Study On The Simulation And Optimal Control Of Oilfield Water Injection System

Oilfield water injection system is a complex fluid network. As Daqing oilfield has entered its high-water-cut late production stage, the energy consumption of oilfield injection system is getting higher and higher. It is an urgent work to optimize the operation of the water injection system of Daqing oilfield. Integrated simulation, optimization and controlling schemes were proposed in this work on the basis of practical application. Mathematical models for simulating, optimizing and in-line optimal controlling were established. Methods were proposed to simulate the equilibrium joint pressure of water injection network. A strained step-size self-adjusting method and a pattern searching method were proposed for the optimization of water injection network. It was the first time that large capacity frequency regulators were successfully applied in oilfield water injection. Computer controlling techniques were applied in water injection station to ensure the head loss between pumps and pipes are in appropriate ranges. The mathematical model and sofware were checked on Shanan water injection system of Daqing Oilfield. Oilfield test data showed that the mathematical mode and calculation method adopted in this work is well suitable for oilfield water injection system and its calculation precision is enough for industrial application in oilfield production. Significant energy saving results were achieved.