Negative Operational LL with Wellesley

Kallåsen (35/12-6 S) – Surface section

What happened:

A large volume (350 m3) bentonite mud was mixed before running casing for filling casing, emergency circulating casing down in tight hole and for circulating annulus prior to cement job, The excess mud not used was circulated out prior to cement job, after stinger was stabbed in.

What was planned:

Dispose of Bentonite mud

What was learned:

This mud cannot be dumped straight out of pit, and can not be backloaded to town. Managed to pump open float valves when pumping with 2500 lpm before cmt job (observed mud coming out on seabed between 30″ and 13 3/8″ casing.)

What actions are required:

Awareness that it is not advisable to pump it out inside 13 3/8″ casing after cmt job.