Abstract
Coiled-tubing drilling (CTD) is a well-established, common application in some areas, particularly Western Canada. However this practice has not grown to similar activity levels in the North Sea. Two CTD projects have been carried out on UK North Sea platforms since 1999 and it is over 4 years since the most recent operation.
As a result of the sustained high oil price, North Sea operators are looking for methods of sidetracking existing wells to access isolated or stranded oil reserves. The condition of some North Sea drilling rigs is such that a significant financial investment is required if they are to return to conventional drilling. CTD is one option that enables operators to access these reserves, without the need to recommission the original drilling facility.
The extremely low activity levels of CTD in the UK has led to the challenge faced by service companies of supplying suitable equipment and experienced personnel, to safely and effectively manage and perform a CTD operation.
This paper discusses the challenges faced and some solutions developed for a recent CTD operation carried out on the Gannet ‘A’ platform, located in the Central North Sea.
In addition to the challenges mentioned above, to deliver a successful well, several new technologies and equipment were incorporated into the application of CTD to the Gannet field.
