THE CHALLENGE
As part of slot recovery and redrill on a North Sea field, the operator needed 9 7/8”, 62.8#, P110, Vam SLIJ-II (8.5” special drift) full string to 2678m Measured Depth Below Rotary Table (MDBRT). Inclination was from 0deg to 72deg max. The centralizers needed to pass through 13 3/8”, 72#, L80 New Vam (existing casing) to 600mMDBRT and then through 11 3/4”, 60#, P110, TSH W523 (10.625” special drift) liner to the 11 3/4” shoe at 1281m MDBRT. They then needed to continue in the open hole to TD.
THE SOLUTION
The Drilling Engineer ran a total of 140 UROS-CT centralizers (9 7/8” x 11 3/4”) in combination with Protech bonded stop collars (8mm blades) with a mixture of 1 and 2 centralizers per joint.
THE RESULT
No issues were seen during onshore installation of the centralizers. The operator successfully ran the casing to depth with no problems. Running forces matched T&D model and the cement job went as planned, delivering all annular isolation objectives. Casing was ran through a salt diapir consisting predominantly of halite with polyhalite stringers and anhydrite caprock at TD.
