Geology Petrophysical Formation Factor Archie Calculator
Independently calibrated Archieformation factorF=aφ^−m, dimensionless interconnected porosity. Not saturation, shaley conductivity model or universal m=2coefficient.
Description
Archie's formation factor relates porosity to calibrated tortuosity and cementation terms.
Archie's formation factor relates porosity to calibrated tortuosity and cementation terms.1
It does not by itself determine water saturation or brine resistivity. Use this tool to calculate the stated observation or conditional model from supplied measurements.
When to use Geology Petrophysical Formation Factor Archie Calculator
Use this tool to calculate the stated observation or conditional model from supplied measurements. Establish the sample and coordinate basis, matching units, calibration source and applicable model assumptions.
How to use Geology Petrophysical Formation Factor Archie Calculator and understand its results
- Establish the sample and coordinate basis, matching units, calibration source and applicable model assumptions.
- Enter actualPorosityFraction, callerFormationTortuosityCoefficient, callerFormationCementationExponent, using the field meanings and rules below, then run the tool.
- Read result.conditionalArchieFormationFactor. Interpret each field using the units, signs and evidence rules below.
- If input validation fails, correct the reported field and run again. Before applying a successful result, check the stated reference scope, units, assumptions and any retained unknown evidence.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| actualPorosityFraction | Actual porosity fraction | number | Required |
| callerFormationTortuosityCoefficient | Caller formation tortuosity coefficient | number | Required |
| callerFormationCementationExponent | Caller formation cementation exponent | number | Required |
Require porosity fraction in (0,1], positive tortuosity coefficient and positive cementation exponent. Return a/porosity^m. No saturation exponent or water resistivity is used.
formationFactor=a/porosityFraction^m Apply the field units and exact ordering, boundary and evidence rules above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Structured result containing the calculation or selected reference fields below | object |
| result.conditionalArchieFormationFactor | Conditional Archie Formation Factor; use the units, sign convention and calculation stated above | number |
{
"input": {
"actualPorosityFraction": 0.5,
"callerFormationTortuosityCoefficient": 1,
"callerFormationCementationExponent": 2
},
"output": {
"result": {
"conditionalArchieFormationFactor": 4
}
}
}Limitations and assumptions
It does not by itself determine water saturation or brine resistivity. Results depend on the independently established measurement basis and the exact model assumptions above.
Every listed input requires an explicit value. Unexpected fields, incorrect value types, nonfinite numbers and sparse numeric arrays fail validation; tool-specific bounds and alignment rules apply as described above. Extremely large inputs or outputs can also be rejected. An input error is distinct from a successful calculation that reports a false comparison or retains unknown evidence.
Alternative or Complementary methods
Use Geology Petrophysical Waxman Smits Water Saturation Calculator to examine a related aspect: Waxman–Smits saturation interpretation accounts for an adopted shaly-formation conductivity model.
Use Geology Petrophysical Shaly Sand Simandoux Water Saturation Calculator where its separate inputs and scope apply: Simandoux saturation interpretation requires a declared conductance model and formation inputs.
References
Similar or alternative tools
- Geology Petrophysical Waxman Smits Water Saturation Calculator
Waxman–Smits saturation interpretation accounts for an adopted shaly-formation conductivity model.
- Geology Petrophysical Shaly Sand Simandoux Water Saturation Calculator
Simandoux saturation interpretation requires a declared conductance model and formation inputs.