US Patent 7584794 Mechanical and fluid jet horizontal drilling method and apparatus

A device useful for conducting lateral or transverse excavating operations within a wellbore comprising a rotating drill bit with jet nozzles on a flexible arm. The arm can retract within the housing of the device during deployment within the wellbore, and can be extended from within the housing in order to conduct excavation operations. A fluid pressure source for providing ultra high pressure to the jet nozzles can be included with the device within the wellbore. The device includes a launch mechanism that supports the arm during the extended position and a positioning gear to aid during the extension and retraction phases of operation of the device.