多向线性聚能切割弹的研究与应用

针对油气井、矿井卡钻问题,设计一种多向线性聚能切割弹,其结构特点是:圆柱形炸药的四周均匀布置12根空心铜管。采用LS-DYNA程序中的Lagrange算法对该切割弹的爆炸作用原理及侵彻钢管过程进行数值模拟,并将计算结果与实验比较。数值模拟结果表明:12根铜管在爆轰压力作用下形成12股金属射流刀以及伴随其运动的杵体和"尾翼",12股射流刀分别沿着炸药及12根铜管的中轴线形成的12个平面(各平面之间夹角为30°)向四周运动,其头部速度高达3530 m·s-1,杵体速度约1180 m·s-1;钢管首先受到爆轰产物的作用发生膨胀和断裂破坏,然后受到12股射流刀的侵彻作用(侵彻速度约2550 m·s-1),最终在钢管上形成12条切缝。数值模拟得到的钢管切割变形效果及切缝数量与实验结果十分吻合,所设计的切割弹成功应用于处理某铜矿300 m深度的钻井卡钻事故,与目前常用的切割弹相比装药量减少了80%以上,成本降低至少50%,且具有结构简单、加工方便的特点。

Application of the Multi-directional Linear Cumulative Cutter

According to the characteristics of the drill-jamming accidents, a kind of multi-directional linear cumulative cutter in which twelve hollow copper pipes distributed evenly around the cylindrical explosive was designed. The linear cumulative cutter explosion principle and penetration process were studied through the numerical simulation method, which used the lagrange method of the LS-DYNA procedure, then the numerical calculations and experimental results were compared. The numerical simulation results showed that the twelve copper pipes formed twelve jets, slugs and ''tails'' which moved after the jets under the pressure of detonation. Then these twelve jets moved along twelve different planes which were formed from the central axis of the copper pipes and explosive respectively(the angle between two neighboring planes was 30°). The velocity of the jet tip and slug were approximately up to 3530 m·s^-1 and 1180 m·s^-1 respectively. The target steel pipe primarily formed swell and fracture under the detonation pressure, then it was cut by twelve jets(the penetration velocity was about 2550 m·s^-1), eventually resulting in the formation of twelve slits. The steel pipe deformation results and the quantity of slits are in consistent with the experimental results, and this technology is applied successfully to the drill-jamming accident of three hundred meters deep drilling. Moreover, it is noted that the charge and cost are reduced respectively by 80% and 50% at least compared with existing normal cutter. In addition, the structure of cumulative cutter is simple and easy to be processed.