Experiment study on reverse circulation drilling of anchor borehole in floor of mine roadway

According to rapid drilling difficult problem of anchor borehole in floor of mine roadway,the paper analyzed drilling mechanism of anchor borehole with press urized pumping reverse circulation and pump suction reverse circulation and pump suction reverse circulation drilling with pump suction force to discharge slagging at bore hole bottom with central channel of drilling rod would be feasible theoretically and technically. Based on the function mechanism of reverse circulation drilling,a set of revers e circulation drilling tools was researched and developed and could make a drilling experiment of pressurized pumping reverse circulation and pump suction reverse circula tion.The site experiment showed that due to borehole wall and drilling rod sealing problems,the pressured pumping circulation would be hard to realize rapid drilling of anch or borehole in floor.Under suction force of pump,pump suction reverse circulation could make cutting flushing fluid successfully discharged from borehole and rapid deep b orehole drilling of anchor borehole could be realized. The high borehole completed quality and good operation environment would be ideal selection for rapid drilling of anc hor borehole in floor of mine roadway.