Abstract: The invention relates to the alignment of a tubing hanger (14) when installed in a subsea wellhead (11). Sensors (39a,b; 40a,b) detect when the orientation is correct and send a signal to the surface to provide positive confirmation of correct orientation, before a XMT (15) is installed on the wellhead (11) and the HP riser (31) removed, etc.

Abstract: 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.

Abstract: The invention relates to the drilling of subsurface oil and gas wells and the installation of subsurface equipment (11). A lifting vessel 7 brings heavy equipment such as Xmas trees or manifolds and wet parks this equipment (11) on the seafloor (5) during good weather when the significant wave height is low. The equipment (11), once it is underwater, has much lower weight and may easily be moved into place onto a wellhead (10) at an appropriate time using lower capacity lifting gear. The timing of this operation is much less sensitive to weather conditions because the equipment does not need to pass through the splash zone (sea surface). This makes for efficient use of expensive drilling rig time, and allows for acceleration of production of first wells on the template as critical heavy lifts could not else be done until rig has left the location. (FIG. 1).

Abstract: 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.

Abstract: The invention relates to the drilling of subsurface oil and gas wells and the installation of subsurface equipment (11). A lifting vessel 7 brings heavy equipment such as Xmas trees or manifolds and wet parks this equipment (11) on the seafloor (5) during good weather when the significant wave height is low. The equipment (11), once it is underwater, has much lower weight and may easily be moved into place onto a wellhead (10) at an appropriate time using lower capacity lifting gear. The timing of this operation is much less sensitive to weather conditions because the equipment does not need to pass through the splash zone (sea surface). This makes for efficient use of expensive drilling rig time, and allows for acceleration of production of first wells on the template as critical heavy lifts could not else be done until rig has left the location. (FIG. 1).

Abstract: 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.