Page 154 - Formulas and Calculations for Petroleum Engineering

Drilling engineering formulas and calculations Chapter 2 147

2.172 Pressure analysis—Pressure by each barrel of mud in casing

Input(s)
Dh: Hole Dia (in.)
Dp: Pipe Dia (in.)
mw: Mud wt (ppg)

Output(s)

P: Hydrostatic Pressure (psi/bbl)

Formula(s)

mw
P ¼ 1029:4 0:052
2 2
ð DhÞ Dpð Þ

Reference: Formulas and Calculations for Drilling, Production and Workover, Second Edition, Lapeyrouse, Page: 138.

2.173 Pressure analysis—Surface pressure during drill stem test

Input(s)
h: Total Vertical Depth (ft)
EMW: Equivalent Mud Weight for Formation Pressure (ppg)
SG: Oil Specific Gravity (fraction)

Output(s)
P: Hydrostatic Pressure (psi/bbl)

Formula(s)

ð
P ¼ 0:052 h EMW SG 8:33Þ

Reference: Formulas and Calculations for Drilling, Production and Workover, Second Edition, Lapeyrouse, Page: 138.

2.174 Pressure gradient

Input(s)
mw: Mud weight (ppg)

Output(s)
PG: Pressure Gradient (psi/ft)

Formula(s)

PG ¼ mw 0:052

Reference: Formulas and Calculations for Drilling, Production and Workover, Second Edition, Lapeyrouse, Page: 1.