The present invention provides a downhole auxiliary drilling apparatus, including an impact energy generator capable of converting the energy of the drilling fluid to the axial impact energy, and an impact energy distributor capable of redistributing the impact energy generated by the impact energy generator to convert the axial impact force into a combined impact force, which provides the drilling bit with a high-frequently changing combined impact force, thus greatly improving the rock breaking efficiency and the rate of penetration of the drilling tool. The downhole auxiliary drilling apparatus is further provided with a shock-absorbing and torque-stabilizing device arranged between the impact energy generator and the impact energy distributor, which can reduce the axial vibration of the drilling tool and the damage on the drilling bit, and greatly extend the lifetime of the drilling bit.

A device for generating pressure waves in a well or a wellbore. The device includes a housing containing an impact-generating mechanism for generating the pressure waves and a connector for connecting the housing to a conveyor for transporting the device to any desired location within the well or the wellbore. The device may be used for a number of downhole applications such as cleaning perforations, fracturing processes, vibration of a casing to prevent fluid flow in a cemented annulus, hydraulic jar operations for freeing stuck downhole objects, generating data to optimize pumping parameters and as an enhancement to percussion drilling techniques.

A jarring apparatus includes first and second jarring assemblies rotatable relative to each other. A first impact surface is provided on the first jarring assembly and a second impact surface is provided on the second jarring assembly, wherein, in use, the first and second impact surfaces are biased together. A first lifting structure is rotatably fixed relative to the first jarring assembly and a second lifting structure is rotatably fixed relative to the second jarring assembly, the first and second lifting structures being configured to cooperate during relative rotation therebetween to cause cyclical relative displacement in one axial direction to define a lifting phase and relative displacement in a reverse axial direction to define a dropping phase. The first and second lifting structures are axially fixed relative to their associated jarring assembly during the lifting phase to provide axial separation between the first and second impact surfaces, and the second lifting structure is axially released relative to the second jarring assembly prior to initiation of the dropping phase to permit the first and second impact surfaces to be axially impacted together.

A jarring apparatus includes first and second jarring assemblies rotatable relative to each other. A first impact surface is provided on the first jarring assembly and a second impact surface is provided on the second jarring assembly, wherein, in use, the first and second impact surfaces are biased together. A first lifting structure is rotatably fixed relative to the first jarring assembly and a second lifting structure is rotatably fixed relative to the second jarring assembly, the first and second lifting structures being configured to cooperate during relative rotation therebetween to cause cyclical relative displacement in one axial direction to define a lifting phase and relative displacement in a reverse axial direction to define a dropping phase. The first and second lifting structures are axially fixed relative to their associated jarring assembly during the lifting phase to provide axial separation between the first and second impact surfaces, and the second lifting structure is axially released relative to the second jarring assembly prior to initiation of the dropping phase to permit the first and second impact surfaces to be axially impacted together.

The present invention relates to a hydraulically powered percussion mechanism (12), comprising a piston (6) to impact a percussion bit (8). The percussion mechanism also includes a first accumulator assembly (3a) for hydraulic fluid. The first accumulator assembly comprises a plurality of first accumulator elements (27). In a first aspect, the plurality of first accumulator elements are arranged in a common housing (14). In a second aspect, each of the first accumulator elements is arranged at the same proximity to the piston. In a third aspect, each of the first accumulator elements comprises an accumulator membrane (32) or piston, and wherein the primary direction of movement of the membrane or piston in contact with the hydraulic fluid is substantially parallel to a longitudinal axis of the mechanism.

The present invention relates to a hydraulically powered percussion mechanism (12), comprising a piston (6) to impact a percussion bit (8). The percussion mechanism also includes a first accumulator assembly (3a) for hydraulic fluid. The first accumulator assembly comprises a plurality of first accumulator elements (27). In a first aspect, the plurality of first accumulator elements are arranged in a common housing (14). In a second aspect, each of the first accumulator elements is arranged at the same proximity to the piston. In a third aspect, each of the first accumulator elements comprises an accumulator membrane (32) or piston, and wherein the primary direction of movement of the membrane or piston in contact with the hydraulic fluid is substantially parallel to a longitudinal axis of the mechanism.

A pressurized fluid flow system for a down the hole drill hammer has main and auxiliary chambers that exert work on the piston. The auxiliary chambers are formed around respective waists on the piston and externally delimited by respective cylinders which are arranged longitudinally in series. A set of supply chambers filled with the pressurized fluid are defined by annular recesses in the external surface of the piston for supplying said fluid to the chambers. Supply channels and discharge channels are formed in between the outer casing and the cylinders for respectively supply pressurized fluid through exit ports in the cylinders to the supply chambers and emptying the chambers through discharge ports in the cylinders. The supply and discharge of the chambers is controlled in a cooperative way by the piston and the cylinders. A normal circulation drill hammers is provided having this system.

A jarring apparatus includes first and second jarring assemblies rotatable relative to each other. A first impact surface is provided on the first jarring assembly and a second impact surface is provided on the second jarring assembly, wherein, in use, the first and second impact surfaces are biased together. A first lifting structure is rotatably fixed relative to the first jarring assembly and a second lifting structure is rotatably fixed relative to the second jarring assembly, the first and second lifting structures being configured to cooperate during relative rotation therebetween to cause cyclical relative displacement in one axial direction to define a lifting phase and relative displacement in a reverse axial direction to define a dropping phase. The first and second lifting structures are axially fixed relative to their associated jarring assembly during the lifting phase to provide axial separation between the first and second impact surfaces, and the second lifting structure is axially released relative to the second jarring assembly prior to initiation of the dropping phase to permit the first and second impact surfaces to be axially impacted together.

A fluid operated drilling device for drilling a hole said device having a hammer, a rotation device and a drill rod. The hammer includes a tubular main body, a back head, a cylindrical piston housing, a reciprocating piston, a space, a valve unit and a fluid pressure supply unit. A hollow portion of the piston is open to lead pressurized operating fluid directly to the hollow portion from the fluid pressure supply passage. The hammer includes an axial exhaust passage formed between the main body and the piston housing. The valve unit includes a valve exhaust passage and the piston has a lower part and an upper part detachably connected to each other. The invention also relates to a method for drilling a hole using the fluid operated drilling device.

A fluid operated drilling device for drilling a hole said device having a hammer, a rotation device and a drill rod. The hammer includes a tubular main body, a back head, a cylindrical piston housing, a reciprocating piston, a space, a valve unit and a fluid pressure supply unit. A hollow portion of the piston is open to lead pressurized operating fluid directly to the hollow portion from the fluid pressure supply passage. The hammer includes an axial exhaust passage formed between the main body and the piston housing. The valve unit includes a valve exhaust passage and the piston has a lower part and an upper part detachably connected to each other. The invention also relates to a method for drilling a hole using the fluid operated drilling device.