AutoBoost and Gas Lift System

Abstract

Abstract This paper will describe a new surface boosting system AutoBooST® used as an artificial lift, it can be defined also as a surface auto gas lift system, fully automated and self-powered with real time monitoring and optimization of well production. Sonatrach and Expro Gulf with its partner Innovative Production Services (IPS) have introduced this technology in Hassi Messaoud field to increase oil production from the low wellhead pressure wells located away from the central facility where gas lift network is already deployed, as well as the remote fields. AutoBooST® operating principle is to separate the oil, water and gas at well level and re inject the separated gas into the well hence it is a system using the well associated gas as a gas lift and fuel gas of the unit which makes the unit fully autonomous with no external gas source nor energy requirement as the unit generates the necessary power to run all the utilities. Produced gas is recycled in a closed loop, therefore gas will be accumulated along with the operation and provides a wide range of gas rate to perform optimization of the gas lift injection parameters versus the produced oil. During the optimization or once optimum rate is set the excess of gas is diverted to the export line via an automated control valve. For down hole part, two options were used for the gas injection point either down hole circulating device SSD or SPM to allow gas lift injection from annulus to production tubing_ unloading valves are not required since compressor discharge pressure can reach 160 bars_ or run concentric tubing 1.66 inside the production tubing as velocity string. AutoBooST® application was very successful and gave an increase of production from 50% to 150%, particularly at well HMD-A with an increase from 2m3/h (301 bpd) @ Qginj = 0m3/d to 11 m3/h (1658bpd) @ Qginj = 23000 m3/d during the optimization phase then the well was set to produce at 6 m3/h (904 bpd) considering reservoir management aspects. As in conventional gas lift the production increase depends mainly on the well and reservoir parameters hence candidate well selection is the key factor. AutoBooST® application was already extended to target two to three wells with one package knowing that a current unit max compression capacity is 25000 to 40000 m3/d which is prone to improvement, however it is possible to use several units at manifold level to cover a large number of wells which will make a remote mini gas lift station. AutoBooST® is proven successful technology; it is an ideal solution for remote wells and fields. In addition to the production application it can be used to evaluate the gas lift conventional project prior to major investment decision.