Hydrostatic pressure is created by fluid column. Two factors affecting hydrostatic pressure are mud weight and True Vertical Depth. So this post will demonstrate how to calculate hydrostatic pressure in different oilfield units.
1. Calculate hydrostatic pressure in psi by using mud weight in PPG and feet as the units of True Vertical Depth.
Hydrostatic pressure equation:
HP = mud weight in ppg x 0.052 x True Vertical Depth (TVD) in ft
Example: mud weight = 12.0 ppg
True Vertical Depth = 10,000 ft
HP = 12.0 ppg x 0.052 x 10,000 ft
HP = 6,240 psi
2. Calculate hydrostatic pressure in psi by using pressure gradient in psi/ft and feet as the units of True Vertical Depth.
Hydrostatic pressure equation:
HP = Pressure gradient in psi/ft x True Vertical Depth (TVD) in ft
Example: Pressure Ggradient = 0.5 psi/ft
True Vertical Depth = 10,000 ft
HP = 0.5 psi/ft x 10,000 ft
HP = 5,000 psi
3 Calculate hydrostatic pressure in psi by using mud weight in lb/ft3 and feet as the units of True Vertical Depth.
Hydrostatic pressure equation:
HP = 0.006944 x mud weight, lb/ft3 x TVD, ft
Example: mud weight = 80 lb/ft3 true vertical depth = 10,000 ft
HP = 0.006944 x 80 lb/ft3 x 10,000 ft
HP = 5,555 psi
4. Calculate hydrostatic pressure in psi by using mud weight in PPG and meters as unit of True Vertical Depth.
Hydrostatic pressure equation:
HP = mud weight, ppg x 0.052 x TVD in meters x 3.281
Example: Mud weight = 12.0 ppg true vertical depth = 5000 meters
HP = 12.0 ppg x 0.052 x 5000 x 3.281
HP = 10,237 psi
Download the Excel sheet for calculating hydrostatic pressure
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Quite a nice one, but you are solving without explanation. How are people suppose to know where you got 0.052 from, and how are suppose to know that when computing using the pressure gradient that the 0.052 wouldnt be used
ReplyDeletehttp://mexicokeandme.wordpress.com/2013/02/07/coefficient-of-hydrostatic-pressure-in-oilfield-applications/
ReplyDeleteSee the explanation for the unit conversion here