Pipe flow experiments for the analysis of two-phase liquid-liquid pressure drop in horizontal wells

Recently, there has been a great deal of interest in the importance of wellbore pressure drop in horizontal wells. The pressure drop is important in horizontal well performance in certain situations, including low drawdown, overlying gas and/or underlying water zones, etc. Several contemporary studies have dealt with numerical or analytical solutions to the problem of determining wellbore pressure drop for single-phase wellbore flow. At the same time, ever increasingly sophisticated multiphase pipe flow models are being developed.;This study examines for the first time the effect of influx into a two-phase flow system, as occurs in many horizontal wells. The purpose of the present research was to analyze the pressure drop behaviour of two-phase oil-water flow in a physical pipe model with influx. A close-loop pipe flow model was designed and constructed for the purpose of these experiments. Varying turbulent oil-water pipe flow and influx flow rates were generated using the apparatus, with the experiments recorded using photographic and video equipment. Comparative modeling of the experimental pressure drop and holdup data was performed using a recent and widely accepted pipe flow correlation model. A pipe flow correlation method was developed for analysis of oil-water flows. The significance of the influx disturbance with respect to wellbore pressure drop was examined. An analysis of the experimental results leads to the adaptation and development of field-scale predictive models for horizontal wellbore pressure drop and specific inflow profile.;Based on the experimental results, it is concluded that: the pipe flow correlation method examined provides adequate pressure gradient predictions for oil-water flows; and accelerational model of pressure drop across a single perforation is inadequate in its prediction capability; and at sufficiently high perforation-to-axial flow velocity ratios, the dominant factor determining the pressure drop across a single perforation is a constriction-disruption, or venturi-type effect.