Reservoir Real-time Optimization With Constraints Based on Variational Theory

• 1、College of Petroleum Engineering in China University of Petroleum(East China)

Abstract：Reservoir production optimization depends on adjusting the output and injection status of reservoirs in order to achieve the maximization of production profit, which is not only a typical optimal control problems but also one of the cores of smart oil field. Reservoir is recognized as a complex dynamic system in this research. A optimal mathematical model of reservoir production is established, which goal is to maximize net present value of production. Combined with maximum principle, the corresponding adjoint model is deduced and solved high-efficiently to obtain optimal production schedule. Because the optimized object here is the development of oil field, it must relate to some constrained conditions such as the boundary limits of a single well and the total injection rate of reservoir block etc. To solve these problems, the article used logarithmic transformation and the average gradient method to realize constrained production optimization. Based on the above theoretical study, applied examples of reservoir are analyzed. The results show optimal production scheme are coincident with the demand of actual field and it will provide a strong theoretical basis and technical support for smart field system.

Keywords： smart field, production optimization, adjoint model, constrained optimization