Electric-actuated choke apparatus and methods

Abstract

In one aspect, a choke apparatus includes a choke body through which fluid is adapted to flow, a bonnet assembly connected to the choke body, and an electric actuator operably coupled to the bonnet assembly. The choke apparatus operates to control the imposition of backpressure on the fluid. In one embodiment, an actuator stem of the electric actuator is toollessly operably coupled to a choke stem of the bonnet assembly. In another embodiment, an adapter is connected to the bonnet assembly. In yet another embodiment, an absolute position sensor is disposed within a housing of the electric actuator. In still yet another embodiment, a measurement scale is used to indicate choke position. In certain embodiments, the choke apparatus provides for manual override. A method of assembling a choke apparatus is provided. A method of retrofitting a choke apparatus is provided.

What is claimed is: 
     
         1 . A choke apparatus, comprising:
 a choke body through which fluid is adapted to flow, the choke body comprising a seat;   a bonnet assembly connected to the choke body, the bonnet assembly comprising a gate adapted to move, relative to the seat, to control imposition of backpressure on the fluid when the fluid flows through the choke body;   an electric actuator operably coupled to the bonnet assembly, the electric actuator comprising:
 a housing at least partially defining an internal region; and 
 a translation component disposed within the internal region, the translation component being operably coupled to the gate, and adapted to move within, and relative to, the housing to cause the gate to move, relative to the seat, to control the imposition of backpressure on the fluid when the fluid flows through the choke body; 
   and   an absolute position sensor operably coupled to the translation component and disposed within the internal region in which the translation component is disposed, wherein the absolute position sensor is adapted to detect the location of the translation component within the housing and thus indirectly detect the position of the gate.   
     
     
         2 . The choke apparatus of  claim 1 , wherein the electric actuator is adapted to be energized and is adapted to operate to cause the gate to move when so energized, but is not adapted to cause the gate to move when de-energized; and
 wherein, after the electric actuator has been de-energized and re-energized, the absolute position sensor allows the choke apparatus to resume operation without recalibration.   
     
     
         3 . The choke apparatus of  claim 1 , wherein the translation component comprises a nut to which the absolute position sensor is operably coupled;
 wherein the electric actuator further comprises a linear roller screw extending through the nut and adapted to rotate within the housing; and   wherein, when the linear roller screw rotates within the housing, the nut moves within the housing and causes the gate to move, relative to the seat, to control the imposition of backpressure on the fluid when the fluid flows through the choke body.   
     
     
         4 . The choke apparatus of  claim 1 , wherein the electric actuator further comprises an electric motor adapted to cause the translation component to move within, and relative to, the housing, and wherein the electric motor comprises a motor controller with which the absolute position sensor is in communication. 
     
     
         5 . The choke apparatus of  claim 1 , further comprising at least one controller in communication with the absolute position sensor and to which the absolute position sensor transmits output related to the position of the gate; and
 wherein the at least one controller controls the movement of the gate based on the output transmitted from the absolute position sensor.   
     
     
         6 . The choke apparatus of  claim 5 , wherein the output comprises one or more electrical current signals. 
     
     
         7 . The choke apparatus of  claim 1 , wherein the absolute position sensor comprises a linear transducer. 
     
     
         8 . The choke apparatus of  claim 1 , wherein the electric actuator further comprises axially-spaced first and second end blocks between which the housing extends;
 wherein the first and second end blocks at least partially define the internal region in which the transducer is disposed; and   wherein the transducer extends between the first and second end blocks.   
     
     
         9 . A choke apparatus, comprising:
 a choke body through which fluid is adapted to flow, the choke body comprising a seat;   a bonnet assembly connected to the choke body, the bonnet assembly comprising a gate adapted to move, relative to the seat, to control imposition of backpressure on the fluid when the fluid flows through the choke body; and   an electric actuator operably coupled to the bonnet assembly so that the electric actuator is adapted to cause the gate to move, relative to the seat, to control the imposition of backpressure on the fluid when the fluid flows through the choke body, wherein the electric actuator comprises:
 an electric motor adapted to be energized; 
 a gearbox operably coupled to the electric motor, wherein the electric motor is adapted to drive the gearbox when the electric motor is energized; 
 a linear actuator operably coupled to the gearbox, and operably coupled to the bonnet assembly to operably couple the electric actuator to the bonnet assembly, wherein the gearbox is adapted to drive the linear actuator to cause the gate to move; 
 a clutch operably coupled to the gearbox; and 
 a stem having:
 a first position in which the stem is operably decoupled from the clutch; and 
 a second position in which the stem is operably coupled to the clutch to provide manual override; 
 
 wherein, when the electric motor is energized, the electric motor is adapted to drive the gearbox when the stem is in either the first position or the second position. 
   
     
     
         10 . The choke apparatus of  claim 9 , wherein the manual override is provided so long as the electric motor is not energized. 
     
     
         11 . The choke apparatus of  claim 9 , wherein a torque is adapted to be applied to the stem when the stem is in the second position. 
     
     
         12 . The choke apparatus of  claim 11 , wherein the stem is permitted to drive the gearbox to cause the gate to move, thereby providing the manual override, when the stem is in the second position and the torque applied to the stem is less than a predetermined maximum value. 
     
     
         13 . The choke apparatus of  claim 12 , wherein the clutch is adapted to slip so that the stem is no longer permitted to drive the gearbox, thereby preventing damage to at least one of: the gearbox, the linear actuator, and the bonnet assembly, when the stem is in the second position and the torque applied to the stem reaches the predetermined maximum value. 
     
     
         14 . The choke apparatus of  claim 13 , wherein, when the stem is in the second position and the torque applied to the stem is less than the predetermined maximum value, the manual override is provided so long as the electric motor is not energized. 
     
     
         15 . A choke apparatus, comprising:
 a choke body;   an electric actuator adapted to be operably coupled to the choke body; and   a gantry connected to each of the choke body and the electric actuator so that the choke body supports the electric actuator via at least the gantry;   wherein the electric actuator and at least a portion of the gantry are adapted to be displaced relative to the choke body and along at least one of: a first axis; a second axis that extends perpendicular to the first axis; and a trajectory that extends about the choke body in a plane that is perpendicular to the second axis.   
     
     
         16 . The choke apparatus of  claim 15 , wherein the first axis extends horizontally and wherein the second axis extends vertically. 
     
     
         17 . The choke apparatus of  claim 15 , wherein the gantry comprises:
 a base assembly connected to the choke body; and   a carrier assembly connected to the electric actuator, the carrier assembly being rotatably coupled to, and supported by, the base assembly.   
     
     
         18 . The choke apparatus of  claim 17 , wherein the carrier assembly comprises a carrier plate operably coupled to the base assembly, the carrier plate being adapted to rotate relative to the base assembly;
 wherein the electric actuator and the at least a portion of the gantry are adapted to be displaced relative to the choke body and along the trajectory; and   wherein, when the electric actuator and the at least a portion of the gantry are displaced relative to the choke body and along the trajectory, the carrier plate rotates relative to the base assembly.   
     
     
         19 . The choke apparatus of  claim 17 , wherein the carrier assembly comprises a carrier plate operably coupled to the base assembly, and a carrier beam operably coupled to the carrier plate by a plurality of rollers, the carrier beam being adapted to be axially displaced relative to the carrier plate via the plurality of rollers;
 wherein the electric actuator and the at least a portion of the gantry are adapted to be displaced relative to the choke body and along the first axis; and   wherein, when the electric actuator and the at least a portion of the gantry are displaced relative to the choke body and along the first axis, the carrier beam is axially displaced relative to the carrier plate via the plurality of rollers.   
     
     
         20 . The choke apparatus of  claim 17 , wherein the carrier assembly comprises a carrier plate operably coupled to the base assembly, a carrier beam operably coupled to the carrier plate, and a lift-shaft coupled to the carrier beam and the electric actuator, the lift-shaft being adapted to be displaced vertically relative to the carrier beam;
 wherein the electric actuator and the at least a portion of the gantry are adapted to be displaced relative to the choke body and along the second axis; and   wherein, when the electric actuator and the at least a portion of the gantry are displaced relative to the choke body and along the second axis, the lift-shaft is displaced vertically relative to the carrier beam.