Study On Ternary Copolymer Nanocomposite Plugging Agent,Plugging System And Plugging Performance

China’s deep low-permeability unconventional oil and gas,including shale oil and gas reserves,has become an important target for oil and gas energy development.The cracks and micro-cracks of this type of reservoir,especially the sealing of micron-sized cracks in diameter,are one of the important factors determining the efficiency of mining.It is urgent to study the effective sealing technology.Therefore,this paper has designed a drilling fluid compounding system composed of polypropylene nanocomposite ultrashort fiber and functional polymer nanocomposite microspheres.The short fiber skeleton and its nanocomposite microsphere combination system are adsorbed in the crack space to form a viscous mesh-like plugging structure,Under the action of pressure difference,the plugging system deforms and migrates and accumulates to the depth of the crack to plug the crack step by step.The study selected(AM/AA/AMPS)/I-MMT nanocomposite microspheres and modified polypropylene nanocomposite(PPNC)ultrashort fibers as blocking materials.Optimizing the I-MMT release sheet in the inverse polymerization in situ suspension(AM /AA/AMPS)ternary copolymer microspheres to control the microsphere swelling characteristics;Polypropylene nanocomposite(PPNC)ultrashort fiber was prepared by polypropylene melt intercalation montmorillonite.The AMPS was grafted onto the surface of composite fiber by chromic acid oxidation pretreatment and suspension grafting reaction initiated by dicumyl peroxide.A modified fiber having better hydrophilicity and dispersibility.Through the study of the compounding system of nanocomposite microspheres and modified fibers,the compounding system has shown good fluid loss,and its API fluid loss can be controlled at 5ml.At the same time,the system also has good salt resistance and high temperature resistance.The water filtcation loss of API standard can be controlled at 8ml under high salinity.The sealing experiment of cracks shows that the system can form compact filter cake and seal cracks effectively.Therefore,the system can be used as a new functional material for effectively sealing cracks.