(32e) High-Viscosity Oil Multiphase Pipe Flow

High-Viscosity Oil Multiphase Pipe Flow

Hong-Quan Zhang, Cem Sarica and Eduardo Pereyra

The University of Tulsa

Heavy
oil, extra heavy oil and bitumen make up about 70% of the world's total oil
resources of 9 to 13 trillion bbls.  Many recent large development projects
have been targeting heavy oil.  The high viscosity of heavy oil poses
great challenges for its production and transportation through wells and pipelines.
 Experimental results show that the high-viscosity oil multiphase flow behavior
is significantly different from the low viscosity oils.  Most of the
available mechanistic multiphase flow models were developed based on low-viscosity
oil experimental results.  When compared with high-viscosity oil data,
these models displayed significant differences.

In
this paper, previous experimental findings on high-viscosity oil multiphase
pipe flow behavior are reviewed and compared with low-viscosity oil
experimental results.  These include flow pattern, pressure gradient, holdups,
slug characteristics, oil/water mixing, core annular flow, gas-lift effect, and
film distribution.  Modeling approaches, such as that of Zhang et al.
(2003) model, are summarized.  Individual closure relationships are analyzed
based on experimental measurements and observations.  These closure
relationships include slug length, slug liquid holdup, slug translational
velocity, interfacial shear, wetted wall fraction, liquid entrainment fraction
in gas core, oil/water dispersion and inversion, emulsion viscosity, etc.  Finally, future experimental needs and modeling issues are
discussed.