Abstract: In Shanshan and Wenmi blocks of Tuha oilfield,due to high water injection pressure and serious formation plug,the water injection is difficult to meet the requirements of injection allocation and the conventional acidification construction cannot remove deep formation pollution.Therefore a new type of hydrogen acid acidification system has been developed.Through laboratory experiments,compared with the soil acid,the new type of hydrogen acid system is of slow corrosion,long distance of effectiveness,preventing the formation of the secondary precipitation,low cost,and many other advantages.The new system hydrogen acid formula and technology have been determined.Site test of 23 wells indicates this new type of hydrogen acid system can decrease water injection pressure of 7.8 MPa,with daily increased amount of 29.5 m3,the validity of 108 days,and remarkable decreased pressure and increased injection effect.