Screening And Deployment Optimization Of Deep Control And Flooding Technologies In Long-Term Water-Flooding Sandstone Reservoirs

E oilfield is a long-term water-driven sandstone reservoir with high porosity and high permeability.It is in the period of ultra-high water cut development,so it is urgent to control water cut rise.However,E oilfield has high salinity,calcium and magnesium ion and iron ion content,leading to poor profile control effect of polymer flooding and chrome gel.Therefore,it is necessary to screen effective deep profile control and flooding technology.In addition,different levels of channeling channels are developed in E oilfield reservoir,and the characteristics of channeling channels at all levels are quite different,so the effect of single regulation and flooding system is poor.Firstly,by studying the characteristics of channeling channel and formation water environment in E oilfield test area,this thesis proposed the concept of enhanced oil recovery based on stage adjustment and flooding:(1)Screening the low-temperature salt-resistant iron-resistant p Henolic crosslinked polymer gel system to seal the channeling;(2)Screening inorganic microgel-polymer composite gel particle system for deep modulated flooding.In terms of gel system,salt-resistant polymer and organic p Henolic crosslinking agent system were screened.Sodium carbonate,which can react to remove iron ions,was added,and the concentration of each component of gel system was optimized.Finally,the plugging performance of gel system with or without iron ions stabilizer was evaluated based on sandstone core filling.The results show that the plugging ability of the gel system with sodium carbonate is much higher than that of the gel system without sodium carbonate.For the composite gel particle modulated flooding system,firstly,the reaction principle of inorganic microgel and composite gel particle modulated flooding system was defined,and then the mechanism of action of the system was studied.It was found that when the concentration ratio of OMGL to Ca Cl2 was 1:1,the amount of inorganic microgel was the largest.OMGL solution is alkaline;The formed inorganic microgel has the function of wetting modification.Then,the concentration of inorganic microgel and composite gel particle system was optimized.Based on the formation water of E oilfield,the optimal concentration of OMGL was 1.5% and the optimal concentration of polymer was 0.06%.Finally,the performance evaluation of polymer,inorganic microgel system and composite gel particle system was carried out.The results showed that compared with polymer flooding,inorganic microgel system flooding could improve the oil recovery by 10.34%,composite gel large particle system flooding could improve the oil recovery by 14.94%compared with inorganic microgel flooding,and compared with polymer flooding,it could improve the oil recovery by 25.29%.Finally,the CMG STARS chemical flooding module was used to optimize the grading adjustment and flooding scheme of well group2655.On the basis of characterizing the two p Harmaceutical systems,sensitivity analysis and orthogonal test were used to optimize the injection parameters of the two p Harmaceutical systems of well group 2655.The comparative tests of water flooding,polymer flooding,profile control,post-profile control polymer flooding and deep profile control flooding were set up,and the results showed that the deep profile control flooding accumulated the most oil and had a good development effect.