Optimization Study Of Oil Gathering And Transferring Process By Double Pipes Reinjecting Water In Wellblock Ji-7 Of Changji Oilfield

The reservoir in Wellblock Ji-7 of Changji Oilfield is general viscous oil,using double pipes reinjecting hot water process to gather and transfer oil.The problems in oilfield are high water reinjecting quantity,long time crude oil dehydrating,high energy consumption and so on.In view of the technical characteristics,this paper suggests Wellblock Ji-7 adopt“Keep the water’s temperature constant,reduce the water’s content”to optimize the reinjecting water system.Firstly,this paper tests the properties of crude oil and water in oil emulsion.Secondly,it makes plenty of PIPEPHASE simulations for the gathering line network.Combining with the measured oil well back pressure and the results of the reducing mixed water test,it filters out MB formula.Revising the values of the total heat transfer coefficient to increase hydraulic simulation’s accuracy,it filters out the hydraulicthermal simulation model that is suitable for Wellblock Ji-7.The simulation model’s average absolute value of relative error is 15% and the absolute average error is 0.05 MPa.Afterwards,this paper studies the effects of different reinjecting water content on the wellhead back pressure,the inlet temperature of central gathering station and the energy consumption of the phase changeable boiler.At last,on the basis of the research findings above and the development index’s production datas,it simulates the gathering line network at the development index’s condition,minimum reinjectingn water quantity condition and the non-reinjecting water condition to forecast the non-reinjecting water’s time and propose an optimized scheme for reinjecting water in 2016~2021.This paper finds out that under the optimized plan,the phase changeable boiler less consumes about 1300 cubic metres natural gas per day(saving one million three hundred and seventy thousand RMB per year)than the development plan,providing a theoretical basis for Wellblock Ji-7 that operates at the low reinjecting water content and low energy consumption condition in the further.