Drilling contractors and operators have more
options than ever before to reduce their diesel fuel costs, without sacrificing
performance. Creating an integrated and fuel-flexible hybrid power solution
offers sustainability benefits and stability that’s required in the oil field.
BERRIE, Caterpillar Oil & Gas
drilling operations have relied on diesel and Dynamic Gas Blending (DGB) to
supply the required power to the rig and ensure the capability to support the
transient power load spikes seen in the drilling application, Fig. 1.
The compelling cost and emissions advantages that running on field gas provides,
compared to using diesel, is persuading companies of all sizes to implement
gas-powered alternatives that not only deliver the reliability operations
demand, but that also support ESG (Environmental, Social and Governance) goals.
In many cases, this is a partnership that occurs among multiple stakeholders:
supplier, contractor and operator.
natural gas power generation offers a superior environmental and cost profile
compared to diesel, its historically slower responsiveness to transient power
demand requirements has hindered its adoption for applications such as drilling.
for natural gas power generation. The answer to this dilemma lies in the
integration of multiple technologies to create a complete solution. Fully
autonomous gas-hybrid systems use Cat’s latest controls technology, which fully
integrates natural gas generators and energy storage to provide an optimized
power solution to the operator. These systems, which are automated and
optimized to efficiently power drilling rigs, can be retrofitted into existing
rigs and future builds, enabling seamless operation.
leveraging the capability of this system, which includes the latest in genset
controls, bidirectional power inverters and microgrid master controllers,
operators can boost fuel economy and reduce engine maintenance and emissions.
In the process, they increase uptime and capital efficiency. The result is
exceptional performance in the field that provides operators the flexibility to
run on a wide variety of fuel types that align with their strategic goals.
systems can be powered by several fuel sources, such as CNG or LNG transported
to the site; however, for drilling projects, the power source can be much simpler.
Field gas can be directly connected to gas-hybrid systems to provide power that
can be stored or delivered as needed. Not all gas is created equal, and some
gas sources can have heavy hydrocarbons, which are of great value to the
customer. These heavy hydrocarbons can be easily removed at the field level, to
both provide a consistent flow of dry gas to the rig and return the NGLs back
to customer operations. Providing an end-to-end solution allows operators to
reap the full benefits of natural gas while ensuring the operational
reliability critical to a successful drilling program.
in Colorado. A
drilling site in the Mountain State demonstrates how far gas power generation
has come in recent years. A supermajor operator sought to power their
super-spec Helmerich & Payne FlexRig® (Fig. 2) with field gas, to
lower emissions and operational costs. The plan was to use field gas,
sourced from an adjacent pad, for drilling system power generation. While Cat could
run directly from the field gas, the operator was advised that a more
economical solution would be to remove the heavy hydrocarbons and return them before
the gas was used for power generation.
Caterpillar Oil & Gas designed an end-to-end approach to
meet these needs. First, field gas was processed with Cat’s gas treatment
partner, GTUIT, to remove NGLs and return them to the operator. The treated gas
was then piped to a gas-hybrid system to run the super-spec rig. Multiple
Caterpillar G3512 gas generator sets were integrated with energy storage to
create a microgrid power supply. To optimize power supply to the rig, the
system included the Energy Storage Solution (ESS), Fig. 3. This solution
fully integrates lithium-ion batteries with Cat’s inverter and microgrid master
controller, storing and discharging power, as needed, in harmony with the
G3512s, to ensure an optimized power supply to the rig. Employing the microgrid
master controller ensured the system worked together seamlessly to provide
uninterrupted power, autonomously turning generators on and off as needed, rather
than relying on manual controls.
Historically, natural gas systems have not been optimized to
ensure transient support in drilling operations, unlike diesel-powered systems.
Cat’s gas-hybrid system, however, used energy storage and an integrated
controls strategy to deliver optimized power for Helmerich & Payne’s operation.
Additionally, incorporating gas treatment services transformed the NGLs from an
inconvenience to a revenue stream, further improving the operation’s total
As with many new technological innovations, commitment was
needed from all parties in the field. Helmerich & Payne’s experience
deploying alternative rig power systems provided a customizable platform for
the new technology. Several modifications to rig equipment were required,
including VFD (variable frequency drive) skid modifications, recoding, rewiring
and fine-tuning the power system to work with the FlexRig fleet design. This
established a firm foundation to ensure successful communications and controls.
A constant stream of communication was needed for successful
implementation. Rapid response to change and commitment to the overall goal of
the project created an environment conducive to continuous improvement and
innovation. This was achieved through weekly meetings with all parties
involved, reviewing data and capturing key insights as the project continued.
Over the course of the drilling program, this end-to-end
gas-hybrid solution produced significant reductions in regulated emissions,
operating expenses, fuel costs and runtime. NOx emissions were reduced by approximately
80%, with CO2E reduced up to 11%. Using CNG reduced fuel costs by more
than 30%, while using field gas saw an 85% fuel cost reduction. The integrated controls
automation improved transient response while decreasing engine run time by up
to 30%, supporting lower maintenance requirements and increased site safety. Additionally, connecting the assets via Cat’s
Remote Fleet Vision provided a continuous feedback loop and regular KPI analysis,
to support the customer’s results reporting.
The future of drilling. The oil and gas industry can
benefit from advances in other sectors that also rely on complex equipment
requiring reliable power. Since 2009, Caterpillar has been using key elements
of this technology in construction and mining equipment, leveraging
field-proven inverters, controllers and years of microgrid experience. This collective
expertise informed the approach in Colorado, fostering a holistic solution tailored
to meet the needs of the drilling operation.
As ESG goals become increasingly important for oil and gas drilling
contractors and operators both large and small, the need for custom solutions that
allow for profitable gas-powered operation, the flexibility to use different
types of gas (from field to LNG and CNG) and minimized environmental impact is even
more important. For service providers, finding ways to provide flexible
drilling solutions that can run on a range of fuel sources to align with customers’
KPIs is essential.
Natural gas demonstrates clear advantages in terms of
environmental emissions, costs and equipment footprint. Integrating automation,
redundant capability and control mechanisms ensures that companies can achieve
the operational effectiveness and efficiencies they seek. Companies looking to
move to natural gas power generation for their drilling operations can improve
their operational bottom line while maintaining exceptional performance, with
end-to-end solutions that encompass these considerations. WO
CHRISTOPHER BERRIE is the
Drilling Account manager for Caterpillar Oil & Gas. He joined Caterpillar
in 2008 and is also the chair of the Emerging Executives Committee for the
Energy Workforce & Technology Council. He holds a Bachelor of Science degree
from Loughborough University, UK.