Phase Behavior and ThermodynamicsFluid Properties
Formation Water Salinity from Density Formula
Formation Water Salinity from Density calculates water salinity or solids concentration for fluid properties workflows in phase behavior and thermodynamics.
How engineers use this formula
Use this formula when the listed inputs (SG_w) 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, C_mg_l equals 74,289.32 mg/L.
SG_wdimensionless
1.0476
Inputs
SG_w
dimensionlessFormation Water Specific Gravity
Outputs
C_mg_l
mg/L
Water Salinity or Solids Concentration
SG_w
dimensionless
Formation Water Specific Gravity
C_ppm
ppm
Water Salinity
C_wt
wt%
Water Salinity
Source and review
reviewedWater salinity from density equation, McCain, W.D. Jr., Pengtools
McCain, W.D. Jr. 1990. Properties of Petroleum Fluids; Pengtools Water Salinity from Density Equation.
Source