Application of hydraulic sand jetting perforation to coalbed methane development

According to the nozzle jammed, nozzle with serious sputering.aw seric lfe,hard to form effictive perforation problem occured in the ihyaraulic sandjet peroration procss ofthe coalbed methane wel.he paper ad a study on the factors affectedto the ihydraulieparameters of fferent hole size ijecto.With the optmization on the hyrauli parameters and stoucture of the noczde a newin ecor was designed and the tools combination of the available hydraulic sand perforation wasimproved.The study resuits showed that under the condtions of a 4× 6 mm ijctor.discharge of 1.4 mn~-3min,sand ratio of 8% and pump pressure of 50 MPa.a casingwith a thicknes of 5.5 inches/ 140 mm)could be perorated witin 15 minutes. The optimized nozde and tools combination could sove the problems of the nozde jammed.,poor ani sputtering and the pore verification of previous hydraui: sand jet peroration.The ools combinaton optimized could realize the integraton ofthe sandje perforation and round space fracturing and could reduce the time of the seam reconstruction.