| 摘要 |
A system (10) for drilling a borehole (14) in a subterranean formation (16) containing a fluid (18), comprising: an outer tube (24) defining an outer tube distal end (26) configured for attaching a drill bit (12) thereto and a flow controller receiving section (27) spaced apart therefrom; a flow controller (28) including a flow controller body (30) defining body proximal and distal ends (32 and 34) and securable to the outer tube (24) in the flow controller receiving section (27); and a drilling accessory (36) insertable in the outer tube (24) and through the flow controller (28). The flow controller (28) is movable between open and closed configurations. In the open configuration, the flow controller (28) allows passage of the drilling accessory (36) therethrough. In the closed configuration, the flow controller (28) hinders flow of the fluid therethrough towards the borehole proximal end (20) when the flow controller (28) is located closer to the borehole proximal end (20) than the fluid (18). |
