The present disclosure provides a diffusive gradients in thin films (DGT) probe test device for a sediment core in a lake, including: a sampling tube, where, a settlement limit device is disposed on an outer wall of the sampling tube and a DGT probe and a multi-parameter water-quality detection electrode are installed within the sampling tube; a movable mudguard device comprising a connecting rod and a mudguard, where, the connecting rod rotates around a rotating shaft to drive the mudguard to move from a position where an opening at the lower end of the sampling tube is sealed to a side of the sampling tube; a position-limit mechanism removably installed outside the sampling tube; a hammering device located above the sampling tube and fixedly connected to the sampling tube; and a floating ball located above the hammering device and connected to the hammering device via a first pull rope.

The present disclosure provides a diffusive gradients in thin films (DGT) probe test device for a sediment core in a lake, including: a sampling tube, where, a settlement limit device is disposed on an outer wall of the sampling tube and a DGT probe and a multi-parameter water-quality detection electrode are installed within the sampling tube; a movable mudguard device comprising a connecting rod and a mudguard, where, the connecting rod rotates around a rotating shaft to drive the mudguard to move from a position where an opening at the lower end of the sampling tube is sealed to a side of the sampling tube; a position-limit mechanism removably installed outside the sampling tube; a hammering device located above the sampling tube and fixedly connected to the sampling tube; and a floating ball located above the hammering device and connected to the hammering device via a first pull rope.

A subsea vertical drilling machine is disclosed, having: a drill assembly formed by: a riser pipe having a first end, a second end, and a length extending between the first and second ends; and a drilling machine body, including a drilling head, coupled to the first end of the riser pipe;
and a vertical feed system configured for advancing the drill assembly in a vertical direction.

The riser pipe is provided with at least one rack extending along at least a part of the length of the riser pipe, and the vertical feed system comprises a motor coupled to a pinion, the pinion arranged for engaging with the rack for advancing the drill assembly.

A subsea vertical drilling machine is disclosed, having: a drill assembly formed by: a riser pipe having a first end, a second end, and a length extending between the first and second ends; and a drilling machine body, including a drilling head, coupled to the first end of the riser pipe;
and a vertical feed system configured for advancing the drill assembly in a vertical direction.

The riser pipe is provided with at least one rack extending along at least a part of the length of the riser pipe, and the vertical feed system comprises a motor coupled to a pinion, the pinion arranged for engaging with the rack for advancing the drill assembly.

A vibration generator (9) for a drilling installation comprises a housing (16), at least one rotation body (17), a suspension (24) by means of which the rotation body is suspended rotatably within the housing, the mass centre of the rotation body (17) being eccentric with respect to the rotation axis of the suspension, and a drive (18) for rotating the rotation body. The housing (16) holds a fluid (15) which is in contact with the rotation body (17) whereby relative rotation between the rotation body and the fluid generates a flow resistance and in that the rotation body comprises flow resistance reduction means (25).

A vibration generator (9) for a drilling installation comprises a housing (16), at least one rotation body (17), a suspension (24) by means of which the rotation body is suspended rotatably within the housing, the mass centre of the rotation body (17) being eccentric with respect to the rotation axis of the suspension, and a drive (18) for rotating the rotation body. The housing (16) holds a fluid (15) which is in contact with the rotation body (17) whereby relative rotation between the rotation body and the fluid generates a flow resistance and in that the rotation body comprises flow resistance reduction means (25).

An apparatus is configured for undersea use, such as for penetrating a seabed for forming a borehole therein, including with optional data acquisition and logging capabilities. A first or base module (12) of the apparatus is adapted for engaging the seabed. A first elevator (16) provides longitudinal movement of a second or upper module (14) relative to the base module (12) along a drilling axis. The relative movement of the upper and base modules may be used in the course of independently moving first (18) and second (20) rotary units along the drilling axis to cause a drill rod (R) and a drill casing (C) to penetrate the seabed such that the collapse of the borehole is avoided.

An apparatus is configured for undersea use, such as for penetrating a seabed for forming a borehole therein, including with optional data acquisition and logging capabilities. A first or base module (12) of the apparatus is adapted for engaging the seabed. A first elevator (16) provides longitudinal movement of a second or upper module (14) relative to the base module (12) along a drilling axis. The relative movement of the upper and base modules may be used in the course of independently moving first (18) and second (20) rotary units along the drilling axis to cause a drill rod (R) and a drill casing (C) to penetrate the seabed such that the collapse of the borehole is avoided.

An apparatus for use in marine platform jacking is disclosed herein. In one aspect, a jetting valve includes a valve body with a piston assembly disposed therein. The piston assembly is selectively operated to open and close the valve. A biasing member is coupled to the piston assembly. The piston assembly includes a first piston and a second piston. The dual pistons, in cooperation with the biasing member, allow the valve to self-seal thereby preventing entry of a fluid which is external to the valve.

An apparatus for use in marine platform jacking is disclosed herein. In one aspect, a jetting valve includes a valve body with a piston assembly disposed therein. The piston assembly is selectively operated to open and close the valve. A biasing member is coupled to the piston assembly. The piston assembly includes a first piston and a second piston. The dual pistons, in cooperation with the biasing member, allow the valve to self-seal thereby preventing entry of a fluid which is external to the valve.