The Effect of Distribution of the Perforation Density on the Production Through Perforated Horizontal Wellbore

Abstract

With depletion of oil reserve around the world, focus has been shifted towards deeper exploration in the field that is difficult to reach. Oil production rate is influenced by perforation density distribution's along horizontal wells, specifically in reservoirs with high permeability and low-pressure drawdown. This study investigated the behaviours of the total pressure drop, mixture’s superficial velocity, void fraction and liquid film thickness that occurs with various flow patterns (i.e., bubble, slug, stratified and stratified wave flows). Two perforation density conditions are studied, namely perforation density increase at outlet and perforation density increase at inlet. The friction factor was fulfilled through the perforated and unperforated horizontal wellbore. Production is greater with a perforated horizontal wellbore than with a smooth (unperforated) horizontal wellbore. The total pressure drop, mixture superficial velocity and void fraction increases with the air superficial velocity when the water superficial was constant. The liquid film thickness decreases when the air superficial velocity increased, while the pressure drops increase with increases of mixture Reynolds number. The liquid and air products increase when the perforation density increases at the inlet section (and decreased at the outlet section) of the perforated horizontal wellbore. It was noted that the air product increased with the air flow rate. Liquid product increases with the bubble flow as the transition point of the bubble/stratified flow decreased. Validation with experimental data, as well as data from other researchers show good agreement, conforming the reliability of the numerical code used in this study. The convergence between the results is good through the patterns (bubble flow, dispersed bubble flow, slug flow, transition bubble/stratified flow, and transition stratified/stratified wave flow).