Development And Application Research Of Nanocellulose Used In Drilling Fluid

High performance drilling fluids under the consideration of the environmental protection laws are required with the focus on the environment aspect.There is a lack of the environmental drilling fluids agents,so they are badly in need.Nanocellulose has many excellent features,such as wide sources,cheap,easily degradation,environment friendly,shear thinning,strong stiffness,special thermal stability,specific surface area.Synthesis method of nanocellulose and the modified nanocellulose were optimized.The application and mechanism of nanocellulose used in drilling fluid were explored in this paper.Orthogonal tests and single factor analysis were used to optimize the preparation conditions of nanocellulose?NXW?and modified nanocellulose?DNXW?.Both of them are used as shear strength improving agent with the fluid loss control ability.DNXW shows the better performance of redispersion than NXW.When pH=7,the average grain diameter of NXW is 65.3 nm and the Zeta potential is-63.7mV;the average grain diameter of DNXW is 101nm and the Zeta potential is-38.3mV.The high Zeta potential makes both of the suspentions of NXW and DNXW in a stable condition.NXW suspention and DNXW can improve the dynamic plastic ratio of drilling fluids amost over 50%.Besides they can reduce the filtration of drilling fluids.Both of them are environment friendly.The results of FT-IR,Zeta potential,size distribution,TEM,SEM,flue curve tests reveal the microcosmic mechanism:when the nanocellulose were distributed in the suspention,the networks were formed by the hydrogen bond and Van der Wals forces.The networks would collapse under the shear stress,bud new networks would occur soon.The dynamic plastic ratio of drilling fluids with the addition of nanocellulose increased dramatically,on the other hand,the apparent viscosity keeps stable.Besides,the micro cracks in the mud cake were plugged by the nanocelluse so that the fluid loss reduce dramatically.An environment friendly drilling fluid based on the optimization of NXW.This drilling fluid shows excellent rheology and inhibition properties with high dynamic plastic ratio.It shows remarkable performance with the pollution of 10%NaCl,1.0%CaCl₂,or 10%cuttings.Another system used in 150?was optimized on the base of this drilling fluid system.