Hydrodynamically induced gel breakdown in pipes

Abstract

A new model is reported to describe the dynamics of hydrodynamically induced breakdown of oil gel in pipes. Hitherto, the reported models (Davenport and Somper, 1971;Govier and Fogarasi, 1972; Rao et al. 1985a) cannot predict some observed inherent features of the breakdown process relating to its rates. The present model can predict these desiderata as well as delineate the effects of microscopic parameters such as size and shape of wax crystallites on the dynamics of breakdown. The model is based on a concept that energy imparted to the gelled structures is consumed in the breakdown process. Predictions of this model on breakdown time agree reasonably well with measurements. Important considerations relating to the amount of pressure head required for different diameters of pipe as well as for different dimensions of crystallites are analysed using this model.

The strength of paraffin gels formed under static and flow conditions

“…As noted by Remizov et al (2000), the Casson model describes the nonlinear plastic flow behavior better than the Bingham model, and may therefore be better suited to describe the rheology of waxy oils. Several models have also been proposed to describe the breakdown of wax-oil gels (Ananda Rao et al, 1985;Viswanathan and Khilar, 1989;Sestak et al, 1987;Ronningsen, 1992). Typically in these models an empirical structural parameter, defined by the number of 'links' of the solid crystals in the gel structure, is used to describe the breakdown process.…”