Monikäyttöinen kairauskone, irrotettava ohjauselin ja menetelmä monikäyttöisen kairauskoneen toimintatilan valitsemiseksi

摘要

Abstract There is provided a multi-purpose drilling apparatus, comprising: a drilling actuator unit configured to rotate an outer drill string entering a borehole, wherein space between the outer drill string and the borehole define an outer annulus space and to provide a downward flow of drilling medium inside the outer drill string; and a releasable guiding member configured to guide an upward flow of the drilling medium upwards from the drill bit unit either: via the outer annulus space in order to perform direct circulation drilling, or inside an inner drill string locating concentrically inside the outer drill string in order to perform reverse circulation drilling. (Figure 5) ---- > AIR&SAMPLES 122 DRILLING 126 EXAMPLE LOCATION FOR GUIDING MEMBER 124 108 INNER DRILL STRINGDRILLING -yACTUATOR APERTURE(S) A * ANt Zr K130 iuWER 114 CONNECTING FLANG,, 1LW ACCOMMODATION FLANGE 100 OUTER DRILL STRING 108 INNER DRILL STRING EXTENDS SEE FIGURE 4 106 OUTER ANNULUS SPACE 101 GROUNDN- Y 104 BOREHOLE