Patent Application
20200248821
The present disclosure relates to choke valves in general, and to choke valves having more than one trim set in particular.
To produce oil and gas from a subterranean reservoir, a drilling operation is managed using drives, pumps and other equipment. A drillstring with the drill bit rotates and penetrates a formation (e.g., a seabed) by cutting rock formations, creating the well. While drilling, “mud” is pumped into the drillstring to the bottom of the well and returned through an annulus surrounding the drillstring. One of the main challenges related to drilling is to maintain the pressure in the well within certain pressure boundaries.
In many prior art drilling systems, one or more control valves (sometimes referred to as a “choke” or a “choke valve”; hereinafter referred to as a “choke”) are utilized to control mud pressure within the drilling system. Chokes typically have a stationary member (e.g., a seat) and a translating member (a gate). The gate and seat (which may be collectively referred to as a “trim set”) are configured to mate with one another. Movement of the gate relative to the seat varies the state of the choke, either closing the choke or opening the choke in the positional spectrum between 100% closed to 100% open. Even with this ability to vary the fluid flow through the choke, prior art chokes are limited by the size of the trim set (e.g., a one inch trim set, a two inch trim set, a three inch trim set, etc.). Under most fluid flow conditions, a fully open one inch trim set will provide a larger difference in pressure across the choke than a three inch trim set in the same choke valve. To address this issue, it is known for a choke to be configured to accept different trim sets. For example, a choke may be configured so that the user can install a first trim set (e.g., a one inch mating gate and seat pair). If the user elects to operate the choke within a different control realm, the user may replace the first trim set with a second trim set (e.g., a two inch mating gate and seat pair), but must disassemble the choke to remove the first trim set and install the second trim set. Although chokes designed to accept a plurality of trim sets are useful, the downside is that the user must take the choke off line, remove the first trim set, install the second trim set, and then bring the choke back on line. This is a labor intensive process and requires a stoppage of the well drilling stop during the remove and replace process, or requires the drilling system have a secondary choke that can be used while the primary choke is being reconfigured. The issue of removing and replacing choke trim sets can be avoided by installing multiple chokes each having a different trim set. The downside of this approach includes the cost of multiple chokes, the piping and control system required to utilize the multiple chokes, and the space on the drilling platform consumed by the multiple chokes and associated piping/controls.
What is needed is a choke that overcomes the problems associated with the prior art chokes.
According to an aspect of the present disclosure, a choke valve is provided that includes a valve body, a plurality of seats, and a gate. The valve body has an inlet port and an outlet port. The plurality of seats is in communication with the valve body, where each seat has a fluid flow configuration, and the fluid flow configuration for each seat is different from the fluid flow configuration of each of the other seats within the plurality of seats. The gate is linearly translatable along a gate axis. The valve body is configured so that so that one of the plurality of seats at a time is selectively positionable in an engagement position aligned with the gate axis.
In any of the aspects or embodiments described above and herein, the gate may be configured to mate with each of the plurality of seats.
In any of the aspects or embodiments described above and herein, each of the plurality of seats may have at least one seat sealing surface, and the gate may have at least one gate sealing surface configured to mate with the at least one seat sealing surface of the respective seat.
In any of the aspects or embodiments described above and herein, the fluid flow configuration of each seat may be a fluid flow passage cross-sectional area, and the fluid flow passage cross-sectional area of each seat is different from the fluid flow passage cross-sectional area of each of the other seats within the plurality of seats.
In any of the aspects or embodiments described above and herein, the gate may be configured to mate with each of the plurality of seats in a full mated engagement that prevents fluid flow between the inlet port and the outlet port of the choke valve.
In any of the aspects or embodiments described above and herein, each of the plurality of seats may be disposed within a seat block that is linearly translatable within the valve body, and the seat block is selectively positionable within the valve body so that one of the plurality of seats at a time is in said engagement position aligned with the gate axis.
In any of the aspects or embodiments described above and herein, a fluid pressure source may be utilized to selectively position the seat block within the valve body.
In any of the aspects or embodiments described above and herein, each of the plurality of seats may be disposed within a seat turret that is rotatably mounted relative to the valve body, and the seat turret is selectively positionable within the valve body so that one of the plurality of seats at a time is in said engagement position aligned with the gate axis.
In any of the aspects or embodiments described above and herein, the seat turret may be rotatable about a second axis that is parallel to, and displaced from the gate axis.
In any of the aspects or embodiments described above and herein, each of the plurality of seats may be disposed along the gate axis within the valve body.
In any of the aspects or embodiments described above and herein, at least one of the plurality of seats disposed along the gate axis within the valve body may be configurable in said engagement position and a non-engagement position.
In any of the aspects or embodiments described above and herein, the at least one of the plurality of seats disposed along the gate axis within the valve body may have a plurality of portions, and in the engagement position the plurality of portions are coupled to collectively form the respective seat.
In any of the aspects or embodiments described above and herein, wherein in the non-engagement position, the plurality of portions of the respective at least one of the plurality of seats may be positioned a distance radially away from the gate axis sufficient to present engagement of the plurality of portions of that seat and the gate.
In any of the aspects or embodiments described above and herein, the choke valve may further include a gate stem attached to the gate and a worm gear drive, and the worm gear drive is configured to linearly translate the gate stem and gate.
In any of the aspects or embodiments described above and herein, the worm gear drive may be configured for manual operation, or powered operation, or both.
In any of the aspects or embodiments described above and herein, each combination of the gate and a respective one of the plurality of seats may have a Cv curve associated therewith, and the Cv curve for each combination of the gate and respective one of the plurality of seats is different from the Cv curve for the other combinations of the gate and other respective ones of the plurality of seats.
According to another aspect of the present invention, a choke valve is provided that includes a valve body and a plurality of mating seat and gate pairs. The valve body has an inlet port and an outlet port. The plurality of mating seat and gate pairs are in communication with the valve body. The valve body is configured such that one of the mating seat and gate pairs is in fluid communication with the inlet port and the outlet port at a time. Each mating gate and seat pair has a fluid flow configuration, and the fluid flow configuration for each mating seat and gate pair is different from the fluid flow configuration of each of the other mating seat and gate pairs within the plurality of mating seat and gate pairs.
In any of the aspects or embodiments described above and herein, the plurality of mating seat and gate pairs may include a plurality of seats.
In any of the aspects or embodiments described above and herein, the plurality of mating seat and gate pairs may include a gate configured to mate with each of the plurality of seats.
In any of the aspects or embodiments described above and herein, each of the plurality of seats may have a fluid flow passage cross-sectional area, and the fluid flow passage cross-sectional area of each seat is different from the fluid flow passage cross-sectional area of each of the other seats within the plurality of seats.
In any of the aspects or embodiments described above and herein, each mating seat and gate pair may have a Cv curve associated therewith, and the Cv curve for each mating seat and gate pair is different from the Cv curve for the other mating seat and gate pairs.
According to an aspect of the present disclosure, a choke valve is provided that includes a valve body, a first seat, a second seat, and a gate. The valve body has an inlet port and an outlet port. The first seat is in communication with the valve body, and has a first fluid flow passage cross-sectional area. The second seat is in communication with the valve body, and has a second fluid flow passage cross-sectional area. The first fluid flow passage cross-sectional area is larger than the second fluid flow passage cross-sectional area. The gate is linearly translatable along a gate axis. The valve body is configured so that so that the first seat and the second seat are each selectively positionable in an engagement position aligned with the gate axis, and an out of engagement position.
Referring to
The gate stem 18 is configured for linear translation within the valve body 12 (e.g., see arrow 26); in a first direction toward a seat 24 and in an opposite second direction away from the aforesaid seat 24. In some embodiments, the gate stem 18 may be in communication with a worm gear drive 28. The worm gear drive 28 includes an input shaft and an output shaft (not shown). Rotation of the input shaft of the worm gear drive 28 in a first rotational direction (e.g., clockwise) causes linear translation of the output shaft of the worm gear drive 28 (and the connected gate stem 18 and gate 22) in a first linear direction. Rotation of the input shaft of the worm gear drive 28 in a second rotational direction (e.g., counter clockwise) causes linear translation of the output shaft of the worm gear drive 28 (and the connected gate stem 18 and gate 22) in a second linear direction (i.e., opposite the first linear direction). The worm gear drive 28 provides torque multiplication and speed reduction, and also resists back driving of the gate stem 18 and gate 22. In a manual operated choke, the input shaft of the worm gear drive 28 may be connected with a hand wheel (not shown) that enables the user to turn input shaft. In a powered choke, the input shaft of the worm gear drive 28 may be connected with an electric motor drive directly, or indirectly through a gearbox. In those powered choke embodiments that include a gearbox, the gearbox may be configured to provide torque multiplication and speed reduction. The present disclosure is not limited to worm gear drives 28 for producing linear translation of the gate stem 18 and gate 22. Embodiments of the present disclosure may, however, include manually operated chokes and powered chokes, including those that utilize a worm gear drive 28.
The gate 22 is linearly translatable between a fully closed position where zero fluid flow (0% flow) is permitted between the inlet port 14 and the outlet port 16, and a fully open position where a maximum fluid flow (100% flow) is permitted between the inlet port 14 and the outlet port 16, and a continuum of positions there between. The choke 10 shown in
As stated above, embodiments of the present disclosure chokes have a trim set that includes a gate and a plurality of seats. The gate and plurality of seats permit a present disclosure choke to be operated in a plurality of different operating conditions, each with a different trim configuration (e.g., a different fluid flow parameter, such as a seat flow passage size) and associated flow coefficient (“C,”). Chokes are typically defined in terms of the parameters of the fluid flow passing through the choke. The relationship between the volumetric fluid flow rate (“Q”) through a choke, a difference in pressure across the choke (“ΔP”), and the specific gravity (“SG”) of the fluid passing through the choke may be identified in terms of a flow coefficient (“Cv”) for example by the following equation:
The volumetric fluid flow (“Q”) through the choke, the difference in pressure across the choke (“ΔP”), and the specific gravity (“SG”) of the fluid flowing through the choke may be viewed as operational parameters; i.e., parameters dictated by the end use application of the choke. The flow coefficient Cv of the choke, on the other hand, may be viewed as a characteristic of the choke that may vary as a function of the other parameters. The volumetric fluid flow rate (“Q”) through the choke (as considered within this Eqn. 1) refers to the zero to one hundred percent (0-100%) fluid flow for a given gate and seat combination.
The relationship between the flow coefficient Cv of a choke and the valve opening percentage (i.e., choke position) of the same choke is typically unique to that particular model choke valve.
To illustrate the utility and scope of the present disclosure, non-limiting examples of embodiments of the present disclosure are provided below.
Referring to
The present disclosure is not limited to any particular mechanism for linearly actuating the seat block 127 to position a given seat into an engagement position (and the other seats into out-of-engagement positions). As an example, the seat block may be actuated by fluid pressure from a fluid pressure source 131. Alternatively, the seat block 127 may be coupled with an actuator (e.g., an electric, pneumatic, or hydraulic actuator; not shown) that linearly translates the seat block 127.
Referring to
In the operation of this first embodiment of the multi-seat choke 100, the operator may select a particular seat 124A, 124B, 124C to be utilized. A manifold in connection with the choke 100 may be operated to terminate (or prevent) fluid flow through the choke 100; e.g., reroute fluid flow within the well to an alternative choke. Once the choke 100 is isolated, the operator may adjust the choke 100 from a first choke configuration (e.g., wherein the choke 100 is operating with the second seat 124B) to a second choke configuration (e.g., wherein the choke 100 is operating with the third seat 124C). In this particular example, the operator may actuate the seat block 127 to move the second seat 124B out of alignment with the gate axis 125 (i.e., into a non-engagement position), and move the third seat 124C into alignment with the gate axis 125 (i.e., into an engagement position). Subsequently, the gate stem 118 and gate 122 may be linearly actuated to an appropriate position relative to the third seat 124C for operation of the choke 100. If the operator wishes to close the choke 100, the gate stem 118 and gate 122 may be linearly translated to a position wherein the third sealing surface 138 of the gate 122 is in mated engagement with the sealing surface of the third seat 124C. If the operator wishes to open the choke 100, the gate stem 118 and gate 122 may be linearly translated to a position wherein the third sealing surface 138 of the gate 122 is separated from the sealing surface of the third seat, thereby allowing fluid flow across the choke from the input port to the outlet port.
Referring to
The present disclosure is not limited to any particular mechanism for rotating the seat turret 227 to position a given seat into an engagement position (and the other seats into out-of-engagement positions). As an example, the seat turret 227 may be coupled with an actuator (e.g., an electric, pneumatic, or hydraulic rotary actuator), directly or indirectly in communication with the seat turret 227, configured to selectively rotate the seat turret 227. The specific rotational positioning of the seat turret 227 may be determined, for example, using an encoder in communication with the seat turret 227 or with the actuator.
The gate 222 utilized with the second embodiment of the multi-seat choke 200 may be the same as or similar to the gate embodiment described above in the first embodiment (e.g., See
In the operation of this second embodiment of the multi-seat choke 200, the operator may select a particular seat 224A, 224B, 224C to be utilized. A manifold in connection with the choke 200 may be operated to terminate (or prevent) fluid flow through the choke 200; e.g., reroute fluid flow within the well to an alternative choke. Once the choke 200 is isolated, the operator may adjust the choke 200 from a first choke configuration (e.g., wherein the choke 200 is operating with the second seat 224B) to a second choke configuration (e.g., wherein the choke 200 is operating with the third seat 224C). In this particular example, the operator may actuate the seat turret 227 to rotate the second seat 224B out of alignment with the gate axis 225 (i.e., into a non-engagement position), and move the third seat 224C into alignment with the gate axis 225 (i.e., into an engagement position). Subsequently, the gate stem 218 and gate 222 may be linearly actuated to an appropriate position relative to the third seat 224C for operation of the choke 200. If the operator wishes to close the choke 200, the gate stem 218 and gate 222 may be linearly translated to a position wherein the third sealing surface of the gate 222 is in mated engagement with the sealing surface of the third seat 224C. If the operator wishes to open the choke 200, the gate stem 218 and gate 222 may be linearly translated to a position wherein the third sealing surface of the gate 222 is separated from the sealing surface of the third seat 224C, thereby allowing fluid flow across the choke 200 from the input port 214 to the outlet port 216.
Referring to
The present disclosure is not limited to any particular mechanism for actuating the first and second seat portions 324B-1, 324B-2, 324C-1, 324C-2 between the engagement position and the out-of-engagement position. As an example, the first seat portion 324B-1 of the second seat 324B may be coupled with a first actuator 340 (e.g., an electric, pneumatic, or hydraulic actuator) that moves the first seat portion 324B-1 between the engagement position and the out of engagement position, and the second seat portion 324B-2 may be coupled with a second actuator 341 (e.g., an electric, pneumatic, or hydraulic actuator) that moves the second seat portion 324B-2 between the engagement position and the out of engagement position (a similar arrangement can be used for the third seat portions 324C-1, 324C-1; e.g., actuators 343, 344). Hence, the first and second actuators 340, 341 can be controlled in concert to move the respective seat portions 324B-1, 324B-2 between the engagement position and the out of engagement position. The present disclosure is not limited to a seat having two seat portions or seat portions that are actuated by two actuators; e.g., a seat portion may have a plurality of seat portions and a plurality of actuators. As another example, the first and second seat portions of the respective seat may be biased (e.g., by springs, magnetic attraction, etc.) in the out of engagement position, and may be translatable into the engagement position by a fluid pressure source (e.g., hydraulic, pneumatic, etc.) that drives the first and second seat portions of the respective seat into the engagement position. As stated above, these are examples of a mechanism for actuating the first and second seat portions between the engagement position and the out-of-engagement position and the present disclosure is not limited thereto.
The gate 322 utilized with the third embodiment of the multi-seat choke 300 may be the same as or similar to the gate embodiment described above in the first and second embodiments (e.g., See
In the operation of this third embodiment of the multi-seat choke 300, a selection may be made regarding the particular seat 324A, 324B, 324C to be utilized. A manifold in connection with the choke 300 may be operated to terminate (or prevent) fluid flow through the choke 300; e.g., reroute fluid flow within the well to an alternative choke. Once the choke 300 is isolated, the operator may adjust the choke 300 from a first choke configuration (e.g., wherein the choke 300 is operating with the second seat 324B) to a second choke configuration (e.g., wherein the choke 300 is operating with the third seat 324C). In this particular example, the operator may actuate the first and second seat portions 324B-1, 324B-2 of the second seat 324B from the engagement position to the out-of-engagement position. The operator also actuates the first and second seat portions 324C-1, 324C-2 of the third seat 324C from an out-of-engagement position to the engagement position. Subsequently, the gate stem 318 and gate 322 may be linearly actuated to an appropriate position relative to the third seat 324C for operation of the choke 300. If the operator wishes to close the choke 300, the gate stem 318 and gate 322 may be linearly translated to a position wherein the third sealing surface of the gate 322 is in mated engagement with the sealing surface of the third seat 324C. If the operator wishes to open the choke 300, the gate stem 318 and gate 322 may be linearly translated to a position wherein the third sealing surface of the gate 322 is separated from the sealing surface of the third seat 324C, thereby allowing fluid flow across the choke 300 from the input port 314 to the outlet port 316. Fluid flow is permitted through those seats not being utilized by the choke 300.
Embodiments of the present disclosure have been described above in terms of a seat block 127 and a seat turret 227 (each having a plurality of seats), and multiple independent seats each having two seat portions, any and all of which may be actuated to change the operating configuration of the choke 100, 200, 300. In the description above, the description has generically described the choke operator as involved in the actuation of the respective components. The present disclosure contemplates that the aforesaid components may be actuated manually or automatically, and is not limited to either. A choke embodiment that is configured to “automatically” change choke seats may include hardware and a controller that is configured with instructions (e.g., in the form of software) stored within a memory device. The instructions when implemented by the controller and the hardware cause the choke to change from a first gate/seat configuration to a second gate/seat configuration, etc.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular device configurations to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed herein as the best mode contemplated for carrying out this invention.
