DOE, University of Tulsa to study pipeline paraffin deposits

The US Energy Department, the University of Tulsa, and 14 private companies plan a $2.5 million study of wax accumulation in deepwater pipelines using a highly instrumented flow loop test facility. Paraffin deposits can restrict the flow of oil and gas liquids from platforms.


The US Energy Department, the University of Tulsa, and 14 private companies plan a study of wax accumulation in deepwater pipelines using a highly instrumented flow loop test facility.

DOE said paraffin deposits in deepwater oil pipelines are a problem for producers because they can restrict the flow of oil and gas liquids from platforms.

It will pay $1.2 million and TU and its partners another $1.3 million to fund the 3-year project.

DOE said most crude oils contain long-chained molecules of wax in proportions that can vary up to as much as 60% of the oil's weight. In refineries, the paraffin wax can be separated and sold as a commercial product. But in a pipeline or a wellbore, especially where in the cold subsea temperatures of the Gulf of Mexico, the paraffin can deposit along the pipe wall. It said removing blockages in water depths of around 400 m can cost $1 million/mile or more.

The TU project will begin by enhancing computer models developed in prior DOE projects. Previous experiments using TU's flow loop testing facilities confirmed that a broader collection of experimental data, including other oil samples, is needed to develop more accurate methods for predicting the complex processes of paraffin deposition.

Researchers will pump a variety of crudes and oil/gas mixtures through the test loop. Using data from these experiments, the existing computer programs will be enhanced and tested against field data.

TU's flow loop could also be used to test and qualify subsea measurement sensors that are being developed to detect deposit thickness in flow lines and pipelines.

DOE said better models and paraffin sensors could reduce pigging and help operators place safety valves to minimize the chances of failures due to paraffin fouling.

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