“ArticuLock will be deployed in some of the harshest oil and gas drilling environments in the world and we need its components to deliver optimal performance under extreme operating conditions. The geometry of the pivot joint body is complex and Hardide-T provided the only solution that combined the necessary wear properties with ductility and the ability to coat such designs. The Hardide coating delivers in each of these areas and is an important part of ArticuLock’s success in offering significant cost benefits to oil and gas operators worldwide.”
PROFILE
Well construction specialist, DeltaTek Global develops innovative products for the oil and gas drilling industry that are intelligent and cost saving and can be efficiently implemented. ArticuLock® is a new tool designed to provide operators with longer weather windows to deploy subsea hardware and improve operational reliability by removing bending fatigue through subsea running tools and landing strings. The tool has global relevance; it is equally effective in big wave and strong current environments. ArticuLock® has the potential to save operators multi-millions of pounds/dollars per year; in the UK alone, waiting on bad weather windows costs operators £400 million per year.
CHALLENGE
ArticuLock® is designed to operate in harsh environments where high winds or strong currents frequently delay drilling operations. This is a regular occurrence in regions from the North Sea and West of Shetland to Australia, New Zealand, the Gulf of Mexico, the Caribbean and Africa. A key component of the tool is a 12.5” x 6” pivot joint comprising a ball and socket that can be subject to extreme loads of up to 400MT, 5000psi of working pressure and 30,000ft.lbs of torque while operating in severe weather conditions. The high-wear and acute operating conditions meant that a hard-wearing coating was needed for the pivot joint body, which is manufactured in AISI 4330V alloy steel – widely used in the oil and gas sector. The complex grooved geometry on the ball of the pivot joint body presented a further challenge to achieving the necessary post-coat surface finish.
SOLUTION
DeltaTek evaluated HVOF and Hardide-T as possible solutions and selected the Hardide CVD (chemical vapour deposition) tungsten carbide-based coating due to its ability to coat internal and complex surfaces and achieve a smooth and uniform surface finish without the need for post-coat grinding. Hardide Coatings worked with DeltaTek to coat the pivot joint body and achieve the required hardness, thickness and surface topography from coating and polishing alone, eliminating the need for grinding. With the Hardide-T coated pivot joint in place, ArticuLock® was successfully field-trialled on the Stena IceMAX, the state-of-the-art harsh environment, ice-class drillship.
The trials proved that ArticuLock® enables a level of articulation that allows operators to run tools in weather environments where previously drilling would have been suspended. It can increase operable weather limits for installing subsea equipment by up to 400%, increasing operable wave heights from up to 1m to up to 4 m.
ArticuLock® has now being deployed commercially around the world, including in some of the worlds roughest offshore weather conditions in South Africa. 317
MT of surface casing and landing string was suspended beneath ArticuLock® for 75 hours with 4.3knots of current and up to 5m of wave height. During the
operation, 283m2 of cement slurry was pumped through the tool. The use of ArticuLock® saved 14 days from top hole operations and ~5-600 MT of CO2. No
erosion or mechanical damage was recorded on inspection of the Hardide-T coated pivot joint on completion of the job.
