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's explosion principle and penetration process were studied through numerical simulation method using LS-DYNA procedure

then the numerical calculation and experiment results were compared. The numerical simulation results show that the twelve copper pipes formed twelve jets

plugs and ‘tail’ 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 explosive and every copper pipe respectively(the angle between adjacent two neighboring planes was 30 degree)

the velocity of the jet tip and plug were approximate up to 3 530 m/s and 1 180 m/s respectively. The goal steel pipe primarily came into being swell and fracture failure under the detonation pressure

then it was cut by twelve jets (the penetration velocity was about 2 550 m/s)

eventually resulting in the formation of twelve slits. The steel pipe's deformation results and the quantity of slits are in consistent with the experimental results

and this technology is applied successfully in 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. The numerical simulation

experiment and engineering practice results show that the linear cumulative cutter with suitable structure can reach an ideal cutting effect and improve the energy utilization efficiency and security greatly.