Gas lift optimization and flow instability
type: CreativeWork
description: Gas lift is an artificial lift method used in the oil industry to lift reservoir fluid to the surface, by supplementing the reservoir pressure when it is depleted or insufficient. During oil production, this method can be affected by two-phase (gas-liquid) flow instability within the production tubing, which results in a reduction in the total oil recovered. There are three main flow instabilities caused by, the density wave oscillation, the casing heading pressure and the flow perturbation within the two-phase flow regime. Within this investigation of the flow structure, behaviours and instability of two-phase flow have been investigated experimentally using a high-speed motion imaging with a dedicated processing package “Dynamic studio 2015a” in a vertical transparent pipe (ID: 66 mm, Length: 2 m) thus simulating the prototype sizing of the common artificial gas lift. Numerically a Computational Fluid Dynamics (CFD) models were used with air and water as the working fluids for various cases. The experimental results demonstrated that initial bubble size plays a major role in the development and instability of the upward two-phase flow in the vertical pipe. A new Multiple Nozzle Injection Technique (MNIT) with the aim of reducing initial bubble size and distribution across the simulated vertical column was also utilised, thereby stabilising the gas lift system. Thus the present findings are compared with the current Single Nozzle Injection Technique (SNIT) (or so- called sharp-edge) that are utilised in normal gas lift operation. It has thus been manifested that the new method has the potential to increase the total oil production rate from gas lifted wells. It was found that this new injection technique reduced the overall average bubble size from 7.01 to 5.47 mm and the average overall minimum bubble size from 1.23 to 1.03 mm. The average large bubble size of the Taylor bubble was also reduced from 44.07 to 39.95 mm in the simulated pipe. This perceived to increa…
abstract: Gas lift is an artificial lift method used in the oil industry to lift reservoir fluid to the surface, by supplementing the reservoir pressure when it is depleted or insufficient. During oil production, this method can be affected by two-phase (gas-liquid) flow instability within the production tubing, which results in a reduction in the total oil recovered. There are three main flow instabilities caused by, the density wave oscillation, the casing heading pressure and the flow perturbation within the two-phase flow regime. Within this investigation of the flow structure, behaviours and instability of two-phase flow have been investigated experimentally using a high-speed motion imaging with a dedicated processing package “Dynamic studio 2015a” in a vertical transparent pipe (ID: 66 mm, Length: 2 m) thus simulating the prototype sizing of the common artificial gas lift. Numerically a Computational Fluid Dynamics (CFD) models were used with air and water as the working fluids for various cases. The experimental results demonstrated that initial bubble size plays a major role in the development and instability of the upward two-phase flow in the vertical pipe. A new Multiple Nozzle Injection Technique (MNIT) with the aim of reducing initial bubble size and distribution across the simulated vertical column was also utilised, thereby stabilising the gas lift system. Thus the present findings are compared with the current Single Nozzle Injection Technique (SNIT) (or so- called sharp-edge) that are utilised in normal gas lift operation. It has thus been manifested that the new method has the potential to increase the total oil production rate from gas lifted wells. It was found that this new injection technique reduced the overall average bubble size from 7.01 to 5.47 mm and the average overall minimum bubble size from 1.23 to 1.03 mm. The average large bubble size of the Taylor bubble was also reduced from 44.07 to 39.95 mm in the simulated pipe. This perceived to increa…
author: Elmabrok, KMO
language: en
date published: 2026
date modified: 2026-07-24T04:26:32Z
provider: U. of Salford
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: U. of Salford