Simulation On Whole Fluid Field Of The DTH Hammer Reverse Circulation Coring And Sampling Technology

In order to raising drilling efficiency,employ double-wall drill pipe,fluid flow from double-wall drill pipe's tubular annulus into bore,carry core or sample outflow from inside of the drillpipe to achieve continuous coring or sampling. this kind Of drilling method called reverse circulation continuous coring(sampling)drilling put down-the-hole hammer into continuous coring reverse circulation generate a sort of advanced technique , namely :down-the-hole hammer reverse circulation continuous coring (sampling) drilling technology.To analyse the integrated flow field is necessary. analytic method:theoretical calculation analyse,CFD technology combine field test report and empirical formula, data proceed contrastive analysis.In double-wall drill pipe tubular annulus use doniel bermoulli energy differential equation and Darcy's law as well as gas equation of state elicit thepressure distribution along with the depth of hole.. combination CFD analyse proceed Contrast analyse and comparison to field experiment.To the bit,in order to Increase negative pressure of bottom hole, design for the channel's streamline of injection hole combined CFD soft ware proceed contrastive analysis and gotten some relevant summing-ups.Through the stress condition of drill core,finding suspend condition,according to computational fluid mechanics theory erect mathematical model off from bottom hole flow field. through theoretical calculation work out GQ-89 ,GQ-108, GQ-127 drilling depth,andtwo phase flow's strength of central perforation,analyse two phase flow's media characteristics. And application computational fluid mechanics foundedbottom hole flow field's three-dimensional mathematical model,and proceed discrete solve.