Acid fracturing treatment of deep carbonate reservoirs is to establish communication between the fractures generated and natural fractures and vugs. Based on the variation modes of operating curves of acid fracturing treatment

and the geological effects of the treatment

4 appraisal systems have been suggested each of which corresponds to one of the acid fracturing modes

including no fracture have been created (type Ⅰ)

fractures have just been created and then stop (type Ⅱ)

fracture have been created but have no communication with natural fractures and vugs (type Ⅲ)

and fractures have been created and have communication with natural fractures and vugs (type Ⅳ). Acid fracturing treatments in 27 wells in Tahe oilfield have been categorized and evaluated with this method. Of these wells

56% have reached the type Ⅳ acid fracturing mode and these wells can have high and stable productivities in a relatively long period; 22% are of type Ⅱ and Ⅲ; while the rest 22% are of type Ⅰ

and their acid fracturing effects need to be further improved. The evaluation results are in good agreement with the actual performance of the wells.