Under an atmosphere of high pressure gas, rubber and polymer parts contain dissolved gases (e.g. CO2, H2S, CH4) that have permeated into the amorphous regions of the polymer compound. Damage in the form of cracks or blisters can occur when decompression occurs abruptly because the trapped gas molecules expand and “pop”, causing rubber fracture. NORSOK M710 and ISO 23926-2 are specifications that designate standard conditions to assess such RGD damage. They also define pass/fail criteria based on a comprehensive rating system for the number, length and location of cracks.
Argen participates on the API and ISO committees to guide the proper writing of these specifications. Our labs are fully equipped with hardware, software and know-how for this analysis and we have been testing to these standards for many years. We employ:
We perform RGD testing per NORSOK M710 and ISO-23936-2, and issue compliance certificates.
Fluids used for drilling, completion and production can have adverse effects on the seals and back-up supports. Thermo-chemical attack of the polymer/rubber compounds is where it can all start, whether it is swelling, breaking of chemical crosslinks, polymer chain reactions or extraction of plasticizers or antioxidants.
Argen is fully equipped to qualify polymeric materials and study these effects through our mechanical and chemical testing. We have successfully completed hundreds of such projects from single pot exposures to multi-million dollar joint development programs. We run the standard API, ISO qualifying tests and we develop application-specific tests as well.
Estimating useful life of rubber and polymers is of utmost interest to many of our clients. This work takes the form of accelerated aging whereby elevated temperature and environment is used to hasten the process of degradation. Various models can be applied to treat the data such as Arrhenius, diffusion limited oxidation (DLO), time-temperature superposition master curves and Williams-Landel-Ferry (WLF) or power law.
The oil & gas industry has developed ISO 23936 and NORSOK M710 to standardize life estimation testing with regards to non-metallic materials in contact with fluids. Argen has performed this life estimation testing for major exploration and production companies, service providers and capital equipment manufacturers. We can handle the data analysis for our clients or simply report results of the standardized test with appropriate failure criteria.
Our ability to properly test seals to leakage and failure offers our clients an advanced mode of testing. It is useful in more clearly delineating failure criteria, rather than choosing a certain % drop in a mechanical property. It also enables analysis to be performed on the failed part where we can apply our full range of mechanical and chemical analytics to fundamentally understand the system.
Argen has designed and built multiple test rigs based on API TR 6JI for severe service environments. This enables small seals to be tested in their end use geometry and confined to a gland providing realistic surface area that is exposed to fluid. Since failure and fatigue testing have inherent variability, replicates are often tested. Systems designed for gas exposure measure mass flow for leak detection and permeability. Systems designed for hydrostatic liquid pressurization signal failure as a pressure drop in a closed vessel. The system is fully automated and test parameters and entered through a graphical user interface. Custom temperature and pressure cycles are programmed and cycled until failure is achieved.