Abstract

A multi-fluid drilling system (10) drilling is disclosed for drilling a hole or well (11). The system (10) is coupled to a dual wall drill string (12). The drill string (12) is configured to enable separate flow of a first fluid (14) and a second fluid (16). The system (10) has a hammer (22) and a downhole motor (24). Both the hammer (22) and the motor (24) are supported by and are coupled to the drill string (12). The motor (24) is uphole of the hammer (22). The hammer (22) is arranged so that when supported by the drill string (12) the first fluid (14) when flowing through the drill string (12) is able to flow to and power the hammer (22). As the motor (24) is disposed between the hammer (22) and the drill string (2) the first fluid (14) is also able to flow through the motor (24). To this end the motor (24) has a channel (25) to enable the first fluid to flow from the drill sting (12) to the hammer (22). The channel (25) acts as a part of a flow path or conduit for the first fluid (14).

IPC Classes  ?

• E21B 6/04 - Separate drives for percussion and rotation
• E21B 1/00 - Percussion drilling
• E21B 4/02 - Fluid rotary type drives
• E21B 4/06 - Down-hole impacting means, e.g. hammers
• E21B 4/14 - Fluid operated hammers
• E21B 6/08 - Separate drives for percussion and rotation
• E21B 7/00 - Special methods or apparatus for drilling
• E21B 7/04 - Directional drilling
• E21B 7/24 - Drilling using vibrating or oscillating means, e.g. out-of-balance masses

Abstract

A dual circulation fluid hammer drilling system (10) has a fluid hammer (12) which is coupled to a drill string (14). The system (10) utilises a first fluid (16) and a second fluid (18). The first fluid (16) is delivered through the drill string (14) to drive or otherwise power the fluid hammer (12). The second fluid (18) is also delivered through the drill string (14) but in isolation of the first fluid (16) so they do not mix within the drill string (14). The second fluid (18) passes through a hammer bit (38) of the hammer drill (12) and is directed to flow out from a bit face (20). Thus when the system (10) is in use the second fluid (18) will flow across the bit face (20). The first fluid (16) also exits the drilling system (10) at the hammer drill (12). However the first fluid (16) exits upstream or up-hole of the bit face (20).

IPC Classes  ?

• E21B 21/12 - Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor using drilling pipes with plural fluid passages, e.g. closed circulation systems
• E21B 4/06 - Down-hole impacting means, e.g. hammers
• E21B 4/14 - Fluid operated hammers
• E21B 7/18 - Drilling by liquid or gas jets, with or without entrained pellets
• E21B 10/18 - Roller bits characterised by conduits or nozzles for drilling fluids
• E21B 10/24 - Roller bits characterised by bearing, lubrication or sealing details characterised by lubricating details
• E21B 10/36 - Percussion drill bits
• E21B 10/38 - Percussion drill bits characterised by conduits or nozzles for drilling fluids

Abstract

A ground drill system (10) has a drill string 14 which forms first and second mutually isolated fluid paths (16 and 18) respectively. The drill string (14) has an up hole end (20) coupled to a dual circulation rotation head (22) and a down hole end (24) which is coupled to a drilling tool (12). The drilling tool (12) is operated by the flow of fluid delivered through the first flow path (16). A second fluid outlet (26) is provided intermediate the up hole end (20) and the drilling tool (12). The outlet (26) is in fluid communication with the second fluid flow path (18) and located a constant or fixed distance from the drilling toll (2). The second fluid outlet (26) discharges a flushing fluid flowing through the flushing flow path (18) into a hole being drilled by the drilling system (10). The rotation head (22) provides torque to the drill string (14) and thus the drilling tool (12).

IPC Classes  ?

• E21B 21/12 - Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor using drilling pipes with plural fluid passages, e.g. closed circulation systems
• E21B 4/14 - Fluid operated hammers
• E21B 7/18 - Drilling by liquid or gas jets, with or without entrained pellets
• E21B 17/18 - Pipes provided with plural fluid passages