Coiled Tubing operations in the North Sea are regularlychallenged by crane lift capacity limitations when attemptingto bring coiled tubing reels onboard. Very often the cranecapacity or weather conditions determine the CT size to beused for the application, leading to operations conducted withless then the optimum CT size. The Norwegian sectorgenerally has larger capacity cranes but most operationsregularly involve the use of large OD coiled tubing (2.375" or2.875"). The lengths required can cause logistical problemsdue to the lifting weights of the CT reels used. Currentmethods utilised for keeping weights as low as possibleinvolve using so called split reel systems and thin-walled highstrength parallel CT strings (i.e. constant wall thickness).While these weight reducing measures have proventhemselves for many years now in the Norwegian sector, theycan not resolve equipment weight issues in all cases. Thejoining of 2 or more separate strings together offshore byinstalling butt welds has been standard practice in the UKsector for many years now, mainly involving CT sizes of up to1.75". In the Norwegian sector, butt-weld failures haveoccurred when using larger CT sizes and operators have beenseeking a viable option to butt-welding, especially for larger OD CT.
In response to a direct request by the BJ Services North Seaoperations departments, BJ Services Coiled Tubing Research& Engineering group in Calgary, Canada have developed andcommercialised a LCF (Low Cycle Fatigue) SpoolableConnector to replace offshore butt-welding and resolve weightissues associated with heavy CT reels.
This presentation will discuss the driving factors for thedevelopment of the spoolable connectors and the case historyresults of the world's first three Spoolable Connectoroperations recently completed by BJServices in theNorwegian North Sea.