Optimization for Production and Operation Plan of Oilfield Gathering and Transportation System at High Water-cut Stage

At present, Daqing Oilfield is experiencing the high water-cut stage, which leads to load drop of surface gathering and transportation system, decrease of system efficiency and year-by-year increase of production cost. In order to achieve the high efficiency, low consumption and maximum profit of the oilfield production, a mathematical model for the optimization of system operation plan is established, wherein the lowest expense of the system production and operation is taken as the objective function, and the wellhead back pressure constraint, the wellhead water blending pressure constraint and the inlet crude oil temperature as the constraint conditions; then based on the structural features of this optimal mathematical model, the sequential quadratic programming method is worked out for the solution. According to the results of on-site application on the oil/gas gathering and transportation pipe network in a certain block, the saving on gas and power consumption for each year are 1.7x106m3 and 45x104kW.h respectively.