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Drilling and well technology: Bit of a rough ride

Drilling in the Barents Sea must be conducted just as safely as it is on the rest of the NCS. But conditions in the far north can put both equipment and facilities to a tough test.


Photo of Tore Endresen
Tore Endresen, acting head of the PSA’s drilling and well technology discipline

The drilling and well technology discipline at the PSA works on the development and management of organisations, expertise and capacity for such operations.

Its activities are directed primarily at drilling and well equipment on fixed and mobile facilities, and the actual boreholes on the NCS. Follow-up by the discipline covers the life of a well from the start of project planning until it has been plugged and abandoned.

Everything to be used on the northernmost NCS has to cope with low temperatures. Vessels and equipment must be designed so that reliability and safety are not affected by local factors.These can include cold, icing, drift ice, special weather phenomena and conditions related to disruptions in the Earth’s magnetic field.

“Operational challenges include protecting equipment against lower temperatures than it can cope with,” says Tore Endresen, acting head of the PSA’s drilling and well technology discipline. Drift ice can also knock out important components in well control equipment, while icing caused by high winds and low temperatures can impose excessive loads on equipment.

 Important components such as pressure manifolds are normally not designed for very cold conditions. Nor are piping and control hoses protected against ice in the moonpool on many drilling rigs.

At the same time, icing on the derrick and other tall structures could become a hazard if lumps of ice loosen and fall to the deck.

Accuracy
Disruptions to the magnetic field caused by electric currents in the ionosphere can create uncertainties about the accuracy of measured directional data. Good information of direction is very important for correct positioning of well paths, and for finding the way to a borehole should a relief well need to be drilled. This problem gets worse the further north one goes, and work is now under way to develop equipment and methods which can overcome it.

Tailored
Operational procedures must be specially tailored to the challenges faced in the far north, where rapid changes in weather from Polar lows and other phenomena are typically encountered. These conditions must be assessed and taken into account when planning activities. So must the long distances to supply bases, to avoid running out of mud and other safety-critical supplies.

“Good planning of drilling and well operations is crucial for avoiding incidents,” says Endresen.

 “At the same time, it’s important to have robust solutions for responding to a possible blowout. That includes detailed plans for drilling relief wells and mobilising capping systems.”