33 directional drilling
DESCRIPTION
Directional drillingTRANSCRIPT
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PETE 411Well Drilling
Lesson 33
Directional Drilling
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Directional Drilling
◆ When is it used?◆ Type I Wells ◆ Type II Wells ◆ Type III Wells ◆ Directional Well Planning & Design◆ Survey Calculation Methods
Build and Hold
Build-Hold and Drop
ContinuousBuild
KOP
EOC
I II III
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Read ADE Ch.8 (Reference)
HW #17 due 11-27-02HW #18 due 12-06-02
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Inclination Angleθ,θ,θ,θ,
αααα, I
Direction Angleφ,φ,φ,φ,
εεεε, A
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Max.Horiz.
Depart.?
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Type I Type II Type III
Build and Hold
Build-Hold and Drop
ContinuousBuild
KOP
EOC
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∆∆∆∆x
∆∆∆∆yI
I
r
r∆∆∆∆L
In the BUILDSection
∆∆∆∆x = r (1 - cos I)
∆∆∆∆y = r sin I
∆∆∆∆L = r ΙΙΙΙrad
degI r180
= L
π∆
BUR*000,18r
π=
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Fig. 8.11
42131 xrr and xr <+<
1642131 xrr and xr >+<
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N18E
N55WS20W
S23E
AzimuthAngle
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Example 1: Design of Directional Well
Design a directional well with the following restrictions:• Total horizontal departure = 4,500 ft• True vertical depth (TVD) = 12,500 ft• Depth to kickoff point (KOP) = 2,500 ft• Rate of build of hole angle = 1.5 deg/100 ft• Type I well (build and hold)
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Example 1: Design of Directional Well
(i) What is the maximum hole anglerequired.
(ii) What is the total measured depth (MD)?
(MD = well depth measured along the wellbore,not the vertical depth)
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(i) Maximum Inclination
Angle
ft820,35.1000,18r1 ====
ππππ====
0r2 ====
(((( ))))
ft000,10500,2500,12
DD 14
====−−−−====
−−−−
ft500,4x4 ====
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(i) Maximum Inclination Angle
−−−−−−−−++++−−−−
====500,4)820,3(2
500,4)820,3(2000,10500,4000,10tan 2 22
1-
�3.26max ====θθθθ
−−−−++++++++−−−−−−−−++++−−−−−−−−
====θθθθ −−−−
421
4212
1424141
max x)rr(2x)rr(2)DD(xDD
tan2
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(ii) Measured Depth of Well
ft 395 )26.3 cos-3,820(1
)cos1(rx 1Build
========
θθθθ−−−−====�
ft 4,105 395500,4xHold
====−−−−====∴∴∴∴
ft 265,9L105,4sinL
Hold
Hold
====∴∴∴∴====θθθθ∴∴∴∴
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(ii) Measured Depth of Well
Holdrad11 LrDMD ++++θθθθ++++====
ft 518,13MD ====
265,9180
26.33,8202,500 ++++
ππππ++++====
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* The actual well path hardly ever coincides with the planned trajectory
* Important: Hit target within specified radius
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What is known?I1 , I2 , A1 , A2 ,∆∆∆∆L = ∆∆∆∆MD1-2
Calculateββββ = dogleg angleDLS = β∗100/∆β∗100/∆β∗100/∆β∗100/∆L
DLS = dogleg severity
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