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The H-SERIES HI TORQUE connection is a patented, high-performance,
rotary shouldered connection available in sizes from 2
3/8 to 6 5/8"· The HI TORQUE connection incorporates a
double-shouldered design. A secondary internal shoulder
on the nose of the pin offers an additional friction surface
and mechanical stop. The primary external shoulder still
serves as the connection's sealing surface. As shown in
the figure to the left, the HI TORQUE design has an extended
pin base, pin nose, and box counterbore. These sections
are carefully engineered to provide additional elastic
deformation during make-up. This ensures that the contact
forces are properly proportioned between the two shoulder
surfaces. The additional torsional strength provided by
the HI TORQUE design offers several advantages and unique
solutions in drill string design. |
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Torque
A HI TORQUE connection offers significantly higher torsional
capacity than standard API connections of similar size.
This additional strength provides an extra margin of safety
when drilling in high-risk situations or rugged conditions.
Slim Profile
Another advantage of HI TORQUE's increased torsional strength
is the ability to use a streamlined tool joint that is
suitable for the pipe's torsional strength. The figure
on the next page illustrates the smaller OD and larger
ID for HI TORQUE connections compared to standard API
connections with identical torsional capacity. Using a
streamlined HI TORQUE tool joint allows a larger diameter
drill pipe to be used. This provides increased bit weight
in horizontal drilling, improved hydraulic efficiency,
better hole cleaning, and more drill pipe buckling strength
without sacrificing torsional strength or fishability.
For instance, using a HI TORQUE connection on 5 1/2"
pipe will provide 35% more drill pipe buckling strength
than a 5" drill pipe with an NC5O connection, and
will add only 21% string weight. With HI TORQUE connections,
the ability to fish inside an 8 1/2" hole and have
torsional capacity matched with the pipe is maintained.
Drilling fluid pressure loss is decreased and annular
velocities are increased because of the larger pipe. HI
TORQUE connections can provide a superior solution for
any drilling situation requiring a low-profile tool joint
such as extended reach, horizontal, or slim hole drilling
programs. |
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HI TORQUE's increased torsional strength gives the tool
joint a more streamlined profile that remains matched
with the torsional strength of the pipe. Compared with
an API NC profile with equal torsional strength, HI TORQUE
offers greater flexibility on OD and ID to provide solutions
to today's drilling challenges. |
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Wear
Because of its increased torsional capacity, the HI TORQUE
connection greatly extends the life of the joint by tolerating
more OD wear. For example, an NC38 on 3 1/2" 13.30 lb/ft
G-105 drill pipe is downgraded to Class 2 when the OD
wears below 4 21/32". At this diameter, the tool joint
is less
than 80% as strong as Premium Class pipe. The HT38 HI
TORQUE connection can tolerate wear down to a diameter
of 4 3/8" before its torsional strength falls below
80% of the pipe strength.
The cost of a drill string is a substantial investment.
The extended life provided by the HI TORQUE connection
can protect that investment.
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