An abrasive suspension eroding system has an eroding unit (11), which can be lowered into an existing drilled hole (1), in order to generate a high-pressure erosion jet for the abrasive suspension eroding of material (6, 20) in an existing drilled hole (1). The eroding unit (11) can be connected to a drilling fluid line (9) and is configured to generate a high-pressure erosion jet from a drilling fluid abrasive suspension device.

Methods and arrangements are provided for release of an ROV operable subsea clamp connector, the clamp connector comprising at least two clamp segments hinged to move pivotally, and a drive screw connecting the clamp segments by threaded engagement with trunnions arranged rotatable in the pivoting ends of the clamp segments, the threads of the drive screw and trunnions turned such that the trunnions travel along the drive screw in mutually opposite directions when the drive screw is turned. An axial bore in the drive screw is adapted for accommodation of a waterjet cutting tool having a sideways pointing nozzle in a forward end, the waterjet cutting tool rotatable inside the bore while feeding high-pressure water through the nozzle, towards the wall of the drive screw until the wall of the drive screw is cut through.

Methods and arrangements are provided for release of an ROV operable subsea clamp connector, the clamp connector comprising at least two clamp segments hinged to move pivotally, and a drive screw connecting the clamp segments by threaded engagement with trunnions arranged rotatable in the pivoting ends of the clamp segments, the threads of the drive screw and trunnions turned such that the trunnions travel along the drive screw in mutually opposite directions when the drive screw is turned. An axial bore in the drive screw is adapted for accommodation of a waterjet cutting tool having a sideways pointing nozzle in a forward end, the waterjet cutting tool rotatable inside the bore while feeding high-pressure water through the nozzle, towards the wall of the drive screw until the wall of the drive screw is cut through.

A system includes a plug configured to restrict release of hydrocarbons from a terminal end of an offshore riser by accumulating the hydrocarbons at the plug when the plug is disposed in an internal portion of the offshore riser and at a first vertical location of the offshore riser. The system also includes a vent configured to be disposed at a second vertical location, wherein the vent is configured to provide a path for the hydrocarbons to be released from the offshore riser.

A system includes a plug configured to restrict release of hydrocarbons from a terminal end of an offshore riser by accumulating the hydrocarbons at the plug when the plug is disposed in an internal portion of the offshore riser and at a first vertical location of the offshore riser. The system also includes a vent configured to be disposed at a second vertical location, wherein the vent is configured to provide a path for the hydrocarbons to be released from the offshore riser.

An apparatus including an external surface portion shaped so as to mate with a docking device, and two half-shells having internal surfaces of semi-circular cross section. The apparatus further includes a plurality of segments arranged inside the two half-shells and including teeth for gripping onto a shaft, and an installation tool operable to cause the two half-shells to close around the shaft, thereby securing the apparatus to the shaft.

An apparatus including an external surface portion shaped so as to mate with a docking device, and two half-shells having internal surfaces of semi-circular cross section. The apparatus further includes a plurality of segments arranged inside the two half-shells and including teeth for gripping onto a shaft, and an installation tool operable to cause the two half-shells to close around the shaft, thereby securing the apparatus to the shaft.

A wellbore is plugged using a bismuth alloy. In one embodiment, the bismuth alloy comprises an alloy of bismuth and tin. In another embodiment, the bismuth alloy comprises an alloy of bismuth and silver. The wellbore can be arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance. Other aspects are described and claimed.

A wellbore is plugged using a bismuth alloy. In one embodiment, the bismuth alloy comprises an alloy of bismuth and tin. In another embodiment, the bismuth alloy comprises an alloy of bismuth and silver. The wellbore can be arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance. Other aspects are described and claimed.

A hydraulic arrangement for fail-safe and pump-through of a safety valve. The arrangement allows for compact actuation of a safety valve through accumulators. The arrangement supports automatic closure of the valve in the emergent circumstance of any loss of hydraulic control above the valve. Additionally, the arrangement also allows for a technique of re-opening the valve for long term killing of a well in direct response to the introduction of kill fluid without requiring any added complex interventional measures.