Advancing drone capabilities in the Southern North Sea

The Viking platform, one of the decommissioned unmanned platforms in the Southern North Sea

Mike Spalding
Mike Spalding

This is one in a series of articles about how ConocoPhillips global business units around the globe are using drones to safeguard personnel and property, minimize environmental impact and cut costs.

by Jan Hester

In 2015, ConocoPhillips U.K. began using drones in the Southern North Sea (SNS) to conduct over-the-side inspections on its unmanned platforms, reducing the safety risk to personnel as well as costs associated with offshore inspections.

“If you wanted to visually inspect a jacket, you needed to put a three-man inspection team on ropes to access the structure,” said U.K. Asset Integrity & Technical Safety Manager Mike Spalding, who oversees the inspection program. “Now that’s not necessary, so we also don’t need a standby vessel. Caged drones can go into the structure underneath the platform deck, typically difficult areas for people to access.”

While many of the SNS platforms are being decommissioned, there are still situations where drones could be used, such as a regulator requiring monitoring in cold stack.

“The platforms were not totally removed — there are still structures in the water,” Spalding said. “They’ve been left in a condition where manning the asset is not required. If we needed to do an inspection, we could go out with a small seafaring vessel and a drone pilot and have a quick look. We could cover the entire field in a couple of days without having to man the platforms.”

Initially, the U.K. team thought that unmanned aerial systems’ (UAS) visual quality would only be good enough for general visual inspections. After initial inspections were completed, however, the resulting images were of high enough quality to be considered a “close visual examination.”

A drone equipped with a modern, high-resolution camera can get within three to five meters from an object to conduct a close visual inspection. During a planned inspection visit to the Judy field in the central North Sea, a UAS picked up some minor defects on a flare tip.

“After looking a little closer, we realized that the flare tip would ultimately need to be replaced,” Spalding said.

Because of the long lead time required to source a new flare tip, the team continued to carefully monitor the condition via regular drone inspections, initially on a monthly basis. When they saw no change, they extended inspections to every two months.

“If we hadn’t had that capability, we would’ve had to shut down the entire platform for seven days to conduct a visual inspection,” Spalding said.

The situation remains unchanged and has had no detrimental impact to the performance of the flare or to the environment. Changeout is scheduled for the routine 2019 maintenance shutdown. In the interim, the team will continue to closely monitor the issue.

As drone technology continues to evolve, the team is looking to step up its game beyond fairly basic UASs.

“The drone market is picking up significantly, and we’re seeing units that can carry a payload of up to 25 kilos,” Spalding said. “We’re working with a company here in the U.K. that is developing technology to allow automated classification of corrosion scale, removal of the scale and completion of coating repairs.”

The Corporate Aviation team has carried out initial audits, and the U.K. team is working toward field trials in early 2019 at ConocoPhillips’ onshore Theddlethorpe terminal.

With increased drone capabilities and the possibility of using 3-D technology to image offshore installations in the near future, the sky’s the limit.

Judy platform
Judy platform