Experimental Study On Oil Displacement Of New Nano-micron Biomass Composites

Due to the increasing difficulty in the exploitation of old and low permeability oilfields,the effect of traditional chemicals actually is unsatisfactory.There is an urgent need to develop suitable chemicals to improve oil recovery.In this paper,a new composites is made by mechanical and chemical activation of biomass.In this paper,biomass particles are used as raw materials,and the particle size is micron level after mechanical activation.After adding activator,the particles further shorten and a new system is formed.The system consists of three parts.The first part is a composite gel mainly composed of nano-micron biomass after mechanical activation;the second part is a composite gel mainly composed of low-molecular and macromolecule.The third part is a solution with low and ultra-low interfacial activity based on lignin.The gel is found to be irregular,composed of cellulose and SiO₂,and particles are wrapped in gel.The solution is rich in lignin active agent,which has the characteristics of low surface tension and low interfacial tension.I The system not only has the characteristics of temperature resistance and salt resistance,but also can improve the sweep volume and improve the displacement efficiency.Under the condition of homogeneity,the effects of the concentration ratio,injection rate,injection volume and rock permeability on oil recovery are studied,and the optimal parameters of profile control and flooding are selected.The optimal concentration is 4%main agent with 5%activator,injection rate is 0.5ml/min,injection volume is 0.7PV,and the recovery of medium and high permeability rock is better.The cores in series connection and parallel connection are used to simulate the heterogeneous conditions,and the recovery of the system under the heterogeneous conditions is studied.It is found that when the cores are in series connection,the recovery of series connection from high permeability to low permeability is higher.When the cores are in parallel connection,the recovery of high permeability core is increased by 20%-27%,and that of low permeability core is increased by16-19%.It shows that the composites can significantly improve oil recovery.