A hydraulic protection system for preventing collapse of a hydraulic line is provided. The system includes a pressure sensing assembly which is arranged to monitor a pressure differential between fluid external to and fluid contained within the hydraulic line; a pressure compensation assembly adapted to be coupled to the hydraulic line. In the event of a loss of pressure in the hydraulic line occurring, the pressure compensation assembly employs the pressure of the fluid external to the hydraulic line to increase the pressure of the fluid contained within the hydraulic line. The system is arranged so that the pressure compensation assembly is operated when the pressure differential monitored by the pressure sensing assembly reaches a predetermined level, which is below a collapse pressure of the hydraulic line, so that exposure of the hydraulic line to the collapse pressure is avoided.

The invention discloses a suction cylinder exploitation device and method for marine natural gas hydrates. The exploitation device comprises an exploitation cylinder, a water pump, a sand control device, a liquid-gas filling system and the like. Through the specially-designed exploitation cylinder and mating devices thereof, the exploitation cylinder can sink below a seabed surface to exploit natural gas hydrates deep below the seabed surface and can be withdrawn. A series of problems such as high well drilling and completion cost of traditional deep-sea drilling exploitation methods, and damage, collapses and sand generation of plain concrete wellbores under the effect of formation pressure are solved, and the limitations that traditional capping depressurization methods can only exploit submarine superficial hydrates and are low in exploitation efficiency are overcome. The invention can greatly reduce the exploitation cost of natural gas hydrates deep below the seabed surface and is of great significance for commercial exploitation of marine natural gas hydrates.

An apparatus includes a tube having at least one flow outlet in communication with an interior of the tube. The apparatus includes valves for selectively connecting the flow outlet to one of a fluid return line and an inlet of a fluid pump. The apparatus also includes valves for selectively connecting the outlet of the pump to the fluid return line and closing the pump outlet. A method includes returning mud from a wellbore into a riser extending between the wellbore and a drilling unit on the surface of a body of water. Flow from a tube in the riser is selectively diverted to an inlet to a fluid pump or a mud return line extending from the tube to the drilling unit. When the flow is diverted to return mud flow in the riser is stopped above the tube. When flow is diverted to the inlet of the pump, the pump is operated to lift the mud to maintain a selected mud pressure in the wellbore.

Safe dynamic handover between MPD and well control operations provides the ability to automate MPD, well control, and transitions therebetween while maintaining the wellbore in a dynamic fluid state at all times. In the event a kick is taken, a safe dynamic handover from MPD to well control operations is made, unknown formation fluids within the wellbore are circulated out of the wellbore, and a safe dynamic handover from well control operations to MPD is made while maintaining the wellbore in dynamic fluid state, without ever going static with respect to fluids within the wellbore. Because the wellbore remains dynamic, the formation of gels is prevented, thereby preventing pressure spikes during the start-up of the mud pumps and improving pressure transmission throughout the well system. Pressure may be more precisely managed during all phases of MPD, well control, and transitions therebetween.

What is provided is a method and apparatus wherein a swivel can be detachably connected to an annular blowout preventer thereby separating the drilling fluid or mud into upper and lower sections and allowing the fluid to be displaced in two stages, such as while the drill string is being rotated and/or reciprocated. In one embodiment the sleeve or housing can be rotatably and sealably connected to a mandrel. The swivel can be incorporated into a drill or well string and enabling string sections both above and below the sleeve to be rotated in relation to the sleeve. In one embodiment the drill or well string does not move in a longitudinal direction relative to the swivel. In one embodiment, the drill or well string does move longitudinally relative to the sleeve or housing of the swivel.

What is provided is a method and apparatus which can be detachably connected to an annular blowout preventer thereby separating the drilling fluid or mud into upper and lower sections and allowing the fluid to be displaced in two stages, such as while the drill string is being rotated and/or reciprocated. In one embodiment the sleeve can be rotatably and sealably connected to a mandrel. The swivel can be incorporated into a drill or well string and enabling string sections both above and below the sleeve to be rotated in relation to the sleeve. In one embodiment the drill or well string does not move in a longitudinal direction relative to the swivel. In one embodiment, the drill or well string does move longitudinally relative to the sleeve of the swivel.

What is provided is a method and apparatus wherein a swivel can be detachably connected to an annular blowout preventer thereby separating the drilling fluid or mud into upper and lower sections and allowing the fluid to be displaced in two stages, such as while the drill string is being rotated and/or reciprocated. In one embodiment the sleeve or housing can be rotatably and sealably connected to a mandrel. The swivel can be incorporated into a drill or well string and enabling string sections both above and below the sleeve to be rotated in relation to the sleeve. In one embodiment the drill or well string does not move in a longitudinal direction relative to the swivel. In one embodiment, the drill or well string does move longitudinally relative to the sleeve or housing of the swivel.

A well system for handling downhole particles. The well system may include a mud pump, a shaker including a corrugated shaker screen, a drill string, an imaging device, and a data acquisition system that may include a processor. The processor may be programmed to determine a cross-sectional area of a portion of the corrugated shaker screen occupied by the downhole particles in a first image of the images based on the first image, on a known profile of corrugations of the corrugated shaker screen and a known distance and angle between the imaging device and the corrugated shaker screen to determine a volume of the downhole particles on the portion of the corrugated shaker screen in the first image based on the cross sectional area occupied by downhole particles, a velocity of the downhole particles moving across the corrugated shaker screen, and an image generation rate.

What is provided is a method and apparatus wherein a swivel can be detachably connected to an annular blowout preventer thereby separating the drilling fluid or mud into upper and lower sections and allowing the fluid to be displaced in two stages, such as while the drill string is being rotated and/or reciprocated. In one embodiment the sleeve or housing can be rotatably and sealably connected to a mandrel. The swivel can be incorporated into a drill or well string and enabling string sections both above and below the sleeve to be rotated in relation to the sleeve. In one embodiment the drill or well string does not move in a longitudinal direction relative to the swivel. In one embodiment, the drill or well string does move longitudinally relative to the sleeve or housing of the swivel.

A connection device has a first connection body and a second connection body movable with respect to the first connection body. The connection device is configured for connecting a plurality of control lines terminating in connectors forming part of the first connection body, to corresponding control lines terminating in connectors forming part of the second connection body. The connection device is provided with a first alignment means for rough alignment of the connection bodies. The connection device further has a second alignment means for aligning the rigid holding means of one of the bodies with respect to the connectors of the other one of the bodies, at least one of the rigid holding means movable in a plane perpendicular to a longitudinal axis of the first alignment means.