摘要 |
In a method for producing a cased horizontal string bore extending from a well shaft, a starter drill pipe is driven into the rock mass surrounding the well shaft. A hydraulically driven drill motor is arranged in the starter drill pipe and rotates a drilling tool protruding from the leading end of the starter drill pipe. The drill motor is fixed against rotation and axial displacement by a clamping device. When the final depth of the string bore is reached, the drilling tool is retracted into the starter drill pipe by axial movement of the clamping device and a free space is formed at the drift face of the string bore. The free space is filled and sealed by injection of a quick-setting, expanding filling compound. Afterwards, the clamping device, the drill motor and the drilling tool are removed from the drill pipes.
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