Numerical Simulation Study On Development Characteristics Of Elastic Microsphere Profile Control And Flooding In Offshore Oilfield

In the process of waterflooding development in offshore oil fields,injection well profile control and flooding technology has been widely used in oil fields.It can not only improve the water injection effect,but also reduce the production cost.It is an effective method to improve the oilfield development effect.However,at present,many oilfields have entered the high / special water cut period.It is very difficult to stabilize oil and control water in the development process,and the problems in the development process are becoming more and more complex.In order to solve this problem,various deep profile control and flooding methods have appeared one after another,and certain application results have been achieved.The deep profile control and displacement technology of elastic microspheres used in this paper has attracted extensive attention in recent years.On the basis of literature research,starting from the characteristics of expansion deformation,deep migration and plugging of elastic microspheres,combined with the existing indoor core experiments,this paper carries out numerical simulation research through CMG software.Firstly,the relevant mechanism model is established,and the effectiveness of the model is verified by comparing with the indoor core displacement experiment.Secondly,the sensitivity factors of the mechanism model are analyzed,and the influence laws of different injection parameters on the profile control and flooding effect are obtained.The analysis results show that:(1)with the increase of injection volume,the water cut is generally in a downward trend,which also has an obvious oil increase effect.However,with the increase of injection volume,the injection pressure also increases,which increases the construction difficulty and economic cost;(2)The increase of injection concentration will lead to the increase of injection pressure,the decrease of water content and the increase of oil production.There is an optimal value of injection concentration.When the concentration exceeds a certain value,the oil increase per unit concentration shows a downward trend;(3)There is an optimal value for the injection slug proportion of microspheres with different particle sizes.If the particle size is too small,the microspheres enter the low-permeability layer,which will not only fail to increase oil,but also cause damage to the low-permeability layer.If the particle size is too large,it may lead to pressure holding and injection failure,so it is impossible to take follow-up measures;(4)In the later stage of water injection development,the injection time is early and the oil increase effect is good.Thirdly,combined with the actual reservoir situation and the results of single factor analysis,the orthogonal experimental design is adopted to optimize the injection production parameters in the case of high permeability channel: the earlier the injection time is,the better the injection volume is0.6 PV,the injection concentration is 0.3%,and the injection slug ratio is 2:1.Finally,CMG software is used to simulate the target oilfield,predict and evaluate the effect of profile control and flooding,and provide guidance for the optimization design of injection production parameters in subsequent field expansion tests.