Page 216 - Formulas and Calculations for Petroleum Engineering

Production engineering formulas and calculations Chapter 4 209

Output(s)

w: Average Fracture width at the Wellbore (m)

Formula(s)

πw w
w ¼
4

Reference: Williams, B. B., Gidley, J. L., & Schechter, R. S. (1979). Acidizing fundamentals. Henry L. Doherty Memorial
Fund of AIME, Society of Petroleum Engineers of AIME, Page: 41.

4.11 Average permeability of a hydraulically fractured formation

Input(s)

k avgz : Average Permeability of a Hydraulically Fractured Zone (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.)

Output(s)

k avg : Average Permeability of a Hydraulically Fractured Formation (mD)

Formula(s)

r e
k k ln
avgz r
k avg ¼ ! w
r
r e
f
k ln + k ln
avgz
r r
f w
Reference: Saydam, T., (1967). Principles of Hydraulic Fracturing, ARI Publishing Co., Page: 7.
4.12 Average specific weight of the formation (hydraulic fracturing)

Input(s)
3
γ min : Specific Weight of Minerals (p/cm )
3
γ Liq : Specific Weight of Liquid Phase (p/cm )
Ø: Porosity (fraction)

Output(s)
3
γ formation : Average Specific Weight of the Formation (p/cm )