Page 241 - Formulas and Calculations for Petroleum Engineering

234 Formulas and calculations for petroleum engineering

Formula(s)

J
PR ¼
J
sw
Reference: Horizontal Well Technology, Joshi, Page: 46.

4.69 Productivity ratio calculation of a hydraulically-fractured formation

Input(s)
k avgz : Average Permeability of a Hydraulically Fractured Zone (mD)
k F : Permeability of the Fracture (mD)
k: Permeability of the Formation (mD)
h: Formation Thickness (ft)
W: Fracture Thickness (ft)
r e : Drainage Radius of the Well (in.)
r w : Radius of the Well (in.)
r f : Radius of the Fracture (in.)
k avg : Average Permeability of a Hydraulically Fractured Formation (mD)

Output(s)
PR: Productivity Ratio of a Hydraulically Fractured Formation (mD)

Formula(s)

k
avg
PR ¼
k
or,
" #

kh r e
+1 ln
k W f w
k W r
f
PR ¼ !
k h k W r
r
f e f
+1 ln + ln
kh r r
f w
Reference: Saydam, T., (1967). Principles of Hydraulic Fracturing, ARI Publishing Co., Page: 7.
4.70 Pseudo skin factor due to partial penetration (Brons and Marting method)
Input(s)

h p : Perforation interval (ft)
h: Total pay thickness (ft)
kh: Vertical permeability (mD)
kv: Horizontal permeability (mD)
rw: Wellbore diameter (ft)