Abstract: In the oriented perforation fracturing, current predicting initiation pressure just considers the naked borehole and neglects the effect of casing, which will lead to the greater errors in the engineering applications. Considering the effect of casing, wellbore stress models of directional well are obtained. According to tensile failure criteria, fracturing initiation pressure and angle models of oriented perforation well are presented. A software is developed, which includes the initiation prediction and perforation optimization of oriented perforation well. The software can predict the initiation pressure and initiation angle of oriented perforation fracturing considering the effect of casing, and optimize the perforation angle and length. Comparing to the actual initiation pressures, the maximum error of the prediction initiation pressures in the software is 4.33% and the predicting initiation angles are consistent with actual initiation angles, so as to prove the accuracy of fracturing initiation pressure and angle models. The models and software can offer instructions to the field fracturing and perforation optimization.

Key words: oriented perforation, stress distribution, initiation pressure, perforation optimization, software