Effect Of Scaling On Injection Pressure In Injection Wells

Water injection is an important method for oilfields to increase production,stable yields,and enhance oil recovery.It is widely used in major oil fields in the world.However,in the process of water injection,scaling occurs in the tubing,faucets and formations,which leads to increased pressure loss in the tubing,faucets and stratum.The injection well pressure increases,water injection capacity decreases,and the dynamic analysis of water injection is difficult.In view of the current lack of systematic studies on the scaling of oil pipes,spouts,and formations during waterflooding,this paper presents the different waterflooding stages,water quality,and flow rates based on the dynamic scaling experiments and the relationship between the measured scale and flow rate and temperature.The method of calculating the scale in the tubing,spout and formation of the injection well under temperature conditions,and then the calculation method of the injection pressure of the injection well after scaling is given,and a calculation procedure for the injection pressure of the injection well after scaling is prepared using C#.It can be used to calculate and analyze the scaling,pressure loss and water injection pressure at different nodes of injection wells.The simulation results show that the scaling of injection wells can significantly increase the pressure of water injection.After five years of water injection,the injection pressure can be increased to more than three times.The increase in scale and pressure in injection wells is mainly affected by the composition of water,temperature,pH,and temperature.In the case of the scaling effect on the water injection well pressure in the water injection well,the temperature increase of 10°C may increase the injection pressure by more than 8%;the pH changes from 5.6 to 8 and the injection pressure may decrease by 6.5%;When the water injection rate rises from 150m~3/d to 200m~3/d,the pressure loss decreases by 16%;the ion concentration in the injected water decreases by 40%,and the injection pressure decreases by 6%.