Abstract: A new anti-temperature and anti-salt fluid-loss agent with cationic groups and anionic groups in a molecular structure has been synthesized by adopting the principle of amphoteric polymer mud additives’function. Test results show that amphoteric pherolresin not only inherit the five advantages of methyl sulfonic phenolresin (SMP), but also possess fairly good inhibition for shale hydrating and swell, high efficiency to control filtration as well. The proportion of cationic groups and anionic groups influences the properties of amphoteric pherolresin.

Key words: Phenol resin, Filtration Reducer: Inhibition, Drilling Fluid Additive