LOW-CARBON DRILLING SOLUTIONS
COSL Drilling’s Energy Control System displays fuel
consumption and emissions data on a dashboard. As it
is connected to the rig’s control system, the software can
automatically act upon its own advisory without any input
from the rig crew, but users can also override the system in
case of any unforeseen circumstances. The system is now
deployed on all three of COSL Drilling’s contracted rigs in the
North Sea.

reported fuel consumption as low as 7.6 tons/day. CO2 and NOx
emissions have also fallen by around 50% on the two rigs since
installation. “We were almost shocked to see how much energy we were
consuming in normal drilling operations,” Mr Tollefsen said.

“Even when we first developed this, we thought we would need
all of this energy, but in a normal drilling operation, the actual
requirements can fall so low that they’re well within the capac-
ity of one generator. On average, we can run two or three, but
sometimes we’re down to one generator. That’s almost unheard
of in the industry because you always assume you need some
additional reserves.”
COSL Drilling also installed the system on the COSL Pioneer,
operating on the UK Continental Shelf, in December 2021. In the
three months following installation, the semisubmersible saved
904 tons of fuel compared with the previous three months. This
fuel reduction equated to approximately 2.85 tons of CO2 saved.

The Energy Control System is currently running on all three of
COSL Drilling’s contracted rigs in the North Sea. In March 2022,
the COSL Pioneer began work under a new contract with Ithaca
Energy that is expected to last until Q2 2024. The COSL Promoter
is slated to work for Equinor through Q1 2024, while the COSL
Innovator began a new contract with CNOOC Europe in April
2022. While the Energy Control System was developed for use on
COSL Drilling’s North Sea rigs, Mr Tollefsen said the company is
looking to expand its deployment in other regions, as well.

Engine management
Valaris is looking to enhanced power management systems as
a low-carbon offering in its technology portfolio. In October 2021,
the VALARIS DS-12 drillship became the first vessel in the world
to receive the ABS Enhanced Electrical System Notation EHS-E.

Valaris upgraded the rig’s electrical system to secure the notation,
which recognizes improvements in power system redundancy
16 and reliability. The enhanced system enables the rig to safely
operate with as few as two generators online, thereby reducing
emissions. VALARIS DS-12 worked for a major operator in Angola during
Q4 2021 and Q1 2022 and is expected to be working for the operator
offshore Mauritania and Senegal through the remainder of 2022.

During the Angola campaign, Valaris realized a 5% reduction in
fuel consumption and approximately 600-MT reduction in CO2
emissions compared with the pre-upgrade configuration, which
required a minimum of three generators online. Mr Luca noted
that the mild environmental conditions found offshore Angola
made it an ideal proving ground for this new technology.

The company hopes to install the enhanced power manage-
ment system on more of its floater fleet in the future, but further
deployment will also depend on customer demand. “It’s an invest-
ment to take the rig out of operation for a period of time and install
this system, so we hope to find the right partners who are willing
to invest in that enhancement for the rig, thereby making their
own operations more carbon efficient.”
The engine optimization system is one solution within the
Valaris portfolio of options to reduce GHG emissions. For a
fleetwide view and tracking of these emissions, the company
leverages the Valaris Intelligence Platform (VIP), a monitoring
program that aggregates and displays fuel consumption and GHG
emissions for each monitored rig in its fleet.

The program helps establish a baseline of fuel consumption
and emissions by rig and engine type, which can then help the
company quantify the impact of the various solutions it chooses
to deploy across its fleet.

While the VIP system monitors mission-critical rig equipment,
it also provides dashboards for fuel consumption, CO2, NOx and
SOx emissions over time. Understanding power requirements at
the rig site and comparing against the amount of power available
from the rig power plant enables the technical team to optimize
the gap between the two, based on the operating conditions at
any given time.

The VIP system is currently available on more than half of
active Valaris rigs and is on track for deployment to the remain-
der of the active fleet by year-end.

“VIP is really about streaming systems data into an aggregator
and analytic solution to tell us how our rigs are being run. This
enables us to better monitor our systems and our power plants.

From there, we can visualize the loading of a particular engine in
real time, optimize the loads on the engine, optimize the fuel and
determine where we can reduce emissions,” Mr Luca said.

In addition to the VIP system and enhanced power manage-
ment system, Valaris has installed selective catalytic reduction
(SCR) systems on four drillships – VALARIS DS-15, DS-16, DS-17
and DS-18 – and one jackup, VALARIS 123. SCR is an emissions
control technology that filters out certain potentially harmful
elements from the engine exhaust system. An additive is added
to the exhaust fumes, initiating a chemical reaction that converts
NOx into nitrogen, water and tiny amounts of CO2. While NOx
emissions data from the four drillships are not yet available,
Valaris has reported a 90% reduction in NOx from the VALARIS
123 jackup since the SCR installation.

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LOW-CARBON DRILLING SOLUTIONS
“The SCR system is doing the job for us. It’s a very effective
system in terms of removing NOx byproducts – you cannot
argue with a 90% reduction from the exhaust system,” Mr Luca
said. AI-based systems
In December 2021, Nabors launched Nabors Energy Transition
Solutions (NETS), a portfolio of technologies designed to improve
energy efficiency, reduce fuel consumption and lower emissions.

At the heart of this portfolio is the SmartPOWER Advisory and
Controls engine management software. The advisory system,
which is deployable to Nabors and third-party rigs, applies artifi-
cial intelligence (AI)-based algorithms to real-time drilling data,
advising the driller on the optimal number of engines to run for a
given task in a drilling operation. The SmartPOWER Control sys-
tem, which is expected to launch in Q2 2022, automates the start
and stop of the individual rig engines based on those advisories.

James Hall, Product Line Director at Canrig Drilling Technology,
a Nabors subsidiary, said the software is unique in its ability to
incorporate numerous external factors in its advisory mecha-
nism. SmartPOWER focuses on the true drilling data received
through the electronic drilling recorder (EDR) and uses pro-
prietary AI to recommend the optimal number of engines and
generators to run, both for current and predicted drilling activity.

In addition to real-time drilling data, a separate module within
the system accounts for altitude, coolant temperature, oil condi-
tion and filter condition within the engine to further optimize
decision making. The system also accounts for an engine’s ser-
vice life and maximum capacity.

“Our system evaluates engine condition and other factors to
determine which engines have the highest capacity,” Mr Hall
said. “It’s just as important to know which engines to run as it is
to know how many engines to run.”
Field testing of the advisory system, carried out on a Nabors
rig in Q1 2022, indicated a reduction in diesel consumption in line
with internal models showing up to 20% in certain applications,
with an equivalent reduction in CO2 emissions. This reduction
is with respect to the baseline set from average fuel consumed
during operations running all available engines, with no manual
intervention of the generators.

In Q2 2022, Nabors plans to release a super-capacitor energy
storage system, Canrig PowerFLOW. Similar in function to other
energy storage systems, PowerFLOW uses super-capacitors to
provide immediate power for load spikes during tripping and
other operations, maximizing energy capture during drawworks
braking and reducing the need for diesel-generated power above
baseload. The difference between super-capacitor and battery energy
storage is the super-capacitor’s ability to near instantaneously
store provided power and its speed at supplying power back to the
system. The PowerFLOW’s charge/discharge rate (C rating) ranges
from 25 to 50 C, meaning that it can provide 3,500 amps of power
in just over a minute, and the system can support 1,000-amp dis-
charge for 9.5 minutes. A battery energy storage system’s C rating
typically ranges from 3 to 5 C, meaning that it can discharge a
maximum of 1,500 amps for up to 12 minutes at max capacity.

Last October, the VALARIS DS-12 drillship became the fi rst
rig to receive the ABS Enhanced Electrical System Notation
EHS-E. Valaris upgraded the rig’s electrical system to safely
operate with as few as two generators online.

A higher C rating means that a system can deliver more power
to the system at faster speeds, which is valuable for tasks with
high power demand. It also means that the system can recharge
faster, with recharge times in the range of 1 to 6 seconds, depend-
ing on drilling activities. Due to the fast recharge characteristics
of PowerFLOW, the system is capable of fully charging from “free”
regenerative power, rather than drawing charge from the genera-
tors. This capability makes it easier for users to maintain peak
shaving, avoiding the spikes in power demand that can drive up
diesel usage and, subsequently, emissions.

An additional feature available when combining SmartPOWER
and PowerFLOW is the ability for the super-capacitor power to
be pushed to the AC bus. AC bus frequency can be monitored,
and PowerFLOW can inject AC voltage to the AC bus if frequency
drops, when either large AC or DC loads are felt on the AC bus.

This ensures that the generators maintain constant load and,
therefore, no engine surges occur during any operation.

“Imagine a system that you can fill up with power and discharge
quickly. That’s where super-capacitors have value,” Mr Hall said.

“By using these super-capacitors, you can monitor and control the
discharge rates. For our drilling operations, energy storage isn’t
really about powering the rig when your other sources of power
are removed; it’s about giving you the ability to be more efficient
with power generation. You’re using the super-capacitor to sup-
plement that power generation, and you can run your engines at
a constant load, even though you have these high demand peaks .”
Eliminating drill cuttings waste transport
NOV’s recent low-carbon technology offerings have targeted
mitigating, or outright eliminating, wasteful activities in a drilling
operation. One area of focus for the company is on the treatment
of oil-based drilling waste. Last year, the company launched its
iNOVaTHERM portable treatment unit to allow companies to
treat and dispose of drilling waste on the rig, as opposed to the
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