Arne Olav Fredheim

Experimental shell-side heat transfer and pressure drop in gas flow for spiral-wound LNG heat exchanger

A test plant has been constructed for measurements of local heat-transfer coefficients and frictional pressure drops on the shell side of spiral-wound LNG heat exchangers. Measurements have been performed with gas flow, liquid film flow and two-phase shear flow. This paper focuses on the measurements and the results from the gas flow measurements. 221 gas flow heat-transfer measurements and 80 gas flow frictional pressure drop measurements have been performed at a Re-number range of 5000-170 000 with nitrogen, methane, ethane and methane/ethane mixture as test fluids.

Phase equilibrium calculations for unprocessed well streams containing hydrate inhibitors

Abstract It is shown that the phase distribution of methanol and water between a hydrocarbon gas phase, a hydrocarbon liquid phase and an aqueous phase can be represented using the Soave-Redlich-Kwong equation with a non-conventional mixing rule for the a -parameter suggested by Huron and Vidal. Model parameters are estimated from data for binaries of the type methanolhydrocarbon and waterhydrocarbon. New experimental data are presented for two reservoir fluids and for one model system. The paper further presents a phase equilibrium algorithm for calculating the phase boundaries and the equilibrium compositions at the phase boundary for a system consisting of a gas, a liquid and a mixed aqueous phase.

Viscosity measurements of water-in-crude-oil emulsions under flowing conditions: A theoretical and practical approach

Abstract The influence of emulsion viscosity on multiphase flow calculations is discussed and illustrated with a simple example. Existing methods for calculation and determination of the effective viscosity of a real hydrocarbon/water system under realistic field conditions have been reviewed and are discussed in relation to their applicability. An experimental method using a high-pressure test wheel for flow simulation is under development for the specific purpose of measuring rheological properties in hydrocarbon gas/water/oil systems under realistic conditions, i.e. pressure, temperature and shear. This method is illustrated by measurements performed on a North Sea crude.