Integrated development optimization model and its solving method of multiple gas fields

To optimize production schedule and production plan of multiple gas fields with certain amount of investment and constraints and to maximize their economic benefits under the production sharing contact (PSC) mode, a quantitative relationship was applied to describe the production performance depending on the development status of multiple gas fields in China and abroad. Furthermore, with the PSC-based net present value (NPV) as the objective function, a mixed integer nonlinear programming model for gas fields with optimized production schedule and productivity was established. An adaptive layer-embedded genetic algorithm was proposed to solve this model. Through handling the variables and constraints for solving this model and improving the genetic structure, genetic operators and termination conditions of standard genetic algorithm, modeling and solving techniques were formed for integrated and efficient development of multiple gas fields. Results obtained by three methods, i.e. multi-scheme comparison without mathematical model, standard genetic algorithm which induces penalty function to treat constraints, and adaptive layer-embedded genetic algorithm, were compared. The proposed optimization model is accurate, and the proposed layer-embedded genetic algorithm provides satisfactory convergence and calculation rate, ensuring that multiple gas fields could be exploited orderly.