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National Oilwell Varco, the world's largest independent supplier of
motors, offers the most versatile array of downhole motors available for
straight hole, directional, slim hole and coiled tubing drilling.
National Oilwell Varco provides drilling motors and their component
parts for sale, lease, or rent to clients worldwide. In 1997, National
Oilwell Varco acquired Dreco Energy Services Ltd. and inherited the
Trudril and Vector brand drilling motors. In 2007, National Oilwell
Varco acquired NQL and inherited the BlackMax and Prescott brands. All
National Oilwell Varco drilling motors utilize the industry's best
technology in sealed bearing and mud lube assemblies, adjustable
housings, and power sections. We combine that technology with
inventories and worldwide service to create a powerful source for your
drilling motor requirements.
National Oilwell Varco designs and manufactures bearing assemblies,
driveshafts, adjustable housings and Monoflo power sections that are
used by most major directional drilling companies in their own motor
fleets worldwide. We also provide innovative solutions to a variety of
drilling motor problems for a full range of applications including short
and medium radius work and performance drilling in standard and elevated
temperatures.
As part of its technology package, National Oilwell Varco engineers will
assist a customer to fit National Oilwell Varco components into
client-owned assemblies by designing with connections, lengths and
diameters that will ensure compatibility.
Features and Benefits:
Versatility: National Oilwell Varco offers
the most versatile array of downhole motors available for straight or
directional drilling. Rotary power is produced by a moineau positive
displacement progressing cavity mud motor. The mud motor power sections
offer a wide range of bit speeds and torques and can be tailored to
function in both high bottom-hole temperatures and inverted mud systems.
Motors are available with a fixed or an adjustable housing located
between the motor and the bearing assembly. The adjustable housing is
easily rig adjustable from zero (or straight) to a three-degree bend in
12 increments or a four-degree bend in 18 increments.
Most motors have an optional near bit stabilizer. Concentric or
eccentric stabilizers or pads can also be provided to stabilize the top
or middle of the motor.
National Oilwell Varco manufactures motors from 1 7/16" to 11 1/4"
diameter. National Oilwell Varco offers sales and service support via an
international network of facilities.
Sealed Bearing Assembly: The Sealed Bearing
Assemblies are capable of withstanding extreme radial and axial loads.
Due to the design and axial capacity of the bearing assembly, it is not
necessary to balance bit force against pump-open force.
Bearing assemblies are fully oil bath lubricated, sealed and pressure
balanced. Since no drilling fluid flows through the bearing assembly,
motor bearing life is extended and bit hydraulics are maximized.
The short length of the bearing assembly keeps the adjustable housing
close to the bit and provides better control of the angle build rate and
motor steerability.
Mud Lubricated Bearing Assembly: The Mud
Lubricated Bearing Assembly is designed to withstand extreme drilling
conditions and high temperatures. This makes it suitable to use with
Positive Displacement Power sections or Turbines. The Bearing Assembly
features a high precision bi-directional angular contact bearing pack
that gives a uniform load distribution and high weight on bit capacity.
In addition, this mud lubricated bearing assembly is radially supported
over its entire length and can, therefore, tolerate very high side loads.
Gear Reduced Bearing Assembly: The Gear
Reduced (GR) Bearing Assembly is designed to run when high torque and
lower rotational speeds are desired. The GR Bearing assembly has the
same bearing load capacity as an oil sealed bearing assembly, and it is
designed to run with Positive Displacement Power sections or Turbines.
This bearing assembly can be used with a high speed power section to get
the same torque as multi-lobe power sections, but with a higher
efficiency. The GR bearing assembly could also be used with multi-lobe
power sections when torque goes beyond the limits of power sections are
desired.
Stabilization: Motors are available with a
threaded stabilizer on the bearing assembly immediately above the output
shaft. Stabilizers can be either straight blade or spiral blade. This
stabilizer along with the integral wear pad at the bend of the
adjustable housing provides the full range of stabilization required for
directional and kickoff work. For steerable motor assemblies, a
concentric or eccentric stabilizer may be installed at the top of the
motor and an under-gauge stabilizer on the lower end of the motor. The
angle of bend set in the adjustable housing determines the under-gauge
diameter of the lower stabilizer.
Output Shaft: The Output Shaft is larger in
diameter than most competitive motors. This extra diameter and strength
reduces deflection and stress and allows the motor to be rotated in the
hole with reduced likelihood of fatigue induced failures.
Driveshaft and Universal Joints: The
eccentric motion of the rotor is converted to concentric rotation via a
driveshaft fitted at each end with sealed and lubricated universal
joints. The strength and service life of these joints is greatly
increased over that of conventional joints due to the large internal
clearances available through the adjustable housing.
Power Section: Power Sections are available
for a wide range of drilling applications. Rotational power is provided
by a moineau progressing cavity positive displacement mud motor. These
are available in high speed, low torque applications and in multi-lobe
configuration for low speed, high torque use.
The problem created by high bottom hole temperatures and invert mud
systems may be overcome by modifying standard rotor/stator clearances
and by the use of elastomeric compounds that are less susceptible to
deterioration in a hydrocarbon medium.
Dump Sub: The dump sub is a normally-open
valve which allows mud to by-pass the motor to fill or drain the pipe
while tripping into or out of the hole. This valve will automatically
close when circulation is started. For example: The 6 3/4" dump sub
closes at a flow rate of approximately 120 gpm. The closing flow rate
can easily be changed upon request.
A top sub may be used instead of the dump sub. The string will then fill
through the motor (or it may be filled from the surface) and the string
will be pulled wet.
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