Page 481 - Practical Well Planning and Drilling Manual

Appendix NEW! revised 11/00/bc 1/30/01 3:29 PM Page 457

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Appendix:5

Conductor Setting Depth for Taking
Returns to the Flowline

The minimum depth for the conductor shoe to allow returns to the
flowline can be calculated:

([x + y] pReturns)-(y x pSea)
Penetration =
pFormation-pReturns
where
Penetration = depth of shoe below seabed or surface, feet.
x = height of flowline above sea, feet.
y = water depth, feet.
rSea = sea density, psi/ft.
rReturns = returns density, psi/ft.
rFormation = formation density, psi/ft.

Example
(180x0.55)-(100x0.045) 54
Penetration = = =180’
0.85-0.55 0.3
where
Height of flowline = 80 ft MSL.
Water depth = 100 ft.
Formation density gradient = 0.85 psi/ft.
Seawater in the area = 0.45 psi/ft.
Expected returns gradient = 0.55 psi/ft
Calculate the required minimum penetration for the conductor shoe.

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