A drill head driving system for a drill bit to drill a wellbore, wherein the drill head driving system is provided with a drill head for mounting with the drill bit; a pressing mechanism for applying a pressing force directed down the wellbore, characterised in that the drill head driving system comprises a first coiled tube being coiled from a first strip wound on a first drum and fed into the wellbore, wherein an end of the first coiled tube is attached to the drill head; a tube clamping mechanism arranged in the upper portion of the first coiled tube in a section of the first strip which is already coiled into the first coiled tube; wherein the pressing mechanism is for transferring the pressing force to the tube clamping mechanism, the tube clamping mechanism transfers the force to the section of the first strip which is already coiled into the first coiled tube, and via the first coiled tube to the drill head; wherein the first coiled tube is partially open, and the connection between the tube clamping mechanism and the pressing mechanism constitutes a first interface, the first interface is movable in the opening of the first coiled tube, and the system further comprises a casing tube coiled from a second strip wound from a second drum, wherein the first coiled tube and the casing tube are substantially coaxial, and the diameter of the casing tube is greater than the diameter of the first coiled tube, wherein ends of the first coiled tube and the casing tube cooperate with each other via a second interface, said the second interface transfers the force directed from the first drum, the force is exerted by the end of the first coiled tube on the end of the casing tube, wherein the second interface comprises a first element connected to the drill head and a second element connected to the lower end of the casing tube and arranged within the casing tube, the second interface being releasable under a force directed towards a surface, applied to the first element. a drill head for mounting with the drill bit; a pressing mechanism for applying a pressing force directed down the wellbore, characterised in that the drill head driving system comprises a first coiled tube being coiled from a first strip wound on a first drum and fed into the wellbore, wherein an end of the first coiled tube is attached to the drill head; a tube clamping mechanism arranged in the upper portion of the first coiled tube in a section of the first strip which is already coiled into the first coiled tube; a first coiled tube being coiled from a first strip wound on a first drum and fed into the wellbore, wherein an end of the first coiled tube is attached to the drill head; a tube clamping mechanism arranged in the upper portion of the first coiled tube in a section of the first strip which is already coiled into the first coiled tube; wherein the pressing mechanism is for transferring the pressing force to the tube clamping mechanism, the tube clamping mechanism transfers the force to the section of the first strip which is already coiled into the first coiled tube, and via the first coiled tube to the drill head; wherein the first coiled tube is partially open, and the connection between the tube clamping mechanism and the pressing mechanism constitutes a first interface, the first interface is movable in the opening of the first coiled tube, and the system further comprises a casing tube coiled from a second strip wound from a second drum, wherein the first coiled tube and the casing tube are substantially coaxial, and the diameter of the casing tube is greater than the diameter of the first coiled tube, wherein ends of the first coiled tube and the casing tube cooperate with each other via a second interface, said the second interface transfers the force directed from the first drum, the force is exerted by the end of the first coiled tube on the end of the casing tube, wherein the second interface comprises a first element connected to the drill head and a second element connected to the lower end of the casing tube and arranged within the casing tube, the second interface being releasable under a force directed towards a surface, applied to the first element.