A DOWNHOLE-DRILLING TOOL WITH HIGH-PRESSURE AND CONTINUOUS-FLOW JET AND A METHOD FOR BREAKING THE ROCK

摘要

The invention discloses a downhole-drilling tool with high-pressure and continuous-flow jet and a method for breaking the rock. The downhole-drillin g tool includes a drill pipe, filter, turbine unit, centrifugal pump or axial flow pump and drill bit. The drill pipe is driven by ground rotary table or top driving unit and is provided at its bottom with a drill bit. A high- pressure jet nozzle and a low-pressure jet nozzle is mounted on the drill bi t. A filter, a turbine unit and a multistage centrifugal pump or axial flow pum p are arranged sequently in the direction of the axes of drill pipe inside of the drill pipe. The said turbine unit has a hollow shaft that is connected with the filter. The input end of the pump's shaft is connected with output end of the hollow shaft. The invention can create continuous jet stream with high-pressure down the hole to break the rock and clean the debris so that t he drilling speed is increased.