As the subsea industry continues to evolve to help meet the demands of oilfield operators, there is now an even greater demand for ground-breaking sealing technology.
Andrew Longdon, the UK Technical Manager for Trelleborg Sealing Solutions (pictured right), explains how the pioneering company is leading the way in producing innovative products to support engineers.
Exploration has now moved to greater subsea depths because operators are now trying to maximize the yield from offshore oilfields as much as possible.
Accessing unconventional wells,
previously believed to be too deep for existing capabilities are now being reinvestigated, meaning subsea intervention needs to be even more sophisticated than previously.
Longdon says: “Unconventional wells are essentially any reservoir that requires special recovery operations outside the conventional operating practices. This means the processing technology must be able to meet High Pressure / High Temperature (HP/HT) conditions.
“Conventional subsea operating temperatures of up to +120 °C/ +248 °F increase in unconventional wells to over +200 °C/ +392 °F in deep reservoirs, while typical pressures have on occasion trebled from a previous standard of 69 MPa/ 10,000 psi to 207 MPa/ 30,000 psi.”
Seals are a critical element within subsea systems, particularly subsea valves and downhole tools. They ensure the oilfield equipment is working to its optimum capacity, as wells as being the primary barrier to preventing any system fluid loss or system fluid contamination from external sources.
Subsea seals are the main source of prevention of hydrocarbon leakage from oilfield completion or production equipment and as such, perform a vital role in meeting environmental and workforce safety concerns, in addition to enhancing performance of the tools themselves.
Application Specific Design
“Trelleborg Sealing Solutions are always one step ahead of the industry and we very quickly recognised that standard sealing solutions and materials of previous years were unable to withstand the extreme operating temperatures and pressures of drilling at greater depths,” continues Longdon.
“We knew specialized solutions in both material and seal profile technology would be required in order for the industry to start exploring unconventional wells.”
Rapid Gas Decompression
The company set about developing solutions, which also focused on Rapid Gas Decompression (RGD), a major concern to the oil and gas industry. This occurs when applied system pressure is released, causing absorbed gas to expand, and potentially damaging elastomer seals.
“Trelleborg Sealing Solutions has focused on this issue and developed the XploR™ range of sealing materials, an entire family of advanced elastomers especially developed for oil and gas applications. The portfolio includes compounds in Hydrogenated Nitrile Butadiene Rubber (HNBR), Fluoroelastomer (FKM), Aflas® engineered polymer and Isolast® Perfluoroelastomer (FFKM), each of which demonstrates best-in-class Rapid Gas Decompression (RGD) resistance for its material type.”
Demanding Enhanced Oil Recovery Applications
Trelleborg Sealing Solutions will use the Subsea Expo Conference & Exhibition in Aberdeen this February as a platform to showcase its latest XploR™ elastomer materials – each featuring low compression set characteristics. Specifically engineered for the offshore and subsea industry, the materials match up to the most demanding of upstream requirements and are ideally suited for challenging Enhanced Oil Recovery (EOR) systems.
Longdon adds: “Our specialist XploR™ grades include HNBR materials that exhibit exceptional low temperature sealing performance making them suitable for use within high pressure / low temperature applications, whilst further XploR™ HNBR materials exhibit superior low compression set performance and high temperature sealing capability.
“Additionally, high mechanical strength XploR™ HNBR grades provide outstanding wear and abrasion capabilities, making them suitable for use in dynamic applications.
XploR™ FKM materials have been developed that exhibit superior methanol resistance and optimal chemical resistance for Enhanced Oil Recovery applications, whilst increasing high temperature capability.”
All materials are available in all standard international O-Ring sizes and cross-sections along with custom-engineered solutions and specially designed seal profiles such as V-Stacks.
For further information on selecting the right compound and advice on seal specification for individual applications, end users should consult their local Trelleborg Sealing Solutions marketing company.
Trelleborg Sealing Solutions will showcase the industry’s widest range of NORSOK, ISO and API 6A approved sealing materials for subsea systems at Subsea Expo Conference & Exhibition in Aberdeen, February 7 to 9 2018 on