Synthesis And Filtration Reduction Performance Of Polymer/Montmorillonite Nanocomposites

China is rich in deep oil and gas resources,but the deep formation temperature is usually above 200~oC,and the traditional polymer fluid loss reducer of drilling fluid will degrade and cross link failure under this high temperature.Therefore,it is urgent to develop polymer fluid loss reducer with good high temperature resistance to adapt to high temperature and high pressure formation.In recent years,the introduction of nanomaterials into polymer matrix to enhance polymer rigidity and thermal stability has become one of the hot topics in drilling fluid field.Therefore,it has certain research significance to further improve the comprehensive properties of polymer materials by combining polymer and nanomaterial phases for the application of high temperature formation drilling fluid.Based on this,MSA/O-MMT nanocomposites were successfully prepared in this thesis by in-situ polymerization with organic montmorillonite in the process of polymer synthesis.The influence of the introduction of nanomaterials on the structure and comprehensive properties of polymers was also studied.In this thesis,the organic modified montmorillonite(O-MMT)was prepared by ion replacement method.The structure and properties of o-MMT were analyzed by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR)and thermogravimetric test(TGA).Cetyltrimethylammonium bromide(CTAB)has been successfully verified into the montmorillonite lamellar and the interlayer spacing of montmorillonite increases from 1.23nm to 2.08nm.Secondly,the in situ polymerization method was adopted,using 2-acrylamide-2-methylpropanesulfonic acid(AMPS),sodium p-styrene sulfonate(SSS),4-prope noylmorpholine(ACMO)and organic modified montmorillonite(O-MMT)as raw materials,using azodiisobutyronitrile(AIBN)as initiator.A polymer/montmorillo nite nanocomposite(MSA/O-MMT)has been successfully prepared.The reaction conditions were optimized and the chemical characterization of the compound was analyzed.The results showed that the O-MMT lamellar was dispersed into the polymer matrix,and TGA analysis showed that the MSA/O-MMT nanocomp osites began to decompose at 360℃and had good thermal stability.Then,MSA/O-MMT nanocomposite was added to the base slurry as a fluid loss reducer,and rheological properties and fluid loss were tested.HTHP fluid loss was26m L after aging at 200℃,showing good fluid loss reduction performance and salt resistance at high temperature.Finally,the molecular structure of polymer and the mechanism of action with clay particles were analyzed,and the mechanism of action of MSA/O-MMT fluid loss reducer was analyzed by microscopic means combining with SEM and particle size analysis of drilling fluid.The results show that MSA/O-MMT filter loss reducer is beneficial to the formation of compact and neat filter cake without obvious cracks or voids,and reduce the filtration loss.