Annular blow out preventer
An embodiment uses a symmetrical design with hydraulic pistons on either end (as opposed to a single piston on conventional blow out preventers) which allows for lower actuation forces, reduced friction, and reduced wear and tear. The lower actuation forces correspond to lower operating pressures which allows the body and housing to be smaller, leading to a smaller footprint. The embodiment does not need to necessarily rely on wellbore pressure to close the device (e.g., due to reduced friction and lower actuation forces) and consequently is able to reduce the number of parts used in the device and leak paths present in the device.
1 . A blow out preventor (BOP) comprising:
a first piston including a central channel that traverses the first piston;
a second piston including a central channel that traverses the second piston;
a resilient ring including a central channel that traverses the ring; and
a body including a central channel, the ring, and the first and second pistons;
wherein the channels of the body, the ring, and the first and second pistons align with each other;
wherein the ring is between the first and second pistons and includes: (a) an upper surface that tapers inwards as the upper surface extends upwards towards the first piston; (b) a lower surface that tapers inwards as the lower surface extends downwards towards the second piston; (c) first and second upper slots on the upper surface and first and second lower slots on the lower surface; and (d) a first metal bar included in both of the first upper and lower slots and a second metal bar included in both of the second upper and lower slots;
wherein the first piston is sealed off from the central channel of the body and the second piston is sealed off from the central channel of the body.
2 . The BOP of claim 1 , wherein the BOP does not include a perforated cylinder that directly interfaces the central channel of the body and which is at least partially above or below the ring.
3 . The BOP of claim 2 , wherein:
the first piston is slidingly engaged within a first chamber of the body;
the second piston is slidingly engaged within a second chamber of the body;
the first chamber is isolated from the central channel of the body and is not in fluid communication with any fluid included in the central channel of the body; and
the second chamber is isolated from the central channel of the body and is not in fluid communication with any fluid included in the central channel of the body.
4 . The BOP of claim 3 , wherein:
the body includes a first inner wall and a second inner wall;
the first inner wall is between the first chamber and the central channel of the body;
the second inner wall is between the second chamber and the central channel of the body;
a first axis traverses the channels of the body, the ring, and the first and second pistons but does not intersect any of the body, the ring, or either of the first or second pistons;
a second axis is orthogonal to the first axis and intersects the central channel of the body, first inner wall, and the first chamber;
a third axis is orthogonal to the first axis and intersects the central channel of the body, second inner wall, and the second chamber.
5 . The BOP of claim 4 , wherein:
the second axis intersects the first piston;
the third axis intersects the second piston.
6 . The BOP of claim 5 comprising a sub-assembly that includes the first and second pistons and the resilient ring, wherein:
a fourth axis is orthogonal to the first axis and intersects the resilient ring;
the sub-assembly is symmetrical above and below the second axis.
7 . The BOP of claim 3 comprising:
a first hydraulic port in communication with an upper surface of the first piston;
a second hydraulic port in communication with a lower surface of the second piston;
wherein the first and second hydraulic ports traverse the body.
8 . The BOP of claim 7 wherein:
the first and second hydraulic ports are configured to fluidly couple to at least one hydraulic source;
in response to increasing hydraulic pressure from the at least one hydraulic source, the first and second hydraulic ports are configured to simultaneously and respectively move the first piston down and the second piston up to compress the ring.
9 . The BOP of claim 8 comprising:
a third hydraulic port in communication with a lower surface of the first piston and an upper surface of the second piston;
wherein the third hydraulic port traverses the body.
10 . The BOP of claim 9 wherein:
the third hydraulic port is configured to fluidly couple to the at least one hydraulic source;
in response to increasing hydraulic pressure from the at least one hydraulic source, the third hydraulic port is configured to simultaneously and respectively move the first piston up and the second piston down to decompress the ring.
11 . The BOP of claim 8 comprising:
a third hydraulic port in communication with a lower surface of the first piston;
a fourth hydraulic port in communication with an upper surface of the second piston
wherein the third and fourth hydraulic ports traverse the body.
12 . The BOP of claim 11 , wherein:
the third and fourth hydraulic ports are configured to fluidly couple to the at least one hydraulic source;
in response to increasing hydraulic pressure from the at least one hydraulic source, the third and fourth hydraulic ports are configured to simultaneously and respectively move the first piston up and the second piston down to decompress the ring.
13 . The BOP of claim 3 comprising a first hydraulic port in communication with an upper surface of the first piston and a lower surface of the second piston; wherein the first hydraulic port traverses the body.
14 . The BOP of claim 13 wherein:
the first hydraulic port is configured to fluidly couple to at least one hydraulic source;
in response to increasing hydraulic pressure from the at least one hydraulic source, the first hydraulic port is configured to simultaneously and respectively move the first piston down and the second piston up to compress the ring.
15 . The BOP of claim 3 , wherein:
in an open configuration the central channel of the ring includes a first inner diameter; and
in a closed configuration the ring is compressed between the first and second pistons and the central channel of the ring includes a second inner diameter that is smaller than the first inner diameter.
16 . The BOP of claim 15 , wherein in the closed configuration the first and second pistons simultaneously directly contact the first and second metal bars.
17 . The BOP of claim 15 , wherein:
in the open configuration the first piston is adjacent a lower surface of the body and the second piston is adjacent an upper surface of the body;
in the closed configuration the first and second pistons are both adjacent one another.
18 . The BOP of claim 3 wherein the first and second pistons are slidingly coupled to the first metal bar via at least one slot and at least one protuberance.
19 . The BOP of claim 18 , wherein in response to the first and second pistons being slidingly coupled to the first metal bar via the at least one slot and at least one protuberance, the ring is configured to expand simultaneously with the first and second pistons moving away from each other.
20 . The BOP of claim 3 comprising an additional ring, wherein:
the body includes first and second subcomponents;
the additional ring couples the first and second subcomponents to each other;
an additional axis intersects the first and second subcomponents and the additional ring.