Page 97 - Formulas and Calculations for Petroleum Engineering

90 Formulas and calculations for petroleum engineering

Formula(s)

q
MDR ¼ 67 MW MW Þ
ð
o i 2
ð D Þ
h
Notes: The formula is valid when drilling in large diameter holes (14 3/4 in. and Larger).
Reference: Lyons, W. C., Carter, T., and Lapeyrouse, N. J., 2012, Formulas and Calculations for Drilling, Production and
Workover, Third Edition, Gulf Professional Publishing, Page: 24.

2.36 Conversion of pressure into the mud weight

Input(s)
TVD: True Vertical Depth (ft)
P: Hydrostatic Pressure (psi)

Output(s)
M w : Mud Weight (ppg)

Formula(s)

P
M ¼
w
0:052 TVD
Reference: Lyons, W. C., Carter, T., and Lapeyrouse, N. J., 2012, Formulas and Calculations for Drilling, Production and
Workover, Third Edition, Gulf Professional Publishing, Page: 4.

2.37 Cost per foot during drilling

Input(s)
C b : Bit Cost ($)
C to : Tool Cost ($)
C m : Mud Cost ($)
T d : Drilling Time (h)
T t : Trip Time (h)
T c : Connection Time and Extras (h)
C r : Rig Rate ($/h)
C s : Support Rate ($/h)
C t : Tool Rental Rate ($/h)
F: Footage (ft/h)
T d : Drilling Time (h)

Output(s)

C d : Cost of Drilling Per Foot ($/h)