A
new performance solution for MPD applications was launched to address a
substantial portion of the market between existing entry-level and premier tier
offerings. The author details the differences in these solutions and presents a
case study highlighting performance improvements.
The
challenges inherent in drilling for oil and gas are daunting, none more so than
uncertain downhole pressure conditions. Managed pressure drilling (MPD), as
defined by the International Association of Drilling Contractors, is an
adaptive drilling process used to precisely control the annular pressure
profile throughout the wellbore. Many technologies and methods have been
developed and refined over the past five decades to mitigate and overcome the
unique challenges associated with pressure uncertainties. Ever since
introducing the world’s first rotating control device (RCD) in 1968, Weatherford
has been a pioneer in this part of the industry.
As
an MPD industry leader, Weatherford develops innovative solutions and
technologies to expand the scope and applications of managed pressure. But
managing pressure is not simply controlling the annular pressure profile. It
must take into account the myriad of specific operational conditions, formation
difficulties, and varying location challenges across the globe. Drawing on the
deep knowledge gained by decades of experience, the company’s experts realized
an engineered approach to managing pressure would best address the diverse
challenges rather than a universal system for any applications. With this
philosophy as a guiding principle, different tiers of MPD technologies were
developed to address the various operational needs of operators, no matter the
challenging conditions or environments.
Creating
a closed-loop system with RCD. Rotating control
devices provide safety assurance and flow diversion while serving as the
entry-point technology for MPD. Originally developed in the 1960s, RCDs were
strictly designed for land-based applications, where they were used for flow
diversion above a blowout preventer (BOP) to create a closed-loop circulation
system. The company’s continuous drive to innovate and improve RCD technology
resulted in decades of field-proven success.
MPD
applications expanded to places where higher requirements are demanded from the
current MPD systems, to address new challenges and environmental conditions. This
resulted in the improvement of RCD technology with the introduction of higher pressure
and temperature ratings and even American Petroleum Institute qualifications
for use in pure-gas conditions. One such example is our polyurethane-based high-temperature
sealing element, which increases the temperature rating by 60% over existing polyurethane
elements.
As
the energy industry matured and grew to the offshore market, Weatherford created
new models of RCDs to address the unique challenges of the marine environment,
both shallow water and deepwater. Shallow-water rigs use RCDs above the surface
BOPs, while deepwater applications involving dynamically positioned drilling
vessels typically install RCDs below the tension ring as part of the riser
package. Regardless of the application or environment, the RCD is a key piece
of technology, enabling operations to maintain a constant annular pressure,
create pressure-tight barriers against drilling hazards, and manage inflow from
formations.
Adding
a choke to better manage pressure. While the RCD diverts
fluid returns, the ability to actively manage the downhole pressure profile in
the wellbore is performed by downstream surface equipment, specifically a choke.
Combining this equipment with an RCD enables MPD techniques, providing greater
surface pressure control and management. Weatherford developed the PressurePro Managed
Pressure Solution to work in tandem with RCDs to mitigate downhole pressure
incidents while improving drilling capabilities.
This
system uses a single human-machine interface (HMI) to control the choke.
Displayed on a laptop in the driller’s cabin (“doghouse”) or on the rig floor,
the HMI enables field personnel to control the choke virtually rather than
manually while monitoring important drilling parameters. The operator inputs
the pressure set point, and then the PressurePro system automatically maintains
it by manipulating the applied surface backpressure (SBP). The choke
self-adjusts automatically and instantaneously to variances in downhole
pressure for quick, reliable system corrections.
Automating
responses to mitigate drilling risks. The Victus
Intelligent MPD solution is Weatherford’s premier MPD offering and stands as one
of the most advanced MPD technologies in the market. This technology builds on the
company’s established RCDs and choke equipment and takes accuracy, control, and
automation to unprecedented levels. It precisely maintains bottomhole pressure
by integrating rig equipment for machine-to-machine communication, real-time
analysis of downhole conditions, and rapid automated responses from a central
location.
On
the equipment side, the Victus solution adds accurate flow and density
measurement through the addition of a Coriolis mass flowmeter, and up to four
chokes on a manifold with independent control. An advanced hydraulics model
precisely determines real-time bottomhole pressure by considering the effects
of fluid and formation temperature, fluid compressibility, and wellbore
cuttings. Artificial intelligence (AI)-enabled control algorithms identify well
anomalies, alert the driller and MPD operator, and automatically send
corrective commands to MPD surface equipment. This enables real-time detection
of wellbore influx/losses, and the appropriate adjustments to the equipment can
be made based on the hydraulic modeling and intelligent control without
operator inputs. The programmable logic controller (PLC)-based system easily
integrates anywhere on the rig to provide a reliable, secure MPD infrastructure.
A
simplified user interface helps enable users to stay focused on critical
parameters and sends alerts on unexpected events. Condition-based monitoring
tracks MPD equipment performance and enables proactive maintenance. Reliable
automated reporting, such as daily summaries or post-job analyses, further
optimizes drilling performance. In deepwater operations, remote control via a
single user interface enables robotic riser installation, complete annular
isolation device (AID) shutoff, RCD latching and unlatching, and flow routing.
Data consistency spans from well planning to real-time operations and post-job
reporting. The real-time viewing and engineering evaluation/planning aspects
are managed with the CENTRO Well Construction Optimization Platform.
Current
developments include improved flow measurements with a high-pressure flowmeter (installed
on the standpipe) replacing simple pump stroke counters. Using this new
technology provides fluid rheology and mass flowrate properties on the inlet
side of the closed-loop drilling circuit to compare with the outflow measurements.
This system features better hydraulic modeling with real-time data when
compared against the conventional methods of manual mud checks that are updated
with far less frequency.
Providing
simple, precise pressure management and data capture. PressurePro
and Victus technologies are solutions developed for the entry and advanced
levels of managed pressure applications. Weatherford identified additional applications that
would be best suited to a solution between these tiers. Filling this gap is the
company’s newest system, the Modus Managed Pressure Wells Solution, Fig. 1.
This system was designed for use in a wide array of applications, in hot or
cold environments, and for both land and shallow-water applications. The goal
with this system is simple: focus on performance benefits of managed pressure
techniques, so that operators can drill more effectively with fewer pressure-related
issues.
The
Modus solution uses a modular approach to allow for flexible and efficient
installation. The system incorporates three equipment skids contained within one
sea container, needing only a single lift when unloading at location. The
individual skids can be removed from the shipping container for specific placement
around the wellsite if required.
The
choke manifold arrives in one skid, but the system is configurable to suit each
rig-specific requirement, if the chokes need to be placed within existing
infrastructure. With two digitally controlled chokes, the system has the
flexibility of using either choke independently for isolation or in combination
for higher flowrates. Precise control of these chokes enables improved wellbore
pressure and equivalent circulating density (ECD) management for more efficient
drilling with lighter mud weights. An over-pressure protection system and flow
line are integrated into the manifold.
The
flow measurement equipment arrives in the second skid. This equipment enables
the measurement of the return flow and fluid properties with a Coriolis flowmeter,
the proven industry standard for accuracy. Using this continuous
mass balance data allows the operator to immediately identify downhole pressure
changes in the form of flow anomalies. Real-time visibility of condition
fluctuations empowers fast reactions and adjustments to mitigate pressure issues
before they affect operations, Fig. 2.
The
digital control system is housed in the third skid, and it manages the data and
functions of the measurement and control equipment. This digital platform works
through a laptop-based HMI, and the operator can see the measured conditions
with historical trending and control the pressure through the digital software.
The graphs displayed on-screen instantaneously show trending of the downhole
conditions, enabling better decisions and faster reactions based on data. For
operating in a constant bottomhole pressure mode, the system features snap
pressure functions for use during connection makeups. This allows a single-button
activation that automatically adjusts the chokes and generates the desired
pressure on the wellbore, maintaining constant downhole pressure without flow. Relevant
data are collected, stored for post-job analysis, and can be transferred via a well-site
information transfer (WITS) interface and viewed in the CENTRO platform, Fig.
3.
By automating the management of pressure, the Modus solution
can react to changes in downhole pressure to protect personnel, wellbores, the
environment, and numerous additional assets. As part of an overall well
integrity system, the Modus solution enables safe drilling in narrow, shifting,
and unknown drilling windows by managing ECD, delivering a trusted approach to improve
operational safety and preserve formation integrity.
Demonstrating
success in the field. It was Weatherford’s trusted approach earned
from more than 50 years of experience, thousands of jobs, and millions of
operating hours that drew an operator in Ohio to deploy the Modus solution. Located
in the Utica shale, the operator needed to maintain the 8½-in. hole size down
to the target depth, to meet authorization for expenditure cost goals.
The Modus solution
reduced the time to drill by 60% when compared to the planned well time and
allowed the entire section to be drilled in a single run. Key to this operation
was the use of MPD techniques to maintain the ideal mud weight and minimize
wellbore pressure cycling throughout the lateral section of the drilling plan.
The objective was to avoid potential formation damage from heavyweight muds while
drilling through formations with uncertain pressure profiles.
Weatherford technical experts collaborated with the operator during the preliminary
planning and engineering stages to capture the scope and set drilling targets
for this horizontal well. The teams determined the requirements and created the
service quality delivery plan that would not only coordinate the project’s
execution and logistics but reduce overall costs. Weatherford engineers
recommended the Modus solution as the best option for the operator.
With
the plans in place, Weatherford field personnel performed a rig survey in Ohio,
enabling the local team to prepare the footprint and staging area, as well as
identify and eliminate potential hazards. At the same time, experts in Texas
staged and tested the equipment prior to shipping. The two teams maintained
consistent communication with the operator to coordinate delivering the
equipment on time. When the Modus MPD solution equipment arrived at the rig
site, it was efficiently installed and commissioned for use, and Weatherford’s
engineering team quickly adjusted the MPD operations matrix to accommodate a
change in the operator’s drilling plan.
Shortly
after landing the curve, however, the hole showed signs of a pack-off. After
discussions with the operator, the Weatherford MPD team provided options for updated MPD
programs to address the situation. The preferred option was to add back
pressure while slowly raising the fluid system by 0.5 ppg (0.06 SG). This
enabled the rig to continue drilling without waiting to condition the mud and
without significantly weighing up the fluid system. With this adjustment, the
drilling continued with the same bottomhole assembly and reached the target
depth of the long lateral section in a single trip.
Throughout
the operation, the Modus solution actively monitored gains and losses, enabling
the operator to use a lighter fluid system and save on barite use for weighting
up the fluid system. Complementing the lighter fluid system in the wellbore, the
Modus MPD technology actively applied surface backpressure to easily adjust to
changing downhole conditions. Conventional methods would have required hours or
a day to weight up or lighten the fluid system.
By
deploying the Modus solution, the operator reached target depth nine days ahead
of the 15-day well plan. Additionally, by using a lighter mud weight of 1.0 ppg
(0.12 SG) and adjusting backpressure to compensate for wellbore and formation
pressure, the operator reduced overall costs. The Weatherford solution drilled
an 18,000-ft (5,486-m) lateral in a single trip, achieving an 18% faster rate
of penetration (ROP), as compared to the previous four wells drilled
conventionally.
Envisioning
the future of MPD wells. This recent case of value generated
through performance improvement is just one illustration of the
company’s broader strategy for the Modus solution. In 2024, a fleet of systems
will be deployed to locations across the globe to further expand the use of managed
pressure technologies and enable other operators to understand and achieve the
long-term value of delivering higher-quality wells with fewer surprises.
For
years, the energy industry has applied managed pressure techniques only on the
drilling aspects of the well construction process. Weatherford sees managed
pressure differently. It is a performance-enhancing solution for
numerous, if not all, well classifications, including horizontal, directional,
development, and multi-laterals. By redefining what can be
achieved by managing a wellbore’s pressure, other activities—including
cementation, tubular and completions running—can benefit from a stable
wellbore, avoiding wellbore collapse and formation
damage while improving efficiency.
For
example, by managing pressure during cementing, operators can more proactively
respond to well events, such as gains and losses, improving zonal isolation.
Managed pressure cementing is particularly effective in wells with a narrow
drilling window, weak formations, or very tight margins. When the tools and
techniques developed for managing pressure are applied to completions operations,
it is possible to easily manipulate pressure while setting completions
components, improving efficiency, and reducing risks during this phase of a
well’s lifecycle.
Managing
pressure better within a safe operating window can apply to any well and any
operation. Now, with the introduction of the Modus solution and more appropriate managed
pressure systems for different applications, it is now possible to manage well pressure
in a greater number of wells, positioning Weatherford solutions to deliver
comprehensive pressure management for fewer surprises and higher-quality
wellbores, increased borehole stability, and more productive wells. WO
SCOTT
MCINTIRE is global product line champion for
Weatherford, based in Houston. He has over 26 years of experience in the oil and
gas industry with product development, ranging from wellhead forging design,
downhole equipment and solid expandable technologies to rig floor systems. He
worked as a R&D engineer for 10 years before managing multiple R&D
groups for another decade, prior to branching into business development and
product management roles. Mr. McIntire holds a bachelor’s degree in mechanical
engineering from Texas A&M University and became a licensed professional
engineer in 2005.