A hydraulic hammering device includes a piston front chamber and a piston rear chamber defined between an outer circumferential surface of the piston and an inner circumferential surface of the cylinder and disposed separately from each other at front and rear, respectively, in an axial direction. A switching-valve mechanism drives the piston by switching at least one of the piston front chamber and the piston rear chamber into communication with at least one of a high pressure circuit and a low pressure circuit. An acceleration piston is disposed behind the piston and is configured to come into contact with the piston during a retreat stroke thereof to urge the piston forward, in which a timing where the acceleration piston itself starts to come in contact with the piston is set to be earlier than a timing where the piston is braked by the switching-valve mechanism.

Provided are systems and methods for controlling the fluid flow to and from the flow ports of an autonomous inflow control device (AICD). Features may include the addition of a ball check valve to the AICD. A well system may comprise: a production tubing; a flow control device, wherein the flow control device is disposed onto the production tubing; and a ball check valve disposed between the flow control device and the production tubing to restrict flow into the production tubing through a port in the flow control device, wherein the ball check valve comprises a housing and a ball.

The present invention relates to a drill rod (2) for a fluid-operated apparatus, particularly a percussion drill tool (1). The drill rod (2) comprises a first connection interface (100) at a first end (101) and a second connection interface (102) at a second end (103). The first connection interface (100) is for connection of the drill rod (2) to a second connection interface (102) of a like drill rod (3) or to the apparatus (1). The second connection interface (102) is for connection of the drill rod (2) to a first connection interface of a like drill rod (3) or to a fluid transfer device. The drill rod also comprises a plurality of discrete fluid flow channels (4, 6, 8) through the drill rod, a first member (23) moveably mounted in the first connection interface (100) and a second member (22) moveably mounted in the second connection interface. The first moveable member is the innermost component in the first connection interface and the second moveable member is the innermost component in the second connection interface. When the drill rod (2) is connected to a like drill rod (3) or to the apparatus (1) or to the fluid transfer device, at least two of the fluid flow channels (4, 6) are placed in fluid communication with corresponding channels (4, 6) of the like drill rod or the apparatus or the fluid transfer device by movement of the first (23) and second (22) moveable members only.

The present invention relates to a method for optimising energy usage at a drilling arrangement. The method includes the step of determining an acceleration of a drilling head in the drilling arrangement. The method further includes determining a parameter related to the energy usage at the drilling arrangement based on the determined acceleration. The method even further includes optimising the energy usage based on the determined parameter. The present invention also relates to a system for optimising energy usage at a drilling arrangement, to a computer program, and to a computer program product.

A system comprising a ground drilling device for moving a drill string for the insertion of an earth borehole into the ground, wherein a detection device is provided which is designed to detect the drill string at the end (a) in the region of the ground drilling device and/or (b) in the region of a target pit of the earth borehole to be created.

Provided is an undersea mining base capable of corresponding with slopes and undulations of seabed ore deposits. The undersea mining base includes a seabed mineral mining device configured to form a pit in a seabed ore deposit and a platform equipped with the seabed mineral mining device and capable of self-traveling in at least one of an X direction and a Y direction.

An electrical submersible pump assembly has a motor with a stator stack of limitations. The stack has slots through which magnet wires are wound. An encapsulate surrounds and bonds the magnet wires together within each slot. The encapsulate includes ceramic particles within a polymer adhesive matrix. The polymer matrix may be a fluoropolymer adhesive. Each of the magnet wires may have an electrical insulation layer surrounding a copper core. The ceramic particles are rounded and much smaller than a cross-sectional area of each of the magnet wires. At least some of the magnet wires may be in contact with a perimeter of the slot. The ceramic particles may be porous.

A rock drilling shank adaptor includes an elongate body having an internal flushing bore and an entry hole through the sidewall of the adaptor in fluid communication with the internal bore. The adaptor wall at the region of the entry hole is reinforced such that an internal diameter of the flushing bore at the reinforced region is less than an internal diameter of the bore at a position axially beyond the reinforced region.

A backhead assembly system for a Down The Hole (DTH) hammer operated by a supply of compressed fluid, that comprises mainly a backhead, said backhead having a central hole capable of transporting the pressurized air to the hammer and an inner cylinder, coaxially disposed and coupled with releasable holding mediums to the backhead, were said backhead has an interior frontal cavity and said releasable holding mediums are in the mentioned frontal cavity. The hammer also comprises a wear sleeve, coaxially disposed to the backhead and inner cylinder, in which the backhead is coupled to the rear side of the wear sleeve. In both embodiments of the present invention, the inner sleeve has a rear section of less diameter and a front side of larger diameter; both sections joined through a portion of generally increasing diameter.

A ground drilling device comprising a housing, a lengthwise movable drilling head tip arranged in the housing, and a bearing for supporting the drilling head tip in the housing during its lengthwise movement.