Answer:
Pressure at the botton of 7500 ft column is:
a) P (water) = 3256.508 psig
b) P (drilling mud) = 4229.035 psig
c) P (gas lift) = 18.092 psig
d) P (Natural gas) = 17.092 psig
Explanation:
hidrostatic pressure:
∴ density of fluid ( d.f ) ≡ Kg/m³
∴ aceleration o gravity ( g ) = 9.807 m/s²
∴ column height ( h ) = 7500 ft * ( m / 3.28084 ft ) = 2285.99 m
∴ atmospheric pressure (Po) = 101300 Pa ( Kg /m*s²)
specific gravity:
∴ d H2O = 997 Kg/m³
a) water:
⇒ P = ( 997 * 9.807 * 2285.99 ) + 101300
⇒ P = 22452844,88 Pa * ( psig / 6894.76 Pa ) = 3256.508 psig
b) Drilling Mud
⇒ SG = 1.3 = d.f / 997
⇒ d.f = 1296.1 Kg/m³
⇒ P = ( 1296.1 * 9.807 * 2285.99 ) + 101300
⇒ P = 29158182.16 Pa = 4229.035 psig
c) Gas lift column
⇒ SG = 0.85 = d.f / d.air (ref)
∴ d.air = 0.0765 Lb/ft³ = 1.23 Kg/m³
⇒ d.f = 1.23 * 0.85 = 1.0455 Kg/m³
⇒ P = ( 1.0455 * 9.807 * 2285.99 ) + 101300
⇒ P = 124738.755 Pa = 18.092 psig
d) Natural Gas column:
⇒ SG = 0.6 = d.f / 1.23
⇒ d.f = 0.738 Kg/m³
⇒ P = ( 0.738 * 9.807 * 2285.99 ) + 101300
⇒ P = 117845.003 Pa = 17.092 psig