Numerical Simulation Of Oil Perforating And Cartridge Design

Shaped charge perforation, which has advantages such as rapid construction, mature technology, low cost, high efficiency, etc., means jet is formed due to the gathering energy effect of the perforator. It is in a dominant position in oil exploitation.In this paper, researches on the gathering energy effect, the shaped charge perforating gun technology and the perforating gun were briefly described. The mechanism of jet formation and the jet penetration were analyzed.In this paper, finite element method and adaptive re-meshing technique were used to simulate the forming process of the shaped charge jet for perforating gun. Based on this work, the collision between the cartridge and the casing of the perforating gun was further simulated. Different cases were compared to study the effect of the attached materials on bulge height in perforating gun. Results indict that the bulge height can be deceased obviously by the attachment of soft metal on the perforator. The yield stress of the soft metal can significantly affect the bulge height. With the increase of the yield stress, the dissipated energy is increased in the case of the same strain rate. So, the bulge height can be deceased. The bulge height can be reduced by 52.1% through using 7075 aluminum alloy comparing to the case without any attached metal. Approximate linear relation between the bulge height and yield stress of attached soft metal can be found in the cases with similar strain rates.In this paper, ALE methods were used to simulate the forming process of the shaped charge jet for the perforating bullet and the penetration of the jet on concrete plate. Different cone angles were compared to study the effects on the formation and penetration of the shaped charge jet. Results indicted that cone angle plays a key role on the velocities and the shapes of the jet, the quality of jet head and pestle body and the penetration of width and depth. For smaller cone angle, the penetration is not good enough because the jet head is small and the velocity of the jet body is not higher enough. For bigger cone angle, the diameter of the penetration hole becomes increased and the penetration depth is insufficient. For middle cone angle, the penetration depth is relatively higher although the diameter of the penetration hole is smaller.This work can provide a theoretical basis and reference for the optimization of the perforating gun and perforating charge in different conditions. The current thesis was supported by National Natural Science Foundation of China (10802017) and the National Key Basic Research Special Foundation of China (2010CB832704).