Abstract: Iraq X-oilfield is in the middle stage of field development,M reservoir in X-oilfield is a carbonate reservoir,acidizing with CTU is the traditional treatment in the oilfield stimulation. Multiple wells in the M reservoir show strong heterogeneity and reservoir damage during development,the production rate can't be restored after acidizing treatment. The paper analyzes the characteristics of M reservoir of X-oilfield,based on the characteristics of M reservoir,acid fracturing technology is firstly proposed,common acid,gelled acid and self-diverting acid are analyzed and selected. According to the research findings,the acid fracturing treatment was applied in the X-oilfield,based on the analysis result of mini-frac and main-frac,the geometric parameters of acid fracturing cracks and the acid fracturing parameters were optimized to enhance the effect of acid fracturing. The technology has been applied in the oilfield successfully,and the production rate of the single well increased obviously after operation.

Key words: Iraq, stimulation treatment, acid fracturing, technological design, reconstruction of cracks