Design, Development and First Operation of a New Redirected Gas Lift Mandrel

Abstract

Abstract Traditionally in oil production wells that employ gas lift as an artificial lift method, the injection of lift gas is commonly performed from the annular space to the interior of the production tubing string, at a downward oriented angle (in the opposite direction to the fluid flow delivered by the reservoir). The downward gas jet causes turbulence in the flow due to the sudden changes in flow direction, precisely at the location of the gas lift mandrel, which results in a localized additional pressure drop. Optimization of the geometry responsible for the gas injection into the production tubing string consisting of changing the lift gas injection angle is a strategy aimed at achieving production gains by reducing the localized pressure drop. Theoretical mathematical analysis applied to this fluid flow problem, along with computational simulations and experimental execution, showed that, for high gas injection flow rates and/or the adoption of small diameters of the injected gas jet, it is possible to obtain a production gain at a relatively low cost by reversing the direction of lift gas injection. This paper briefly explains the process of conception, development, qualification and prototype operation of the redirected gas lift mandrel.