Method and device for fusion drilling

Abstract

The invention relates to a method for fusion drilling and to a fusion drilling device for producing dimensionally accurate bores, manholes rock and tunnels in the ground, particularly in rock. A drill hole bottom is molten by a melt and the overburden melt is pressed into the surroundings, particularly the surrounding rock which has cracked open under the effects of the temperature and pressure, and wherein during drilling, a drill hole lagging ( 9 ) is produced around piping formed by line elements ( 1, 2, 3 ). In a recess ( 5 ) of at least one lower line element ( 1 ) of the piping, said recess being particularly centric and open towards the top, metal ( 7 ) in a solid state of aggregation is fed from the top thereof, particularly through line elements ( 2, 3 ) arranged on the top thereof. The metal is molten in said recess ( 5 ) by feeding energy and is conducted through channels ( 6 ) extending from the recess ( 5 ) toward the outside and ending in the lateral surface of a line element ( 1 ) into the outer surroundings of the line element ( 1 ). A rock melt formed beneath the lowest line element ( 1 ) is pressed into the surrounding rock ( 14 ) and forms a metal lagging ( 9 ) surrounding the piping ( 1, 2, 3 ) by solidifying.

1 . In a fusion-drilling method for producing dimensionally accurate boreholes, manholes and tunnels in rock, where a drill-hole floor is melted by a molten metal mass and the molten material of the floor is pressed into the surrounding rock that has been cracked open by temperature and pressure, and where during drilling a drill-hole casing is formed around a well string of line elements by solidifying molten metal, the steps of:
 feeding from above metal in a solid state into a central and upwardly open chamber of at least one lower line element of the well string through line elements thereabove, and   melting the solid metal in the chamber by fed in energy into molten metal that is conducted through passages extending outward from the chamber and ending at the outer surface of the line element into the outer surroundings of the line element, and molten rock thus formed below the lowermost line element is pressed into the surrounding rock and a metal casing is formed surrounding the well string on solidification.   
     
     
         2 . The method according to  claim 1 , wherein the molten rock generated below the lowermost line element, in particular by the molten metal, is superheated by direct energy supply to a greater extent than the molten metal and thus a continuous melting of the rock takes place. 
     
     
         3 . The method according to  claim 1 , wherein energy is supplied to the molten rock or molten metal by an electric current that is conducted through lines from the surface to the lowermost line element or the line element having the passages, or is generated by means of at least one reactor that is integrated into one of the line elements, or takes place by laser radiation that is guided from the surface to pass centrally through all line elements down to the drill-hole floor. 
     
     
         4 . The method according to  claim 1 , wherein for generating an initial molten rock, a molten metal generated in the line element having the passages is fed through the passages and along the outer surface of the line element to the drill-hole floor. 
     
     
         5 . The method according to  claim 1 , wherein for starting a fusion-drilling process first a pilot bore with a drill-hole floor is generated into which a metal pipe is inserted as initial drill-hole casing, wherein into the metal pipe at least one line element having the passages and at least one line element for shaping the metallic drill-hole casing are inserted, and the molten metal exiting through the passages, in particular under inherent pressure, fills a free space between drill-hole floor and drill hole wall and bonds with the metal pipe of the pilot bore to form a metal casing that builds up continuously as drilling progresses. 
     
     
         6 . The method according to  claim 5 , wherein upstream of the line element having the passages at least one further line element is inserted into the pilot bore so as to obtain a desired length of the well string below the passage openings or that the line element having the passages has a desired length below the passage openings, the desired length being determined by the intended drilling depth and the wear of the line element expected for the drilling depth. 
     
     
         7 . The method according to  claim 1 , wherein the infeed of the metal when heating with an electric current is carried out by a solid metal rod fed in through the line elements or, when heating with laser, through the line elements as a tubular metal rod through which the laser beam is guided. 
     
     
         8 . The method according to  claim 1 , wherein the molten rock is heated to a higher temperature than the molten metal so that due to the higher surface tension, the higher density and higher viscosity of the cooler molten metal with respect to the hotter molten rock, a mixing of molten metal and molten rock is prevented and during the drilling progress, on the one hand, a metal drill-hole casing is continuously build up from a single casting and, on the other, the less viscous molten rock is displaced by the high surface tension and the density contrast of the molten metal into the surrounding rock cracked open by temperature and pressure, in particular without metal getting lost in the surrounding rock. 
     
     
         9 . The method according to  claim 1 , wherein the transmission of the melting energy into the melts, or a manipulation of the melts for generating a rotating or pivotable melt, in particular for forming a wear-free melting drill head, or the control of the entire installation by “Electrical Resistance Tomography” is carried out by means of three graphite electrodes integrated and insulated in a lower line element, which graphite electrodes, by means of phase shift and lo different load application during energizing, effect the rotational or pivoting movement of the melts, wherein in particular the ERT program detects the molten metal distribution upstream of the fusion-drilling apparatus and makes it visible on the monitor and allows a fully automatic control of the fusion-drilling method. 
     
     
         10 . The method according to  claim 1 , wherein three types of line elements are used that divide a drilling string formed from the line elements into a hot part, a pulling or cooling part and a cold part, the line elements of the hot part being formed as tubular graphite cylinders, the line elements of the pulling or cooling part being formed from a particularly high-strength metal and being between the hot and the cold part and used for shaping, in particular expanding and finishing the metal drill-hole casing, and the line elements of the cold part being of a particularly pressure-resistant metal construction and used in particular for generating pressure or infeeding control and energy devices as well as solid metal that is conveyed through the line elements to the lower line element, in particular the line element at a lower end of the drill hole where the solid metal is melted. 
     
     
         11 . The method according to  claim 1 , wherein assembly and disassembly of the line elements of the drilling string, provided that the line elements themselves are not equipped as an elevator system, in particular a Maglev system, are carried out by an elevator, in particular a Maglev elevator, by means of which in particular also the supply of solid metal, in particular as metal rod elements for the well bore metal casing, is carried out, in particular if the drilling string does not run from bottom to top through the drill hole. 
     
     
         12 . The method according to  claim 1 , wherein heat is extracted from the metal drill-hole casing via an SC water cooling system, and a power supply is cooled by steam jet chillers. 
     
     
         13 . The method according to  claim 1 , wherein supply lines, in particular lines if the power supply or cooling lines or supply elements or line elements extend along the metal-cased drill hole wall by an electromagnetic step system. 
     
     
         14 . A fusion-drilling apparatus for producing fusion drill holes in rock, by means of which the drill-hole floor can be melted and by means of which a drill-hole casing made of metal can be formed, comprising a well string of line elements, wherein a lowermost line element of the well string, has a central upwardly open chamber into which metal as a solid rod, is fed from above through the line elements thereabove, wherein the solid material in the chamber can be melted by feeding energy and the line element has passages that extend from the chamber toward the outside and open out in the outer surface of the line element so that melted metal can be conducted through the passages into the outer surroundings of the line element. 
     
     
         15 . The apparatus according to  claim 14 , wherein the apparatus comprises a feeding element that is configured as elevator, in particular MagLev elevator, or as sliding element, and by means of which makeup supply material, in particular solid metal or supply material or line elements can be moved or assembled in the longitudinal extension of the metal-lined drill hole. 
     
     
         16 . The apparatus according to any one of the preceding  claims 14 , wherein the apparatus comprises three types of line elements that divide a drilling string formed from the line elements into a hot part, a pulling or cooling part and a cold part, one line element of the hot part being formed as tubular graphite cylinder, one line element of the pulling or cooling part being formed from a particularly high-strength metal and being between the hot and the cold part and used for shaping, in particular expanding and finishing the metal drill-hole casing, and one line element of the cold part being formed from particularly pressure-resistant composite material and comprising in particular control and transport devices and being used for generating pressure or for feeding in solid metal through the line elements to the lower line element, in particular the line element at a lower end of the drill hole, in which line element the solid metal can be melted. 
     
     
         17 . The apparatus according to  claim 16 , wherein one line element of the cold part is inactive and has sliding properties with respect to the drill-hole casing or a fed-in metal rod, which properties are imparted by carbon spacers as sliding elements that are arranged in the surface of the outer or shell of the line element. 
     
     
         18 . The apparatus according to  claim 16 , wherein one line element of the cold part is active and is configured in particular as controlled elevator, in particular magnetic slider having spacing and holding functions with respect to the metal drill hole wall and by means of which a metal rod can be fed toward the drill-hole floor or can be retrieved. 
     
     
         19 . The apparatus according to  claim 14 , wherein at least one line element is configured as an elevator, in particular Maglev elevator and uses the drill hole metal casing as reaction rail or sliding rail for the vertical, in particular contactless transport. 
     
     
         20 . The apparatus according to  claim 14 , wherein feeding the electric cable and feeding the cooling water line, in particular in the TubeCoil system, is carried out electromagnetically by a self-actuating stepping system that is carried on the drill hole wall by magnetic adhesion or is integrated in the drilling string if the drilling string runs continuously through the drill hole. 
     
     
         21 . The apparatus according to  claim 14 , wherein on its outside, the at least one line element of the pulling part expands conically upward and this line element, in particular under the pressure of the line elements arranged thereabove, compacts or expands or smooths the already solidified but still glowing hot, forgeable metal casting casing, in particular in such a manner that in the cold state, the latter provides sufficient space for an air gap of the Maglev elevator. 
     
     
         22 . The apparatus according to  claim 21 , wherein one line element of the pulling part consists of at least one particularly high-strength metal alloy and has a reinforcement layer of zircon. 
     
     
         23 . The apparatus according to  claim 14 , wherein a total length of the line elements strung together is smaller than the spacing between drill-hole floor and the surface and is in particular selected such that a weight of the line elements is achieved that is necessary to press the generated molten rock into the surroundings of the drill hole and to densify the metal casting casing to a desired dimension to expand it or to provide it with a smoothed, in particular mirror-smooth surface. 
     
     
         24 . The apparatus according to  claim 14 , wherein for building up the metal drill-hole casing, the fed in metal rod is fits received in the a cylindrical passage of at least one of the line elements of the hot part, in particular the ones made of graphite, and can be melted in particular electrically or with laser light in a melt zone upstream of or in a line element having passages, a central bore of the line element expanding conically downward, in particular to the extent as it is required by the material expansion due to temperature increase so that by the weight of the metal rod, a required compressive pressure can be generated in the melt. 
     
     
         25 . The apparatus according to  claim 14 , wherein the melt energy supply is carried out per laser beam through a hollow metal rod that feeds in metal and extends into the melt zone of a line element having passages and further down to the drill-hole floor. 
     
     
         26 . The apparatus according to  claim 14 , wherein in an embodiment for melting by an electric current, a line element having the passages, in particular a graphite line element, is closed downward and in an embodiment for melting by laser beam, has a passage opening downward for the laser beam. 
     
     
         27 . The apparatus according to  claim 14 , wherein a lowermost line element, in particular a line element having the passages, comprises at least one electrode, preferably three electrodes, which in particular extend axially in the line element and are arranged at a uniform angular spacing and end in the bottom face of the line element facing the drill-hole floor and can generate a current flow in the melt. 
     
     
         28 . The apparatus according to  claim 14 , wherein the laser beam with its high energy penetrates to the rock of the drill hole floor and with the radiation pressure of the laser, the necessary compression pressure can be generated at the same time in the melt. 
     
     
         29 . The apparatus according to  claim 14 , wherein magnetohydrodynamic valves or check valves are mounted in the line elements of the pulling part so as to prevent the molten metal from rushing up into the metal well string in the event that the laser beam is interrupted or fails. 
     
     
         30 . The apparatus according to  claim 14 , wherein the lowermost line element that in particular forms the actual drilling head, is formed tapered upward, in particular conically tapered.