Page 114 - Formulas and Calculations for Petroleum Engineering

Drilling engineering formulas and calculations Chapter 2 107

Formula(s)

k b f
f
F ¼
CD
k x
f
k b f
f
r ¼ 0:2807
w
k
Notes: r w is valid if F CD <0.1.
Reference: Joshi, S. D. 1991, Horizontal Well Technology. Tulsa, Oklahoma:PennWell Publishing Company. Chapter: 5,
Page: 135.

2.75 Effective wellbore radius in infinite-conductivity fractures

Input(s)
x f : Fracture Half Length (ft)
L: Total Fracture Length (ft)

Output(s)

r w : Effective Wellbore Radius (ft)
r w : Effective Wellbore Radius (ft)

Formula(s)

L
r ¼
w
4
x f
r ¼
w
2
Notes: Check Validity, for x f <¼ 0:30where x e is Half Length of a Side of a Drainage Area Square.
x e
Reference: Joshi, S. D. 1991, Horizontal Well Technology. Tulsa, Oklahoma: PennWell Publishing Company. Chapter:5,
Page: 134.

2.76 Efficiency of block and tackle system
Input(s)

F h : Load Hoisted (lb)
v t : Traveling Block Velocity (fpm)
F f : Load in Fast Line (lb)
v f : Fast Line Speed (fpm)

Output(s)
E: Efficiency (fraction)