Ace Ratchet Collar reduces well cost and delivers high holding force in North Sea

The challenge

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A Stavanger, Norway-based operator working in the North Sea was running a 7-5/8” liner across an 8-1/2” open hole in a non-cemented injection well. The operator opted to run expandable well annular barriers to ensure zero communication between multiple formations.

 

To ensure a full seal, centralizers were run both above and below each barrier to achieve high stand-off. It was essential that the centralisers did not move and the operator were looking for a more reliable solution than traditional “set-screw” type stop collars, without the high expense and logistical issues found when using centralizer subs or other similar solutions.

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The solution

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To anchor the centralizers and annular packers to the 7-5/8” production liner, the Ace Ratchet Collar was recognized as the best solution, giving substantial cost and time savings versus other premium solutions.

 

The patented ARC is rated to over 90,000lbf axial load, providing high load capabilities to arrest axial movement of virtually any accessory. The ARC has a maximum OD of 8.22”and in this instance the standard ARC with ¼” wall thickness was run.   It is designed to maintain sufficient bypass to help prevent formation breakdown during run-in.

 

For this installation, the centralizers were held in place by placing the ARCs both above and below them. All sizes and models of the ARC are fully compatible with just about any centralizer, screen or other tools designed to be slid onto the casing or liner pipe with little to no modifications.

 

Each ARC is easily installed off-line in just a few minutes and doesn’t require pipe preparation or transportation off-site for installation.

 

The result

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Over four hundred ARCs were installed off-line at the pipe yard, within a day, by two trained installers. The liner was shipped to the rig, run in the hole and reached total depth with zero issues.

 

The running of the liner and all accessories was executed flawlessly using a combination of the ARCs with the client’s selected centralizers and well annular barriers.