Negative Operational LL with Wellesley

Kallåsen (35/12-6 S) – P&A

What happened:

WOC for cement plugs in OBM prior to dressing off.

What was planned:

Set P&A cement plugs

What was learned:

End up with a contaminated interface on the top. Pulling straight out is good as it minimizes wet cement on surface to manage and hence skips required. Consider the following: Pumped 10.7, 10.7 and 10.0 m3 for the 3 plugs. If pumped 10.7 m3 on the final plug, it would give further 20 m excess cement inside 9 5/8″ casing.

What actions are required:

Could plan on spacing out to start washing down / dressing off a full stand at theoretical thickening time and do a full circulation without stopping nor breaking a connection, getting the worst of the interface out (and thereby minimizing the risk of getting stuck in green cement) before trying to dress off firm cement,