equinor Fluid Quality Check
Use this skill to check whether a public fluid composition is well-formed before it is used in examples, notebooks, or NeqSim simulations.
When to Use
- When a task includes a gas, oil, condensate, or synthetic composition table.
- When mole fractions should sum close to 1.0 before simulation.
- When an agent should flag negative fractions, missing required components, water, CO2, or H2S.
- When composition validation must avoid confidential or proprietary data.
Inputs
composition: mapping of component name to mole fraction.required_components: optional sequence of components that must be present.tolerance: acceptable absolute deviation from a total mole fraction of 1.0.
Outputs
total_fraction: sum of all fractions.total_within_tolerance: whether the total is close to 1.0.negative_components: components with negative fractions.missing_components: required components absent from the composition.flagged_components: values for water, CO2, and H2S when present.warnings: human-readable quality messages.is_usable: true only when no blocking quality issue is found.
Engineering Method
The checker performs transparent public data-quality checks only. It does not estimate missing components, tune an equation of state, characterize plus fractions, regress binary interaction parameters, or validate laboratory procedures.
Python Usage Pattern
from fluid_quality_check import FluidQualityChecker
composition = {
"methane": 0.82,
"ethane": 0.08,
"propane": 0.04,
"CO2": 0.03,
"water": 0.03,
}
checker = FluidQualityChecker(required_components=("methane", "ethane", "propane"))
result = checker.check(composition)
print(result.is_usable)
print(result.warnings)
If the optional neqsim Python package is available, the result records that fact so an agent can proceed to NeqSim-specific setup checks. If not, the quality checks still run.
Validation Checklist
- Composition values are finite numbers.
- Sum is within the documented tolerance or a warning is emitted.
- Negative fractions are rejected as blocking issues.
- Required components are present.
- Water, CO2, and H2S are flagged without implying proprietary gas quality rules.
- Examples use synthetic compositions.
Common Mistakes
| Symptom | Cause | Fix |
|---|---|---|
| Total fraction is 100 instead of 1 | Percent values were used as mole fractions | Divide by 100 before checking |
| H2S not flagged | Component name spelling differs | Use a recognizable alias such as H2S or hydrogen sulfide |
| Negative component accepted by spreadsheet | Manual copy/paste error | Run the checker before simulation |
Limitations
- No proprietary fluid validation workflow is included.
- No EOS selection, plus-fraction characterization, or lab data reconciliation is performed.
- Water, CO2, and H2S flags are informational only and are not compliance checks.
- Not a replacement for validated PVT analysis or NeqSim thermodynamic calculations.
Related NeqSim Functionality
This educational screening corresponds to validated, rigorous functionality in the NeqSim Java library that a qualified engineer should use for design-grade work:
neqsim.thermodynamicoperations.ThermodynamicOperations#TPflash()— rigorous phase equilibrium for composition quality checks.neqsim.standards.gasquality.Standard_ISO6976— ISO 6976 calorific value, density, and Wobbe index.
In Python the same classes are reachable through the neqsim package (for example from neqsim import jneqsim).
Related Skills
neqsim-benchmark-reference-data— run after this check. A composition that fails the quality check makes any benchmark meaningless, so this skill gates the benchmark; the benchmark skill then compares the resulting properties against independent reference sources and emits thebenchmark_validationblock.
References
- NeqSim repository: https://github.com/equinor/neqsim
- NeqSim Skills Guide: https://github.com/equinor/neqsim/blob/master/docs/integration/skills_guide.md
- Public thermodynamics and PVT texts for general composition quality principles.