Subsea Pipeline Wax Deposition Rate Calculator
Model radial temperature gradient, molecular diffusion flux, and paraffin gel layer accumulation rate (mm/day) across subsea crude pipelines.
Thermal & Hydraulic Conditions
Cloud point from cross-polar microscopy
Must be < WAT for deposition
Deposition Rate & Pigging Schedule
Wax Growth Rate:
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Deposition Driving Gradient (dT/dr):
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Days to 10% Cross-Section Loss:
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Recommended Pigging Frequency:
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Wall Shear Stress (τ_w):
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Condition Status:
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Molecular Diffusion Wax Deposition in Subsea Lines
When subsea pipeline inner wall temperature drops below the Wax Appearance Temperature (WAT), heavy n-alkane paraffin molecules ($C_{20} - C_{60}$) precipitate at the cold boundary. A radial concentration gradient forms, causing continuous molecular diffusion of dissolved paraffin from the warm bulk fluid to the cold pipe wall.
Fick’s First Law of Molecular Diffusion Flux
J_wax = -D_m · (dC / dT) · (dT / dr)
Where $D_m$ is the molecular diffusion coefficient, $dC/dT$ is the wax solubility slope, and $dT/dr$ is the radial thermal gradient across the laminar boundary sublayer.