ALE simulation of ultra deep downhole perforating projectile penetrating super strong sandstone

Abstract As the drilling depth continues to increase, the degree of compaction, strength, and formation pressure of the reservoir rock is also increasing. It is necessary to use super perforating bombs to penetrate the pollution zone, and the combination of super bombs-super target-high confining pressure will increase the difficulty of penetration analysis. In this paper, using LS-DYNA software, combined with the ALE algorithm, taking an oilfield downhole perforation as an example, the HS46 super-strong bullet-gun-liquid-casing-sandstone three-dimensional model is established without confining pressure and 50 MPa confining pressure. By establishing non-reflective boundary conditions, the interference of detonation waves on jet shaping and effects is eliminated; by adjusting the mesh density of key parts and optimizing the mesh coordination between different contact surfaces, numerical distortion is reduced, analysis accuracy is improved, and machine time is reduced. Studies have shown that at 13 μs, the jet energy peak reaches 60 kJ, accounting for 23% of the total energy, and then it decays sharply, and the attenuation is zero at 850 μs; at 16 μs, the jet velocity peaks at 6300 m/s; the penetration depth under 50 MPa confining pressure is 560 mm, which is more It is reduced by 20% without confining pressure. The research in this paper can provide a reference method for the simulation analysis of the downhole super projectile penetrating the high confining pressure super target.