Neqsim Wax Margin Check

Wax Margin Check

Use this skill for a quick, public check of whether a process or pipeline operating point keeps a temperature margin above a known wax appearance temperature (WAT). It is intentionally simple and should guide users toward validated NeqSim wax calculations for real work.

When to Use

• When a user asks whether an operating temperature stays clear of the wax deposition region.
• When a validated NeqSim wax appearance temperature or a public lab WAT is already available.
• When an agent should explain that validated NeqSim methods are required for real wax prediction and deposition design.

Inputs

• operating_temperature: operating temperature in C.
• wax_appearance_temperature: wax appearance temperature in C from a validated NeqSim calculation or public lab measurement.
• min_margin: configurable minimum acceptable margin in C (constructor, default 5.0).

Outputs

• wax_margin_c: operating temperature minus the wax appearance temperature in C.
• below_wax_appearance: whether the operating point is at or below the wax appearance temperature.
• margin_warning: ok, watch, or high.
• neqsim_available: whether the optional NeqSim package is importable.
• assumptions: public assumptions and required follow-up.

Engineering Method

The placeholder method computes the wax margin as operating_temperature - wax_appearance_temperature. A non-positive margin means the operating point is at or below the wax appearance temperature and is flagged high. A small positive margin below min_margin is flagged watch. A larger margin is flagged ok.

This is not a wax thermodynamic or deposition model. The wax appearance temperature must come from a validated NeqSim wax calculation or a public lab measurement with a defined fluid composition and operating envelope.

Python Usage Pattern

from wax_margin_check import WaxMarginModel

model = WaxMarginModel(min_margin=5.0)
result = model.evaluate(
    operating_temperature=33.0,
    wax_appearance_temperature=30.0,
)

print(result.wax_margin_c)
print(result.margin_warning)
print(result.assumptions)

If the optional neqsim Python package is available, the result records that fact so an agent can recommend moving to validated NeqSim wax workflows. If not, the example still runs with fallback placeholder logic.

Validation Checklist

• Operating and wax appearance temperatures are finite.
• The wax appearance temperature came from a validated NeqSim calculation or public lab measurement.
• Above-WAT and below-WAT cases are tested.
• The minimum margin is documented as a configurable public guideline only.
• Results are not used as a deposition rate, pigging interval, or operating limit.
• Real wax work is redirected to validated NeqSim methods and qualified review.

Common Mistakes

Limitations

• No wax phase equilibrium or deposition calculation is performed in this skill.
• No composition, shear, ageing, pour-point, or transient effects are included.
• No proprietary wax models or company operating limits are included.
• Not suitable for flow assurance design, pigging strategy, or operating-limit decisions.

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.thermo.system.SystemInterface#addWaxModel() — solid wax-phase characterisation for the fluid.
• neqsim.thermodynamicoperations.ThermodynamicOperations#calcWAT() — rigorous wax appearance temperature.

In Python the same classes are reachable through the neqsim package (for example from neqsim import jneqsim).

References

• NeqSim repository: https://github.com/equinor/neqsim
• NeqSim Skills Guide: https://github.com/equinor/neqsim/blob/master/docs/integration/skills_guide.md
• Public flow assurance literature on wax appearance temperature for background.