Water Two-phase Horizontal Pipe Flow Pattern

Cocurrent flow of two immiscible liquids such as oil and water in horizontal pipes is a common occurrence in the petroleum industry. Dynamic flow characteristics of oil-water mixtures are of importance and significance in applications and science research. However, the phase of the investigation of oil-water two-phase flow lags far behind the gas-liquid two-phase flow due to its complicated rheological behavior. It has become a obstacle of further research of the multiphase flow, multiphase transportation and multiphase measures. The classification for oil-water flow patterns, the criterion for transition among the several predominant flow patterns and the frictional pressure-gradient prediction models are investigated in this thesis.Emulsion can exhibit Newtonian or non- Newtonian rheological behavior depending on specific oil-water system. The published classification for oil-water flow patterns either was restricted to Newtonian fluids or confused the two different concept in the past. In this study, a new classification for oil-water flow patterns based on published and acquired data is proposed. Umpty flow patterns are identified and classified into two categories: Newtonian flow and non-Newtonian flow.Flow patterns are important for the characteristic of oil-water two-phase flow. The interest on the flow patterns lies on the fact that in each regime the flow has certain hydrodynamic behavior. Some simple methods to identify the different flow patterns such as the flow pattern maps or the classified coefficients of flow pattern can be chose. Nevertheless, with the rapid development of the calculational technology, it's necessary to know the mathematic and physical model of the transition between two different flow patterns when simulate the oil-water two-phase flow numerically. The transition mechanisms between different flow regimes are analyzed and discussed in this thesis. And the criteria on flow pattern transition of stratified flow , dispersed flow and annular flow are gave by analyzing the analytical solution.Pressure drop is another important disquisitive branching in the investigation of oil-water two-phase flow. The pressure-gradient prediction models of stratified flow , dispersed flow and annular flow are presented based on its own flow regimes and characteristic. Meanwhile, the effect and mechanisms of primary influencing factors on the frictional pressure drop are discussed.Moreover, a oil-water two-phase flow program is developed to validate the correctness of the models. Comparison between model predictions and published available experimental data shows satisfactory agreement.