Real Gas Pseudopressure Trapezoidal Increment Formula
Real Gas Pseudopressure Trapezoidal Increment calculates real gas pseudopressure increment for gas properties workflows in phase behavior and thermodynamics.
How engineers use this formula
Use this formula when the listed inputs (D_1, D_2, p_1, p_2) 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, Delta_m equals 476,397,966.594045 psi^2/cp.
123456.79012345678
352941.17647058825
1000
3000
Inputs
D_1
psi/cpPseudopressure Derivative at Lower Pressure
D_2
psi/cpPseudopressure Derivative at Upper Pressure
p_1
psiaLower Pressure
p_2
psiaUpper Pressure
Outputs
Delta_m
Real Gas Pseudopressure Increment
p_2
Upper Pressure
p_1
Lower Pressure
D_1
Pseudopressure Derivative at Lower Pressure
D_2
Pseudopressure Derivative at Upper Pressure
Source and review
reviewedGas permeability measurements from pressure pulse decay laboratory data using pseudo-pressure and pseudo-time transformations, Abdelmalek, B. et al.
Abdelmalek et al. 2017 pseudo-pressure definition; trapezoidal quadrature of the endpoint pseudopressure derivatives.
Source