Sand Erosion Screening

Educational screening of solids (sand) erosion for production and flowline piping. The skill estimates an erosional-velocity ratio, a simplified sand erosion rate, the cumulative wall loss over a design life, the remaining wall thickness, and a remaining-life indicator. It is a public, screening-level placeholder for learning and workflow scaffolding only — it does not implement the validated DNV RP O501 erosion model.

When to Use

• Early sand-management screening when a sand production rate is known or assumed.
• Triaging whether a solids-bearing line warrants a detailed DNV RP O501 erosion study.
• Teaching the link between sand rate, flow velocity, and remaining wall life.
• Building agent or notebook scaffolding before validated erosion calculations.

Do not use this skill for design, fitness-for-service, integrity, or sand-rate allowable decisions. Use the validated NeqSim ErosionPredictionCalculator (DNV RP O501) and qualified engineering review for those.

Inputs

Outputs

Engineering Method

1. Erosional velocity is estimated from the public API RP 14E form Ve = C / sqrt(rho), with the SI continuous-service constant near 122.
2. The velocity ratio compares the flowing velocity to the erosional velocity.

3. A transparent screening proportionality estimates the sand erosion rate:

   $$ \dot{e} = k , f_\mathrm{mat} , \frac{\dot{m}_\mathrm{sand} , v^2}{D^2} $$

   where $k$ is a public screening coefficient (not a DNV RP O501 constant), $f_\mathrm{mat}$ is a material factor, $\dot{m}_\mathrm{sand}$ is the sand rate, $v$ the velocity, and $D$ the pipe diameter.

4. Cumulative erosion is the erosion rate times the design life; the remaining wall is the usable wall (thickness minus corrosion allowance) minus the cumulative erosion.
5. Remaining life is the usable wall divided by the erosion rate.
6. The warning is the more severe of a velocity-ratio band (watch above 0.8, high above 1.0) and a remaining-life band (watch below the design life, high below half the design life).

Python Usage Pattern

from sand_erosion_screening import SandErosionModel

result = SandErosionModel().evaluate(
    fluid_velocity=12.0,
    mixture_density=120.0,
    pipe_diameter=0.1524,
    wall_thickness=12.7,
    sand_rate=50.0,
    corrosion_allowance=3.0,
    material_factor=1.0,
    design_life_years=25.0,
)

print(result.erosion_rate_mm_per_yr)
print(result.remaining_wall_mm)
print(result.remaining_life_years)
print(result.erosion_warning)

Validation Checklist

• Mixture density is evaluated at the flowing line pressure and temperature.
• The sand rate reflects a realistic or conservative solids production estimate.
• The corrosion allowance is consistent with the line specification.
• The material factor reflects the actual pipe material.
• Screening results are confirmed with the NeqSim ErosionPredictionCalculator.
• A qualified engineer reviews any integrity or sand-allowable conclusion.

Common Mistakes

Limitations

• No proprietary erosion models, sand-monitoring data, or company integrity specs.
• The erosion coefficient is a transparent public placeholder, not DNV RP O501.
• No particle-size, geometry-specific (elbow, tee, choke), or impact-angle effects.
• No transient, slug, or intermittent sand-burst behaviour is captured.
• Not suitable for safety-critical, design, guarantee, or standards-compliance work.

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.pvtsimulation.flowassurance.ErosionPredictionCalculator — validated API RP 14E and DNV RP O501 erosion model with sand rate, erosion rate, cumulative erosion, remaining wall thickness, and risk level.
• neqsim.process.equipment.pipeline.PipeBeggsAndBrills — rigorous multiphase pressure drop and velocity profile to source the erosional velocity inputs.

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 erosion references such as API RP 14E and DNV RP O501 for general sand-erosion concepts.