Real Gas Pseudopressure Derivative Formula
Real Gas Pseudopressure Derivative calculates real gas pseudopressure derivative for gas properties workflows in phase behavior and thermodynamics.
How engineers use this formula
Use this formula when the listed inputs (p, mu_g, z) are known and the assumptions behind the cited gas properties 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, dm_dp equals 352,941.176471 psi/cp.
3000
0.02
0.85
Inputs
p
psiaGas Pressure
mu_g
cpGas Viscosity
z
dimensionlessGas Compressibility Factor
Outputs
dm_dp
Real Gas Pseudopressure Derivative
p
Gas Pressure
mu_g
Gas Viscosity
z
Gas Compressibility Factor
Source and review
reviewedGas permeability measurements from pressure pulse decay laboratory data using pseudo-pressure and pseudo-time transformations, Abdelmalek, B. et al., IHS Harmony
Abdelmalek et al. 2017. Gas permeability measurements from pressure pulse decay laboratory data using pseudo-pressure and pseudo-time transformations; Al-Hussainy et al. 1966 real-gas potential concept.
Source