A New Method to Experimentally Investigate Local Pressure Loss of Oil-Water Two-Phase Flow through Pore Throats

Abstract

To investigate the resistance performance of pore throats in porous media, a new method was used to conduct experiments to indirectly measure the local pressure loss of single-phase water and oil- water two-phase flow through pore-throat structures. Four microchannels were designed and manufactured with MEMS technology. One of the four microchannels is a straight duct with no throat and each of the other three has one throat within the passage. By comparison of total pressure drops between the straight duct with no throat and the channel with a throat at the same flow rate, the local pressure loss over a pore- throat structure can be determined. In this paper, the pore-throat structure is defined as a combination of a contraction, an expansion and a throat to stimulate the pore throat in porous media. Experimental results show that local pressure loss, nonlinear with the flow rate, grows up with the decrease of throat size and the increase of oil volume fraction. Local loss coefficient, characterizing the local resistance performance of pore-throat structure, diminishes with the increase of Reynolds number. Reynolds number (in throat part) is in the range of 100-1100. A new empirical correlation of local loss coefficient is proposed for single-phase water and oil-water two-phase flow through pore-throat structure.