Research of novel composite drilling grade bentonite
Shuangchun Yang, Mingzhe Guo, Yi Pan, Wei Li, Haiyan Zhang · 2017
To improve the performance of sodium-modified bentonite in drilling fluids, the natural Ca-base bentonite (Ca-Bent) was modified by microwave wet, which regarded the anionic surfactant SDBS is compounded with inorganic sodium salt as modifier.The effects of different sodium salts, the volume of modifier, the ratio of SDBS to inorganic sodium salt, temperature and time on the modification of bentonite were studied.Moreover, the applicability of modified bentonite in drilling fluid was also evaluated.The result showed that the optimized experimental parameters are obtained as follows: SDBS to Na 2 CO 3 ratio 1:1.5, modified volume 50ml, radiation time 3 mins, and initial temperature 50℃.Under the optimization conditions, the modified bentonite has a swelling volume of 45mL/g.And the pH of 8, the plastic viscosity of 18 mPa•s, yield point and plastic viscosity ratio of 0.25 and sand content less than 0.5% respectively.So, the modified bentonite is regarded as excellent drilling grade bentonite.