栲胶十二烷基酯的凝胶性能和钻井液防沉应用OA北大核心

Tannin gum is a forest product resource rich in phenolic OH,and its application in oil-water emulsion systems such as oil-based drilling fluids can be expanded by introducing hydrophobic modification of long-chain alkanes.Tannin dodecyl esters(CTM)were obtained by one-step esterification reaction using Acacia mangium bark tannin gum as raw material.Emulsion gels of CTM were prepared in various solvents.Specifically,in a white oil/water mixed solvent system(volume ratio of 5∶3),the emulsion gel demonstrated minimum gelatinous concentration of 15 g/L and a creaming index of 18.75％.The formation of CTM oil-water emulsion gels was driven by hydrogen bonding and Van der Waals force as revealed by Fourier-transform infrared spectroscopy(FT-IR)and scanning electron microscopy(SEM)analyses.CTM emulsion gel in a white oil/water mixed solvent system had typical viscoelastic rheological properties and excellent mechanical stability.The drilling fluid weighting agent barite had good dispersion and suspension ability in CTM white oil/water emulsion gels.The oil-based drilling fluid prepared using a white oil/water(volume ratio of 5∶3)mixture as the solvent with 2％CTM anti-settling agent was aged at 180 ℃ for 16 hours,the demulsification voltage was as high as 1 320 V,and the static settlement factor was only 0.508,indicating excellent anti-settling for barite and high temperature rheological stability performance.