Mahdi Khishvand - Amirkabir University ofTchnology
Ehsan Khamehchi

One of the most challenging problems in production operations is gas lift allocation optimization to the wells in such a way that maximizes total oil production benefit of thefield. In literature, this problem is solved in different ways without considering all real constraints. Also, in practice oil price is not acertain parameter. Therefore, present study describes a nonlinear programming approach to maximize daily cash flow of some gas-lifted wellsin an uncertain condition for oil price. Firstly, solution points of each well are obtained by employing a production simulation software and asurrogate model is developed for gas lift performance in each well by use of nonlinear optimization. Then these functions are used to develop a model under capacity, pressure andother real constraints for the production cash flow. Oil price is assumed as a triangle risk function in this model. Results show a significantincrease in cash flow in comparison with old case due to appropriate gas injection parameters. Sensitivity analysis on this problem shows that oilprice, compression cost and water oil ratio variations should be considered in the long-term optimization.

injection rate; gas lift performance curve; Monte Carlo simulation; nonlinear programming; risk optimization