Carboxymethyl cellulose(CMC) was synthesized from natural cellulose through alkalization and etherization. It was widely used in drillings of oil and natural gas. The common CMC couldn't satisfy the need of exploitation in high-temperature and complex stratum, and it is urgent to develop CMC with better heat-resistance. The modification of CMC were studied in many ways, but studies on heat-resistance CMC were absent.After studying the mechanism on improving of heat-resistance of CMC, a approach of adding mo...