Petroleum Fractional Flow Fw Calculator
Named two-phase mobility fractional flow, explicit independently matched relative permeabilities/viscosities and no gravity/capillary gradient, not actual produced water cut or generic mass fraction. Caller independently verifies units, applicability and matching conditions; no operational recipe, safety certification, causal efficacy or legal/resource classification is inferred.
Description
Two-phase fractional flow under a no-gravity, no-capillary-gradient branch divides each phase mobility by total mobility.
Two-phase fractional flow under a no-gravity, no-capillary-gradient branch divides each phase mobility by total mobility.1
This calculator uses independently matched relative permeabilities and viscosities rather than treating a supplied saturation as flow fraction.
When to use Petroleum Fractional Flow Fw Calculator
Use this tool when you need to calculate the stated measurement summary or conditional model from matched observations. Prepare completed matched measurements, SI or explicitly stated oilfield units, and independent evidence for the selected branch or calibration.
How to use Petroleum Fractional Flow Fw Calculator and understand its results
- Prepare completed matched measurements, SI or explicitly stated oilfield units, and independent evidence for the selected branch or calibration.
- Enter callerMatchedWaterRelativePermeability, callerMatchedOilRelativePermeability, observedWaterViscosityPaSeconds, observedOilViscosityPaSeconds, callerNoGravityCapillaryFractionalFlowBranchVerified, following the field table and calculation rules below, then run the tool.
- Read modelWaterFractionalFlow, modelOilFractionalFlow. For result objects, inspect the nested output fields below, including any missing evidence or selected indices.
- Correct any input issues and run again. Before using a successful result, review its units, signs, evidence coverage, and stated model or reference assumptions.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| callerMatchedWaterRelativePermeability | Caller matched water relative permeability | number | Required |
| callerMatchedOilRelativePermeability | Caller matched oil relative permeability | number | Required |
| observedWaterViscosityPaSeconds | Observed water viscosity pa seconds | number | Required |
| observedOilViscosityPaSeconds | Observed oil viscosity pa seconds | number | Required |
| callerNoGravityCapillaryFractionalFlowBranchVerified | Caller no gravity capillary fractional flow branch verified | boolean | Required |
Require positive viscosities and relative permeabilities in [0,1], at least one phase mobility positive, and callerNoGravityCapillaryFractionalFlowBranchVerified=true. Compute water and oil kr/μ and divide each by their sum; the outputs sum to one within numerical precision.
fw=(krw/μw)/(krw/μw+kro/μo); fo=1−fw Read these symbols with the field meanings and branch or reference rules above.
| Output field | Meaning | Value type |
|---|---|---|
| modelWaterFractionalFlow | Model water fractional flow | number |
| modelOilFractionalFlow | Model oil fractional flow | number |
{
"input": {
"callerMatchedWaterRelativePermeability": 0.2,
"callerMatchedOilRelativePermeability": 0.8,
"observedWaterViscosityPaSeconds": 1,
"observedOilViscosityPaSeconds": 2,
"callerNoGravityCapillaryFractionalFlowBranchVerified": true
},
"output": {
"modelWaterFractionalFlow": 0.3333333333333333,
"modelOilFractionalFlow": 0.6666666666666666
}
}Limitations and assumptions
Measurements, unit conventions, branch identity, and model applicability must be independently established. The result does not infer a complete reservoir or flow model, operational settings, or a reserve classification.
Missing required fields, unknown fields, wrong types, and violated calculation rules return input issues. Numeric values must be finite; nonfinite numeric outputs are rejected.
Alternative or Complementary methods
For a related task, use Petroleum Mobility Ratio Calculator: Mobility combines relative permeability and viscosity under a matched displacement-front basis. This calculator compares the displacing phase’s mobility with that of the displaced phase rather than using viscosity ratio alone. For a complementary step, use Petroleum Buckley Leverett Velocity Calculator: Buckley–Leverett characteristic speed uses the derivative of fractional flow with respect to saturation scaled by Darcy flux over porosity. This calculator returns adjacent discrete characteristic speeds rather than choosing a shock or predicting breakthrough automatically.
References
-
Petroleum Fractional Flow Fw Calculator — tool.io
Similar or alternative tools
- Petroleum Mobility Ratio Calculator
Mobility combines relative permeability and viscosity under a matched displacement-front basis. This calculator compares the displacing phase’s mobility with that of the displaced phase rather than using viscosity ratio alone.
- Petroleum Buckley Leverett Velocity Calculator
Buckley–Leverett characteristic speed uses the derivative of fractional flow with respect to saturation scaled by Darcy flux over porosity. This calculator returns adjacent discrete characteristic speeds rather than choosing a shock or predicting breakthrough automatically.