Air-lift reverse circulation drilling technology is often used in geothermal well drilling, but there are many problems along with drilling depth increasing, such as double-wall drill pipe leaking, air-water mixer blo.
[pdf] One of the most significant advancements to reduce costs for drilling multiple horizontal wells from a single surface location or pad is the “walking” rig. A walking rig is self-propelled because it can move short distances (10 metres) without being disassembled and with pipe in the derrick.
[pdf] One of the most significant advancements to reduce costs for drilling multiple horizontal wells from a single surface location or pad is the “walking” rig. A walking rig is self-propelled because it can move short distances (10 metres) without being disassembled and with pipe in the derrick.
[pdf] 
