Office of Technology Transfer – University of Michigan

Wax Deposition Modeling Software for Subsea Pipelines

Technology #6142

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Categories
Researchers
H. Scott Fogler
Managed By
Drew Bennett
Associate Director - Software Licensing 734-615-4004
Publications
A Fundamental Model of Wax Deposition in Subsea Oil Pipelines
AIChE Journal Volume 57, Issue 11, pages 2955–2964, November 2011, 2011
Counterintuitive Effects of the Oil Flow Rate on Wax Deposition
Energy Fuels, 2012, 26 (7), pp 4091–4097, 2012
“Effects of operating conditions on wax deposit carbon number distribution: Theory and Experiment"
Energy Fuels, 2013, 27 (12), pp 7379–7388, 2013

The buildup of wax deposits which occur in deepsea oil transport pipelines can be very costly to the petroleum industry. Wax buildups and blockages can result in decreased production, pipeline shutdown and environmental and safety hazards. In extreme cases, the clogged pipe must be replaced at a cost of $30,000,000 to $100,000,000. The wax deposit is typically removed by “pigging,” using an inspection gauge which is sent into the pipeline to scrape the deposit off of the walls. An appropriate pigging frequency must be used in order to successfully remove build-up.

Wax thickness predictor calculates the correct pigging frequency

The Michigan Wax Predictor model is able to accurately predict the thickness of waxy buildup in the pipeline by solving a series of transport equations which can be tuned to take environmental variations between pipelines into account. Understanding the fluid and wax characteristics in the pipeline allow for the calculation of appropriate pigging frequencies so that the wax buildup can be successfully removed.

Applications

  • Prediction of wax precipitation of crude oil/waxy model mixtures
  • Velocity and temperature profiles in pipeline
  • Wax deposition rate in subsea pipelines
  • Wax content of deposit

Advantages

  • Solves fundamental transport equations
  • Accurate predictions under varied operating conditions
  • Easily tuned to account for precipitation kinetics