Patent Grant
10533399
This application is a U.S. National Stage Entry application of International Application No. PCT/BR2015/050174, filed Oct. 7, 2015, which claims priority to International Application No. PCT/IB2015/054994 filed on Jul. 1, 2015, both, of which are incorporated by reference in their entireties.
The present invention relates to a manifold with unique block architecture and a shared actuator system that is designed to control the flow of fluids from various flow lines, which, for example, may be the flow of oil/gas from oil wells and to wells if the manifold is configured for injection.
A traditional subsea manifold is a device that is designed to control the flow of fluids from oil wells and direct the flow through various production/injection loops that are made of piping, valves, connector hubs and fittings. A traditional subsea manifold also typically includes various flow meters and controls systems for monitoring the flow of the fluids and controlling various valves. The most common joining method for the piping, valves, hubs and fittings is by welding but bolted flange connections are also used.
The manifolds can be classified into: production (oil, gas or condensate), water injection, lift and mixed (production and water injection). They all have a similar basic structure. A typical subsea manifold has a main base which is a metal structure that supports all piping, hydraulic and electrical lines, production and crossover modules, import and export hubs and control modules of the subsea manifold.
Typically, to design a subsea manifold certain information is needed: a flowchart of fluid flow, the number of Christmas (wells) trees that will be linked, and possibly other platforms manifolds. In general, the flowchart of fluid flow is provided by the client. With the requirements of the system, it is possible to begin the process of designing the elaborate arrangement of pipes, valves and hubs that will be part of the subsea manifold. A typical subsea manifold also includes an arrangement of structural members, e.g., a support structure comprised of beams and cross members that are designed to facilitate the installation of the manifold, distribute external loading and also support the arrangement of pipes and other equipment or components of the subsea manifold.
Below is one example of a summary of the steps for preparing the design of the conventional subsea manifold.
1. Flowchart.
2. Prepare the design of the arrangement of pipes, valves and hubs.
3. Prepare the design of the metal support structure.
The conventional subsea manifold promotes the flow of fluid from the oil and gas wells in manner mandated by the fluid flowchart of the project, through a complex arrangement of numerous flow paths that are defined by welded pipes, pipe fittings, such as elbows and/or flanged connections. Valves are positioned within the pipe flow paths to control the flow of fluid and there is a requirement to open and close these valves at various times.
In the depicted example, ignoring the main base 20a and arrangement of structural members 20b, the subsea manifold 20 is comprised of twenty four connections, eighteen spool pieces, which require fifty welding processes, six separate valve blocks and eight hubs 20c, 20d. The key point is that, irrespective of exact numbers (which will change depending upon each application), a typical or traditional manifold requires numerous individual components, and it requires that numerous welding procedures and inspection procedures be performed to manufacture such a traditional manifold. In the depicted example, the subsea manifold 20, including the main base 20a and arrangement of structural members 20b, has an overall weight of about 90 tons—about 33 tons of which are comprised of pressure retaining pipe and equipment and about 57 tons of which are comprised of various structural members 20b and the main base 20a. More specifically, a typical prior art subsea manifold may have an overall length of about 8 meters, an overall width of about 7 meters and an overall height of about 7 meters. Thus, in this example, the traditional subsea manifold 20 has a “footprint” of about 56 m2 on the sea floor and occupies about 392 m3 of space. Of course, these dimensions are but examples as the size and weight of such subsea manifolds 20 may vary depending upon the particular application. But the point is, traditional subsea manifolds 20 are very large and heavy and represent a complex arrangement of piping bends and valves to direct the flow of fluid received from the wells as required for the particular project.
The above noted problems with respect to the weight and dimensions of traditional subsea manifolds 20 is only expected in increase in the future due to the increasing number of valves along with Increases in working pressure and subsea depth, resulting in increased weight and dimensions for future subsea manifolds 20. In short, a traditional subsea manifold 20 is a structure that has a large size and weight that is comprised of many parts: pipes, bends, fittings, and hubs, and involves performing numerous welding operations to fabricate, all of which hinder the process of fabrication, transportation and installation. Installation of a subsea manifold is a very expensive and complex task. The manifold must be lifted and installed using cranes designed for the dynamic conditions created by wave, wind and current conditions offshore. The weight of the manifold combined with the dynamic sea conditions requires large installation vessels that are very expensive to operate. Lifting a manifold typically will require an offshore crane with a lifting capacity that is 2× or 2.5× the weight of the manifold due to the dynamic loading and dynamic amplification that results from motion induced by the sea conditions.
In terms of controlling the operations of subsea manifolds, i.e. the opening and closing of various valves, there are several known actuation means employed to actuate the subsea valves used in subsea manifold systems. One system approach relies on manual valves. With a manual valve equipped manifold, valves are operated by divers (in shallow water applications) or a Remotely Operated Vehicle (ROV) (in deep water applications). A drawback manual valve system is the need to deploy a diver to operate manual valves for shallow water manifolds and deploy an ROV for valve operations when required in a manifold installed in deep water. Another valve actuation method relies on direct connection of hydraulic fluid from the surface to the manifold valve actuator—a direct hydraulics actuation system. One drawback of a direct hydraulic actuation system is the distance between the manifold and the hydraulic supply on the surface. This limitation makes a direct hydraulics actuation system unsuited for deep water or long distance “step-outs”. Another example comprises the use of general hydraulic actuators controlled by an electro-hydraulic Subsea Control Module (SCM). Typically, such a control system consists of an undersea control module (SCM) comprised of an electrical control module used to selectively direct fluid via a series of directional control valves to the manifold valve actuator which is desired to be opened or closed through pipe connected between the actuators and the undersea control module. A compensation system composed of pipe connected to a variable volume chamber is required to receive and discharge fluid that is displace during valve opening or closing. The hydraulic fluid used to power the actuator must be delivered to the control system via an umbilical connecting the hydraulic fluid supply from the surface to the undersea control module. The electrical power and signals to the subsea control module (SCM) can be achieved via dedicated and separate electrical umbilical and hydraulic umbilical or alternately the electrical power and signal transmission wiring can be bundled together with the hydraulic fluid transmission piping within a bundled electric—hydraulic umbilical. The electrical power and signal are transmitted from surface power and signal units through the power, signal and hydraulic umbilical to the undersea control module.
One drawback encountered in this technique is the weight and dimensions of the traditional subsea hydraulic valve actuation system, and this problem is only expected to be more problematic in the future with future subsea manifolds having an increased number of valves along with an increase in the working pressure and the operational subsea depth, all of which result in an increase of weight and size of traditional subsea hydraulic valve actuation systems. Another drawback of this system is the number and/or size of electrical and hydraulic umbilicals and the associated seabed installation costs. Yet another drawback of this technique is the extensive time required for piping installation of electro-hydraulic control system between the SCM and manifold valves—which implies an increase in the time it takes to manufacture the manifolds, plus the associated cost with the necessary equipment such as hydraulic actuators, the subsea control module, the electro-hydraulic umbilical and hydraulic power unit.
An alternative to the technique described above, but less frequently used nowadays, is the use of undersea electric actuators. According to this technique, each manifold valve to be remotely controlled has an electric actuator mounted to the manifold valve and is connected to an electrical control system. The electrical control system consists of a power grid in the manifold to supply power and signals to the actuators connected to an umbilical with electrical leads connecting the undersea system to an electric power unit and control unit located on the surface.
An advantage presented by this second technique is the reduction in time required to manufacture the manifold, since the installation of the hydraulic control system in the manifold is not necessary. However, in spite of reducing the system cost by eliminating the cost of the hydraulic umbilical, the surface power unit and the undersea control module, the use of electric valve actuators makes this system much more expensive than the first one, since such electric valve actuators are expensive items of equipment in the market.
Another known alternative consists of a shared actuation system (SAC). Such a shared actuation system consists of the use of a structure located along one side of the manifold with an actuation tool that is displaced by a mechanism to the interface of each valve at the time of their actuation. In this alternative, the manifold contains only manual valves without remote actuation, and the actuation of any manifold valve is accomplished by use of the SAC. The mechanism, which displaces or moves the actuation tool to a desired location above a valve to be actuated, does it through a Cartesian coordinate positioning system that is moved by hydraulic pistons on rails and operated by an electro-hydraulic control system. The position of the actuation tool is checked by position and flow sensors located in the SAC. The actuation tool consists of a device that enables the interface with the valve stem and applies torque through a hydraulic power system. The number of turns applied is verified through the flow-through in the tool. Typically, the electro-hydraulic control system comprises a hydraulic pipe connected to the SAC, an undersea electro-hydraulic control module, a SAC compensation system, an umbilical containing hoses and electrical leads to supply fluid, electrical power and signals, connected to the hydraulic pressure unit on the surface and the electrical and control power unit also located on the surface. The SAC can be installed separately and removed from the manifold for repair if necessary. As it is known by those skilled in the art, this third alternative was used only once in the industry for remote actuation of valves.
A shared actuation system (SAC) may be employed in an attempt to minimize the drawbacks of the techniques described above. However, the costs of the undersea control module, hydraulic umbilical and surface hydraulic power unit are still present. Another drawback presented by the use of ashared actuation system (SAC) consists of the constructive characteristic of the Cartesian positioning of the system, which requires that the equipment has the same dimensions as the plane where the valves are contained. Such a requirement makes the equipment heavy and difficult to be installed and removed in case of failure or maintenance. In addition, the large size of the equipment compromises the integration of shared actuation system with the manifold, making it complex and difficult or almost impossible to promote interchangeability.
Other control systems of undersea devices are described in the prior art. Patent application US 2010042357 discloses a system and method for determining the position of an articulated member relative to a plane, and said system may be adapted for undersea use. Patent application US 2008109108 discloses a control system for a manipulator arm for use in undersea remotely operated vehicles (ROVs). U.S. Pat. No. 6,644,410 discloses a modular control system composed of independent segments for use in undersea equipment, including manifolds. Patent application US 2009050328 discloses a system for undersea installation of insulation on flowlines, connectors and other undersea equipment from a remotely operated vehicle. Patent application EP 1070573 describes a system for the application and monitoring of undersea installations, such as manifolds valves. However, none of the abovementioned documents discloses the subject matter of the present invention, which advantageously solves the drawbacks of the remote actuation systems of undersea valves described by the prior art to date, namely, excess weight and large size of the system, high costs, long manufacture period, and restrictions on the repair and replacement of parts and the equipment itself.
The present application is directed to an improved manifold with a unique block architecture and shared actuator system that may eliminate or at least minimize some of the problems noted above with respect to traditional subsea manifolds.
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an exhaustive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.
Disclosed herein is an illustrative system for receiving fluid flow from a plurality of external flow lines, wherein each of the external flow lines is connected to a respective one of a plurality of sources of fluid to be provided to the system. In one illustrative embodiment, the system comprises a manifold and a shared valve actuation system that is operatively coupled the manifold at a single location. In this example, the manifold is comprised of a block with at least one drilled header hole formed within the block, a plurality of drilled flow inlet holes formed within the block, wherein the number of drilled flow inlet holes corresponds to the number of the plurality external flow lines, and wherein the drilled flow inlet holes are in fluid communication with the at least one header via at least one other drilled hole formed within in the block, and a plurality of isolation valves coupled to the block wherein the valve element for each of the isolation valves is positioned within the block. In the example depicted herein, the shared valve actuation system comprises an arm that is adapted to rotate about an axis that is normal to an upper surface of the block of the manifold, a plurality of structural elements that are coupled to one another via rotary joints and a tool that is adapted to engage and actuate one of the plurality of isolation valves.
The present invention will be described with the described drawings, which represent a schematic but not limiting its scope:
While the subject matter disclosed herein is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
Various illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
The present subject matter will now be described with reference to the attached figures. Various structures, systems and devices are schematically depicted in the drawings for purposes of explanation only and so as to not obscure the present disclosure with details that are well known to those skilled in the art. Nevertheless, the attached drawings are included to describe and explain illustrative examples of the present disclosure. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.
According to the figures, it is observed that the manifold system (10) disclosed herein comprises a block (1) that is positioned on a base 27 (see
The block 1 is provided with drilled or machined holes “wells lines” (2) wherein the number of inlet holes (2) corresponds to the number of wells and/or desired manifolds that provide fluid flow to the manifold (10) via various flow lines (not shown). The holes (2) are responsible for the fluid flow (7) (shown schematically in
The block 1 also comprises a plurality of machined holes or intersections (9) (crossover lines) that may be used to route fluid from the inlet holes (2) to the headers (3) via the actuation of one or more of the valves (5). That is, the machined/drilled holes (2) and (3) in the block (1) in combination with the intersections (9) constitute a network of machined/drilled holes that provide for the routing of the fluid stream within the block 1. Thus, the flow of the fluids originating in production wells will go through the holes (2), the intersections (9) and holes (3). This characteristic is extremely relevant to the manifold (10) disclosed herein. That is, by forming this network of machined holes within the block 1, the need for the design and manufacture of piping (see 20g in
From
In this particular example the block 1 also comprises four intersections (9) (crossover lines) that may be used to route fluid entering the holes (2) to the headers (3) via the actuation of one or more of the valves (5). Thus, the flow of the fluids originating in production wells will go through the holes (2), the intersections (9) and header holes (3).
In this particular example the block 1 also comprises six intersections (9) (crossover lines) that may be used to route fluid from the holes (2) to the headers (3) via the actuation of one or more of the valves (5). Thus, the flow of the fluids originating in production wells will go through the holes (2), the intersections (9) and header holes (3).
Of course, as will be appreciated by those skilled in the art after a complete reading of the present application, the novel manifold comprises provides a very flexible approach that may be extended beyond the illustrative examples depicted herein without departing from the scope of the inventions disclosed herein, For example, in some applications, it may be required to design a manifold that accommodates more than six Christmas trees (wells) connected to the manifold 10. In such instances, it is envisioned that multiple blocks 1 will be required to accommodate all of the isolation valves 5 (and/or valves 6). More specifically, in one example it is contemplated that multiple blocks (e.g., multiple versions of the block 1a) may be connected together to accommodate all of the isolation valves in the manifold 10. Such multiple blocks 1a may be operatively coupled together using any of a variety of fastening mechanisms, e.g., such as bolts or other means securing one block 1a to an adjacent block 1a. Of course, the illustrative caps 1b. 1c may or may not be employed in such an application. In the case where multiple blocks (like the blocks 1a are employed) the headers 3 will be aligned to insure unobstructed flow of fluid or pigs. etc. through the combined assembly of the blocks 1a. A seal will be provided between the block 1a to insure pressure tight integrity between the interfaces between the blocks 1a at each header 3.
As will be appreciated by those skilled in the art after a complete reading of the present application, the novel manifold comprises all of the isolation valves need to control fluid flow within for the manifold are positioned in the block 1, i.e., the valve element for each of the isolation valves is positioned within that block. The block also includes a network of drilled or machined holes 2, 3 within block. The isolation valves 5 may be selectively actuated so as to control and direct the flow of fluid from oil wells within the block 1 to the headers 3. These characteristics, above described, give the novel manifold disclosed herein at least some of the following advantages relative to traditional subsea manifolds:
1. the manufacture of the manifold disclosed herein is faster and simpler;
2. the manifold disclosed herein has a reduced overall weight and size;
3. simplifies and reduces the logistics and transportation of the manifold;
4. reduces numbers of parts of the manifold (e.g., connections, spool pieces, pipes);
5. reduces the need for welding:
6. promotes standardization of the production line of the manifold.
The following is a table making a simple comparison of one embodiment of the manifold disclosed herein relative to a conventional subsea manifold (Table 1):
As noted above, the manifold disclosed herein substantially reduces the complexity of production, assembly, transport, installation and operation of a manifold. The manifold disclosed herein may be produced in any material as is appropriate for the application. The material should be resistant to temperature, pressure and corrosive environment, when dedicated to subsea applications.
With continuing reference to the drawings, in the depicted example, the number and the diameter of the holes 2 and 3 and the intersections 9 (crossovers) may vary depending upon the particular applications. In the illustrative example depicted herein, the manifold 10 is comprised of two headers 3. However, in some applications, the manifold 10 may contain only a single header 3, or it may contain several headers 3 (e.g., the manifold 10 may contain three headers 3 wherein one of the headers is used for well testing). Thus, the number of headers 3 and openings 2 should not be considered to be a limitation of the presently disclosed inventions. Typically, the headers 3 may have a larger diameter than the holes 2, and/or intersections 9, although such a configuration may not be required in all applications. In one particular example, the headers 3 may have a diameter of about 250 mm, while the holes 2 and intersections 9 may have a diameter of about 130 mm. However, in other applications, the headers 3 and holes 2 may have the same diameter.
The isolations valves 5, 6 disclosed herein may be any type of valve, e.g., a gate valve, a ball valve. etc. that is useful for controlling the fluid flow as described herein. The valves 5, 6 are mounted to the block 1 by a flanged connection, and they are mounted such that their valve element, e.g., a gate or a ball, is positioned within the block 1. In the depicted example, the valves 5, 6 do not have their own individual actuators, i.e., they are mechanically actuated valves that may, in one embodiment, be actuated by the shared valve actuator 30 as described more fully below. However, as noted above, the shared valve actuator system 30 may not be employed in all applications, i.e., in some cases the isolation valves 5, 6 may be actuated by other means, such as an ROV, or each of the valves 5, 6 may be provided with their own individual actuator (hydraulic or electric) while still achieving significant benefits via use of the unique block architecture disclosed herein.
With reference to
In the example depicted herein, all of the well flow (inlet flow) isolation valves 5 are positioned within the body portion 1a of the block 1, while the header isolation valves 6 are positioned within the inlet end cap 1b. Importantly, unlike prior art subsea manifolds, all of the isolation valves associated with controlling the flow of fluid to and through the manifold 10 are positioned within a single block 1 (the combination of portions 1a-c), along with the network of drilled (machined openings (2, 3, 9) where fluid may flow within the block 1. The isolations valves 5, 6 disclosed herein may be any type of valve, e.g., a gate valve, a ball valve, etc. that is useful for controlling the fluid flow as described herein. In the depicted example, the valves 5, 6 do not have their own individual actuators, i.e., they are mechanically actuated valves that may, in one embodiment, be actuated by the shared valve actuator 30 as described more fully below. However, the shared valve actuator system 30 may not be employed in all applications. i.e., in some cases the isolation valves 5, 6 may be actuated by other means, such as an ROV, or each may be provided with their own individual actuator. In one example, the block 1 (the combination of portions 1a-c) disclosed herein has an overall length of about 2.5 meters, an overall width of about 1.5 meters and an overall height of about 1 meter.
With reference to
With reference to
Note that unlike prior art subsea manifolds, using the novel manifold disclosed herein, the horizontal flow path between mating connector of an external flow line. e.g., from a well or other manifold into the holes 2 to the block 1 that contains the isolation valves 5 is a straight, turn-free flow path without any bends. With reference to
As described above, the holes/openings 2, 3 and the intersections 9 (crossovers) are straight constant-diameter holes that are machined (drilled) into the block 1 (1a-1c). Of course, as noted above, the diameter of the holes 2, 3 and the intersections 9 may be different from one another. These holes are sized so as to provide sufficient diameter for the passage of cleaning devices, such as pigs, through one or more of the flow paths defined in the block 1. Thus, the flow of the fluids originating in production oil wells will readily pass through the holes (2), the intersections (9) and headers (3), i.e., the network of holes within the block 1.
Additionally, using the novel block 1 disclosed herein, substantially all of the piping loads associated with coupling the spools or conduits 15a-c to the various flow lines that are coupled to the manifold are absorbed by the block 1. That is, using the novel manifold and block 1 depicted herein, all or significant portions of the arrangement of structural members 20b (See
Additionally, relative to the prior art subsea manifold depicted in
As will be appreciated by those skilled in the art after a complete reading of the present application, the novel manifold 10 disclosed herein provides several advantages in terms of manufacturing as compared to traditional manifolds, such as those described in the background section of this application. More specifically, the manufacturing process for a traditional manifold involves delivering various components, valves, pipe, fittings, tees, hubs and structural steel, etc., to a fabrication yard where the manifold is fabricated where welding is used as the primary method of joining the components together. Welding is a critical process and requires extensive prequalification of welding processes and welding personnel and inspection methods such as ultrasonic and x-ray inspections. In contrast, the novel manifold disclosed herein eliminates many of these components by drilling various openings in the block of the manifold using proven machining operations that are performed for other equipment, such as subsea Christmas tree blocks. Moreover, the manufacture of the novel manifold disclosed herein may be performed within a controlled manufacturing environment, i.e., a sophisticated machining shop, as opposed to a fabrication yard. Additionally, relative to manufacturing a traditional manifold, manufacturing the novel manifold disclosed herein involves a considerable reduction in welding operations which translates into a reduced reliance on welding, inspection and testing.
In accordance with the drawings, one illustrative example of the shared actuation system (30) disclosed herein comprises a valve actuation tool (39), which may be properly positioned through the movement of a plurality of rotary joints (33, 34, 35) and an arm 60 generally comprised of structural elements (36, 37). The shared valve actuation system 30 is operatively coupled the manifold 10 at a single location such that the arm 60 can rotate about a vertical axis 61 that is normal to an upper surface 1u of the block 1, i.e., the arm 60 generally rotates in a substantially horizontal plane around the axis 61. As described more fully below, the shared valve actuation system 30 also comprises various structural members that are coupled to one another by rotary joints.
A tool 39 is attached to the end of the arm 60 and it may be actuated so as to actuate one of the valves 5 or 6 in the manifold 10. The structural elements (36, 37) of the arm 60 have a hydrodynamic profile and connect to a sail element (38), which assists in steading and smoothing the movement of the arm 60 in an undersea environment. The hydrodynamic profile was developed to facilitate the movement of the arm 60 in a subsea environment, where the forces induced on the arm 60 during the movement of the arm 60 could be minimized. The sail element (38) is positioned around two units (47, 48) (one on-line and the other one being a spare), each of which contain some of the electronic elements responsible for the autonomous movement of the arm 39. The shared actuation system 30 may be articulated to move the arm 60 as disclosed herein. More specifically, as shown in
The rotary interface 33 between the manifold 10 and the shared actuation system 30 of the present invention is performed through the contact of a single element in the actuation system 30 and a single element in the manifold 10. In one example, with reference to
Due to the rotary interface 33, the tool 39 may be rotated about 360 degrees around the funnel or guide 52. The rotary interface feature 33 provides an advantage by allowing the attachment of the shared actuation system 30 to the manifold 10 after or near the completion of the assembly of the manifold 10. Moreover, the rotary interface 33 feature and the associated pin/guide interface also enhance interchangeability between systems and manifolds. The rotary interface 33 feature and the associated pin/guide interface are also important in manufacturing situations in terms of scale and facilitating the ability to replace defective units. The manifold is usually designed to be used in deep water (e.g. 1000-2000 m) for many years (e.g. 25 years), and the maintenance and installation of this equipment has to be done remotely so it is desirable to have a simpler connection so as to facilitate the installation and removal of the shared actuation system 30 as needed.
Furthermore, the straightforward rotary interface 33 and the associated pin/guide interface between the shared actuation system 30 and the manifold 10 provides significant advantages during the replacement operation of the system at the seabed by remotely operated vehicles (ROVs). This advantage is due to the use of the single interface rotary connection 33, rather than multiple interfaces with the manifold, thereby allowing easy installation and removal of the shared actuation system 30. Additionally, to facilitate replacement operations, the structural elements (36, 37) of the system may be constructed of lightweight composite material (41), and filled with floating elements (42) so that the submerged weight of the unit is on average less than 100 kg, with this weight being the acceptable limit by most ROV operators to lift with handlers operated by electric or hydraulic motors.
Other advantages of the actuation system 30 disclosed herein relative to prior art Cartesian coordinate based systems described in the background section of this application are related to the protection of the mechanisms responsible for the movement of the tool 39 from harsh effects of the environment, e.g., corrosion, growth of lime and magnesium deposits due to cathode protection systems and growth of marine life. In the shared actuation system 30 disclosed herein, the positioning of the tool 39 in the desired location (e.g., above a valve that is to be actuated) is performed by means of actuating motorized rotary joints (rotary joints 33, 34, 35) so as to cause movement of the structural elements (36, 37), which transform the rotary movement of the joints into the desired movement and positioning of the end of the arm 60 where the operating tool 39 is positioned. Thus, all components that are used to cause movement of shared actuation system 30 disclosed herein have sliding moving parts that are contained in rotary joints. The mechanisms or elements of the rotary joints are sealed from exposure to the external environment and they are further protected by lubricating oil so as to protect the mechanisms or elements from possible adverse effects from the environment, as described above. Note that this protection from the environment is not possible or practical when using the relatively long sliding mechanisms (e.g., rails) commonly found on prior art Cartesian coordinate based shared actuation systems as the required rails, that are used to position a valve actuator in the desired location, are typically exposed to seawater.
The strategy of using rotary joints for conducting the translational movements can be observed both for achieving the horizontal movement and for achieving the vertical movement of the tool 39, through the use of a four-bar mechanism.
Another advantage presented by the shared actuation system 30 disclosed herein consists of the minimization of the energy needed for the movement of the components of the arm 60 and ultimately the tool 39. The reduction is a consequence of the hydrodynamic geometry in the structural elements (36, 37) of the system and the use of a structure with sail 38 opposite to the structural elements (36, 37) so that the moment imposed by marine currents acting on the system is neutralized. For example, a dedicated robot (in the form of the depicted shared valve actuation system 30) could be provided on the manifold 10 while another dedicated robot could be added to a Christmas tree or PLET or PLEM. The structural steel 57 and cover 11 shown in
In this sense, the shared actuator system 30 disclosed herein may also be advantageously applied to the execution of other tasks in addition to the operation of the valves 5, 6 in the manifold 10. That is, by the inclusion of appropriate tools that may be attached to or replace the tool 39 other operations may be performed with the actuator system 30 disclosed herein, e.g., tools associated with as leak detection systems, cameras, sensor readers, transducers, among others, may be attached to or replace the tool 39. Additionally, the shared actuation system 30 can be expanded to perform tasks on other undersea equipment such as Christmas trees, Pipeline End Module (PLEM), Pipeline End Termination (PLET) and others. Accordingly such undersea equipment may include one or more shared actuation systems 30 disclosed herein.
In one illustrative example, the shared actuation system 30 disclosed herein is adapted for use in positioning the tool 39 on any valve interface submerged on an oil production station located in subsea structure. In general, the shared actuation system 30 comprises an actuation tool 39 which may be positioned by the actuation of the rotary joints (33, 34, 35) and structural elements (36, 37) which have a hydrodynamic profile and connect to a sail element 38 suitable for movement in the undersea environment.
In one particular example, the actuation tool 39 disclosed herein is adapted for interaction with valve interfaces and may for instance be a rotary tool for opening and closing of valves, e.g., the isolation valves 5, 6 disclosed above. The actuation tool 39 may be positioned at a distal part of an assembly of structural elements (36, 37), in the form of arms, connected to each other by rotary joints 33, 34, 35. The degree of freedom for the part with the tool 39 is thereby dependent on the number of arms and joints and the type of joints in the assembly. The structural elements (36, 37), or at least one of the structural elements have a hydrodynamic profile in that when it is moved through water, the forward edge of the element moving facing the water when moved through water has a relative thinner cross section compared with the trailing part of the same structural element. As one longitudinal structural element may normally be operated in one plane relative the structural element it is attached to, rotating around one axis in the rotary joint which is perpendicular to the longitudinal direction of the structural element, the structural element may be formed with a relative thinner cross section at two forward edges opposite each other compared with the trailing part of the structural element in the movement directions. The distal structural element may in one configuration together with the additional other structural elements and the joints, be arranged to be rotational about two parallel axis and possibly also one axis perpendicular to these two axis. These are just examples or possible degrees of freedom of the different elements and how they then may be made with a hydrodynamic profile. The sail element 38 may be connected to the assembly of structural elements and joints, in an opposite position compared with the actuation tool. The sail element 38 has one function of providing stability to the assembly of structural elements and joints, as this is rotated and extended to interact with different valve interfaces. The sail element 38 holds two units 47, 48 (one on-line and the other one spare) which contain the electronic elements as the robotic motion unit and the robotic drive unit responsible for the autonomous movement of the arm.
As mentioned above, the shared actuation system 30 may comprise a single rotary interface 33 with the subsea equipment (e.g. a manifold 10) based upon the interface between a single element on the actuation system 30 and a single element in the equipment. In one illustrative embodiment, the element in the actuation system 30 is a pin 51 and the element in the manifold is a funnel 52. It is also possible to have different single interfaces, or to have the funnel 52 and pin 51 arranged on the opposite parts of the actuation system 30 and the equipment, respectively.
According to another aspect there is provided a shared actuation system 30 for positioning a tool 39 relative to several valve interfaces on a subsea structure as a manifold. During normal operation, the shared actuation system 30 is attached to the subsea structure. It may be arranged to be separately retrievable from the subsea structure and may have retrieving means (not shown) in for instance an attachment device for an ROV or line deployed from vessel. Attached to the connection device there is at least one structural element, possibly two, three or four structural elements, all connected to each other through rotary joints, providing at least two degrees of freedom for a distal end of the structure elements where an actuation tool 39 is positioned. The assembly of structural elements and rotary joints may for instance provide three degrees of freedom for the distal end of the assembly. The tool 39 is positioned for interaction with the valve interfaces or other equipment on the subsea structure. The structural elements are further connected to a sail element 38. The sail element 38 is designed to hold the robotic motion and drive units responsible to control the movements of the robotic arm and compensate the weight. The structural elements assembled may be of different kinds and or some may be similar. In one possible embodiment the structural elements may be a post rotating around its own axis, a joining element arranged pivoting relative to the post about an axis perpendicular to the rotation axis of the post, and an arm element attached to the joining element forming a distal element in the assembly. The arm element may also be rotational attached to the joining element with a rotation axis mainly parallel with the rotation axis of the post.
According to another aspect the actuation system 30 disclosed herein comprises a control system arranged to operate the arm 60. The operation consists on moving the rotary joints to position the tool 39 relative the desired valve interface for interaction with a particular valve. The control system may be provided integral with the actuation system 30 or it may be attached to the structural elements (36, 37) of the system. The actuation system 30 operates in an autonomous way, knowing the movements necessary to reach the desired position for the tool 39. In the depicted example, the control system is positioned within f the sail element 38, which holds the electronic systems necessary to operate the actuation system 30. The electronic system is comprised of a robotic drive unit and a robotic motion unit. The robotic motion unit has an electronic motion controller board, system power supply boards, with line couplers and memories. The robotic drive unit has the motor drive and power supply. The control system may also comprise a communication unit for communication with a remote located operator. Such communication may be accomplished using hard-wired or wireless communication tools and techniques. The rotary joints are operated by signals coming from the electronic unit and a remote signal from a control unit arranged on the subsea structure or a transmitter or communication unit arranged on the subsea structure receiving operating signals from a remote operator.
According to another aspect of the subject matter disclosed herein there is also provided a subsea system, comprising a subsea structure and a shared actuation system 30 according to what is explained above where the shared actuation system 30 is connected to the subsea structure in one fixed position. Moreover, in this example, there is at least two structural elements (36, 37) connected by a rotary joint, arranged such that the tool 39 at the distal end of the structural elements (36, 37) or arm 60 may be operated to interact with several valve interfaces arranged around this fixed position and at different radial distances from the fixed position.
In another example, the actuation system 30 may be, in effect, an independent actuation system that may be positioned on the sea floor, without being connected to a surface umbilical. In such an embodiment, the actuation system 30 may be operatively coupled to a moveable device, such as and ROV (that is not coupled to the surface by umbilicals) or it may be mounted to a subsea structure such that the actuation system 30 may be used to perform any of a number of operations on a variety of items of subsea equipment, e.g., trees, flowlines, manifolds, etc. In this particular embodiment, a plurality of tools (not shown) for performing a variety of different services may be located or positioned at or near a subsea “home” for the actuation system 30, and they may be accessed as needed by the actuation system 30 so as to enable it to perform its intended function on such subsea equipment.
The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. For example, the process steps set forth above may be performed in a different order. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Note that the use of terms, such as “first,” “second,” “third” or “fourth” to describe various processes or structures in this specification and in the attached claims is only used as a shorthand reference to such steps/structures and does not necessarily imply that such steps/structures are performed/formed in that ordered sequence. Of course, depending upon the exact claim language, an ordered sequence of such processes may or may not be required. Accordingly, the protection sought herein is as set forth in the claims below.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/BR2015/050174 | 10/7/2015 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2017/000051 | 1/5/2017 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3504741 | Talley, Jr. | Apr 1970 | A |
| 3777812 | Burkhardt et al. | Dec 1973 | A |
| 3897805 | Casey | Aug 1975 | A |
| 3957079 | Whiteman | May 1976 | A |
| 4625805 | Ladecky | Dec 1986 | A |
| 6644410 | Lindsey-Curran et al. | Nov 2003 | B1 |
| 20080109108 | Lawson | May 2008 | A1 |
| 20090050328 | Bath et al. | Feb 2009 | A1 |
| 20100042357 | McCoy, Jr. et al. | Feb 2010 | A1 |
| Number | Date | Country |
|---|---|---|
| 1070573 | Jan 2001 | EP |
| 2284839 | Jun 1995 | GB |
| 0052370 | Sep 2000 | WO |
| Entry |
|---|
| International Search Report of the International Searching Authority issued in PCT/BR2015/050174 dated May 13, 2016 (2 pages). |
| Written Opinion of the International Searching Authority issued in PCT/BR2015/050174 dated May 13, 2016 (6 pages). |
| Number | Date | Country | |
|---|---|---|---|
| 20180187522 A1 | Jul 2018 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/IB2015/054944 | Jul 2015 | US |
| Child | 15741199 | US |
