Gas Produced by Gas Expansion Formula
Gas Produced by Gas Expansion calculates gas produced by gas expansion for material balance and production workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (A, h, phi, S_wi, B_g, B_gi) are known and the assumptions behind the cited material balance and production relationship match the engineering case being checked.
Assumptions
- Input values are representative for the well, reservoir, fluid, or equipment case being evaluated.
- The declared units match the field-unit constants used in the formula.
- The cited formula applies to the selected petroleum engineering workflow.
Limitations
- The calculation does not replace a full engineering model or operating procedure.
- Accuracy depends on the source correlation, assumptions, input quality, and unit consistency.
Common mistakes
- Mixing unit systems without converting the inputs.
- Using default example values as field recommendations.
- Applying the formula outside the source assumptions.
Default example
Using the default inputs, G_p equals 2,613,600,000 SCF.
160
50
0.2
0.25
0.005
0.004
Inputs
A
acreDrainage Area
h
ftReservoir Thickness
phi
fractionPorosity
S_wi
fractionInitial Water Saturation
B_g
ft3/SCFCurrent Gas Formation Volume Factor
B_gi
ft3/SCFInitial Gas Formation Volume Factor
Outputs
G_p
Gas Produced by Gas Expansion
A
Drainage Area
h
Reservoir Thickness
phi
Porosity
S_wi
Initial Water Saturation
B_g
Current Gas Formation Volume Factor
B_gi
Initial Gas Formation Volume Factor
Source and review
reviewedAdvanced Reservoir Engineering, Ahmed, T., McKinney, P. D. (2005)
Ahmed, T. and McKinney, P. D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter 3, Page 202.
Source