In order to take exploratory well, production well ( development well), and reservoir p-retection into account. Multi-functional treatment agent used in drilling fluid and completion flui-d which called MFA-1 has been successfully developed by the equilibrium principle of dispersion and accumulation. The result shows that MFA-1 is fluorescenceless and low (no)toxicity. Also, it has many perfect properties such as filtration reducing, lubrication, anti-collapsing, plugging, re-servoir protection, strong anti-temperature (＞150°C) ,strong anti-salt,ect. Its whole effect is bett-er than sulphonating asphalts HL-Ⅱ and SAS.So MFA-1 is a good succedaneum of sulphonating asphalts.In more than 20 wells of Tarim Oilfield,drilling fluid and completion fluid which prepared with MFA-1 has been successfully used to solve many problems. Such as drill pipe sticking w-hile testing and the underground complex incidents,ect. As a result,it takes good social benefits a-nd good economic benefits.