Coil Tubing has been used in many oilfield applications worldwide both offshore and onshore, upstream and recently downstream. Apart from upstream coil tubing applications such as workovers, well interventions, paraffin/scale removal, jetting, acidizing and coil fracturing, it is employed more and more actively for pipelines precommissioning operations subsea, especially dewatering. With a slight modification (there is no need in Blowout Prevention (BOP) System in this case) the coil tubing unit is positioned on a vessel’s deck and connected to compressors spread injecting pressurized air down the coil tubing string to the hot stab connection of the pipeline to be dewatered. Pressure drops across the tubing string and other connections and flow patterns can be simulated using proprietary software CIRCA. For the deep offshore applications high pressure boosters are often employed.
展开▼
