Preparation and Evaluation of Hyperbranched Emulsifiers for Oil-Based Drilling Fluids
In order to improve the emulsifying stability of oil-based drilling fluids,tall oil fatty acids,dimeric acids,methyl cocoate,diethanolamine,diethylenetriamine,white oil,etc.are used as raw materials.The carboxyl groups on the fatty acids will form amide bonds with the amino groups of the polyamines through dehydration reactions.The resulting polyamide center nodes connect multiple fatty acid molecules to form functionalized hyperbranched amide polymers,which are then compounded with white oil to form a hyperbranched main emulsifier with a"sea anemone"effect;A co emulsifier was prepared using Tall oil fatty acid,oleic acid,methyl oleate,and triethanolamine as raw materials.By measuring the microstructure,particle size,interfacial tension,wettability,and stability of the emulsion with a fixed main auxiliary emulsion ratio of 4∶1,a total dosage of 4%,and an oil-water ratio of 80:20,the best emulsifier with the best emulsion stability performance was selected among the four emulsifiers.Further study the effects of emulsifier dosage,oil-water ratio,temperature,and density on the formulated oil-based drilling fluid.The results showed that the emulsion composed of main emulsifier and auxiliary emulsifier with hyperbranched amide polymer was spherical in shape,evenly distributed,non aggregating,with an average particle size of≤4.5 μm,interface tension of≤0.4 mN/m,contact angle of≤40°,and demulsification voltage of≥400 V;The prepared oil-based drilling fluid has stable rheological properties after aging under conditions of 90～180℃,oil-water ratio of 75∶25～85∶15,and density of 1.1～1.9 g/cm3.The demulsification voltage is≥800 V,and the high-temperature and high-pressure filtration loss is≤3 mL.It can meet the operational requirements of complex wells such as offshore high-temperature deep wells and large displacement horizontal wells.
oil based drilling fluidhyperbranched emulsifierlotion stabilityhigh temperature deep well
万方数据
维普
