The Experimental Study On Particle Jet Impact Rock

Particle impact jet drilling is based on high speed particle impact broken rock, water and mechanical rock fragmentation under a new drilling technology.Particles mainly through pipes to accelerate, nozzle period of acceleration, constant speed core acceleration process,by the force analysis of particles in high pressure pipe and nozzle, the particle motion equation is established according to Newton’s second law.Applied the Hertz theory and Newton’s second law to establish differential equation of particle effect on rock,Particles of broken rock volume and broken rock depth relationship is obtained by equation.Erosion theory is applied to determine water rock volume and broken rock depth,rock fracture strength formula is used to determine the rock crack length,through the rock crack force analysis,rock fracture strength equation is established,the ratio of the fracture strength factor of the rock and rock fracture toughness is defined as the stability factor of the rock,to determine the relationship between water jet speed and stability coefficient of rock.Through indoor test,to analyze the debris and then scan the rock by electron microscope,rock crack size is consistent with the theoretical calculation.Based on ANSYS/LS-DYNA simulation platform,to make a study of Particle diameter,incident Angle and the process of the same Specific energy ball hit in the the rock,in order to obtain the relation of energy absorption ratio of rocks, broken rock depth and broken rock volume,to put forward the effective particle diameter of broken rock, impact velocity and Angle values specification.Based on self-developed particle impact rock test apparatus,particle jet impact rock series experiment was carried out, respectively to carry out the rock breaking efficiency experiments of the particle diameter,jet velocity, particle mixed proportion, the incident Angle, through the analysis of experimental results and demonstration, verificated and perfected the theory research,and elaborated the particle jet rock-breaking process.