Offshore Technology Reports

From sour service and high pressure, high temperature (HPHT) finds to shale and deepwater plays, oil and gas operators are increasingly moving into ever-more hostile frontiers.

In such severe environments, and bearing the brunt of shock loads and HPHT, components can become deformed, causing fractures, chipping and ultimately catastrophic equipment or tool malfunction. In addition, sand, seawater, sour oil and gas containing aggressive H2S, other grades of crude containing CO2 and acidic fluids can quickly lead to corrosion, abrasive wear and erosion of components – all common causes of premature failure responsible for unscheduled and costly downtime.

The economics of these challenging operating conditions that are now commonplace in the quest to extract reserves from technically demanding reservoirs are often marginal, so optimising equipment performance and reducing cost are key drivers.

Hardide Coatings, innovator in advanced tungsten carbide coating technology, develops and provides new solutions to help the oil and gas industry solve difficult engineering problems thereby improving tool efficiency, reducing downtime and saving operational costs. Using Hardide coatings, the lifetime of critical components is increased dramatically so more time is spent producing than maintaining.

Oil and gas customers from operators and major international service companies to flow control specialists and technology-based tool designers are using Hardide coatings on a wide range of critical components subjected to high levels of wear, erosion, corrosion, galling and shock loading. Typical applications include:

Hardide chemical vapour deposition (CVD) coatings are a novel family of advanced nanostructured tungsten carbide-based coatings that consistently outperform alternatives by providing a unique combination of exceptional abrasion, erosion, corrosion and chemical resistant properties while also being tough, ductile and impact resistant. The coatings are crystallised from the gas phase atom-by-atom in a vacuum chamber reactor at around 500C, producing a conformal coating which can be applied to internal (non line-of-sight) and external surfaces and complex geometries.

The CVD coatings are a metallic tungsten matrix with dispersed nano-particles of tungsten carbide typically between 1 and 10 nanometres, giving the material enhanced hardness which can be controlled and tailored. The Hardide-T coating, which is typically used in oil and gas applications, has a standard range of hardness of between 1100 and 1600 Hv. Typical coating thickness is 50 μm (0.002”). Abrasion resistance is up to 12 times better than hard chrome plating (HCP) or 500 times better than Inconel. 

Nanostructured materials possess unique toughness, crack and impact resistant features: Hardide-T can withstand 3000 microstrain deformation without any damage. This deformation will crack or chip most other thick hard coatings.

Other key properties include resistance to acids (including H2S) and a volume porosity of <0.04% making it effectively pore-free, with no through porosity from 1 μm of coating thickness. Unlike sprayed tungsten carbide, the Hardide coating does not use cobalt which can be affected by acids; this is especially important for processing sour oil. 

The Hardide CVD coating has a smooth, as applied, surface finish of 0.4 – 0.6 microns Ra which can be polished to 0.2 – 0.3 microns Ra without the need for grinding (although, if required, the coating can be machined by grinding, honing and other common techniques). The coating can be super-finished to 0.02 microns Ra. Eliminating or reducing the need for post coat grinding is particularly attractive to oil and gas customers as it removes a cost, speeds up process time and enables the coating of complex shapes that would be difficult or impossible to grind.

Another advantage of Hardide CVD coatings is their ability to retain surface finish in operation in abrasive or corrosive environments. The coating wears uniformly and the coating surface may actually improve due to its homogeneous structure which includes tungsten carbide nanoparticles. This is an important quality on applications such as hydraulic actuators, rotating shafts and bearings as the hard coating retains a good surface finish and remains seal-friendly thus reducing the wear of elastomeric and PTFE seals.

Contact:
Hardide Coatings
11 Wedgwood Road
Bicester
Oxfordshire, OX26 4UL

Telephone:
UK: +44 (0) 1869 353830
USA: + 1 (832) 491-4720
Email: info@hardide.com
Web: www.hardide.com