Overpressure compensation systems and assemblies for a subsea manifold
Systems, methods, and devices for compensating overpressure associated with thermal expansion of fluid within a closed cavity of a subsea manifold assembly. At least one piston assembly may be included and selectively fluidly connected to the closed cavity to counteract or reduce a pressure produced within the closed cavity.
1 . An overpressure compensation assembly for reducing an overpressure within a closed cavity of a subsea manifold, the overpressure generated by thermal expansion of a fluid within the closed cavity caused by high-temperature fluid within an active portion of the subsea manifold, the overpressure compensation assembly comprising:
a piston assembly comprising:
a piston having a first end and a second end opposite the first end;
a first portion disposed proximate the first end of the piston, the first portion fluidly coupled to the closed cavity of the subsea manifold to compensate a pressure within the closed cavity of the subsea manifold, the pressure associated with the thermal expansion of the fluid within the closed cavity; and
a second portion disposed proximate the second end of the piston, the second portion configured to allow expansion of fluid within the closed cavity of the subsea manifold through actuation of the piston; and
a valve disposed in a fluid path between the closed cavity of the subsea manifold and the first portion, the valve configured to selectively connect and disconnect the piston assembly from the subsea manifold,
wherein the valve is controlled automatically based at least in part on a pressure within the closed cavity of the subsea manifold.
2 . The overpressure compensation assembly of claim 1 , wherein the second end is open to an environment of the piston assembly to thereby allow free expansion of the fluid within the closed cavity.
3 . The overpressure compensation assembly of claim 1 , wherein the second end is coupled to a spring.
4 . The overpressure compensation assembly of claim 1 , wherein the piston assembly further comprises:
a main body stem; and
a flange secured to the main body stem via a plurality of nuts disposed radially about a center of the main body stem.
5 . The overpressure compensation assembly of claim 4 , wherein the piston assembly further comprises:
a gasket; and
one or more O-rings configured to provide a seal.
6 . The overpressure compensation assembly of claim 5 , wherein the piston assembly further comprises:
a position indicator extending from an end of the piston assembly configured to indicate a position of the piston.
7 . The overpressure compensation assembly of claim 1 , further comprising:
a pressure sensor disposed within the closed cavity; and
a control unit coupled to the valve.
8 . An overpressure compensation assembly for reducing an overpressure within a closed cavity of a subsea manifold, the overpressure generated by thermal expansion of a fluid within the closed cavity caused by high-temperature fluid within an active portion of the subsea manifold, the overpressure compensation assembly comprising:
a piston assembly comprising:
a piston having a first end and a second end opposite the first end;
a first portion disposed proximate the first end of the piston, the first portion fluidly coupled to the closed cavity of the subsea manifold to compensate a pressure within the closed cavity, the pressure associated with the thermal expansion of the fluid within the closed cavity of the subsea manifold; and
a second portion disposed proximate the second end of the piston and coupled to a spring; and
a valve disposed in a fluid path between the closed cavity of the subsea manifold and the first portion, the valve configured to selectively connect and disconnect the piston assembly from the subsea manifold,
wherein the valve is controlled automatically based at least in part on a pressure within the closed cavity of the subsea manifold.
9 . The overpressure compensation assembly of claim 8 , further comprising:
a relief valve disposed in at least one fluid path between the closed cavity and the first end of the piston assembly.
10 . The overpressure compensation assembly of claim 9 , further comprising:
a check valve disposed in the at least one fluid path between the closed cavity and the first end of the piston assembly.
11 . The overpressure compensation assembly of claim 8 , wherein the spring is selected based at least in part on a spring constant of the spring.
12 . The overpressure compensation assembly of claim 8 , further comprising:
a pressure sensor disposed within the closed cavity; and
a control unit coupled to the valve.
13 . The overpressure compensation assembly of claim 8 , wherein a first end of the spring is secured to the piston and a second end of the spring is secured to a portion of a piston housing of the piston assembly.
14 . The overpressure compensation assembly of claim 13 , wherein the spring is configured to be compressed when a pressure within the closed cavity is above a predetermined pressure threshold.
15 . An overpressure compensation assembly for reducing an overpressure within a closed cavity of a subsea manifold, the overpressure generated by thermal expansion of a fluid within the closed cavity caused by high-temperature fluid within an active portion of the subsea manifold, the overpressure compensation assembly comprising:
a first piston assembly comprising:
a piston having a first end and a second end opposite the first end;
a first portion disposed proximate the first end of the piston, the first portion fluidly coupled to the closed cavity of the subsea manifold to compensate a pressure within the closed cavity of the subsea manifold, the pressure associated with the thermal expansion of the fluid within the closed cavity of the subsea manifold; and
a second portion disposed proximate the second end of the piston, the second portion comprising a barrier fluid disposed therein, the barrier fluid distinct from the fluid within the closed cavity of the subsea manifold; and
a valve disposed in a fluid path between the closed cavity of the subsea manifold and the first portion, the valve configured to selectively connect and disconnect the first piston assembly from the subsea manifold,
wherein the valve is controlled automatically based at least in part on a pressure within the closed cavity of the subsea manifold.
16 . The overpressure compensation assembly of claim 15 , further comprising:
a relief valve disposed in a fluid path between the closed cavity and the piston, the relief valve configured with a cracking pressure below a limit of one or more components associated with the closed cavity.
17 . The overpressure compensation assembly of claim 15 , further comprising:
a second piston assembly comprising:
a piston;
a first end fluidly connected to the second end of the first piston assembly; and
a second end fluidly comprising a pressurized fluid distinct from the barrier fluid.
18 . The overpressure compensation assembly of claim 17 , further comprising:
a relief valve disposed in a first fluid path between the first piston assembly and the second piston assembly.
19 . The overpressure compensation assembly of claim 18 , further comprising:
a check valve disposed in a second fluid path between the first piston assembly and the second piston assembly.
20 . The overpressure compensation assembly of claim 19 , wherein the barrier fluid prevents mixing of the fluid within the closed cavity and the pressurized fluid.