Application effect and prospect of organic sepiolite used in oil-based drilling fluid
Aiming at the problem that the conventional oil-based drilling fluid and its supporting treatment agent are easy to fail in high temperature environment.A fibrous clay mineral"sepiolite"with high tem-perature mechanical stability was analyzed and studied,and its crystal structure,physical-chemical proper-ties and organic modification methods were discussed.The results showed that the organic modified sepio-lite could form a"messy grass pile"spatial grid structure with strong structural force in the oil-based drilling fluid,which could make the drilling fluid have an obvious thixotropy.This thixotropy only depen-ded on the mechanical parameters of the fiber structure,not on the electrostatic attraction of the particles,and the temperature resistance can reached more than 240 ℃.The process of the sepiolite fiber which dis-persed in the drilling fluid penetrating into the stratum with the drilling fluid,a thin and dense fiber layer could be formed at the wellbore,to block the filtration of the drilling fluid to the stratum.In addition,sepi-olite has almost the same slurry mixing effect in saturated brine and fresh water due to its own structural water,and has strong salt water pollution resistance.The research on the organic modification process of sepiolite and its application in oil-based drilling fluid are gradually becoming an important direction for the investigation of ultra-high temperature drilling fluid in the future.
oil-based drilling fluidhigh temperature and pressureorganic sepiolitespatial grid struc-tureflow pattern regulationfiltration reduce
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