Pressure gradient correlations analysis for liquid-liquid flow in horizontal pipes

Oil-water flow commonly occurs in the production system. All models and correlations for pressure gradient presented in the literature have been developed and validated for a restricted set of data. In this study, a physical and statistical analysis of pressure gradient models and correlations are presented. A data base of 2132 points has been collected from the literature. Two pressure gradient models for stratified flow and one for semi dispersed and dispersed flow, are evaluated, with thirty-seven friction factors and twenty-one mixture viscosities correlations. The results showed, combinations with average errors between twenty-six and sixty-seven percent, depending on flow pattern (ST, ST&MI, Do/w & w, Do/w, Dw/o, Dw/o & Do/w). A nonlinear fitting for each combination of semi dispersed and dispersed patterns was also made to improve the response of the models. The pressure gradient models that take into account interfacial properties were found to work better in the case of stratified flows. For dispersed and semi dispersed flows, all models perform better for water continuous patterns than oil continuous.