Page 10 - Formulas and Calculations for Petroleum Engineering

Reservoir engineering formulas and calculations Chapter 1 3

1.149 Volume of gas adsorbed in coalbed methane reservoirs 64 1.156 Water-drive recovery 68
1.150 Volumetric heat capacity of a reservoir 65 1.157 Water expansion term in gas reservoirs 68
1.151 Water breakthrough correlation in vertical 1.158 Water formation volume factor—McCain correlation 68
wells—Bournazel and Jeanson 65 1.159 Water influx—Pot aquifer model 69
1.152 Water breakthrough correlations in vertical 1.160 Water influx constant for the van Everdingen
wells—Sobocinski and Cornelius 66 and Hurst unsteady-state model 69
1.153 Water content of sour gas 66 1.161 Water two-phase formation volume factor 70
1.154 Water cut—Stiles 67 1.162 Waxman and smits model—Clean sands 70
1.155 Water-drive index for gas reservoirs 67 1.163 Welge extension—Fractional flow 70

1.1 API gravity

Input(s)
SG o : Specific Gravity of Oil Phase (fraction)

Output(s)

API: API Gravity (dimensionless)

Formula(s)

141:5
API ¼ 131:5
SG o

r oil
Notes: SG ¼ at 60 F.
o
r water
Reference: Wikipedia.org.

1.2 Average permeability for linear flow—Layered beds

Input(s)
k 1 : Permeability for Layer 1 (mD)
k 2 : Permeability for Layer 2 (mD)
k 3 : Permeability for Layer 3 (mD)
2
A 1 : Area of Layer 1 (ft )
2
A 2 : Area of Layer 2 (ft )
2
A 3 : Area of Layer 3 (ft )
Output(s)
k avg : Average Permeability in Linear Systems when there is no crossflow between layers (mD)

Formula(s)
k A + k A + k A 3
1
2
2
1
3
k ¼
avg
A + A + A 3
2
1
Reference: Ahmed, T. (2006). Reservoir Engineering Handbook. Elsevier, Page: 238.