Variable buoyancy subsea running tool
View Patent ↗A variable buoyancy subsea running tool for use with subsea transportable devices, such as a tree cap. The buoyancy of the running tool may be varied through fluid or gas displacement in one or more containers. Alternatively, the running tool may be configured with a buoy that has static buoyancy, with the buoyancy of the running tool being varied through the addition of a counterweight. The running tool can be used to install or uninstall a tree cap on a subsea tree. Installation of a tree cap may be actuated by a remotely operated vehicle. Additionally, the running tool may be moved by a remotely operated vehicle and may have additional features such as a position locator device.
1. A subsea running tool comprising:
a body member having a first connection mechanism adapted to selectively connect a subsea transportable device to the body member;
a buoyancy mechanism that is capable of varying the buoyancy of the subsea running tool;
wherein the buoyancy mechanism comprises a flotation device connected to the body member and a counterweight connection mechanism adapted to selectively connect a counterweight to the body; and
wherein the counterweigh connection mechanism is a rotatable shaft and tab.
2. The subsea running tool of claim 1 , wherein the first connection mechanism is adapted to secure a tree cap.
3. The subsea running tool of claim 1 further comprising a location signaling device.
4. The subsea running tool of claim 1 , wherein the counterweight has a substantially equal submerged weight as the subsea transportable device.
5. The subsea running tool of claim 1 , wherein the flotation device is configured to provide a buoyant force that is substantially equal to the combined submerged weight of the running tool and the counterweight.
6. The subsea running tool of claim 1 further comprising a latch mechanism that is configured to selectively secure the subsea running tool to a subsea tree.
7. The subsea running tool of claim 1 , wherein the buoyancy mechanism comprises a container having an enclosed variable volume of a gas connected to the body member, wherein varying the volume of gas changes the displacement of the subsea running tool.
8. The subsea running tool of claim 7 , wherein the container comprises one or more sea chest cylinders.
9. The subsea running tool of claim 7 wherein the container is configured to be capable of providing a buoyant force that is substantially equal to the combined submerged weight of the subsea running tool and a connected subsea transportable device.
10. The subsea running tool of claim 7 wherein the volume of gas within the container is varied by a remotely operated vehicle through an actuation port.
11. The subsea running tool of claim 1 further comprising a connection point that is configured to connect to a remotely operated vehicle.
12. A subsea running tool comprising:
a body member having a first connection mechanism adapted to selectively connect a subsea transportable device to the body member; and
a buoyancy mechanism that is capable of varying the buoyancy of the subsea running tool, the buoyancy mechanism comprises a floatation device connection to the body member and a counterweight connection mechanism adapted to selectively connect a counterweight to the body, wherein the counterweight is configured to be detached from the running tool and supported by a support member that is connected to a subsea tree.