Evaluating the Effect of Surface Tension on Two-Phase Flow in Horizontal Pipes

Abstract

Abstract Two phase gas/liquid flow in pipes is common occurrence in the petroleum, chemical, nuclear and geothermal industry. In the petroleum industry, it is encountered in the production, transportation and processing of hydrocarbon from oil and gas field. In designing these systems, accurate prediction of pressure drop is imperative which is determine from flow pattern and flow regime map. Unfortunately, most of the flow regime maps were developed for air-water system and widely used for the oil/gas system. In spite of the practical importance the general applicability of these maps is not addressed. In order to improve generality of flow regime maps it is necessary to evaluate the effect of surface tension which differ by great magnitude (air/water = 72 dyne/cm and gas/oil = 35 dyne/cm) on flow regime map. Thus, this study aims to evaluate the effect of surface tension on the flow regime map and address its application. A number of flow regime maps in the area of gas-liquid flow in horizontal pipes have been developed. Further, to formulate the flow regime maps, some mapping parameters and dimensionless groups are used as coordinates. To generalize the applicability of the flow regime maps, combination of parameters and dimensionless number are used. Therefore, to generate these maps lots of experimental data is required and usually it is not feasible to evaluate the effect of each individual parameter (density, viscosity, surface tension, pipe size or geometry) on the flow regime map. The objective of this study is to evaluate the effect of surface tension on flow regimes in horizontal pipe for air water system. The experiments were carried out with two phase water-air system to evaluate the effect of surface tension. The effect of surface tension has been introduced by reducing the surface tension with the aid of surfactant. The experimental data was utilized to generate flow pattern map and the effect of surface tension was evaluated based on the variation in the boundaries of different flow patterns. Four different concentrations (0.01, 0.05 0.1, 0.5%) of a surfactant have been selected to evaluate the effect of the surface on the boundaries of different flow patterns.