考虑炸高和相位角影响的射孔枪卡枪及强度流固耦合分析

Fluid-solid interaction analysis for perforation gun jamming and strength considering effects of blasting height and phase angle

射孔作业过程中常发生射孔枪卡枪、损坏等安全事故,影响勘探开发进程。首先建立射孔弹-射孔枪-射孔液-套管-砂岩三维有限元模型,结合ALE(arbitrary Lagrangian-Eulerian)算法,实现射孔液-射流-枪-套管-砂岩之间的流固耦合,分析不同炸高和相位角对射流侵彻过程中射孔枪毛刺和应力强度的影响。研究表明:单枚弹、炸高12 mm时,毛刺4.1 mm,最大应力1075 MPa,孔道周围超过材料屈服极限的应力区域直径达到61 mm;炸高18 mm时,毛刺3.9 mm,最大应力997 MPa,超过材料屈服极限的应力区域直径达到45 mm;炸高24 mm时,毛刺3.6 mm,最大应力912 MPa,超过材料屈服极限的应力区域直径达到38 mm;炸高增加,毛刺高度和最大应力以及对射孔枪材料的损伤区域范围均减小;炸高12 mm,相位角30°、60°、90°时,毛刺高度较单枚时变化很小,超过材料屈服极限的应力区域直径分别为55 mm、42 mm、66 mm,此区域内,在高爆轰压力下,射孔枪将发生向外鼓胀,即所谓的“胀枪”,引起卡枪事故,所以相位角60°时射孔枪的强度安全性更好;通过研究,解决了聚能爆轰仿真时常发生的分析意外终止和速度超限溢出问题,可为射孔爆轰侵彻类问题研究提供思路。

Safety accidents,such as,perforation gun jamming and damage often occur in process of perforation operation to affect process of exploration and development.Here,firstly,the 3 D finite element model of perforating charge-perforating gun-perforating fluid-casing pipe-sandstone was established.Combined with ALE(arbitrary Lagrangian-Eulerian)algorithm,the fluid-structure interaction among perforating fluid-jet-gun-casing pipe-sandstone was realized,and effects of different blasting heights and phase angles on burr and stress intensity of perforating gun in jet penetration process were analyzed.The results showed that when the blasting height of a single projectile is 12 mm,the burr is 4.1 mm,and the maximum stress is 1075 MPa,the diameter of the stress area around channel exceeding material yield limit can reach 61 mm;when the blasting height is 18 mm,the burr is 3.9 mm and the maximum stress is 997 MPa,the diameter of the stress area exceeding material yield limit can reach 45 mm;when the blasting height is 24 mm,the burr is 3.6 mm and the maximum stress is 912 MPa,the diameter of the stress area exceeding material yield limit can reach 38 mm;with increase in blasting height,burr height,maximum stress and damage area of perforating gun material decrease;when the blasting height is 12 mm and the phase angle is 30°,60°and 90°,respectively,the burr height changes little compared with the situation of a single projectile,the diameter of the stress area exceeding material yield limit is 55 mm,42 mm and 66 mm,respectively;in this stress area,under high detonation pressure,the perforating gun can bulge outward,this is called“bulging gun”to cause the accident of perforation gun jamming,so the strength safety of perforating gun is better when the phase angle is 60°;this study can solve problems of analysis terminated unexpectedly and velocity overrun overflow in energy accumulation detonation simulation to provide an idea for studying perforation detonation penetration.