Method and drilling apparatus for down-the-hole drilling

Abstract

A method and drilling apparatus for drilling. The drilling is carried out by a drilling apparatus including a drilling device including a casing part and at least during drilling a drilling unit. At the drilling head of the drilling apparatus are at least first drilling elements, a second drilling element, a flushing flow arrangement and a pressure medium operated hammering device. The first drilling elements are coupled with the second drilling element power-transmittedly in order to carry out cooperation thereof at least during drilling with the second drilling elements for a rotational motion, a feeding motion and the hammering motion, and are coupled removably to enable removal thereof from the hole. For producing the hammering motion a hammering device is used that is operated essentially by a water-based pressure medium. At least a part of the water-based pressure medium operating the hammering device is used as the flushing medium.

1 . A method for down-the-hole drilling, the drilling being carried out by a drilling apparatus, having a drilling device that comprises a casing part and at least during a drilling situation an essentially inside thereof existing drilling unit, at the drilling head of which there are at least; a first frame part, a drilling surface of which being provided with first drilling means for drilling a center hole; a second frame part, a drilling surface of which being provided with second drilling means for reaming the center hole for the casing part; a flushing flow arrangement first of all for leading of flushing medium into the drilling head internally in the drilling device, such as through a drill rod/rods and the drilling unit, and on the other hand for leading of drilling waste by influence of the flushing medium to outside of the drilling device, at least partly upward along the outer surface of the drilling device; and with respect to the casing part an internal pressure medium operated hammering device, being placed at an end of a drill rod or rods, at a back part of the drilling unit in order to transmit a hammering motion to the drilling means for drilling, whereby the first drilling means are coupled with the second drilling means first of all power-transmittedly in order to carry out cooperation thereof at least during a drilling situation with the second drilling means for a rotational motion, a feeding motion and the hammering motion, and on the other hand removably in order to enable removal thereof from the hole, whereby the casing part is arranged to be drawn to a hole to be drilled by the drilling unit without rotating the casing part around its longitudinal axis, whereby for producing the hammering motion a hammering device is being used that is operated essentially by a water-based pressure medium and, whereby at least a part of the water-based pressure medium operating the hammering device is used for flushing, wherein the water-based pressure medium is led from the hammering device by the flushing flow arrangement, such as by transmission of a flow channel existing at a center of the drilling unit, to the first and the second drilling means, such as to the drilling surfaces of the first and the second frame parts. 
     
     
         2 . The method according to  claim 1  when operating with a drilling apparatus, wherein the drilling organs of the first and the second drilling means comprise an integrated drilling part, separate drilling pieces, bits or like and, wherein a casing shoe is being exploited for coupling of the drilling unit with an end of the casing part, wherein at least a part of the pressure medium operating the hammering device is being lead by guidance of flow grooves or like in the frame part/parts furthermore radially at an outer periphery of the drilling device in order to assist drifting thereof to outside of the casing part. 
     
     
         3 . The method according to  claim 1 , wherein water, water-polymer mixture, water-bentonite mixture and/or like is being used as the water-based pressure and flushing medium. 
     
     
         4 . The method according to  claim 1 , wherein a reamer is being used as the second drilling means that is rotationally symmetrical and that has an essentially continuing drilling surface radially, when viewed in a cross-section perpendicular to a longitudinal direction(s) of the drilling unit. 
     
     
         5 . The method according to  claim 1 , wherein a reamer is being used as the second drilling means that operates on eccentric principle, being non-symmetrical and that opens radially outwards for drilling. 
     
     
         6 . A drilling apparatus for down-the-hole drilling that has a drilling device, comprising a casing part and at least during a drilling situation an essentially inside thereof existing drilling unit, at the drilling head of which there are at least; a first frame part, a drilling surface of which being provided with first drilling means for drilling a center hole; a second frame part, a drilling surface of which being provided with second drilling means for reaming the center hole for the casing part; a flushing flow arrangement first of all for leading of flushing medium into the drilling head internally in the drilling device, such as through a drill rod/rods and the drilling unit, and on the other hand for leading of drilling waste by influence of the flushing medium to outside of the drilling device, at least partly upward along the outer surface of the drilling device; and with respect to the casing part an internal pressure medium operated hammering device, being placed at an end of a drill rod or rods, at a back part of the drilling unit in order to transmit a hammering motion to the drilling means for drilling, whereby the first drilling means are coupled with the second drilling means first of all power-transmittedly in order to carry out cooperation thereof at least during a drilling situation with the second drilling means for a rotational motion, a feeding motion and the hammering motion, and on the other hand removably in order to enable removal thereof from the hole, whereby the casing part is arranged to be drawn to a hole to be drilled by the drilling unit without rotating the casing part around its longitudinal axis, whereby the drilling device of the drilling apparatus has a hammering device that operates essentially by a water-based pressure medium, and, whereby at least a part of the water-based pressure medium operating the hammering device is used for flushing, characterized in that the flushing flow arrangement, such as a flow channel existing at a center of the drilling unit, is arranged to lead the water-based pressure medium, such as water, water-polymer mixture, water-bentonite mixture and/or like from the hammering device to the first and the second drilling means, such as to the drilling surfaces of the first and the second frame parts. 
     
     
         7 . The drilling apparatus according to  claim 6 , wherein the drilling organs of the first and the second drilling means comprise an integrated drilling part, separate drilling pieces, bits or like and, wherein a casing shoe is being exploited for coupling of the drilling unit with an end of the casing part, characterized in that wherein at least a part of the pressure medium operating the hammering device is lead by guidance of flow grooves or like in the frame part/parts radially at an outer periphery of the drilling device in order to assist drifting thereof to outside of the casing part. 
     
     
         8 . The drilling according to  claim 6 , wherein the second drilling means comprise a reamer that is rotationally symmetrical and that has an essentially continuing drilling surface radially, when viewed in a cross-section perpendicular to a longitudinal direction(s) of the drilling unit. 
     
     
         9 . The drilling apparatus according to  claim 6 , wherein the second drilling means comprise a reamer that operates on eccentric principle, being non-symmetrical and that opens radially outwards for drilling.