Research On Flow Characteristics Of The Oil-gas-water Three-Phase In Vertical Wellbores

The theory of oil-gas-water three-phase flow in vertical wellbores is the significant fundamental theory for choosing artificial lift means and analyzing the production performance of wells. Although the field has plentiful valuable research outcomes, there remains much task waiting being resolved now. Based on study the of research outcomes in association area at home and abroad, by used fluid mechanics theory and experimental study method, the flow mechanism of the oil-gas-water three phase along vertical wellbore is researched. The division method, alternation characteristic and transformation criteria of flow patterns of the oil-gas-water three phase along vertical wellbore are studied. The phase inversion theory and condition of oil-water fluid are searched. Using the double fluid model, the transformation boundary equations of each flow pattern of the oil-gas-water three phase along vertical wellbore have been derived. Calculation formulas of void fraction for the four flow patterns are established. The entire water phase friction pressure gradient, friction pressure gradient, gravitational pressure gradient and total pressure gradient for each flow pattern of oil-gas-water liquid flow in vertical wellbore are calculated by using established model. By using experimental apparatus, used the air, tap water and diesel oil three phase fluid as medium, the relationship between viscosity of oil-water mixture and water cut are researched, comparisons of the solution of each flow patterns using established pressure gradient computational model through are given. Allied calculator procedure is programmed to account example which are used to analyze the affecting factors of void fraction and pressure gradient, for example gas superficial velocity, liquid superficial velocity, water in liquid.