1. Drilling Engineering 1 Course (2nd Ed.)

2. 1. Drillstring Tubulars
A. Drill Pipes
a. properties of drill pipes
B. Drill Pipe Elevator
C. Drill Collars & Heavy Wall Drill Pipes

3. 1. Drillstring Equipment
A. Special Tools
2. Connections; Make–up and Break–out
3. Other Drillstring Equipment

5. Drillstring equipment
Several drilling equipment are used in the
drillstring.
The most important are:
stabilizers,
provide localized additional support points
(localized larger diameter)
in one or more positions along the drillstring.
reamers,
hole–openers.
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6. Advantages of drillstring
For vertical wells, the stabilizer prevents low
frequency vibration in the drillstring during
rotation.
The advantages are:
reduce wear (of both drillstring and casing),
reduce mechanical fatigue,
reduce mechanical instability of formation (caving),
reduce tortuous hole.
Stabilizers are essential equipment for directional
drilling.
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7. Stabilizer special characteristics and
types
Suitable choice of
number and position of
stabilizers in the
drillstring lend to the
bottom hole assembly
(BHA, the lower part of
the drillstring composed
of drill collars, stabilizers
and HWDP)
special characteristics in
terms of inclination
control:
angle build–up,
angle drop–off,
angle hold.
Stabilizer may be of the
following types:
integral blade,
interchangeable blade,
non–rotating blades,
replaceable blades,
clamp–on
near-bit,
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8. The diameter of stabilizers
The diameter of stabilizers can be in gauge or under
gauge.
More recently, remote adjustable blade stabilizers
were introduced.
Changing suitably the diameter of the stabilizers provide
a level of control in the directional behavior of BHAs.
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9. Some Stabilizers
(a)
integral,
(b)
interchangea
ble,
(c)
non–
rotating,
(d)
replaceable
Spring14 H. AlamiNia Drilling Engineering 1 Course (2nd Ed.) 9

10. Reamers
The purpose of the reamer is to keep
the diameter of the open hole in
gauge, that is, with the expected
original diameter of the bit.
Two reasons may cause
a decrease in the original diameter:
formation swelling (hydrated shales,
moving salt),
bit diameter reduction (hard and
abrasive formations).
The reamer also functions as a
stabilizer since the rollers touch the
borehole wall.
Different types of rollers can be
selected to suit the formations being
reamed.
A roller reamer
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11. The hole–opener
The hole–opener is a tool designed to
enlarge the diameter of a previously (or
simultaneously drilled smaller borehole.
Three situations (at least) are possible:
 to drill the borehole section with a smaller bit,
and later to enlarge to the final diameter (a
special tool called bull nose is connected in the
place of the bit, to guide the hole opener along
the pre-drilled hole),
 to drill the borehole section with a smaller bit
and simultaneously enlarge to the final
diameter,
 to enlarge a section below a casing with a
diameter larger than the internal diameter of
the casing.
 In this case, a special hole opener (also caller
underreamer) with hinged arms actuated
hydraulically is used (the drilling fluid pressure
actuates in rams that open the arms forcing the
cutters against the borehole wall).
A fixed hole–opener
Spring14 H. AlamiNia Drilling Engineering 1 Course (2nd Ed.) 11

13. manual tongs
To make–up and break–out the pipe connections
(during normal operations and drillstring trips),
big self–locking wrenches called manual tongs
are used to grip the drillstring and apply torque.
The tongs are kept suspended at suitable height
above the rotary table (3 to 5ft)
balanced by counter–weights.
They work in pairs,
one turns to left (counterclockwise) and
the other to right (clockwise).
They are mechanically or pneumatically
actuated by the cathead
(special rotating spools connected to the drawworks).
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14. Manual tongs.
Left tongue (break-out). Right tong (make–up).
Spring14 H. AlamiNia Drilling Engineering 1 Course (2nd Ed.) 14

15. make–up and break–out
To make–up a connection,
the left tong
grips the upper tool joint
(box) of the lower pipe,
and the right tong
grips the lower tool joint
(pin) of the upper pipe.
The left tong
is connected by a steel rope
to a fixed point in the
derrick,
and the right tong
is connected to the cathead
(turns the upper pipe).
To break a connection,
the left tong
grips the lower tool joint
(pin) of the upper pipe,
and the right tong
grips the upper tool joint
(box) of the lower pipe.
The right tong
is connected by a steel rope
to a fixed point in the
derrick,
and the left tong
is connected to the cathead
(also turns the upper pipe).
Spring14 H. AlamiNia Drilling Engineering 1 Course (2nd Ed.) 15

16. Technical notes about tongs
When set and ready to apply torque,
the angle between the arms of the tongs
should be either 90 or 180
(the ideal is zero degrees but operational difficulties
make this position not practical).
It is important to leave the rotary table unlocked,
to avoid damage to the pipe caused by the slips.
Compressed air tongs or spinners
are also used to speed–up the operation,
but the torque to make–up or to break–out
the connection is always done using the manual tongs.
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17. Compressed air tongs (spinners) &
Tongs
A spinner Tongs in position to make–up a connection
Spring14 H. AlamiNia Drilling Engineering 1 Course (2nd Ed.) 17

18. The angle between
the arms of the tongs
To make–up or
break–out a
connection,
the drillstring
must be
resting on the
master
bushing using
the slips
(DP and
HWDP) or
slips+safety
clamp (DC and
any other slick
equipment.)
Spring14 H. AlamiNia Drilling Engineering 1 Course (2nd Ed.) 18

19. Make–up Torque
It is very important to apply the right torque
during the make–up of a connection.
Too little torque
will not provide a suitable seal
between the pin and box shoulders,
and leakage might wash out the threads
causing failure of the connection.
Too much torque
may cause mechanical failure of the threads,
either in the box or in the pin.
The API RP7G tables present the maximum (tb.9) and
minimum (tb.10) torques for each standard connection.
Spring14 H. AlamiNia Drilling Engineering 1 Course (2nd Ed.) 19

22. Drill Bit
The bit is connected to the lower end of the drill collars.
Bits are manufactured with a pin, so that to connect
to the lower pin of the drillstring, a bit sub is used.
The bit sub is a short sub (11/2 to 2 ft) with two box connections.
There are a large variety of bits.
Each type is designed to drill rocks of different hardness,
composition, abrasiveness, etc, encountered during drilling
operations.
It is a duty of the drilling engineer
to select the most appropriate bit and the drilling parameters
(nozzle sizes, weight-on-bit, rotation speed, and flow rate)
to optimize the performance of the operation.
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23. Other Drillstring Equipment
In addition to the kelly–rotary table assembly,
two other methods can be used to promote
rotation to the bit:
Top drive,
Bottom hole motors
(positive displacement motors and turbines).
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24. top drive
The top drive, also called power swivel,
takes the place of the kelly, and the torque is applied to
the top of the drill pipe section by mean of hydraulic or
electric motors.
The assembly slides along tracks
(most models incorporate a swivel in the design,)
and is suspended by the hook.
The reactive torque is transmitted to the rig structure
directly through the tracks or by a torque reaction beam.
Spring14 H. AlamiNia Drilling Engineering 1 Course (2nd Ed.) 24

25. advantage of using a top drive
A great advantage of
using a top drive is
the possibility to drill a full
stand (3 or 4 drill pipes)
without interruption,
saving time in
connections.
Another advantage is
the possibility of rotating
the drillstring during the
trips reducing the drag to
pull–out or slack–off the
drillstring in the hole for
high inclination drilling.
An electrical top drive
Spring14 H. AlamiNia Drilling Engineering 1 Course (2nd Ed.) 25

26. Bottom hole motors and Turbines
Bottom hole motors
are special engines located above the bit
to promote bit rotation.
convert hydraulic power of the drilling fluid (P = q ∆p)
into mechanical (rotational) power.
Turbines
use fluid momentum conversion on the blades of
stator/rotor to generate rotation and torque.
operates in high speed and
has a narrow range of operation.
The torque decreases steadily from the maximum at 0 rpm
(stalled) to zero at the maximum speed.
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27. A bottom hole turbine
Spring14 H. AlamiNia Drilling Engineering 1 Course (2nd Ed.) 27

28. Positive displacement motors
Positive displacement motors (PDM)
use continuous displacement of constant volume
compartments created between an elastomer stator and
a steel rotor to generate rotation and torque.
The rotation speed of a PDM is function of the flow rate, and
the torque is directed related to the pressure differential across
the motor (easily monitored from the surface).
The use of bottom hole motors
is essential for directional drilling.
The use of bent sub or bent housing
provides a good deal of control of the inclination and the
azimuth, allowing to drill complex trajectories.
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29. A bottom hole PDM
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30. 1. Jorge H.B. Sampaio Jr. “Drilling Engineering
Fundamentals.” Master of Petroleum
Engineering. Curtin University of Technology,
2007. Chapter 3

31. 1. Hydraulic Introduction
A. Hydrostatic Pressure
a. Calculation for Incompressible Fluids
b. Calculation for Compressible Fluids
c. Buoyancy
B. Drillstring Design
a. Length of Drill Collars; Neutral Point Calculation