18 Casing Design Example

# 052 125 8000 1125 pc 5850 psi req d at the bottom

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Unformatted text preview: * design factor = 0.052 * 12.5 * 8,000 * 1.125 Pc = 5,850 psi ← req' d at the bottom. Further up the hole the collapse requirements are less severe 12 Casing Design Req’d: Burst: 6,600 psi Collapse: 5,850 psi 13 Casing Design Note that two of the weights of N-80 casing meet the burst requirements, but only the 53.5 #/ft pipe can handle the collapse requirement at the bottom of the hole (5,850 psi). The 53.5 #/ft pipe could probably run all the way to the surface (would still have to check tension), but there may be a lower cost alternative. 14 To what depth might we be able to run N-80, 47 #/ft? The maximum annular pressure that this pipe may be exposed to, is: Depth Casing Design Pressure Collapse pressure of pipe 4,760 Pc = = = 4,231 psi design factor 1.125 15 Casing Design First Iteration At what depth do we see this pressure (4,231 psig) in a column of 12.5 #/gal mud? Pc = 0 .052 * 12 .5 * h 1 Pc 4 , 231 ∴ h1 = = = 6 ,509 ft 0 . 052 * 12 . 5 0 . 052 * 12 . 5 16 Casing Design This is the depth to which the pipe could be run if there were no axial stress in the pipe… 6,509’ 8,000’ But at 6,509’ we have (...
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## This note was uploaded on 12/03/2012 for the course PMRE PMRE6004 taught by Professor M.tamim during the Summer '12 term at Bangladesh University of Eng and Tech.

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