Drilling with a continuous coiled string presents an array of opportunities for reducing drilling costs and improving production potential. It offers exciting perspectives for enhanced resource management in established oil and gas provinces.
A Shell operating company recently completed a horizontal sidetrack with coiled tubing onshore the Netherlands. A medium radius horizontal lateral was drilled with a 2-inch coiled tubing. This operation was the first step towards the development of a comprehensive Coiled Tubing Drilling (CTD) system able to re-enter and re-complete wells without conventional rig assistance.
Operations in the Netherlands provided key parameters for evaluation of the potential and limitations of CTD. This experience indicates that CTD is a suitable technology for the optimization of mature North Sea fields. It offers potential cost advantages and should help to maximize hydrocarbon recovery in this area.
New developments are required to meet the challenges of the offshore environment, under-balance operations, short-radius multiple drainholes or through tubing drilling to name but a few. Investments in these directions are well worth while, in view of the opportunities that CTD offers for enhancement of the drilling and production process.