Comprehensive Treatise on Shut-in and Restart of Waxy Oil Pipelines

Abstract

A conservative analytical method is presented to provide reliable predictions for waxy oil pipeline shut-in and restart. A comprehensive bench-top characterization regimen establishes in situ gel properties, utilizing thermodynamic modeling, differential scanning calorimetry, and rheometry to forecast the wax-gel mechanical response. For flow commencement modeling, pressure wave propagation simulators have recently emerged with correct predictions for the acoustic, viscous, and gel degradation regimes. Scaling analysis shows that the viscous wave is determinative for achieving timely restart in long pipelines. The informed rheology serves as a useful input to simulate restart flows. For gelation and shut-in flow predictions, a heuristic approach is currently recommended.

Keywords:

• Paraffin wax
• pipeline restart
• pipeline shut-in
• pressure wave propagation
• rheology

ACKNOWLEDGMENTS

K. G. Paso acknowledges Olav Sendstad, Peter Borg, Olaf Skjæraasen, and Karin Hald at the Institute for Energy Technology (IFE) in Kjeller, Norway. The IFE report “Literature survey for shutdown and restart of pipelines with waxy crude” served as a precursor for the current publication.

Notes

Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/ldis.