As often found, there were some changes to the original plan, with the field operator's drilling crew on site and preparing to drill the conductor socket, concerns emerged that whipping of the drillstring at the congested cellar deck level might lead to clashes with surrounding steelwork or piping.
"The general feeling was that the provision of a drill bush in the guide at the splash-zone level would not be adequate to contain the problem and that a temporary guide was required at the cellar deck," explains Bob Leggett, Claxton's project manager (http://www.claxtonengineering.com/
This was overcome by installing a temporary guide in the opening through the cellar deck and to provide a bush that could be run on the drillstring to sit in the guide. Once landed in the guide, the bush, which had a polymer lining and formed a clearance fit around the drillstring, was locked in place to provide the necessary restraint at the critical point. With the initial drilling complete, the temporary guide was removed and the conductor was run into the hole.
In another break from the original plan, the drilling crew decided not to install the conductor centraliser within the splash-zone guide. This was due to the concerns regarding problems engaging the centraliser within the guide and the potential effect this might have on the drilling schedule. An alternative centraliser was used which allowed for a retrofit within the guide after the drilling activity was completed.
As with this example, Claxton cleverly combine experienced project engineers, a fast and efficient design-analyse-
Overcoming such challenges and ensuring the success of unusual projects or bespoke offshore engineering (http://www.claxtonengineering.com/