Page 22 - Formulas and Calculations for Petroleum Engineering

Reservoir engineering formulas and calculations Chapter 1 15

Formula(s)

43560
reh ¼ sqrt A
3:14
4 ! !
L reh

a ¼ sqrt :5+ sqrt 0:25 + 2
2 L

kh
b ¼ sqrt
kv
L
2
rwd ¼ reh 0 1
2 ! ! h
L b L
b
1+ sqrt 1 h*
a @ A
2 a 2 rw
Reference: Horizontal Well Technology, Joshi, Page: 90.

1.30 Effective wellbore radius of a horizontal well—Method 1—Isotropic
reservoirs
Input(s)

L: Horizontal Well Length (ft)
h: Pay Zone Thickness (ft)
r w : Wellbore Radius (ft)
k h : Horizontal Permeability (mD)
k v : Vertical Permeability (mD)
A: Drainage Area (acre)

Output(s)
r eh : Effective Drainage Radius (ft)
a: Horizontal wellbore variable from Joshi (dimensionless)
r wd : Effective Wellbore Radius (ft)

Formula(s)

43560
reh ¼ sqrt A
3:14
! !
4
L reh
a ¼ sqrt :5+ sqrt 0:25 + 2
2 L
L
2
rwd ¼ reh
0
! ! h 1
2
L h L
a @ 1+ sqrt 1 A
2 a 2 rw
Reference: Horizontal Well Technology, Joshi, Page: 90.