AN IMPROVED METHOD FOR GAS LIFT ALLOCATION OPTIMIZATION

A new method for finding the optimum gas injection rates for a group o f continuous gas lift wells to maximize the total oil production rate is established. The new method uses a quasi-Newton nonlinear optimizat ion technique which is incorporated with the gradient projection metho d. The method is capable of accommodating restrictions to the gas inje ction rates. The only requirement for fast convergence is that a reaso nable estimate of the gas injection rates must be supplied as an initi al point to the optimization method. A method of estimating the gas in jection rates is developed for that purpose. A computer program is dev eloped capable of implementing the new optimization method as well as generating the initial estimate of the gas injection rates. This progr am is then successfully tested on field data under both unlimited and limited gas supply. The new optimization technique demonstrates superi or performance, faster convergence, and greater application.