Petroleum Engineering 406

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Petroleum Engineering 406

• Lesson 20
• Directional Drilling
• (continued)

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Lesson 17 - Directional Drilling contd

• Tool-Face Angle
• Ouija Board
• Dogleg Severity
• Reverse Torque of Mud Motor
• Examples

3
Homework

• READ
• Applied Drilling Engineering, Chapter 8
• (to page 375)

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Tool Face (g)
Solution
Fig. 8. 30 Graphical Ouija Analysis.
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Over one drilled interval (bit run)
GIVEN a 16o De 12o aN 12o
Tool Face (g)
Solution
New Inclination - 12o
De 12o
g ? o b ? o
Initial Inclination 16o
Fig. 8. 30 Graphical Ouija Analysis.
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Fig. 8.33 Basis of chart construction is a
trigonometric relationship illustrated by two
intersecting planes
b
a
aN
b dogleg angle
De
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Problem 1

• Determine the new direction (eN) for a
  whipstock set at 705 m with a tool-face setting
  of 450 degrees right of high side for a course
  length of 10 m.
• The inclination is 70 and the direction is N15W.
  The curve of the whipstock will cause a total
  angle change of 30/30 m.

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Problem 1

• a 7o (inclination)
• e 345o (azimuth)
• g 45o (tool face angle)
• L 10 m (course length)
• d 3o/ 30 m (dogleg severity)
• eN ? o

g 45o
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Solution to Problem 1, part 1

• I. Use Equation 8.43 to calculate .
• The dogleg severity,

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Solution to Problem 1, part 2

• 2. Use Equation 8.42 to calculate the direction
  change.
• New direction 3450 5.30 350.30 N9.7W

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Problem 2

• Determine where to set the tool face angle,
  for a jetting bit to go from a direction of 100
  to 300 and from an inclination of 30 to 50. Also
  calculate the dogleg severity, assuming that the
  trajectory change takes 60 ft.
• a 3
• e 10
• Find

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Solution to Problem 2, part 1

• 1. Find b using Equation 8.53

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Solution to Problem 2, part 2

• 2. Now calculate ? from equation 8.48.

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Solution to Problem 2, part 3

• 3. The dogleg severity,
• ? 4.01o / 100 ft
• Alternate solution Use Ouija Board

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Fig. 8.31 Solution to Example 8.6.
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Problem 3

• Determine the dogleg severity following a jetting
  run where the inclination was changed from 4.3o
  to 7.1o and the direction from N89E to S80E over
  a drilled interval of 85 feet.
• 1. Solve by calculation.
• 2. Solve using Ragland diagram
• L 85 ft

Da 7.1 - 4.3 2.8. De 100 - 89 11
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Solution to Problem 3, part 1

• 1. From Equation 8.55

b 3.01o
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Solution to Problem 3, part 1

• 1. From Equation 8.43
• the dogleg severity,

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Solution to Problem 3, part 2

• 2. Construct line of length ? (4.3o)
• Measure angle ?? (11o )
• Construct line of length ?N (7.1o)
• Measure length ?
• (Measure angle ?)

4.3
11o
b
7.1
Ragland Diagram
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Some Equations to Calculate b
Eq. 8.53

Eq. 8.54
Eq. 8.55
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Overall Angle Change and Dogleg Severity

• Equation 8.51 derived by Lubinski is used to
  construct Figure 8.32,
• a nomograph for determining
• the total angle change ? and
• the dogleg severity, ?.

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Fig. 8.32 Chart for determining dogleg severity
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(aaN)/2 5.7o
aN - a 2.8o
b 3o
De 11o
d 3.5o/100 ft
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(aaN)/2 5.7o
De 11o
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aN - a 2.8o
b 3o
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b 3o
d 3.5o/100 ft
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(aaN)/2 5.7o
aN - a 2.8o
b 3o
De 11o
d 3.5o/100 ft
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Problem 4 - Torque and Twist

• 1. Calculate the total angle change of 3,650 ft.
  of 4 1/2 inches (3.826 ID) Grade E 16.60 /ft
  drill pipe and 300 ft. of 7 drill collars (2
  13/16 ID) for a bit-generated torque of 1,000
  ft-lbf. Assume that the motor has the same
  properties as the 7 drill collars. Shear modules
  of steel, G 11.5106 psi.
• 2. What would be the total angle change if
  7,300 ft. of drill pipe were used?

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Solution to Problem 4

• From Equation 8.56,

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Solution to Problem 4, cont.
radians
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Solution to Problem 4, cont.

• If Length of drillpipe 7,300 ft.,
• ?M 0.001043 ?15.6822278.88
• 4.77 radians

3/4 revolution!
137.2
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Example 8.10

• Design a kickoff for the wellbore in Fig. 8.35.
  

e S48W 228o eN N53W 307o
a 2o L 150 ft aN 6o
De 79o Find b, g and d
From Ouija Board, b 5.8o, g 97o
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New Direction
Where to Set the Tool Face
b 5.8o g 97o
High Side
High Side
Present Direction
Fig. 8.36 Solution for Example 8.10.
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Dogleg Severity

• From Equation 8.43
• the dogleg severity,

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With jetting bit 325o
345o
qM 20o
307o
Fig. 8.36 Solution for Example 8.10.
228o
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Tool Face Setting
Where to Set the Tool Face
Compensating for Reverse Torque of the Motor
New Direction
Present Direction
High Side
High Side
Fig. 8.36 Solution for Example 8.10.