LOW-CARBON DRILLING SOLUTIONS
COSL Drilling Europe initially installed its Energy Control System on two semisubmersibles in the North Sea, the COSL Promoter
(pictured) and the COSL Innovator . The software monitors the rig’s diesel generators during a given operation and advises
users on the actions likely to require the least amount of power consumption. CO 2 and NOx emissions have fallen by nearly
50% on the two rigs since installation, and the system has since been installed on the COSL Pioneer as well.

Energy Control System
In 2020, after six years of development, COSL Drilling Europe
launched its Energy Control Project, designed to save energy on
COSL rigs operating in the Norwegian North Sea. The project is
primarily centered on reducing fuel usage of engines and gen-
erators on COSL rigs and, subsequently, reducing greenhouse gas
(GHG) emissions.

The main deliverable from the Energy Control Project is the
Energy Control System, an automated software program that
monitors power consumption during a given operation. The sys-
tem advises users on the courses of action likely to require the
least amount of power consumption, estimating the kilowatts
needed, the amount of fuel needed and the subsequent CO2 and
NOx emissions. These estimates are displayed on a dashboard
that users can access from anywhere.

The system is connected to the rig’s control system so it can act
upon its advisory without any input from the rig crew. However,
it also has manual override capabilities for unforeseen circum-
stances, like a weather event where users may need to shut down
more generators than expected.

Torfinn Kalstø, ICT & OT Manager at COSL Drilling Europe, said
the monitoring and advisory capabilities in the Energy Control
System provide essential insights and help maximize efficiency
gains from the rig. “We’re looking to produce the most efficient
kilowatt hours from the generator. This is the whole idea. It’s all
about maintaining high performance and, at the same time, low-
ering the power usage.”
In 2020, COSL Drilling installed the Energy Control System on
two semisubmersibles in the North Sea – the COSL Promoter,
working for Equinor on the Troll field , and COSL Innovator, work-
ing for Chrysaor . The rigs are each powered by six diesel genera-
tors with maximum capacities of 4,800kW . These previously ran
continuously during drilling operations, but pre-installation anal-
ysis showed these generators were rarely used at full capacity.

Running the Energy Control software, COSL Drilling found that
it could shut down, on average, four of the six diesel engines dur-
ing operations.

The company has already seen a significant reduction in fuel
consumption on these rigs. Prior to installation, the rigs averaged
27 tons/day of fuel consumed in Posmoor/ATA mode (where the
rig is running a thruster-assisted mooring control system) and 29
tons/day in full DP3 mode. After installation, COSL Drilling now
sees averages of 14/tons day in Posmoor/ATA mode and 20 tons/
day in DP3 mode. Depending on the operation, the company has
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