extract all possible hydrocarbons from complex reservoirs, advanced RSS and LWD
technologies improve overall drilling efficiencies and lower construction costs
over the life of the well.
LORETO, BRAD ZUKIWSKY, ALY BASSIOUNY and ONOCHIE MICHAEL
the search for additional hydrocarbon resources compelled operators to rethink
conventional drilling ideas, non-vertical wellbores were born. To reach these
additional deposits, operators needed a means to drill in a particular
direction. Traditionally operating from a single surface location and
established vertical wellbores, early versions of directional drilling deployed
non-rotating bent subs to divert the drill bit, aiming it toward untapped
resources in the formations. The unconventional horizontal well market quickly
became the answer to the question of how to maintain the demands of the energy
industry in the modern marketplace.
good as conventional directional drilling became, it still lacked the precision
and reliability required to drill extended-reach wells and realize a reservoir’s
true potential. These long, tortuous horizontal wells often need convoluted
trajectories to bore through complex formations and make contact with targeted
hydrocarbons. To address these new pressures, Weatherford innovated and
developed a fit-for-purpose tool specifically geared to extending the viability
of oil and gas fields and doing so in a more reliable manner.
combines high-performance drilling with full directional control. Weatherford
developed the Magnus® rotary-steerable system (RSS), Fig. 1. Using a
push-the-bit design, the RSS combines reliable, high-performance drilling with
precise directional control to enable operators to extend the performance of
each drilling run, providing faster drilling, better wellbores, and
rugged design of the Magnus RSS makes it possible to remain in the wellbore for
extended periods of time and keep costs as low as possible. Often, most
drilling operations can be performed in one run. The RSS features a streamlined
design with minimal bottomhole assembly (BHA) stabilization, a fully rotating
bias unit, and an optimized junk slot area to reduce the risk of expensive
stuck pipe events. The metal-on-metal pistol seals in the mud-actuated pad
enhances mechanical integrity in high-pressure, harsh drilling environments and
improves overall system stability.
independent pads and valves deliver proportional control and enable the pads to
fully retract for tight-hole
applications, reaming, or cement/shoe drilling. The three pads actively manage
the direction of the bit through the entire drilling process and are only
activated as needed to maintain the well trajectory. This selective pad
activation is what enables proportional steering and provides drastically
improved wellbore quality by eliminating unnecessary pad activations. This
independence serves as a redundant system in the event of pad or valve failure
to improve reliability.
The Magnus RSS can use standard drill bit designs, enabling any
operator anywhere to avoid lengthy lead times and reduce the need for
additional inventory. A proportional control system in the RSS makes efficient drilling
adjustments to minimize tortuosity, providing a smooth, high-quality wellbore
that can reduce the costs of future well-construction operations. In addition,
with a high-dogleg capability of up to 10°/100 ft, the RSS can build the curve
section, eliminate correction runs, and contact the pay zone sooner. An
electronic control system samples data at rapid rates to confirm the toolface
orientation and deliver full control.
Accurate, real-time information, supplied by advanced LWD tools,
help steer the RSS with real-time near-bit data for improved overall
productivity. Continuous azimuthal gamma ray and inclination measurements,
taken in as little as 6 ft behind the bit, enable effective wellbore placement
and geosteering changes to stay in the target zones. Innovative electronic
systems and autopilot functionality, including the capacity of self-regulated
adjustments, provide closed-loop control for course correction during drilling.
A real-time bidirectional communication system operates without interrupting
drilling, sending control signals to the RSS and then verifying the information
so that steering adjustments immediately take effect.
prepare the wellbore for installation of contingency liners and casing or
completions equipment, operators need to underream the hole. Optimally, and to
keep costs low, reaming and directional drilling should be performed in the
same run. To meet operators’ desire for hole-enlargement-while-drilling,
Weatherford engineers developed the RipTide drilling reamer. Often coupled with
the RSS, the RipTide reamer drills a smooth, concentric underreamed hole to TD
in one trip, Fig. 2. The drilling reamer enlarges wellbores up to 44%
beyond bit diameter and deliver high-quality, completion-ready boreholes.
a mass-balanced, triple cutter-block arrangement that works with the RSS to
minimize vibrations while drilling, the Riptide reamer can be activated in
multiple methods: a mechanical ball-drop system, pressure-cycle activation, or
electronic radio-frequency identification (RFID) tags. The RFID system leads the
industry in delivering unlimited downhole activation cycles, full through-bore
internal diameter, and gives operators the ability to place multiple reamers in
the drilling assembly.
Mexico. The RFID system proved itself a key component to a successful
operation in Mexico. In an offshore field, an operator needed to drill and
enlarge a 2,657-ft thick salt dome from the casing shoe. Making the operation
more problematic were the frequent stuck pipe issues typical for this field,
especially with hole diameters from 12¼-in. to 14¾-in. In previous offset runs,
the operator required two trips to achieve the desired results.
recommended the RipTide reamer be incorporated into the drilling assembly and
deployed into the wellbore. Using RFID tags, the drilling reamer was activated
below the casing shoe and enlarged the salt dome interval. With the enlargement
complete, the underreamer was deactivated via RFID tags. This enabled the
operator to close the section while drilling conventionally to the target depth
without additional trips.
choosing the unlimited, on-demand activation and deactivation feature of the
RFID reamer, the operator optimized downhole time and reduced exposure time for
the salt formation. The job was completed in one run, saving four days of rig
time and approximately $680,000 (assuming a daily cost of $170,000).
another Mexican application, an operator required a new borehole through a salt
dome with a heavy oil-based mud of 2.19 gr/cc (18.3ppg). The drilling fluid
contained high solids content (above 40%) and was mainly designed to drill in
the salt formation despite recurrent emulsion instability problems. The
operator typically experienced tool failures associated with the high
concentration of solid, stuck pipes in the salt formation, and high drilling
torque and torsional vibrations. The best course of action would be to deploy
an RSS power with batteries to overcome previous failures related to high
solids content. Additionally, a multi-activation drilling reamer would not only
enlarge the salt formation and reduce the risk of stuck pipe, but also be
deactivated after drilling the salt formation to maximize rate of penetration
RSS met the requirements for this job, specifically with the flexible power capability
that enables the tool to operate using only battery power to enhance the flow
inside the tools with no restrictions caused by turbine propellers, often the
cause of premature failures due to solids in offset wells. Additionally, the
RSS can be set in “steering off” mode, enabling the operator to drill through
zones with high vibrations while minimizing tool wear and improving hole
quality. A crucial factor in the success of this operation was the Centro™ well
construction optimization platform, where all drilling data were collected in
real time and the drilling parameters were monitored and optimized by engineers
located in the real-time operating center.
completed the section in a single run, saving four days and approximately
$165,000. The RSS effectively overcame all the challenges related to lateral
vibrations and high mud solids that had caused turbine impeller pack-off on other
RSS tools. The RipTide reamer enlarged the section with an ROP of 67.68 ft/hr,
126% higher than expected. The enlargement of the salt section prevented all
stuck pipe events, challenges that cost the operator hundreds of thousands of
dollars in lost time on previous wells.
an operator in Turkey, the challenge zeroed in on logging. Because of borehole
conditions in the limestone formation, conventional wireline tools were not
able to log a vertical section from 9,255 ft to 10,541 ft. As such, the
operator had no way of obtaining high-resolution borehole image data to identify
fractures in a well filled with 14.84 ppg (1.78 g/cc) oil-based mud.
engineers recommended a suite of LWD tools anchored by the UltraWave®
ultrasonic imager, Fig. 3. The imager provides high-resolution borehole
images and borehole caliper measurements while drilling in oil- or water-based
mud systems. It records the amplitude and travel time of ultrasonic acoustic
waves reflected from the borehole wall. These measurements are recorded in 128
azimuthal sectors around the circumference of the borehole, providing
high-resolution, 360°, borehole images while drilling.
logging suite also included a real-time telemetry system, an MWD
hostile-environment-logging system, an azimuthal gamma ray sensor, a resistivity
tool, and a sonic tool. The LWD tools were deployed into the wellbore and the
UltraWave imager acquired high-resolution amplitude images for reservoir and
evaluation. The other LWD tools collected gamma ray, resistivity and sonic
data, all of which made it possible to directly identify fractures and other
features in the hostile environment of the wellbore.
technology produces long-lasting results. To extract all possible
hydrocarbon assets from reservoirs, operators must overcome complex well
geometries to drill extended-reach, unconventional horizontal wells.
Directional drilling technology—like the innovative Magnus RSS and RipTide
drilling reamer as steered by advanced LWD technology—can improve overall
drilling efficiencies and lower well construction costs. These tools and
services enable operators to stay downhole longer, in harsher operating
environments and deliver long-lasting, productive results over the life of the
LULIO LORETO is V.P. of drilling
services at Weatherford. He is dedicated to the oil and gas industry for over
25 years with an ability to evaluate business environments to implement
cost-effective solutions, in multi-cultural and multi-site projects. Mr. Loreto
is enthusiastic on social responsibility, having personally supported multiple
projects to enhance the living conditions of the communities where Weatherford
BRAD ZUKIWSKY is global product
manager for RSS at Weatherford, based in Houston. Mr. Zukiwsky has nearly 20
years of experience in the drilling services business with a background
specializing in product development, operations management, and business
development. He has held various management positions in several countries
around the world and was responsible for launching the Magnus rotary steerable
system as product champion.
ALY BASSIOUNY is MLWD product
manager for Weatherford International, based in the UK. He has over 21 years of
industry experience in a variety of roles for both service and operating
companies. For the last 12 years, Mr. Bassiouny’s effort has been concentrated
on measurement and application of logging-while-drilling technologies. He began
his career with BP (GUPCO) in 1999 and has worked in operation log analysis and
petrophysics. He has published numerous technical papers. Mr. Bassiouny holds a
double B.S. degree in geology and geophysics from Ain Shams University, Egypt.
He is also a member of the SPE, SPWLA and AAPG.
MICHAEL OKORIE is global product line manager for directional drilling and borehole
enlargement at Weatherford. He has 11 years of experience in the oil and gas
industry and, prior to joining the global management team, he has held several
management positions leading applications engineering, operations and business
development across the Middle East, North Africa and Asia.