A method is for performing work in a well and on a vessel. A wellbore assembly such as a tool string is suspended on a first flexible elongate member from the vessel. The wellbore assembly is used to perform work in the well. The wellbore assembly such as a tool string is suspended on a second flexible elongate member from the vessel. The wellbore assembly on the first flexible elongate member is removed from the well, and after the removal, the wellbore assembly on the second flexible elongate member is inserted into the well. The inserted wellbore assembly in the well can then be used to perform further work. The wellbore assemblies may be deployed and retrieved on independently operable wirelines. A related vessel and apparatus is also described.

A method is for performing work in a well and on a vessel. A wellbore assembly such as a tool string is suspended on a first flexible elongate member from the vessel. The wellbore assembly is used to perform work in the well. The wellbore assembly such as a tool string is suspended on a second flexible elongate member from the vessel. The wellbore assembly on the first flexible elongate member is removed from the well, and after the removal, the wellbore assembly on the second flexible elongate member is inserted into the well. The inserted wellbore assembly in the well can then be used to perform further work. The wellbore assemblies may be deployed and retrieved on independently operable wirelines. A related vessel and apparatus is also described.

A subsea tree assembly with a flow monitoring and measuring apparatus includes a production wing valve block coupled to a production wing branch, the production wing valve block including a wing block connector, and a fluid processing module including a frame, a module connector including an inlet and an outlet, and a fluid flow loop coupled between the inlet and the outlet, wherein the module connector is fluidicly coupled to the wing block connector. A production fluid flow goes from the production wing valve block and returns to the same block via the wing block connector, the module connector, and the fluid flow loop. A flow monitoring and measuring apparatus for a subsea tree assembly includes a module frame, a module connector connectable to a production wing valve block, the module connector including an inlet and an outlet, and a fluid flow conduit forming a loop from the outlet of the module connector back to the inlet of the module connector.

A multipurpose latch assembly (MPLA) for installation above the bore of a blowout preventer includes an annular sidewall extending between a top flange and a bottom flange and having an interior bore surface defining an interior bore. A plurality of latching slots extend through the sidewall and a latching dog is slidably positioned in each latching slot. Actuators are connected to the latching dogs to extend and retract them through the latching slots. A tool having an external slot can be inserted into the bore of the MPLA and selectively engaged by the latching dogs to secure the tool in the bore of above the blowout preventer.

A multipurpose latch assembly (MPLA) for installation above the bore of a blowout preventer includes an annular sidewall extending between a top flange and a bottom flange and having an interior bore surface defining an interior bore. A plurality of latching slots extend through the sidewall and a latching dog is slidably positioned in each latching slot. Actuators are connected to the latching dogs to extend and retract them through the latching slots. A tool having an external slot can be inserted into the bore of the MPLA and selectively engaged by the latching dogs to secure the tool in the bore of above the blowout preventer.

The invention relates to the introduction of pressurized fluid, e.g. acid, into a subsea well directly from a vessel (33). A fluid injection assembly (20) is fitted to the top of a subsea Xmas tree (3), the assembly (20) including fail safe closed valve (21) which is controlled via a hydraulic line (31) from the vessel. The hose and assembly and valve are designed with an internal bore allowing a large diameter ball to be dropped (required for acid stimulation). The subsea subsea control module (8) on the Xmas tree is controlled from the producing platform.

The invention relates to the introduction of pressurized fluid, e.g. acid, into a subsea well directly from a vessel (33). A fluid injection assembly (20) is fitted to the top of a subsea Xmas tree (3), the assembly (20) including fail safe closed valve (21) which is controlled via a hydraulic line (31) from the vessel. The hose and assembly and valve are designed with an internal bore allowing a large diameter ball to be dropped (required for acid stimulation). The subsea subsea control module (8) on the Xmas tree is controlled from the producing platform.

A double-layer coiled tubing double-gradient drilling system, on the basis of conventional drilling equipment, includes a double-layer coiled tubing system, spacer fluid, a downhole lifting pump system, throttling control systems and a data monitoring system. Power fluid enters an annular space of the tubing through an adapter, passes through a downhole lifting pump, enters an inner pipe through a bridge channel, and enters the bottom hole through the drill bit. Return fluid enters an annular channel of the tubing through a recovery hole, then enters the inner pipe through the bridge channel and enters the lifting pump, and then enters a solid control system through the adapter and the control systems in sequence. Gradient control of the bottom hole pressure is realized through monitoring of the spacer fluid and control of the drilling pump unit and throttling control systems. The problem of narrow safe drilling density window is solved.

A double-layer coiled tubing double-gradient drilling system, on the basis of conventional drilling equipment, includes a double-layer coiled tubing system, spacer fluid, a downhole lifting pump system, throttling control systems and a data monitoring system. Power fluid enters an annular space of the tubing through an adapter, passes through a downhole lifting pump, enters an inner pipe through a bridge channel, and enters the bottom hole through the drill bit. Return fluid enters an annular channel of the tubing through a recovery hole, then enters the inner pipe through the bridge channel and enters the lifting pump, and then enters a solid control system through the adapter and the control systems in sequence. Gradient control of the bottom hole pressure is realized through monitoring of the spacer fluid and control of the drilling pump unit and throttling control systems. The problem of narrow safe drilling density window is solved.

The present invention relates to methods of inserting and removing tools and/or robots into/from inside subsea oil wells. In this scenario, the present invention provides a system for insertion and removal of a device (30) in a subsea oil well (20), said system comprising (i) a WCT assembly (10) comprising a removable protective cap (40) and (ii) a WCT tool (50) connected to a receptacle (60) comprising within it the device (30), wherein the WCT tool (50) is suitable for being inserted in the place where the protective cap (40) is coupled, wherein at least one of receptacle (60) and WCT tool (50) is able to be opened or closed, releasing the device (30) into the subsea oil well (20) or retaining same inside the receptacle (60). The invention further provides methods of inserting and removing a device (30) into/from a subsea oil well (20).