A drilling tool is disclosed. The two ends of the drilling tool are respectively connected with an upper drilling tool and a drill bit. The drilling tool includes an axial striking part, a torsional striking part, and an auxiliary part. Under the combined action of a spring and a high-pressure drilling fluid, the hammer of the axial striking part generates an axial striking force to strike the upper housing; and the pendulum of the torsional striking part generates a torsional striking force to strike the lower housing. The reversing switch and the center tube are plugged together to simultaneously reverse torsion and axial striking forces, respectively. The high-pressure drilling fluid pushes the hammer and the pendulum to generate axial and torsional striking forces, respectively, to effectively increase the ROP and reduce the stick-slip phenomenon. The drilling tool is stable and reliable in a complex and changeable downhole environment.

A drilling tool is disclosed. The two ends of the drilling tool are respectively connected with an upper drilling tool and a drill bit. The drilling tool includes an axial striking part, a torsional striking part, and an auxiliary part. Under the combined action of a spring and a high-pressure drilling fluid, the hammer of the axial striking part generates an axial striking force to strike the upper housing; and the pendulum of the torsional striking part generates a torsional striking force to strike the lower housing. The reversing switch and the center tube are plugged together to simultaneously reverse torsion and axial striking forces, respectively. The high-pressure drilling fluid pushes the hammer and the pendulum to generate axial and torsional striking forces, respectively, to effectively increase the ROP and reduce the stick-slip phenomenon. The drilling tool is stable and reliable in a complex and changeable downhole environment.

A down the hole drilling assembly having an elongate casing, a fluid powered piston, top and bottom working chambers, a plurality of fluid passages and an exhaust system, wherein the sum of the top work area and a top intermediate work area of the piston is equal to the cross-sectional area of the casing bore.

A down the hole drilling assembly having an elongate casing, a fluid powered piston, top and bottom working chambers, a plurality of fluid passages and an exhaust system, wherein the sum of the top work area and a top intermediate work area of the piston is equal to the cross-sectional area of the casing bore.

A jarring apparatus includes first and second jarring assemblies which are axially moveable relative to each other between first and second axial configurations, and a thrust assembly interposed between the first and second jarring assemblies to limit relative axial movement therebetween at the second axial configuration and permit axial loading in one axial direction to be transferred between the first and second jarring assemblies via the thrust assembly. The apparatus further includes a jarring mass axially moveable within the jarring apparatus in reverse first and second directions upon relative rotation between the first and second jarring assemblies.

A jarring apparatus includes first and second jarring assemblies which are axially moveable relative to each other between first and second axial configurations, and a thrust assembly interposed between the first and second jarring assemblies to limit relative axial movement therebetween at the second axial configuration and permit axial loading in one axial direction to be transferred between the first and second jarring assemblies via the thrust assembly. The apparatus further includes a jarring mass axially moveable within the jarring apparatus in reverse first and second directions upon relative rotation between the first and second jarring assemblies.

A method for maintaining a penetration rate of a drilling operation, where the drilling operation is carried out by a drilling rig having a hammer drill apparatus. A reference penetration rate for the hammer drill bit is chosen. A starting depth of cut is computed from the reference penetration rate, the measured hammer frequency, and the drill bit parameters. The system measures the actual penetration rate of the drill bit and computes an actual depth of cut. From the actual depth of cut a target bit rotation speed is computed. The target rotation speed is compared to the actual rotation speed, and the rotation speed is adjusted up or down to set the bit rotation speed at a value that will maintain the target rotation speed, notwithstanding changes in hammer frequency or ground conditions.

A method for maintaining a penetration rate of a drilling operation, where the drilling operation is carried out by a drilling rig having a hammer drill apparatus. A reference penetration rate for the hammer drill bit is chosen. A starting depth of cut is computed from the reference penetration rate, the measured hammer frequency, and the drill bit parameters. The system measures the actual penetration rate of the drill bit and computes an actual depth of cut. From the actual depth of cut a target bit rotation speed is computed. The target rotation speed is compared to the actual rotation speed, and the rotation speed is adjusted up or down to set the bit rotation speed at a value that will maintain the target rotation speed, notwithstanding changes in hammer frequency or ground conditions.

There is disclosed a device for boring holes in a ground surface comprising: a core barrel having a barrel top and an open barrel bottom, the barrel top having a shaft mounted thereto for engaging with a rotary power source for rotating the core barrel; at least one cutting member mounted to the core barrel at the open barrel bottom; and a pressurised fluid source in fluid communication with the shaft for delivering a supply of pressurised fluid to the shaft; wherein the at least one cutting member is configured such that when it is mounted to the core barrel at the open barrel bottom, the pressurised fluid causes the at least one cutting member to perform a cutting motion to remove the ground surface.

A hydraulic rock breaking machine and an apparatus and method for monitoring operation of the same is provided. The apparatus includes at least one pneumatic sensor arranged for monitoring an inner space of the machine and at least one control unit configured to receive and process the pneumatic sensing data.