The current oil and gas market is showing signs of growth, however the cost of extracting resources is at an all-time high. Economics has become key in deepwater and marginal field development. Oil companies are leaning towards economical extraction methods to keep capex to an absolute minimum.
With global rates for semi-submersible rigs averaging around $250,000 per day in 2016, jack-ups in Europe and Asia remain considerably cheaper at approximately $100,000 per day.
Jack-up rigs are becoming increasingly popular. Traditionally used in shallow water, they have evolved into robust innovations – stretching to subsea limits, these rigs operate in up to 575 feet (175 metres) of water and drill up to 35,000 feet.
Economical to construct and offering the flexibility of extracting oil or gas in multiple shallow or subsea locations, the jack-up rig is a comprehensive model in terms of efficiency, performance and capability.
It looks like everything is covered – but have you considered the elastomer seals installed in jack-up rig equipment?
With jack-up rigs offering the flexibility to locate to different wells, the impact on elastomer seals is a common oversight. Elastomer sealing systems which may have been developed for shallow operating conditions can be transferred to subsea conditions without considering the consequences.
Elastomer seals developed for specific oil and gas applications are optimised for the exacting operating conditions for that application – with considerations including pressures, temperatures and the impact of chemical aggression.
There is a commonality with elastomer seals failing in these Jack up rigs used for subsea applications.
Advanced elastomer materials developed for subsea oilfield equipment have proven chemical and temperature resistance. These unique polymers reflect the difficult conditions the equipment may see when operating, with enhanced resistance to explosive decompression (ED) and chemical degradation, specifically from sour gas (H2S).
Oilfield elastomer materials, such as the high strength HNBRs, have greater chemical resistance than conventional AED grades, as well as improved capabilities in extreme temperatures – down to -51°C and up to +180°C. These specialist oilfield elastomers are also compliant with many recognised industry standards for explosive decompression and sour gas resistance.
The challenge faced by oil companies is meeting exploration and production goals in the most cost effective method, and reducing the Capex.
Standard elastomer seals used in jack-up equipment are often inexpensive compared to the high performance seals for critical subsea applications.
The priority of changing seals can be seen as insignificant and not critical in comparison to operating the oil rig and for either drilling or production.
However a seal is only inexpensive until it fails. By selecting the correct sealing material for the application, you could reduce long term ownership costs and increase equipment uptime by longer periods between scheduled maintenance cycles.
The importance of specifying the right family of elastomer materials from FKM, FFKM, Aflas or HNBR can have a significant positive impact on your drilling operations.