Pipework system, in particular conveyor pipework system, supporting pipework system or anchoring pipework system for a downhole heat exchanger for obtaining geothermal energy, in particular deep geothermal energy, wherein thermal energy is transported by means of a preferably liquid heat transfer medium from a deep region into an upper region of the downhole heat exchanger, (a) having an outer pipe made from a metal and (b) having an inner pipe which is provided within the outer pipe, is made from a thermally insulating plastic, and consists of a plurality of inner pipe sections, (c) wherein the inner pipe is connected to the outer pipe at two or more axial positions of the pipework system by means of in each case one load transmission device for introducing axial forces which act on the inner pipe onto the outer pipe, characterized (d) in that the inner pipe sections are coupled in axial sections between two load transmission devices at coupling points between in each case two immediately adjacent ends of the inner pipe sections and/or at least at a coupling point between one of the two load transmission devices and the immediately adjacent end of the relevant inner pipe section, wherein the coupling is generated or at least assisted by way of axial pressure forces at the coupling points without an integrally joined connection, (e) in that the outer conveyor pipe consists of a plurality of outer pipe sections and in that the load transmission devices provided between the upper and the lower end of the pipework system in each case have a projection which protrudes in a radial direction beyond the inner circumference of the outer conveyor pipe and which engages in an axial spacer gap between end faces, facing each other, of in each case two adjacent outer pipe sections or which engages in one or more fold-like recesses, which are formed on the inner edge of one or both end faces, facing each other, of in each case two adjacent outer pipe sections, and (f) in that the load transmission devices in each case consist exclusively of a single load transmission element (25, 33, 39, 41, 43, 45), which is formed substantially hollow cylindrical and is provided in the axial course of the inner conveyor pipe, wherein the inner wall of the load transmission element (25, 33, 39, 41, 43, 45) also forms the inner wall of the inner conveyor pipe. (a) having an outer pipe made from a metal and (b) having an inner pipe which is provided within the outer pipe, is made from a thermally insulating plastic, and consists of a plurality of inner pipe sections, (c) wherein the inner pipe is connected to the outer pipe at two or more axial positions of the pipework system by means of in each case one load transmission device for introducing axial forces which act on the inner pipe onto the outer pipe, characterized (d) in that the inner pipe sections are coupled in axial sections between two load transmission devices at coupling points between in each case two immediately adjacent ends of the inner pipe sections and/or at least at a coupling point between one of the two load transmission devices and the immediately adjacent end of the relevant inner pipe section, wherein the coupling is generated or at least assisted by way of axial pressure forces at the coupling points without an integrally joined connection, (e) in that the outer conveyor pipe consists of a plurality of outer pipe sections and in that the load transmission devices provided between the upper and the lower end of the pipework system in each case have a projection which protrudes in a radial direction beyond the inner circumference of the outer conveyor pipe and which engages in an axial spacer gap between end faces, facing each other, of in each case two adjacent outer pipe sections or which engages in one or more fold-like recesses, which are formed on the inner edge of one or both end faces, facing each other, of in each case two adjacent outer pipe sections, and (f) in that the load transmission devices in each case consist exclusively of a single load transmission element (25, 33, 39, 41, 43, 45), which is formed substantially hollow cylindrical and is provided in the axial course of the inner conveyor pipe, wherein the inner wall of the load transmission element (25, 33, 39, 41, 43, 45) also forms the inner wall of the inner conveyor pipe.