THE CHALLENGE
A 13-3/8 in. liner needed to be run and set inside 16 in. casing above a 14-1/2 in. x 17-1/2 in. underreamed hole. The 13-3/8 in. string used flush-joint connections and was run through the subsea wellhead in more than 8,000 ft of water.
The operator needed a centralizer capable of withstanding demanding downhole conditions without coming loose, potentially sticking the liner or creating junk in the hole.
A slim centralizer design was also required to pass through the 14-3/4 in. drift of the 16 in. casing. This was particularly critical at the mudline wellhead restriction, where insertion forces impose the highest load on the centralizer.
THE SOLUTION
Working through a major service company, Centek supplied the UROS-CT as a fit-for-purpose solution.
Centek UROS-CT close-tolerance centralizers feature end bands manufactured to tight tolerances, with an ID only 0.030 in. greater than the maximum casing OD.
The UROS-CT is specifically designed to pass tight restrictions while effectively managing surge and swab, supporting faster running speeds in wells with narrow operating margins.
The units can be installed offline at the pipe yard without special pipe preparation or dedicated off-site fitting.
THE RESULT
Fifteen Centek UROS-CT centralizers were installed offline at the pipe yard before the casing was transported to the rig.
The liner was successfully run through the subsea wellhead in more than 8,000 ft of water and reached a total depth of more than 12,500 ft at 70° inclination.
The annulus was circulated clean, and cement was pumped as planned.
The successful installation demonstrated the UROS-CT’s suitability for demanding deepwater, close-tolerance applications.
