Abstract：Hydraulic fracturing treatments of oil wells in petroleum industry are affected greatly by the perforation parameters selected. A three-dimensional finite element model together with the tensile criterion of rock materials is employed to investigate systematically the influences of perforation in vertical wells on formation fracturing pressure，including perforation density，perforation orientation，perforation diameter and perforation length. Based on a six-month simulation research in University of Petroleum，China，several conclusions are drawn. Perforation density and orientation angles are the most important factors of all to affect formation fracturing pressure. However，as for perforation diameter and perforation length，their influences are much slight. The conclusions reached provide valuable guidance to the designers of hydraulic fracturing treatment and engineers of oil fields.
