Directional drilling involves deviating a wellbore along a planned path between a starting point and ending target. It was initially used for remedial operations but now enables access to reservoirs that would otherwise be inaccessible. This document discusses well profiles, directional drilling assemblies, measurement tools, different directional well types like build-up and drop-off wells, and applications like sidetracking, fault drilling and extended reach wells. Directional drilling calculations involve determining radii of curvature and inclination angles to achieve a desired well path.
1. DIRECTIONAL DRILLING MOTOR
Major Project Submitted
In partial fulfillment of the requirements
For the award of the degree of
MASTER IN TECHNOLOGY IN PETROLEUM EXPLORATION
BY
S.SURESH
(Reg.no. -709212345011)
DELTA STUDIES INSTITUTE
College of Science and Technology
Andhra University
Visakhapatnam
2010
2. DEFINITION
Controlled directional drilling is the science and art of
deviating a wellbore along a planned course from a starting
location to a target location, both defined with a given
coordinate system.
4. Directional drilling was initially used as
a remedial operation, either to sidetrack
around stuck tools, bring the wellbore
back to vertical, or in drilling relief
wells to kill blowouts.
Interest in controlled directional
Drilling began about 1929 after new
and rather accurate means of measuring
the hole angle were introduced during the
development of the Seminole field, Oklahoma, USA.
HISTORY
12. •The stabilizer above the bit is removed &
an additional collar is added making the
bottom-hole assembly more flexible
•Gravitational forces acting on the bottom
collar and bit, causing the hole to lose or
decrease the angle
PENDULUM PRINCIPLE
13. FULCRUM PRINCIPLE
•The fulcrum uses a stabilizer inserted
into the drill string just above the bit
•With the bit rotating on bottom,
enough weight is applied to cause the
bottom collars to bow.
•In holes with 5° or more of
inclination, the bow is towards the low
side of the bow causes the bit against
the top of the hole, resulting buildup.
14. NEW ERA OF AUTOMATIC DOWN-HOLE
NAVIGATION
Rotary Steerable Systems
•Allow drilling of smoother, more precise well paths
than earlier.
• Longer reach is possible
• Ability to place wellbore through multiple targets
greatly
•improves recovery from single well
•Elimination of sliding and resulting friction
•Less time spent on short trips and back reaming
15. ROTARY STEERABLE SYSTEM
•Rotating Shaft is
deflected in center
between bearings
with dual eccentric
cams
• Results in bit tilt
inopposite
direction
16. MWD Tool is lowered along
with the drill collar
(Inclination, BAP, 3-axis
Azimuthal Gamma,
Resistivity tool, Pulser,
Batteries
Latest Development for Rss
17. Further Developments for Geo-
Pilot
IN-BIT
TECHNOLOGY
• Box-up design allows
room for
instrumentation package
• Currently testing with
vibration and
temperature
18. RIG VISIT EXPERIENCE
Rig E760M at GMDN site KG Basin Field
Sequential order of BHA:
Bit
Mud Motor
Stabilizer
Mull shoe sub
Non mag collars
21. First Case R > D2
The maximum inclination angle max for type I trajectory is given by:
Second Case R < D2
Radius of curvature(R) build up section:
22. Measured length of build-up section Tangent Section
Where α = maximum inclination angle at the end of buildup section.
•Vertical length of tangent section:
V2 – V1 = R1 x sin α
Horizontal displacement at end of tangent section:
D1 = R1 × (1-cosα)
23. Tangent Section:
•Measured length of tangent section:
•Vertical length of tangent section:
V3-V2 = MD3× cosα
•Horizontal Displacement at end of the tangent section:
D2=D1+MD3 × sin α
•Total measured depth for type I wells:
TMD= MD1
+ MD2
+ MD3
26. Radius of curvature (R1) of build-up section:
Radius of curvature of drop-off section
Where, DOR = Drop off rate, degrees/100ft
D3 > R1 + R2
D3 < R1 + R2
27. Tangent section:
Vertical depth at end of tangent section:
For wells that return to vertical at end of drop-off
section:
For S-wells wells that partially drop angle and maintain a certain inclination to
target,
V3 given by:
Measured length of tangent
section:
Horizontal displacement at end of tangent
section:
30. Y = R1
+ R2 cosα2
+( V5-V4)tan α2
-D4
If
For S well that do not return to vertical, first calculate D3
D3 = D4 - (V5-V4) tan α2
31. Build-up Section
Measured length of build-up section
Where α1 = maximum inclination angle at end of build-up section
Vertical depth at end of the build-up section
For wells that return to vertical at end of drop-off section:
32. Tangent section
Vertical depth at end of tangent section:
For wells that return to vertical at end of drop-off
section:
For S-wells wells that partially drop angle and maintain a certain inclination to target,
V3 given by:
Measured length of tangent
section:
Horizontal displacement at end of tangent section:
33. Drop-off section:
Measured length of drop-off s wells that return to
vertical:
Where α2= maximum inclination angle at end of drop section
Total measured depth for s wells that return to vertical:
Measured depth at end of a partial drop section where the angle of
inclination is maintained to target is given by:
Total measured depth at end of a S well where the angle of inclination is
maintained to target
34. Calculation as per well data
Kick-off depth = 1,200 ft
Build-up rate = 2.0 degrees/100 ft
Drop-off rate = 3.5 degrees/100 ft
TVD at end of drop-off section (V4
) = 8157 ft
Total horizontal displacement (D3
) = 2136 ft
Final inclination angle in reservoir = zero degrees
35. Radius of curvature
Build-Up section
Also given D3 = 2,136 ft
Since (R1+R2) is greater than D3, equation must be used for determining the
maximum inclination angle αmax
Given that V4=8157ft, V1=1200ft
αmax = 19 degrees
44. CONCLUSION
Directional drilling has become a very important
drilling process. It has enabled producers all over
the world to develop subsurface deposits that
could never have been reached economically in
any other manner. In this module, directional
drilling was defined along with its technical
calculations of directional well as well as the
features of a well profile were also covered. The
module also included information related to
directional drilling motor and its components.
