Pressure Drop In Two-Phase Flow Of A Flashing Fluid

Publication Rights Reserved This paper is to be presented at the 39th Annual Fall Meeting of the Society of Petroleum Engineers on Oct. 11–14, 1964, in Houston, Tex., and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of JOURNAL OF PETROLEUM TECHNOLOGY or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in JOURNAL OF PETROLEUM TECHNOLOGY or SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted on request, providing proper credit is given that publication and the original presentation of the paper. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and considered for publication in one of the two SPE magazines with the paper. Presented are experimental results obtained for pressure drop in a two-phase flow of a flashing fluid. Liquid propane, the flashing fluid, and kerosene were mixed at different pressures and flashed in a one-half inch insulated horizontal copper line 140.3 feet in length. Twenty-six test runs were performed. Initial saturation pressures varied from 35 to 65 psia, and mass flow rates varied from 281 to 412 lb/ft sec. An equation based on a homogeneous model and including the kinetic energy term was developed. The data obtained when using this equation were compared with results obtainable when using the original Lockhart-Martinelli and the University of Houston correlations, as well as modifications of these two equations which included the kinetic energy term. It was observed from the flow tests that the friction factor for a flashing fluid is a function of the position in the line. It is recommended that a two-phase friction factor should be used when computing pressure losses in two-phase flow. Introduction Today more than ever before, there is an intensified need for a reliable method of predicting pressure drop in two-phase flow. Previous investigators have attempted to correlate frictional pressure drop with fluid properties, mass velocities, conduit diameter, and length in two-phase flow. Of these approaches the most widely accepted correlations have utilized the following methods, The Homogeneous Model In this method the two phases are treated as an equivalent single-phase having average properties. Typical of this approach is the work of Bankoff. The Annular Flow Model In this approach the liquid occupies the outer ring and the gas flows as a central core in the conduit. Most noteworthy of this approach is the experimental work of Lockhart and Martinelli and the theoretical approach by Levy.