Study On Thermal Stability And Related Mechanism Of Organoclay Used In Oil-Based Drilling Fluids

In this paper,two-component organic montmorillonite and organic sepiolite were prepared by wet method with Kazuo sodium montmorillonite and Spanish sepiolite,four different types of quaternary ammonium salt cationic surfactants were used as modifiers.XRD,SEM,surface wetting contact angle and TG-DTG were used as the research methods to study the effects of the type,combination and ratio of modifier on the structure,morphology and physical and chemical properties of organic montmorillonite.The organic montmorillonite and organic sepiolite were hot roll aged in 5# white oil,and characterized by six-speed viscometer and Brookfield digital rotary viscometer,the influence of the type,combination and proportion of modifier on the thermal stability of organic clay was studied;by using the selected organic montmorillonite and organic sepiolite to compound,the influence of compound combination and proportion on the thermal stability of compound organic clay in oil-base drilling fluid system was investigated;the mechanism of the structure and composition of modifiers on the thermal stability of organoclay was explored.The research results show that:(1)The layer spacing of organic montmorillonite modified by two-component is larger than one-component;the two-component organic montmorillonite is more loose and curly than the one-component organic montmorillonite;Gemini modifier has poor thermal stability,the thermal stability of the organic montmorillonite is improved.(2)In the white oil based system,the properties of the organic montmorillonite 1821+G12-OMt and 1821+1827-OMt prepared by the two-component cationic surfactant are superior to those of the other two-component organic montmorillonite.(3)In the white oil based system,the thermal stability of the composite organic clay is better than that of the single component organic clay.