A long-distance core drilling method suitable for a horizontal geological core drilling rig. (1) An active drill rod is connected to a drill rod, which is connected to a wireline-coring outer-tube drilling tool. (2) A steel-pipe string is connected to a fishing device, and the fishing device is connected to a spearhead on a core tube, which is placed to a designated position through a pipe-feeding mechanism. (3) A washing pump is started. (4) A core drilling is carried out. (5) A core is pulled out. (6) The steel-pipe string and the fishing device are reconnected. (7) The core tube is salvaged. (8) The core tube and drill pipe are replaced. (9) A hole is swept. (10) Steps (1)-(9) are repeated until the hole is drilled to a designated depth. (11) The core tube and the wireline-coring outer-tube drilling tool are recovered.

A drilling mechanism of a coring drilling rig has a central rod, a fluid channel starting module, an outer barrel, an outer barrel unlocking module, a flow diverging module and a drill bit. The central rod penetrates the fluid channel starting module. The outer barrel unlocking module and an inner cavity of the flow diverging module from back to front. The fluid channel starting module is behind the outer barrel and is connected to the outer barrel unlocking module. The flow diverging module is in front of the outer barrel unlocking module, and a hydraulic motor is connected in front of the flow diverging module. The outer barrel has a driving section that is a rotor of the hydraulic motor. The outer wall of the outer barrel is fixedly connected to a centralizer, and the front end of the outer barrel is connected to the drill bit.

A drilling mechanism of a coring drilling rig has a central rod, a fluid channel starting module, an outer barrel, an outer barrel unlocking module, a flow diverging module and a drill bit. The central rod penetrates the fluid channel starting module. The outer barrel unlocking module and an inner cavity of the flow diverging module from back to front. The fluid channel starting module is behind the outer barrel and is connected to the outer barrel unlocking module. The flow diverging module is in front of the outer barrel unlocking module, and a hydraulic motor is connected in front of the flow diverging module. The outer barrel has a driving section that is a rotor of the hydraulic motor. The outer wall of the outer barrel is fixedly connected to a centralizer, and the front end of the outer barrel is connected to the drill bit.

A drilling control mechanism of a core drilling rig has a tooth drill and a core drilling rig. The core drilling rig is inside the tooth drill and engages with the drill in a sliding manner. A locking recess is formed at an inner wall of the tooth drill. A locking latch recess is formed at an outer wall of the core drilling rig and has a locking latch therein. The locking latch has a spring. When the locking recess is directly opposite the locking latch recess, the spring extends and the locking latch partially enters the locking recess. The core drilling rig has a central rod, a fluid channel activation module, an outer barrel, and outer barrel unlocking module and a flow diverging module. The central rod passes through the inner cavities of the fluid channel activation module, the outer barrel unlocking module and the flow diverging module.

A drilling control mechanism of a core drilling rig has a tooth drill and a core drilling rig. The core drilling rig is inside the tooth drill and engages with the drill in a sliding manner. A locking recess is formed at an inner wall of the tooth drill. A locking latch recess is formed at an outer wall of the core drilling rig and has a locking latch therein. The locking latch has a spring. When the locking recess is directly opposite the locking latch recess, the spring extends and the locking latch partially enters the locking recess. The core drilling rig has a central rod, a fluid channel activation module, an outer barrel, and outer barrel unlocking module and a flow diverging module. The central rod passes through the inner cavities of the fluid channel activation module, the outer barrel unlocking module and the flow diverging module.

In preparation for directional drilling, a wedge supported distally ahead of a tubular drill string is advanced along a parent hole. The wedge is connected to the drill string by a rigid link that extends along a central longitudinal axis through an annular cutting head. The wedge may be connected to the drill string via an inner dropper mechanism that can be engaged by a wireline lifting system. After locking the wedge at a kick-off point in the hole at a desired azimuth, the connection of the link is broken. The dropper mechanism can then be retrieved and replaced by an inner core tube, without moving the drill string. The drill string is then advanced to drill a daughter hole that branches from the parent hole on the azimuth determined by the wedge. Advantageously, there is no need to withdraw the drill string before drilling the daughter hole can commence.

In preparation for directional drilling, a wedge supported distally ahead of a tubular drill string is advanced along a parent hole. The wedge is connected to the drill string by a rigid link that extends along a central longitudinal axis through an annular cutting head. The wedge may be connected to the drill string via an inner dropper mechanism that can be engaged by a wireline lifting system. After locking the wedge at a kick-off point in the hole at a desired azimuth, the connection of the link is broken. The dropper mechanism can then be retrieved and replaced by an inner core tube, without moving the drill string. The drill string is then advanced to drill a daughter hole that branches from the parent hole on the azimuth determined by the wedge. Advantageously, there is no need to withdraw the drill string before drilling the daughter hole can commence.

A reverse-circulation drilling assembly having an overshot subassembly and a head subassembly. In the event retrieval of the drilling assembly by reverse-circulation fails, the drilling assembly can be retrieved using a secondary overshot.

A coring drill tool driving structure has a driving motor (7), an outer cylinder (23) and a coring drill tool (8). The driving motor comprises an outer rotor (73) and an inner stator (75), the inner wall of the outer rotor and the outer wall of the inner stator are provided with ribs (77) mutually matched, the outer rotor and inner stator are in clearance fit, the clearance between the outer rotor and the inner stator is a driving liquid flow path (74), the outer rotor length is smaller than the inner stator length, the outer rotor is located between front and rear ends of the inner stator, the outer rotor is connected to the outer cylinder, a front end of the outer cylinder is connected to the coring drill tool, and a rear end of the inner stator is connected to a coupling (76).

In preparation for directional drilling, a wedge supported distally ahead of a tubular drill string is advanced along a parent hole. The wedge is connected to the drill string by a rigid link that extends along a central longitudinal axis through an annular cutting head. The wedge may be connected to the drill string via an inner dropper mechanism that can be engaged by a wireline lifting system. After locking the wedge at a kick-off point in the hole at a desired azimuth, the connection of the link is broken. The dropper mechanism can then be retrieved and replaced by an inner core tube, without moving the drill string. The drill string is then advanced to drill a daughter hole that branches from the parent hole on the azimuth determined by the wedge. Advantageously, there is no need to withdraw the drill string before drilling the daughter hole can commence.