Aberdeen-based Helix Well Ops recently completed an offshore well intervention project from a class-light vessel using riser-based coil tubing.
The project was carried out from one of the company’s mobile offshore drilling unit (MODU) vessels, Well Enhancer.
Performing well intervention from a class-light vessel is seen by some as a potential game changer for the industry because it is cheaper than traditional rig-based methods.
The recent project took place in the central North and involved drifting and milling to 4,400m and performing a reservoir saturation tool (RST) log before perforating 267m (877ft) of reservoir section in four runs, followed by a clean-up.
Initial results of the intervention indicate an increase in daily oil output of over 1,500 barrels of oil equivalent per day (boepd).
Helix Well Ops’ coiled tubing intervention system is designed to operate in water depths of between 80m and 200m and can deploy a variety of coil sizes up to 2⅜in and 20,000ft in length.
When combined with Well Ops’ patented technology and equipment, coiled tubing units virtually eliminate the effect of vessel motion and reduce coil fatigue.
Steve Nairn, Helix Well Ops (U.K.) vice president, said: “This recent riser-based coiled tubing project represents an important step in the development of the intervention industry. It clearly demonstrates the production potential and cost-effectiveness that coiled tubing intervention can deliver.
“Mobilising a rig to undertake coiled tubing interventions is a complex process and the time and costs involved could outweigh any potential benefit. Unsurprisingly, coiled tubing intervention on subsea wells has been an underutilised practice in the North Sea as a result.
“However, it is hoped that our proven technology will enable operators to open up opportunities that were previously thought uneconomical or unviable.
“Every business operating in the North Sea has a responsibility to contribute to maximising the recovery of hydrocarbons. Through our fleet of well intervention vessels and innovative technologies we are playing our part in this.”