DRILL BITS AND DIAMOND TOOL Russian patent published in 1994 - IPC

FIELD: well drilling. SUBSTANCE: flushing fluid is advanced along drill pipe string in drill bit cavity and pressure jet is formed in drill bit packing in form of two concentrical flows; external flow is twisted. Drill bit 1 with roller bits 2 is provided with additional packing 4 disposed inside the basic one in axial. Spiral shaped members 5 intended for twisting external flow are placed in space between packing 3 is disposed higher than lower edge of additional packing 4. So face is subjected to effect of combined jet of flushing fluid which consists of internal linear flow and rotational-eddy flow. Face of the well and teeth of drill bit are cleaned from slime. EFFECT: improved mechanical speed of drilling. 1 dwg