**Drilling cost per foot** is the total drilling cost per footage drilled. This value is used for evaluating drilling projects, bit performance, drilling performance, etc.

The formula for drilling cost per foot as shown below;

**CT = (B + CR (t + T)) ÷ F**

Where:

CT = drilling cost per foot

B = bit cost

t = drilling time

CR = Rig cost per hour. This number must include all fixed daily cost not just only drilling contractor rate.

T = round trip

F = footage drill

**Example:** Determine the drilling cost per foot (CT) using the following data:

Bit cost (B) = 27,000 $

Drilling time (t) = 50 hours

Rig cost (CR) = $3500/hour

Round trip time (T) = 12 hours

Footage per bit (F) = 5000 ft

CT = (27,000 + 3,500 (50 + 12)) ÷ 5000

CT = 48.8$ per foot

Please find the excel sheet for **calculating drilling cost per foot.**

**Ref books: **Lapeyrouse, N.J., 2002. Formulas and calculations for drilling, production and workover, Boston: Gulf Professional publishing.

Bourgoyne, A.J.T., Chenevert , M.E. & Millheim, K.K., 1986. SPE Textbook Series, Volume 2: Applied Drilling Engineering, Society of Petroleum Engineers.

Mitchell, R.F., Miska, S. & Aadny, B.S., 2011. Fundamentals of drilling engineering, Richardson, TX: Society of Petroleum Engineers.