Page 103 - Air and Gas Drilling Manual
P. 103
Chapter 3: Downhole Equipment 3-31
Figure 3-25: Dual wall pipe drill string schematic showing three drill bit string options
and two downhole air hammer string options. Nomenclature of above; 1) adapter sub, 2)
air swivel, 3) O-ring, 4) air swivel inlet, 5) O-rings, 6) shaft adapter, 7) O-rings, 8) saver
sub adapter, 9) O-rings, 10) center tube, 11) saver sub, 12) O-rings, 13) dual wall drill
pipe, 14) interchange connector tube, 15) O-rings, 16) interchange sub, 17) standard
down-the-hole (DTH) air hammer, 18) connector tube for reverse circulation downhole air
hammer, 19) O-rings, 20) reverse circulation downhole air hammer, 21) O-rings, 22) bit
connector sleeve, 23) rock bit sub, 24) wear sleeve, 25) tri-cone bit, 26) open face drag bit
for coring and, 27) latching bit sub (courtesy of Foremost Industries Incorporated).
