Casing centraliser for extreme wells

Paul Boughton

Downhole Products’ casing centraliser Blade Runner has been used to perform an installation,  in the Caspian Sea.

A major operator recently ran Blade Runner casing centralisers in an extremely demanding well on the company’s Chirag production platform located 120 km offshore Baku, Azerbaijan, in the Caspian Sea. To carry out the running operation, 270 Blade Runner LD (low drag) centralisers measuring 9-5/8 inc and 540 Downhole Products Spir-o-lok DI stop collars were used to install the 9-5/8 in casing.

Centralisers were spaced at one centraliser per joint throughout the open-hole section and inside the casing lap.

Following the successful run, the operator analysed the results that were recorded during the operation.

“Fortunately, the results reflected that an exceptionally low level of just 0.20 friction was experienced in cased and open-hole sections during both pick-up and slack-off phases of the operation,” said Bill Barron, Director of Downhole Products. “Given the fact that high levels of static friction had been an ongoing issue for a number of other Chirag wells, it was very satisfying to see that no significant levels of static friction were experienced during the Blade Runner operation. In view of this extremely positive performance, the installation was considered a resounding success,” he added.

Introduced to the industry just 12 months ago, the Blade Runner range consists of three primary types of centraliser: the Blade Runner LT (low torque), Blade Runner LD, and the Blade Runner LT-LD (low torque and low drag.) It remains the first-of-its-kind solid centraliser designed to significantly reduce drag and torque while running casing, liners and tubing for today’s extreme wells.

Since November 2004, Blade Runner centralisers have been successfully run in more than 20 extreme wells around the world, in the North Sea, Caspian Sea, Sakhalin Island, Norway and Newfoundland. With the Blade Runner LT, operators are reporting their lowest ever rotating torque at average rates of 30–40 per cent less than that achieved when using Downhole Products’ line of Spir-o-lizer zinc alloy centralisers.

“Fortunately, the Blade Runner is quickly becoming the centraliser of choice for those running casing, liners and screens for extreme wells. With a healthy order book of over 25 repeat orders pending forthcoming trials in Australia, the South China Sea, Trinidad, Europe and the Americas, the future certainly looks bright for the Blade Runner, and the entire industry,” said Barron.

The specialist centraliser features specially engineered Teflon inserts moulded into Spir-o-lizer blades that greatly reduce sliding forces – or drag – while running inside previous casings. Downhole Products designed the inserts from Teflon because it has a very low friction coefficient of just .04, which is the lowest available for any centraliser material on the market today. The Blade Runner is also fitted with internal engineered Teflon bushings that reduce start-up torque by up to 50 per cent during liner or casing rotation. 

For more information, visit www.downhole.co.uk

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