Kermit F. Brown, Dept. of Petroleum Engineering, University of Texas; Carlos Canalizo, Otis Engineering Corp.
The proper design of a continuous flow gas lift installation depends on accurate well data. In many instances, gas lift installations are made with a complete lack of vital well information. For this reason a flowing pressure survey is beneficial after the first installation in order to allow a correct respecting of the valves. In many instances, however, good has lift installations have resulted even with a minimum amount of well information. It is generally conceded that the most important factor in continuous flow design is the determination of the correct point of gas injection. Past well performance has shown that the lower the gas injection point, the lower the injection gas-oil ratio. The principal governing factors in design are (a) the available injection gas pressure and volume, (b) the wellhead tubing back pressure, (c) the flowing bottom hole pressure, (c) the flowing bottom hole pressure, (d) the well fluids, which include oil, gas, and water, and (e) the size and depth of the educator tube.