McCain Solution Gas-Water Pressure Derivative Formula
McCain Solution Gas-Water Pressure Derivative calculates brine solution gas-water pressure derivative for fluid properties workflows in phase behavior and thermodynamics.
How engineers use this formula
Use this formula when the listed inputs (P, T, S) are known and the assumptions behind the cited fluid 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, dRsw_dP equals 0.002927 scf/STB/psi.
3000
180
5
Inputs
P
psiaPressure
T
deg FTemperature
S
wt%Salinity
Outputs
dRsw_dP
Brine Solution Gas-Water Pressure Derivative
dRswp_dP
Pure-Water Solution Gas-Water Pressure Derivative
F_s
Brine Gas-Solubility Salinity Correction Factor
B_mccain_rsw
McCain Pure-Water Rsw Coefficient B
C_mccain_rsw
McCain Pure-Water Rsw Coefficient C
Source and review
reviewedFormation Water PVT Properties, McCain, W.D. Jr., Petroleum Office, AAPG Wiki
McCain, W.D. Jr. 1991. Reservoir-Fluid Property Correlations-State of the Art; Petroleum Office Formation Water PVT Properties.
Source