The Application And Calculation Of Oil-Water Flow Pressure Drop Model With High Water Percentage In Horizontal Pipelines

Flow patterns of oil-water flow with high water percentage in horizontal pipelines are firstly classified in this paper, then criterions for flow pattern transition are established between flow patterns, finally the pressure loss models are developed for each pattern and applied for predicting pipes pressure loss. By investigating internal and external flow pattern experiments of oil-water two phase flow in horizontal pipes, appeared flow patterns are summed up. Moreover, flow patterns with water percentage above 80% are mainly researched. After deeply analyzing descriptions of each flow pattern, the flow pattern classification for oil-water two phase flow with high water percentage in horizontal pipelines is induced, that is, stratified flow, dispersed flow and mixed flow(dispersion of oil in water over a water layer O/W&W). The rheology properties of Daqing crude oil and emulsions are studied in indoor experiment. The rheology regulation is found for crude oil and emulsions. The relationship of oil in water emulsion viscosity vs. water percentage is chiefly researched, for selecting a better viscosity equation to simulate emulsion viscosity with high water percentage. On the base of the above flow patterns with high water percentage, two criterions for flow pattern transition are established for oil-water two phase flow in horizontal pipes. One is criterion for stratified flow stability, which defines the transition boundary from stratified flow to mixed flow. The other is criterion for dispersed flow stability, which defines the transition boundary from mixed flow to dispersed flow. In this study, the pressure loss model of each pattern is established according to consistence equation, momentum equation, fluctuation equations and some experimental equations. Application procedure is programmed according to the above theory models. Changing regulations of flow pattern with different parameters and pressure loss with different patterns are predicted. By comparing the predicted results of the model with the experiment results, the relative error is less than 10%. Therefore, the models could be applied for predicting the pressure drop of oil-water flow with high water percentage in horizontal pipeline.