing, illustrated by examples of recent testing programmes.