Method and apparatus for mining an underground ore stratum with a drilling and mining tool which first drills a hole into the strata as it is assembled section by section until a desired depth is reached. The tool includes an outer conduit that is screwed together and at least two stab fitted inner conduits that are rotatable relative to the outer conduit for providing at least three conduit systems for conducting processing fluids into and out of the ore strata; and means for independently controlling, from the surface, the rate of flow in each conduit. During mining, one conduit system directs the flow of a mining liquid downwardly and into the ore stratum through a mining nozzle to create a slurry of ore and liquid, a second conduit system directs a slurry lifting fluid downwardly into and through a slurry lifting means, while a third conduit system conducts the slurry to the surface. During drilling, flow switching means communicating with one of the conduit systems is provided to direct a fluid through a drill bit into the hole being formed to wash the cuttings to the surface. During both drilling and mining the portion of the tool extending into the hole is rotated. In the first illustrated embodiment the slurry is lifted by an eductor pump, while an air lift is provided for additional embodiments.
A device for borehole hydraulic mining includes a pipeline for delivering fluid into the hole accommodated inside a pipeline for bringing pulp to the surface and featuring a constant inside diameter along the entire length of this pipeline. The pipeline for delivering fluid into the hole carries a hydraulic jet. The device also has a hydraulic elevator with a fluid and pulp mixing chamber secured to the lower end of the pipeline for bringing pulp to the surface, and a nozzle secured to the lower end of the pipeline for delivering fluid into the hole. The fluid and pulp mixing chamber and the nozzle of the hydraulic elevator enclose the pipeline for drilling fluid into the hole with clearances allowed.
A method and an apparatus for excavating pile holes of various shapes, including a pile hole with a widened bottom and a pile hole with a widened top and widened bottom, by means of an excavating bit and widening bits.
A wellbore jetting tool has a novel packer assembly which enables the tool to be raised, lowered and rotated while operating, a nozzle which automatically raises to extend radially from the tool, and a flow system for returning slurry in an inner tube of cross section. The packer assembly is hydraulically actuated, and traps fluid to provide lubrication, which enables raising, lowering and rotation during operation while substantially maintaining the necessary sealing. The nozzle is raised by a torque generated by vanes disposed within the nozzle head reacting to fluid flow, and also by thrust from the cutting jet. The nozzle discharges this jet at an angle, thus biasing the nozzle appropriately. A breakaway feature allows abandonment of the nozzle if it jams when it is extended, ensuring that the pipestring may always be retrieved. The return of slurry through its own conduit reduces chances of a particle lodging in the slurry return line.
A method and apparatus for removing drilling mud within entrained cuttings is provided using a pump for forcing fluid into a borehole, such that the fluid mixes with cuttings formed during the formation of the hole. The pipe receives the fluid and entrained cuttings at a first end of the pipe and returns the fluid and entrained cuttings to the surface at the second end of the pipe. At the first end of the pipe, air is injected into the drilling fluid with entrained cuttings to form bubbles therein, thereby increasing the velocity of the fluid and entrained cuttings through the pipe. In one alternative embodiment, a suction is provided at one end of the pipe to increase the speed of fluid and entrained cuttings therethrough. In a third embodiment of the present invention, an Archimedes screw is used to remove the fluid and entrained cuttings from the borehole.
