Negative Casing LL with DNO

Oselvar (A-1 H, A-2 H, A-3 HT2) – Production section

What happened:

DONG handover documentation: The Odfjell CRTi (Casing Running Tool internal) was used to fill casing when running 9-5/8″. The tool weas also contingency if casing had to be worked / turned past obstructions. During preparations it was discovered that the tool does not have a check (mud saver) valve, so the IBOP had to be used and time given for mud to drain prior to raising TDS. The operation was modified so casing was filled every 10 joints to reduce time spent on waiting on draining. It took approx 10 min per filling, 33 times during the run. Both crews tried setting and unsetting CRTi in casing and it worked fine and was easy to learn. Due to space out in case FAC (back-up) was needed very long (20 ft) bails were used.

External Actions

If using CRTi as a contingenct again is should be used together with auto filling shoe, this way there is no need to fill or wait. If circutation is required the shoe will convert and casing have to be filled onwards. Using the CRTi as casing make up and running tool is definately the ideal solution and would speed up casing job. First jobs should be on casing without torque turn to give drillers experience in a less delicate operation, then later it can be run for torque turn requiring strings.