Development Of Organic Clay And Temperature Sensitive SiO₂ For Drilling Fluid And Research On Rheological Properties

In order to further enhance the ability of drilling fluid mud to carry rocks and sands,viscosity modifiers are usually used to adjust the rheological properties of oil-based drilling fluids and improve drilling efficiency.At present,oil-based drilling fluids commonly use organic clay and tackifier to improve the rheological properties of drilling fluids.In this study,to improve the suspension stability and temperature resistance of bentonite,and to improve the viscosity-increasing performance of nano-hybrid materials,on the basis of the temperature-resistant and viscosity-increasing mechanism of bentonite and nano-hybrid materials,select the appropriate modification agents and methods to modify bentonite,developed organic bentonite and temperature-sensitive SiO₂nano-hybrid materials together as an oil-based drilling fluid viscosity modifier.The organic bentonite can still maintain good rheological properties at 150 ?,the sensitive nano-SiO₂ hybrid material can improve the stability and viscosity increasing performance of W/O drilling fluid.?1?Using a co-modification method,the bentonite?Bent??Hexadecyl trimethyl ammonium Bromide: CTAB?and silane coupling agent?Hexadecyltrimethoxysilane: HDTMS?are used to be modified.First,the interlayer of CTAB increases the base spacing of bentonite,the covalent bond of HDTMS and bentonite sheet improves the thermal stability of bentonite.The prepared organic bentonite?OBent?was analyzed by infrared analysis,X-ray diffraction analysis,thermogravimetric analysis and scanning electron microscopy.The hydrophobicity,solubility,viscosity and tribological properties of OBent were also tested.The test results show that the hydrophobicity of the co-modified bentonite is significantly improved,and is higher than that of the single modifier CTAB or HDTMS.bentonite.Compared with bentonite modified by a single modifier,the bentonite modified by CTAB and HDTMS has stable rheological properties and a low coefficient of friction,because more HDTMS enters the interlayer space and is sandwiched by the bentonite form a chemical bond with the surface.?2?A temperature-sensitive PNM/SiO₂-D nano-hybrid was prepared through copolymerization ofmonomer of polymer and nano silica with double bond.PNM/SiO₂-D nano-hybrid was analyzed by infrared spectrum,nuclear magnetic hydrogen spectrum and rheological properties,and the viscosity-increasing and temperature-resistant mechanism of the temperature-sensitive nano-hybrid material were discussed.The viscosity-increasing agent exhibited a more sensitive temperature response behavior in emulsions with high water content.When the heat-associated temperature?Tass?is reached,it can effectively improve the viscosity of water-in-oil drilling fluid,and the optimal addition amount is 1.5wt%,the viscosity increasing effect is more obvious in the case of higher water-oil ratio.The tribological properties of PNM/SiO₂-D nano-hybrid in different types of drilling fluid were explored.The friction coefficient in water-in-oil drilling fluid base slurry is reduced less.In oil-based slurry,the friction coefficient is the lowest when the dosage of PNM/SiO₂-D nano-hybrid is 1.5 wt%.In water-based slurry,the friction coefficient is the lowest when the concentration of PNM/SiO₂-D nano-hybrid is 1 wt%,which was reduced by 18.2%.?3?The above-prepared organic bentonite and tackifier were used together as viscosity improver for water-in-oil drilling fluids.The temperature resistance,lubricating properties,rheological properties and drilling fluid stability performance of the drilling fluids were evaluated.Comparing commercial organic bentonite with commercial tackifier,the W/O drilling fluid composed of HDTMS?1?-CTAB?0.5?-bent and PNM/SiO₂ exhibited good stability and lubricity,and the constant rheology property with the increase of temperature.