Assume the standard rig floor arrangement shown the lecture lbf
Drilling System Design
Khalil Rahman
Principal Geomechanics Specialist Baker RDS, Perth, Australia
Email: Tel: 93542793
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HOISTING SYSTEM:Derrick
respectively.
BLOCK & TACKLE
The frictionless system efficiency, E = Ph/Pi = 1,
Because nFf = W for the frictionless system.
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Line Rope Specification
• A derrick usually has four legs,
• Loads applied on all legs may not be equal,
• All legs must be strong enough to carry its load,• Legs are designed based on the maximum load,• How to calculate the maximum load carried by a leg,• What is derrick efficiency factor usually used in the industry?
Derrick Design
Depends on the arrangement of the
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Derrick Design
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W = 300,000 lbf; n = 8, E = 0.841 (from Table 1.2),
(1) Ff = W/En = 300,000/(0.841 x 8) = 44,590 lbf
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| 1 | | .0 841 | | .0 841 8 | ||||||||||
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| E | F d | 382,090 | ||||
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F de | 450 ,000 |
DESIGN OF HOISTING SYSTEM
DESIGN OF HOISTING SYSTEM
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Strength/Ff = 2; i.e. strength = 2x74316 = 148,633 lbf
DESIGN OF HOISTING SYSTEM
DESIGN OF HOISTING SYSTEM
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