Deepwater resonator array with gravity distribution

Abstract

A deepwater resonator array includes at least one elongated panel extending along a longitudinal axis. The panel includes a plurality of resonator cups formed therein, and the resonator cups are open along an underside / downward facing surface of the panel to receive a working gas. The panel further includes a gas inlet area located proximate a first longitudinal end of the panel and a gas outlet area located proximate a second longitudinal end of the panel opposite the first longitudinal end. At least one gutter is formed in the underside surface of the panel and extends along the surface from the gas inlet area to the gas outlet area.

Description

DEEPWATER RESONATOR ARRAY WITH GRAVITY DISTRIBUTIONBACKGROUND

[0001] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and / or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

[0002] Subsea noise, its sources and impacts are being increasingly scrutinized by nongovernmental organizations and regulators. Noise emissions from shipping, defense and other operations and their consequences are being increasingly documented and understood. The development of subsea oil and / or gas facilities and resultant deployment of underwater production trees, machinery and processing equipment on the seabed may generate long-term lower frequency noise that is transmissible over long distances. It may be desirable to reduce the noise output of such equipment.

[0003] Arrays of panels having resonator cups are one potential solution to mitigate noise output in subsea environments. However, one limitation of such resonators is that they must be gas filled (and periodically re-filled) to maintain noise mitigation performance on deepwater processing facilities by disrupting sound emitted by subsea machinery. Therefore, it is presently recognized that a need exists for a system and method for efficiently distributing gas to such resonators in a subsea environment.SUMMARY OF THE INVENTION

[0004] A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.

[0005] In accordance with aspects of the disclosure, a deepwater noise mitigation system includes: a support frame configured to be deployed in a deepwater environment to surround at least a portion of equipment located subsea and configured for subsea use; a first elongatedpanel extending along a first longitudinal axis, the first panel configured for deepwater use and coupled to the support frame, wherein the support frame is configured to hold the first panel such that the first longitudinal axis is inclined with respect to a horizontal plane, the first panel including: a plurality of resonator cups formed therein, the plurality of resonator cups being open along a lower surface of the first panel to receive a working gas; a first gas inlet area located proximate a first longitudinal end of the first panel; a first gas outlet area located proximate a second longitudinal end of the first panel opposite the first longitudinal end of the first panel; and at least one gutter formed in the lower surface of the first panel and extending along the surface from the first gas inlet area to the first gas outlet area.

[0006] In accordance with other aspects of the disclosure, a deepwater noise mitigation system includes: a structural support frame configured to be deployed in a deepwater environment to be positioned around subsea equipment located at or proximate the seafloor; a deepwater resonator array movably connected to the structural frame, the deepwater resonator array including a plurality of elongated panels connected to a central beam / gas manifold, each elongated panel having a plurality of inverted resonator cups formed therein; wherein the deepwater resonator array is configured to be selectively transitioned between a collapsed configuration and an expanded / deployed configuration, wherein in the collapsed configuration the plurality of elongated panels are collapsed toward the central beam / gas manifold, wherein in the expanded configuration the plurality of elongated panels are expanded in a direction away from the central beam / gas manifold for use.

[0007] In accordance with other aspects of the disclosure, a deepwater subsea oil and / or gas facility includes: subsea equipment configured for deepwater use positioned at or proximate the seafloor; and a deepwater noise mitigation system, the deepwater noise mitigation system including: a structural support frame positioned around the subsea equipment; and a deepwater resonator array coupled to the support frame and including at least a first elongated panel and a second elongated panel, each of the first and second elongated panels being inclined with respect to a horizontal plane, wherein each of the first and second panels includes: a plurality of inverted resonator cups formed therein and open along a surface of the panel to receive a working gas; a gas inlet area located proximate a first end of the panel; a gas outlet area located proximate a second end of the panel opposite the first end of the panel; and at least one inverted gutter formed in the surface of the panel and extending along the surface from the gas inlet area to the gas outlet area.

[0008] In accordance with other aspects of the disclosure, a method includes: delivering a working gas at a gas inlet area located proximate a first longitudinal end of a panel of adeepwater resonator array configured for deepwater use, the panel extending along a longitudinal axis that is inclined relative to a horizontal plane and having a plurality of resonator cups that are open along a downward facing surface of the panel; directing the working gas in a direction of the longitudinal axis via one or more gutters formed in the downward facing surface of the panel, the one or more gutters extending from the gas inlet area to a gas outlet area proximate a second longitudinal end of the panel, the second longitudinal end located vertically higher than the first longitudinal end; and filling the plurality of resonator cups with the working gas as the working gas moves from the gas inlet area toward the gas outlet area via gravity.

[0009] In accordance with other aspects of the disclosure, a method of installing a deepwater noise mitigation system includes: providing the deepwater noise mitigation system including: a structural support frame; and a deepwater resonator array movably coupled to the structural frame, the deepwater resonator array including a plurality of elongated panels connected to a gas manifold, each elongated panel having a plurality of resonator cups formed therein; positioning the structural frame of the deepwater noise mitigation system over subsea equipment located at or proximate the seafloor with the deepwater resonator array being in a collapsed configuration in which the plurality of elongated panels are collapsed toward the central beam / gas manifold; lowering the deepwater resonator array in the collapsed configuration with respect to the subsea equipment so the deepwater resonator array passes between two components of the subsea equipment; and transitioning the deepwater resonator array from the collapsed configuration to an expanded / deployed configuration in which the plurality of elongated panels are expanded in a direction away from the central beam / gas manifold.BRIEF DESCRIPTION OF DRAWINGS

[0010] The drawings illustrate only example embodiments and are therefore not to be considered limiting in scope, as the example embodiments may admit to other equally effective embodiments. The elements and features shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the example embodiments. Additionally, certain dimensions or positions may be exaggerated to help visually convey such principles. In the drawings, reference numerals designate like or corresponding, but not necessarily identical, elements.

[0011] FIG. 1 is a block diagram of an example oil and / or gas facility utilizing a deepwater resonator array to mitigate noise associated with subsea equipment of the facility, in accordance with an embodiment of this disclosure.

[0012] FIG. 2 is an example of a subsea compressor system fitted with a deepwater resonator array, in accordance with an embodiment of this disclosure.

[0013] FIG. 3 is a front cross-sectional view of a horizontal resonator panel for a deepwater resonator array, in accordance with an embodiment of this disclosure.

[0014] FIG. 4 is a front cross-sectional view of an inclined resonator panel for a deepwater resonator array, in accordance with an embodiment of this disclosure.

[0015] FIG. 5 is a schematic view of a deepwater resonator array with multiple stacked panels, in accordance with an embodiment of this disclosure.

[0016] FIG. 6 is a front view of an arrangement of resonator panels and transition blocks that may be stacked vertically, in accordance with an embodiment of this disclosure.

[0017] FIG. 7 is a side cross-sectional view of a resonator panel, in accordance with an embodiment of this disclosure.

[0018] FIGS. 8 A and 8B are perspective views of another resonator panel, in accordance with an embodiment of this disclosure.

[0019] FIGS. 9A and 9B are perspective views of subsea equipment surrounded by a noise mitigation system including multiple deepwater resonator arrays, in accordance with an embodiment of this disclosure.

[0020] FIGS. 10A and 10B illustrate a deepwater resonator array attached to a support frame of a noise mitigation system, in accordance with an embodiment of this disclosure.

[0021] FIG. 11 is a perspective view of an array of resonator panels in a resonator support frame, in accordance with an embodiment of this disclosure.

[0022] FIGS. 12A and 12B are perspective views of a horizontal transition block for connecting two panel lengths in a row to form a longer resonator panel, in accordance with an embodiment of this disclosure.

[0023] FIG. 13 is a cross-sectional view of a stack of resonator panels showing porting in the vertical transition blocks between panels, in accordance with an embodiment of this disclosure.

[0024] FIG. 14 is a first vertical transition block providing a portion of the porting in the panel stack of FIG. 13, in accordance with an embodiment of this disclosure.

[0025] FIG. 15 is a second vertical transition block providing another portion of the porting in the panel stack of FIG. 13, in accordance with an embodiment of this disclosure.

[0026] FIG. 16 is a perspective view of roof-mounted deepwater resonators integrated into a horizontal support frame to cover a subsea equipment module, in accordance with an embodiment of this disclosure.

[0027] FIG. 17 is an underside view of a roof-mounted array of horizontal resonator panels attached to a resonator support frame, in accordance with an embodiment of this disclosure.

[0028] FIGS. 18A-18C illustrate an example foldable deepwater resonator array, in accordance with an embodiment of this disclosure.

[0029] FIG. 19A shows an example foldable deepwater resonator array in an a deployed / unfolded state in accordance with an embodiment of this disclosure.

[0030] FIG. 19B illustrates the upper portion of the deployed / unfolded resonator array of FIG. 19A to show the gas filling flow path, in accordance with an embodiment of this disclosure.

[0031] FIGS. 20A-20C illustrate a portion of the foldable deepwater resonator array of FIGS. 19A and 19B moving from a collapsed configuration to an expanded configuration, in accordance with an embodiment of this disclosure.

[0032] FIG. 21 is a partial cutaway view of an arrangement of resonator panels and transition blocks within a foldable deepwater resonator array, in accordance with an embodiment of this disclosure.

[0033] FIGS. 22A and 22B illustrate a resonator panel connected to hinge mechanisms, in accordance with an embodiment of this disclosure.

[0034] FIG. 23 illustrates a horizontal transition block for connecting two panel lengths in a row to form a longer panel, to integrate a fixation pin interface to a supporting structure for the foldable array of FIGS. 19A and 19B, in accordance with an embodiment of this disclosure.

[0035] FIGS. 24A and 24B illustrate a first vertical transition block without porting, to integrate a fixation pin interface to a supporting structure for the foldable array of FIGS. 19A and 19B, in accordance with an embodiment of this disclosure.

[0036] FIGS. 25 A and 25B illustrate a second vertical transition block with porting, to integrate a fixation pin interface to a supporting structure for the foldable array of FIGS. 19A and 19B, in accordance with an embodiment of this disclosure.

[0037] FIGS. 26A and 26B illustrate a third vertical transition block with porting, to integrate a fixation pin interface to a supporting structure for the foldable array of FIGS. 19A and 19B, in accordance with an embodiment of this disclosure.

[0038] FIGS. 27A-27I illustrates an example subsea module installation sequence for installing a noise mitigation system around subsea equipment, in accordance with an embodiment of this disclosure.DETAILED DESCRIPTION OF THE INVENTION

[0039] As set forth above, it may be desirable to mitigate noise generated by any one or a combination of underwater production trees, machinery and processing equipment on the seabed. In accordance with embodiments of this disclosure, gas bubble based acoustic resonators (e.g., Helmholtz resonators), for example as disclosed in U.S. Patent Nos. 8689935, 9343059, 9488026, and 9607601, which are incorporated by reference herein in their entirety, are adapted from shallow water use (e.g., 50 meters or less) to a deep water application (e.g., at least 1000 m) by also utilizing gas filled resonators arranged in an array - hereinafter referred to as a deepwater resonator array. The array may include, for example, a mesh or network of inverted cups that are at least partially filled with gas, creating gas voids that are specifically tuned to address specific acoustic frequencies of concern emitted from the equipment / machinery at a particular installation depth. The equipment / machinery that emits the frequencies of concern may include, by way of non-limiting example, rotating equipment / machinery such as a compressor module or pump module that are a part of a subsea installation, or other types of subsea equipment (e.g., trees, chokes, etc.).

[0040] As noted, the deepwater resonator array requires the provision of gas to fill individual cups of the array. In particular, resonator cups must be gas filled to maintain noise mitigation performance on deepwater processing facilities by diffusing sound emitted by subsea machinery. It is believed that no gas distribution mechanisms have been developed for this purpose in deepwater environments, as the application of such arrays in deepwater environments continues to be developed. In addition, gas distribution systems that can be used for gas bubble based acoustic resonators deployed in shallow water (e.g., at depths of less than approximately 100 meters) are not appropriate for use in deepwater environments. Existing gas distribution systems used in shallow water environments use air that is supplied from the surface. In deepwater environments, if air were provided from the surface it would need to be compressed (e.g., in canisters) to be provided to the gas resonator array. Due to the challenges of supplying gas to deepwater locations, it is important to ensure that working gas is not wasted. As such, efficient gas usage and a precise allocation of gas to the resonator array is desired for the resonator array to be used in a deepwater environment. This is very different from gas distribution commonly used for resonators deployed in shallow water with a continuous air supply. In those shallow water implementations, it is common and even desirable to “flood” the resonators with air to form an “air curtain” of bubbles moving upward and not necessarilysettling into resonator cups on the underside of the resonators. This type of gas distribution and flooding of the resonator with gas would waste too much working gas in a deepwater environment. Therefore, it is now understood that a need exists for a system and method for precise allocation of working gas to a resonator array if the resonator array is to be deployed in a deepwater environment.

[0041] A robust and operationally viable gas distribution methodology is required to ensure the resonator cups maintain continuous minimum fill level for noise mitigation. In addition, for deepwater use, limited gas availability will necessitate precise and economical filling of resonator cups with working gas.

[0042] The systems, apparatus, and methods disclosed herein define a methodology to ensure precise, targeted, efficient, and consistent gas distribution and retention within deepwater resonator arrays. In particular, the disclosed systems, apparatus, and methods incorporate one or more of the following enhancements: 1. Individual resonator panels configured to ensure precise and efficient distribution of working gas to minimize the frequency of gas replenishment needed in the field; 2. Individual resonator panels designed with an integrated inverse gutter or skirt to maximize gas ‘hold up’ and minimize individual resonator cup losses from ambient water (cross) current flow; 3. An array of panels that incorporates a methodology for passive distribution of working gas within the array by utilizing internal porting for upward gas migration to minimize wastage and / or maximize interval of refill frequency.

[0043] Other features will be discussed in detail below as well. The disclosed systems, apparatus, and methods may ensure precise, efficient, and consistent placement of working gas across the entire resonator array to maintain continuous and reliable noise mitigation performance for deepwater subsea equipment where continuous compressed air sparging (as used in shallow water on a temporary deployment basis) is not practical.

[0044] Due to deepwater operational constraints for long term use, the embodiments of this disclosure may encompass a variety of configurations, an example of which is depicted in FIG. 1, which is a block diagram of a subsea oil and / or gas facility 10. In FIG. 1, the subsea oil and / or gas facility 10 is an oil and / or gas production system (a hydrocarbon production system) utilizing subsea equipment with noise mitigation features, all of which is configured for deepwater use. In the illustrated embodiment, the subsea oil and / or gas facility 10 includes a subsea processing station 12 that processes production fluids (e.g., oil, gas, or a mixture thereof) received from subsea production trees and manifolds 14. The processed production fluids generated by the subsea processing station 12 are transmitted to topsides processing equipment 16 by one or more flow lines 18 that cross a water line 20 (e.g., a shoreline or to atopside facility). The topsides processing equipment 16 may include, by way of non-limiting example, a liquefied natural gas (LNG) plant, a gathering and separation facility, a petroleum- fired power plant, or the like. The subsea oil and / or gas facility 10 may also include certain supporting features that are not shown, such as umbilicals and a local in field floating utility support platform or other supporting facility above the waterline. Umbilicals may be used to transmit electrical power and / or signals, hydraulic power and / or signals, or both, between the subsea production trees and manifolds 14, the subsea processing station 12, or a combination, and the in field floating utility support platform or other topside support facility.

[0045] The subsea processing station 12 as illustrated is positioned on the seabed 22 via one or more structures. Such structures may include one or more mud mats 24 and one or more structural frames 26. The subsea processing station 12 may include one or more systems (or modules) that process produced fluids, such as by separation, heat exchanger, pumping, and / or compression. The one or more systems may include rotating equipment / machinery located subsea and configured for subsea use. Such rotating equipment / machinery may include pumping equipment / machinery (e.g., a pumping module) having one or more pumps, or compression equipment / machinery (e.g., a compression module) having one or more compressors, or both, for processing oil and / or gas generated by the subsea oil and / or gas facility 10. The illustrated subsea processing station 12 includes a fluid separation system 28 configured to separate produced fluids into its liquid components 30 and gaseous components 32, a subsea pumping system 34 configured to pump the liquid components 30 and a subsea compression system 36 configured to compress the gaseous components 32. Pressurized liquid 38 from the subsea pumping system 34 and compressed gas 40 from the subsea compression system 36 are transmitted through the flow lines 18 to the topsides processing equipment 16. Although not shown, in some embodiments there may be flowlines that recycle at least a portion of the pressurized liquid 38 and the compressed gas 40 back to the fluid separation system 28.

[0046] Each of the systems illustrated include their respective components that process the produced fluids in the station 12. Specifically, the fluid separation system 28 includes separation equipment 42. The subsea pumping system 34 includes one or more subsea pumps 46 (which may be part of one or more pumping modules); and the subsea compression system 36 includes one or more subsea compressors 50 (which may be part of one or more compression modules). The systems are supported by one or more structural frames 26 and accordingly the one or more mud mats 24 to secure and support the mass of installed equipment.

[0047] To mitigate at least some of the noise generated by the subsea pumps 46 and / or subsea compressors 50, the station 12 may include a noise mitigation system 54 configured for deepwater use. The noise mitigation system 54 may be positioned in specific locations to disrupt sound waves generated by equipment / machinery noise at its source to avoid sound transmission over long distances - especially at lower frequencies. Various embodiments of the subsea oil and / or gas facility 10 may utilize any one or a combination of the noise mitigation systems 54 described herein. In the illustrated embodiment, the subsea compression system 36 includes one or more noise mitigation systems 54 located proximate (e.g., around) the subsea compressor(s) 50 (e.g., around the compression module assembly or in close proximity to the subsea compressor housing).

[0048] During operation, the rotating equipment / machinery such as the pump(s) 46 and compressor(s) 50 produce noise, and it may be desirable to mitigate the noise produced by either or both of these. In accordance with the described embodiments, the subsea compression system 36 and the subsea pumping system 34 may each include one or more noise mitigation systems 54 located proximate (e.g., around) the equipment noise source (e.g., around the module assembly or in close proximity to the subsea compressor / pump housing).

[0049] The noise mitigation system 54 includes at least one deepwater resonator array 56 configured for deepwater use and comprising an array of resonators (e.g., an array of resonator cups) filled with gas to mitigate noise. The noise mitigation system 54 also includes a gas source 58 and a gas distribution system (not shown) to fill the resonator cups. The gas source 58 may include one or more storage tanks, a device or system that performs water electrolysis, a compressed gas line, or a combination of these. The gas distribution system may include one or more accumulators, control valves, gas pipes, manifolds, emitters, and / or ports, which may be incorporated into structural components of the deepwater resonator array 56. Filling the cups of the resonator array 56 forms resonators that absorb or otherwise disrupt noise generated during operation of the subsea pump(s) 46 and / or the subsea compressor(s) 50. Although the components of the noise mitigation system 54 are only illustrated for the subsea compression system 36, it should be noted that in various different embodiments these components may be replicated for the subsea pump system 34, or may be utilized for both the subsea compression system 36 and the subsea pumping system 34, or may only be associated with the subsea pump system 34. A similar noise mitigation system 54 may be used with other types of subsea equipment as well (e.g., subsea chokes, etc.), not just rotating equipment / machinery. The noise mitigation system 54 may be permanently installed for the operating life (which may be on the order of 25-50 years) of the subsea equipment / machinery for which it is mitigating noise.

[0050] The deepwater resonator array 56 of this disclosure may have any appropriate shape and material construction that is suitable for mitigating noise generated by the subsea equipment / machinery mentioned above and may depend on the configuration utilized. As the deepwater resonator array 56 is configured to be used in a subsea installation, the deepwater resonator array 56 may be “tuned” to target specific frequencies in its design to ensure noise reduction targets are achieved at a water depth of at least 100 meters, at least 500 meters, at least 1000 meters, at least 1250 meters, at least 1500 meters, at least 2000 meters, or at least 2500 meters; for example between 1000 meters and 1500 meters, or between 2000 meters and 3200 meters. The deepwater resonator array 56 may be configured to mitigate noise at an operational (“dynamic”) design temperature of 2°C to 30 °C. In one non-limiting embodiment, the deepwater resonator array 56 may be configured to mitigate noise at an operational temperature of between 25 °C and 30 °C at an operational depth of between 100 m and 150 m. In another non-limiting embodiment, the deepwater resonator array 56 may be configured to mitigate noise at an operational temperature of between 3 °C and 5 °C at an operational depth of between 1200 m and 1500 m. In a further non-limiting embodiment, the deepwater resonator array 56 may be configured to mitigate noise at an operational temperature of between 3 °C and 5 °C at an operational depth of up to 3200 m.

[0051] The configuration of the deepwater resonator array 56 may include shape, thickness, size, arrangement, and material construction selected such that the deepwater resonator array is configured to attenuate noise having particular frequencies, such as the low frequency portion of the spectrum, the medium frequency portion of the spectrum, the high frequency portion of the spectrum, or any combination thereof. Generally, the deepwater resonator array 56 may be configured to attenuate noise having a frequency ranging from 5 Hz to 10,000 Hz. In a first embodiment, at least one deepwater resonator array 56 is configured to mitigate noise output from one or more pumps, the noise having a range of between 40 Hz and 700 Hz. In a second embodiment, at least one deepwater resonator array 56 is configured to mitigate noise output from one or more compressors in a range of between 600 Hz and 2500 Hz.

[0052] The components of or associated with the noise mitigation system 54 may be further appreciated with respect to Figures 2-271. FIG. 2 illustrates an example noise mitigation system 54 surrounding subsea equipment (e.g., a subsea compression module 36). As shown, the noise mitigation system 54 may include multiple deepwater resonator arrays 56A-56D and a gas distribution system 60 for distributing working gas from a connected gas source to the different resonator arrays 56. Each resonator array 56 includes a plurality of panels 90, witheach panel 90 having a plurality of resonator cups 92 formed therein. The panels 90 may be elongated, as shown.

[0053] The gas distribution system 60 in this embodiment includes supply tubes for the working gas (e.g., nitrogen, hydrogen, and / or air), which is provided by the gas source (not shown) and is distributed to multiple locations. At least one supply line may be provided for each deepwater resonator array 56.

[0054] The resonator arrays 56 may be supported by one or more relatively rigid structural frames 94 of the noise mitigation system 54 that surround or otherwise include the acoustic resonator arrays 56. The material construction, cup size, and cup distribution of the resonator arrays 56 and the gas distribution system 60 may depend on the frequencies that are targeted, along with other considerations such as the temperatures and pressures at which the noise mitigation system 54 may be used.

[0055] It is desirable to maintain the gas fill of the resonator cups 92 formed in each deepwater resonator array 56 to provide the desired noise mitigation. Due to the noise generating subsea equipment (e.g., subsea compression module 36) being in a deepwater environment, an efficient method for filling / re-filling the resonator cups 92 with working gas is needed. As discussed in further detail below, the gas distribution system 60 and the resonator arrays 56 use a low flow rate gravity distribution method to fill / refill the resonator cups 92 in a smooth and efficient manner where little, if any, gas is lost to the environment. The gas distribution system 60 may supply multiple emitters via supply tubes to directly feed gas to resonator panels 90 from a distribution manifold. When the resonator cups 92 in a resonator array 56 need to be refilled (or “topped off’), an actuated valve will open to release gas from an accumulator to a group of emitters allowing working gas to distribute up the resonator array 56 in a controlled low velocity flow rate.

[0056] The disclosed design for the gas distribution system 60, individual panels 90, and overall resonator arrays 56 may provide a targeted, efficient, and consistent gas distribution and retention system. The gas distribution and retention system may provide full coverage of the noise generating module with the following enhancements for deepwater long term use: 1. Precise and efficient distribution of working gas to minimize the frequency of gas replenishment in the field; 2. Resonator panels with integrated inverse gutters to maximize gas ‘hold up’ and minimize losses from current flow; and 3. Integral distribution of working gas within a resonator array by utilizing internal porting for upward gas migration.

[0057] FIG. 3 illustrates an example resonator panel (hereinafter “panel”) 90 for a deepwater resonator array in accordance with an embodiment of the present disclosure. The panel 90 maybe an elongated single panel or series of panels that are stacked or extend along a longitudinal axis. The panel 90 includes a plurality of resonator cups 92 formed therein. The resonator cups 92 are each open along a downward facing surface 110 of the panel 90, thus allowing the resonator cups 92 to receive and retain a working gas therein. A gas inlet area 112 is located proximate one longitudinal end of the panel 90, and a gas outlet area 114 is located proximate an opposite longitudinal end of the panel 90. The gas outlet area 114 may provide transmission of gas to a subsequent panel (e.g., above panel 90) via porting shown on the right side of the panel 90 in FIG. 3. At least one inverted gutter 116 is formed in the downward facing surface 110 of the panel 90 and extending along the surface from the gas inlet area 112 to the gas outlet area 114, e.g., to sequentially fill the cups as gas migrates by gravity from the gas inlet area 112 to the gas outlet area 114. The panel 90 may include one or more ports 118 extending vertically through the panel at the gas outlet area 114 to transmit gas to the next panel (could be above or adjacent the panel 90). FIG. 3 shows the direction of working gas flow (via arrows) from the gas inlet area 112, along the length of the gutter 116, and finally exiting the panel 90 via one or more ports 118 at the gas outlet area 114. In an embodiment in which the panel 90 is not vertically stacked with respect to other panels, there will not be port(s) extending through the panel 90.

[0058] In FIG. 3, the panel 90 is shown oriented horizontally. In some embodiments, for example, as shown in FIG. 4, the panel 90 is inclined with respect to horizontal. This may make the panel fill easier, more uniform, and more efficient. The panel 90 may be coupled to a structural frame (e.g., 94 of FIG. 2) that holds the panel 90 such that the longitudinal axis of the panel 90 is angled with respect to a horizontal plane, as shown in FIG. 4. Inclining the panel 90 in this manner, with the gas outlet area 114 being located higher than the gas inlet area 112, allows for working gas to fill the resonator cups 92 via gravity migration of the working gas along the gutter(s) 116 of the panel 90. The angle of the inclined panel 90 and the velocity of working gas provided to the panel 90 may be selected to maintain a slow velocity and laminar flow of the working gas along the panel 90 to ensure passive filling of the resonator cups 92. The working gas may fill the resonator cups 92 sequentially (e.g., one after the other in the axial direction) along the length of the panel 90 from inlet to outlet.

[0059] FIG. 5 illustrates an example resonator array 56 including five panels 90 stacked one over the other in a vertical direction. As shown, the panels 90 may be oriented parallel to each other (e.g., horizontally). In other embodiments, for example, as shown in FIG. 6, the panel orientations may be inclined to optimize gas filling. As shown in both FIGS. 5 and 6, the panels 90 are connected to enable working gas to flow sequentially from the lowest panel to the highestpanel via gravity migration. Each panel 90 extends along its own longitudinal axis and has a similar construction as the panel 90 described above with reference to FIGS. 3 and 4. The direction of gas flow along each panel 90 reverses from one level to the next. For example, in both FIGS. 5 and 6, the lowest positioned panel has a gas inlet area 112 proximate its left end and a gas outlet area 114 proximate its right end. The next highest positioned panel has a gas inlet area 112 proximate its right end and a gas outlet area 114 proximate its left end. At least one connector (e.g., 120 in FIG. 5, or 172 / 174 in FIG. 6) couples the right ends of the two lowest panels. The connector(s) may include porting that allows gas to flow from the gas outlet area 114 of the lowest panel to the gas inlet area 112 of the next highest panel. The entire group of panels 90 may be connected in a similar manner such that the resonator array 56 provides a back-and-forth movement of gas from one level to the next, enabling gas distribution from a single emitter at the bottom of the assembly. The working gas may begin to fill the resonator cups 92 at the bottom row, with the gas filling each cup in sequential order as it flows from one end to the other, and then continue to flow to the next panel level for filling via gravity.

[0060] As discussed above, the panel(s) 90 may each have at least one inverted gutter formed therein to facilitate gas movement and minimize gas losses and water cross flow that may displace gas out of the individual resonator cups 92 as the filling takes place. One embodiment of the gutter 116 is shown in FIG. 7. The gutter 116 may be an ‘inverse gutter’ that facilitates filling of cups from the gas stream flowing horizontally during a resonator array filling sequence. Lower skirts (sides) 130 of the gutter 116 may retain and distribute gas horizontally and reduce water cross flow gas displacement out of the resonator cup 92 above. While only a single gutter 116 is shown in the cross-section of FIG. 7, it should be noted that other embodiments may include multiple parallel gutters formed on the lower surface 110 of the panel 90.

[0061] FIGS. 8 A and 8B illustrate an example panel construction. The panel 90, as shown, may include several rows (e.g., parallel rows) of resonator cups 92 positioned axially along the length of the panel 90. While the example panel has five rows of resonator cups 92, other embodiments may have other numbers of resonator cups 92 (e.g., one, two, three, four, six, seven, eight, nine, ten, or more resonator cups). The panel 90 may include resonator cups 92 having different relative sizes and / or shapes, as shown. In other embodiments, all resonator cups 92 on the panel 90 may have the same size and shape. In either case, the cup size and count may be optimized to mitigate specific frequencies of concern emitted by the subsea machinery. The panel 90 may include interlocking features 140 formed at both longitudinalends. These features 140 may allow multiple panels 90 to be fastened together in various series configurations using specially designed interlocking connectors. For example, two such panels 90 may be coupled together lengthwise via a horizontal connector to extend the overall length of the panel 90. As another example, two panels 90 may be connected one over the other via vertical connectors attached to the corresponding interlocking features 140 on the same end of both panels 90. The panel 90 may include one or more gutters (or channels) 116 formed on its lower surface 110 (which has the openings to the resonator cups 92). The gutter(s) 116 may run the entire length of the panel 90, as shown. The illustrated panel 90 has five gutters 116, each aligned with a different row of resonator cups 92. Other numbers or arrangements of gutter(s) 116 may be used in other embodiments. The gutter(s) 116 assist in the process of filling each resonator cup 92 with working gas from a single lowest point, when the panel 90 is fluidly coupled to the gas distribution system.

[0062] FIGS. 9A and 9B illustrate an example subsea equipment module 150 (specifically, a compressor and transformer module) with the maximum practical coverage of the noise mitigation system 54. The noise mitigation system 54 includes multiple resonator arrays 56 covering four sides and the roof of the subsea equipment. Certain boxes and areas visible in FIG. 9A cannot be shielded with resonator panels due to interface connection requirements for the subsea equipment, in this example. As such, resonator panels cannot be positioned over these areas. In the illustrated embodiment, the total surface area coverage of the noise mitigation system 54 around the outside of the subsea equipment module 150 (excluding the bottom face, located on the seafloor) may be over 80%. As such, the noise mitigation 54 may be capable of mitigating a substantial amount of noise from the subsea equipment module 150.

[0063] Certain structural components that make up the noise mitigation 54 system of FIGS. 9 A and 9B will now be described with reference to FIGS. 10A-18C. FIGS. 10A and 10B illustrate a portion of the noise mitigation system 54 that may be located along a side of the subsea equipment module (e.g., 150 of FIGS. 9A and 9B). This portion may include a deepwater resonator array 56 secured to a structural support frame 160 of the noise mitigation system 54. The illustrated resonator array 56 includes multiple groups of panels 90 that are positioned within a resonator support frame 162. The resonator support frame 162 may include multiple vertical dividers 164 coupled to one or more horizontal frames 166. The vertical dividers 164 may define multiple vertically oriented compartments. The vertical dividers 164 may be spaced approximately one panel length apart, as shown. However, in other embodiments where multiple panels 90 are connected horizontally, the vertical dividers 164 may be spaced multiple panel lengths apart from each other.

[0064] FIG. 11 shows stacks of panels 90 positioned in the resonator support frame 162. The resonator support frame 162 is a structural frame configured to enable panels 90 and vertical connectors to be inserted (e.g., lowered and / or slid) into the cage 162 during assembly of the resonator array 56. The resonator panels 90 may be stacked vertically (along with connectors) in the resonator support frame 162, without bolted connections.

[0065] Turning back to FIG. 10 A, the illustrated resonator support frame 162 may hold four vertical stacks of panels 90 (e.g., one in each vertical “column” formed by the resonator support frame 162). However, other numbers of vertical stacks of panels 90 may be placed into a resonator support frame 162, e.g., as shown on different sides of the noise mitigation system 54 in FIGS. 9 A and 9B. Each panel stack may be independently supplied with working gas injected at the lowest panel level.

[0066] FIG. 10B shows a connection of the resonator support frame 162 to the structural support frame 160 of the noise mitigation system. The resonator support frame 162 may be bolted to the structural support frame 160 at each corner. In an example, the resonator support frame 162 and the structural support frame 160 may each be constructed from structural steel with a suitable coating system and cathodic protection.

[0067] Turning back to FIG. 6, the figure illustrates a resonator panel stack 170 in accordance with an embodiment of the present disclosure. As shown, the resonator panel stack 170 may be configured such that a resonator support structure holds the panels 90 at an incline. For example, each panel 90 may be angled approximately 1.5 degrees with respect to horizontal. This angle ensures that the inclination of the panels 90 is correct while accounting for an installation tolerance (e.g., + / - 1 degree) of the subsea equipment module when deployed on seabed. The direction of the angle may be reversed from one row to the next row moving up through the resonator panel stack 170. The different angles of inclination from row to row may be accomplished using different sizes of transition blocks 172, 174 located between adjacent stacked panels 90. Dashed arrows 176 in FIG. 6 illustrate the flow of working gas through the resonator panel stack 170. The angling of the panels 90 may facilitate accurate and efficient filling of the resonator cups 92 from the bottom panel to the top panel of the resonator array.

[0068] In some embodiments, it may be desirable to connect one or more panel lengths together to form a longer panel 90. FIGS. 12A and 12B show a horizontal transition block 180 that may be used to connect two panel lengths 90A, 90B end to end to ensure continuity of the inverted gutters 116. Like each of the panel lengths 90A, 90B being connected, the transition block 180 may include one or more gutters 116 formed in a bottom surface thereof to direct the gas to flow longitudinally along the bottom of the panel 90 to fill the resonator cups 92. Horizontaltransition blocks 180 may be used to connect panel lengths to form longer panels 90 in any desired resonator array of the noise mitigation system (e.g., in a roof-mounted resonator array and / or a foldable resonator array).

[0069] FIGS. 13-15 show vertical transition blocks 172, 174 that may be used as connectors to vertically connect panels 90 that are stacked one over the other. FIG. 13 shows the different transition blocks 172, 174 and how they may be arranged to enable flow of working gas from one panel level to the next. The vertical transition blocks 172, 174, as shown, may include ports 190 formed therethrough. The ports 190 connect the gas outlet area 114 of a lower panel 90 to the gas inlet area 112 of an adjacent upper panel 90. The different sizes or types of transition blocks 172, 174 may be attached to panel ends to ensure consistent vertical panel spacing within a resonator support structure (e.g., resonator support frame 162 of FIGS. 10A- 11). The panels could include one panel length across each layer or multiple panel lengths attached end to end with horizontal transition blocks (e.g., as shown in FIGS. 12A and 12B).

[0070] FIG. 14 shows a first (taller) size of vertical transition block 172. This block is designed to transfer working gas between lower and upper panel rows while keeping the stacked resonator panels 90 at the correct inclination by ensuring consistent vertical spacing. Like the panel 90 to which it is connected, the vertical transition block 172 may include one or more gutters 116 formed in the lower surface thereof. The gutter(s) 116 in the vertical transition block 172 may direct the gas to flow longitudinally along the bottom of the vertical transition block 172 to one or more openings that feed into one or more vertical ports 190 through the block.

[0071] FIG. 15 shows a second (shorter) size of vertical transition block 174. This block is designed to transfer working gas between lower and upper panel rows while keeping the stacked resonator panels 90 at the correct inclination. This vertical transition block 174 may not include gutter(s) formed along a surface thereof, since the transition block 174 may be configured to sit atop the taller vertical transition block (as shown in FIG. 13). As illustrated, the shorter transition block 174 may include one or more vertical ports 190 formed therethrough to transfer gas flow from a lower panel 90 to an upper panel 90.

[0072] Other embodiments of the resonator array having vertically stacked panels 90 may include other types or constructions of transition block(s) 172, 174 between adjacent panels. For example, the shorter transition block 174 could include gutter(s) formed therein to match those of the panel 90, while the taller transition block 172 may not include gutter(s) but instead would sit as a spacer beneath the shorter vertical transition block 174. In other embodiments,the multiple transition blocks 172, 174 may be combined into a single vertical transition block that is directly connected to two panels 90.

[0073] As shown in FIG. 6, each panel may be attached to the first vertical transition block 172 (FIG. 14) at one longitudinal end and to the second vertical transition block 174 (FIG. 15) at the opposite end, allowing the assembly of the panel 90 and two connected transition blocks 172, 174 to be easily stacked into a resonator support structure (e.g., resonator support frame 162 of FIGS. 10A-11) to form a new level of the resonator panel stack 170.

[0074] FIG. 16 illustrates roof-mounted resonator arrays 56 installed in support frames over a subsea equipment module 150. Each horizontal resonator array support frame may include multiple panels 90 that are connected longitudinally and arranged side by side to each other to maximize effective coverage. A gas supply manifold (not shown) may be fluidly coupled to the gas inlet area of each connected panel 90 in the resonator array 56 to enable filling of the resonator cups of the different panels 90 in parallel. As illustrated by the dashed arrows 200, working gas flows in the same direction along each of the panels 90 in each resonator array 56, from an outside location inward (and upward) toward a central axis 202 of the roof.

[0075] In the illustrated embodiment, horizontal runs of fluidly coupled resonator array panels 90 are supported in six identical resonator frames 204. Example panel transition pieces to allow mechanical and gas connections can be seen in FIG 12A and 12B. However, other numbers and arrangements of roof-mounted resonator array panels 90 may be used in other embodiments. The resonator frames 204 may be bolted to the roof structural frame 206 with a small inclination angle (e.g., 1.5 degrees) upward in the direction of the central axis 202 of the roof. This allows working gas supplied to the outside of the roof to flow inward because of the inclination of resonator panels 90. The panels 90 may include one or more inverted gutters, as discussed above, to direct working gas along the lower surface of the panel 90 from one longitudinal end (outside location of the roof) to an opposite longitudinal end (central axis 202 of the roof). The gas distribution system for the noise mitigation system may include individual manifolds at the inlet area of the horizontal run of each resonator panel so that the working gas does not first have to flow all the way up the side mounted panels before reaching the roof assembly. This provides greater flexibility in being able to have removable elements in the noise mitigation system without disturbing gas distribution to other parts of the system. In some embodiments, the roof-mounted panels 90 and the resonator frames 204 in which they are placed may form a roof assembly that can be selectively removed from the top of the subsea equipment to enable access to components of the subsea equipment 150 without removing the entire noise mitigation system.

[0076] FIG. 17 more clearly shows the underside of a roof-mounted resonator array 56 having multiple connected runs of horizontal resonator panels 90 located in a resonator frame 204. As illustrated, the roof-mounted resonator array 56 may include panels 90 formed from multiple panel lengths coupled end to end via horizontal transition blocks 180. The transition blocks 180 may be bolted to the resonator frame 204, which sits above the resonator panel 90.

[0077] FIGS. 18A-18C illustrate an example of a foldable resonator array 220. The illustrated foldable resonator array 220 may be used in a noise mitigation system, for example, on a side of the subsea equipment having one or more obstacles (e.g., pipe connections) that must extend outside of the noise mitigation system. As an example, the foldable resonator 220 is shown in use in an expanded / deployed configuration in FIG. 9A. The foldable resonator array 220 may be movably connected to the support frame of the noise mitigation system that is positioned around the subsea equipment. The foldable resonator array 220 includes a plurality of elongated panels 90 connected to a central beam that may contain a gas distribution manifold 222 (e.g., centrally located in the array). The foldable resonator array 220 may include shorter panels 90A coupled to opposite sides of the central beam at an upper portion of the resonator array and longer panels 90B (formed by connecting multiple panel lengths) at a lower portion of the resonator array 220. The foldable resonator array 220 is configured to be selectively transitioned between a collapsed configuration and an expanded / deployed configuration (as seen in 18A and 18B respectively).

[0078] The stacked resonator panels 90 may be connected to each other via one or more vertically oriented support structures (e.g., stabilizers) 224 located between the central beam 222 and the outer end of the panels. The vertical support structures 224 may be coupled to horizontal transition blocks (e.g., 356 of FIG 23, or 180 of FIGS. 12A and 12B) coupling the different panels together and / or to the outer ends of the panels 90. The vertical support structures 224 may be coupled to the panels 90 and / or transition blocks (e.g., 356 / 350 / 352 / 354 of FIGS. 23-26B, or 180 of FIGS. 12A and 12B) via pin connections that allow the panels 90 to rotate or hinge with respect to the vertical support structure 224 / 324.

[0079] FIG. 18A shows the foldable resonator array 220 in the collapsed configuration, in which the panels 90 of the array are collapsed toward the central beam 222. FIG. 18B shows the foldable resonator array 220 in the expanded configuration, in which the panels 90 of the array are expanded in a direction away from the central beam 222. FIG. 18C shows a portion of the foldable resonator array 220 in the expanded position with dashed arrows 226 indicating the direction of gas migration along the length of the panels 90. The central beam 222 contains the gas supply manifold that is fluidly coupled to the gas inlet area of each panel 90 to enablefilling of the resonator cups in the panels 90 in parallel. Each panel 90 includes at least one inverted gutter formed therein to direct gas flow from the gas manifold toward an extended end of the elongated panel 90 to fill the resonator cups of the panel 90.

[0080] In the illustrated collapsed configuration of FIG 18 A, the resonator panels 90 are each inclined in a downward direction away from the central beam 222. In the illustrated expanded configuration of FIG 18B, the resonator panels 90 are each inclined in an upward direction away from the central beam 222. This enables gas to be emitted into the gutter(s) of each panel 90 and transmitted along the length of each panel 90 via gravity migration from the central gas manifold on the central beam 222 to the extended end of the panel 90.

[0081] Having the foldable resonator array 220 in the collapsed configuration allows for the resonator array 220 to be lowered between pipe connections (or other equipment interface obstacles) located at an upper location of the subsea equipment. In the collapsed configuration, panels 90 of the resonator array 220 are directly stacked on top of each other for improved stability during installation of the resonator array 220. Once the foldable resonator array 220 has been lowered between the obstacles of the subsea equipment, the array can be unfolded to the deployed position. The unfolding may be a controlled movement of all resonator panels 90 as they remain in a stacked formation. The unfolding may be initiated via downward movement of the central beam containing the gas manifold 222. Once unfolded, the panels 90 are kept at a suitable inclination for the working gas to flow outward from the central gas manifold 222 to the outer edges of the panels 90.

[0082] FIGS. 19A-20C illustrate another example of a foldable resonator array 320. The illustrated foldable resonator array 320 may be used in a noise mitigation system, for example, in a similar location and manner as the foldable resonator array 220 shown in FIG. 9A. The resonator array 320 may be movably connected to the support frame of the noise mitigation system that is positioned around the subsea equipment. The foldable resonator array 320 includes a plurality of elongated panels 90, with the lowest two panels 90 connected to a gas manifold (not shown) at the bottom of the assembly. The elongated panels extend outward from opposite sides of a central beam 322. The foldable resonator array 320 may include shorter panels 90A coupled to opposite sides of the central beam at an upper portion of the resonator array and longer panels 90B (formed by connecting multiple panel lengths) at a lower portion of the resonator array 320. The foldable resonator array 320 is configured to be selectively transitioned between a collapsed configuration and an expanded / deployed configuration.

[0083] The stacked resonator panels 90 may be connected to each other via one or more vertically oriented support structures (e.g., stabilizers) 324 located between the central beam 322 and the outer end of the panels. The vertical support structures 324 may be coupled to horizontal transition blocks (shown in more detail in FIG. 23) coupling the different panels together and / or to the outer ends of the panels 90. The vertical support structures 324 may be coupled to the panels 90 and / or transition blocks via pin connections that allow the panels 90 to rotate or hinge with respect to the vertical support structure 324.

[0084] FIG. 19A shows the full resonator array in its expanded / deployed configuration, in which the panels 90 of the array are expanded in a direction away from the central beam 322 of the foldable resonator array 320. FIG. 19B shows a portion of the foldable resonator array 320 in its expanded configuration with dashed arrows 326 indicating the direction of gas migration along the length of the panels 90 in one half of the foldable resonator array 320. As shown, the panels 90 of the foldable resonator array 320 may be in a parallelogram construction with intermediate panels for working gas flow. Working gas may be communicated downward along the central beam 322 and then output to the lowest resonator panels 90 on both sides of the central beam 322 (e.g., via two emitters, one on each side).

[0085] FIG. 20A shows a portion of one half of the foldable resonator array 320 in the collapsed configuration, in which the panels 90 of the array are collapsed toward the central beam 322 of the foldable resonator array 320. FIG. 20B shows a portion of one half of the foldable resonator array 320 being unfolded and expanded outward toward the expanded configuration. FIG. 20C shows a portion of one half of the foldable resonator array 320 in the fully expanded / deployed configuration. One or more gas manifolds may be fluidly coupled to the gas inlet zones of each of the lower two panels 90 of the resonator array (one on each side of the central beam 322). In the expanded configuration, the foldable resonator array 320 may facilitate gas flow in an upwardly cascading manner (vertically from one panel 90 to the next) to enable filling of the resonator cups in both halves of the resonator array 320 from the bottom up. Each panel 90 includes at least one inverted gutter formed therein to direct gas flow from one end of the panel 90 to the opposite end of the panel 90 to fill the resonator cups of the panel 90.

[0086] In the illustrated collapsed configuration (FIG. 20A), the resonator panels 90 are each inclined in a downward direction away from the central gas manifold 322. In the illustrated expanded configuration (FIG. 20C), the stacked resonator panels 90 alternate between being inclined in an upward direction away from the central beam 322 of the resonator array 320 and being inclined in a downward direction away from the central beam 322. This enables gas tobe emitted into the gutter(s) of the two lowest panels 90 and transmitted upward from one stacked panel 90 to the next via gravity migration until it reaches the top panels 90 of the resonator array 320.

[0087] Having the foldable resonator array 320 in the collapsed configuration allows for the resonator array 320 to be lowered between pipe connections (or other interface obstacles) located at an upper location of the subsea equipment. In the collapsed configuration, panels 90 of the resonator array 320 are directly stacked on top of each other for improved stability during installation of the resonator array 320. Once the foldable resonator array 320 has been lowered between the obstacles of the subsea equipment, the array can be unfolded. The unfolding (FIG. 20B) may be a controlled movement of all resonator panels 90 as a result of the parallelogram construction (the panels 90 remain stacked one over the other but their relative inclinations begin to change). The unfolding may be initiated via downward movement of the central beam 322 of the resonator array 320 relative to a stationary structure to which the resonator array 320 is attached. Once unfolded, the panels 90 are kept at suitable alternating inclinations for the working gas to flow back and forth up the panels 90 in both halves of the resonator array 320. In the illustrated embodiment, the working gas flows from one panel level vertically upward to the next panel level, and so forth. Transition blocks at opposing ends of the panels 90 may ensure efficient transfer of working gas between adjacent panels 90.

[0088] FIG. 21 shows a cross sectional layout of panels 90 in the expanded configuration in one half of the foldable resonator array 320 of FIGS. 19A-20C. The panels 90 shown in FIG. 21 are the shorter panels 90A visible at the upper part of FIG. 20C. As indicated in FIG. 21, three types of vertical transition blocks 350, 352, 354 may be used to provide mechanical support of the parallelogram construction during unfolding and full expansion of the panels 90. The transition blocks may be attached to a resonator frame (e.g., the central beam 322 and the vertical support structure(s) 324) using hinge pins (instead of bolts), thus preventing any fixtures from sticking out above or below the panels 90. This allows for flat interfaces between the panels 90 when the panels 90 are folded into the collapsed configuration.

[0089] FIGS. 22A and 22B show an example of vertical transition blocks 350, 352 with the pin connections at the ends of a panel 90 and horizontal transition blocks 356 with pin connections between panel lengths of the panel 90. The panel shown in FIGS. 22A and 22B is a longer panel 90B visible at the lower part of FIG. 20C. As shown in FIGS. 21 and 22A, at least one hinge component 358 may be coupled between an end of the panel 90 and a location on the resonator cage (e.g., on the central beam) to facilitate the controlled unfolding of the panels 90 from the collapsed position to the expanded position.

[0090] FIG. 23 illustrates an example horizontal transition block 356 having an aperture 370 through which a pin connection can be made. One or more horizontal transition blocks 356 may be used to form the longer panels (e.g., 90B of FIG. 20C).

[0091] FIGS. 24A and 24B show a first type of vertical transition block 350 that may be positioned at the gas inlet zone end of each panel in the resonator array. This first type of vertical transition block 350 is a closed end block that has no porting. These vertical transition blocks 350 may be used with both the shorter panels (e.g., 90A of FIG. 20C) and the longer panels (e.g., 90B shown on the lower part of FIG. 20C).

[0092] FIGS. 25 A and 25B show a second type of vertical transition block 352 that may be positioned at the gas outlet zone end of certain panels in the resonator array. This second type of vertical transition block 352 has porting extending therethrough to enable gas flow from one panel level to the next. These vertical transition blocks 352 may be used on the inner side (closest to the central beam 322) of the shorter panels (e.g., 90A of FIG. 20C) and on both sides of the longer panels (e.g., 90B of FIG. 20C).

[0093] FIGS. 26 A and 26B show a third type of vertical transition block 354 that may be positioned at the gas outlet zone end of certain panels in the resonator array. This third type of vertical transition block 354 has porting extending therethrough to enable gas flow from one panel level to the next. These vertical transition blocks 354 may be used on the outer side (furthest from the central beam 322) of the shorter panels (e.g., 90A of FIG. 20C). These vertical transition blocks 354 are similar to the second type of vertical transition block 352 shown in FIGS. 25A and 25B but have a greater height to compensate for larger spacing between the panels.

[0094] An installation sequence for the noise mitigation system of FIGS. 9A and 9B will now be described with reference to FIGS. 27A-27I. As shown in FIG. 27A, the subsea equipment module 150 (e.g., compressor and transformer module) is deployed to the seafloor. FIG. 27B shows the installation of guide pins 230 into or around the subsea equipment module 150. As shown, there may be two vertical guide pins 230 with different heights. The guide pins 230 may be installed into catchers, or other receiving features, on a support frame 232 of the subsea equipment module. The boxes 234 shown in FIG. 27B represent space reserved for interface obstacles surrounding the subsea equipment module 150. FIG. 27C shows the structural support frame 160 of the noise mitigation system, along with the foldable resonator array 220 (or resonator array 320 in other embodiments), being lifted through the splash zone and toward the subsea equipment module 150. Although FIGS. 27C-27I do not show other resonator arrays on the four sides of the support frame 160, this is merely for ease of visualizing theinstallation process. Resonator arrays 56 would be pre-installed into the support frame 160, as shown and described with reference to FIGS. 9A-10B, prior to the steps shown in FIGS. 27C- 271. In FIG. 27C, the structural support frame 160 with the resonator arrays may be lifted through the splash zone and toward the subsea equipment module. A vertically movable support beam 400 retains the foldable resonator array 220 strength during deployment, especially during transition through the splash zone.

[0095] FIG. 27D shows the initial engagement of the structural support frame 160 (e.g., with the foldable resonator array 220) being lowered onto the first and second guide pins 230 extending upward from the subsea equipment module 150. The support frame 160 initially engages the longer guide pin 230 A, followed by the shorter guide pin 230B. The support frame 160 may be continually lowered with respect to the subsea equipment module 150, guided by the guide pins 230. As shown at FIG. 27E, the support beam 400 for the foldable resonator array 220 may engage with two corner pins 235 on top of the subsea equipment module. As the support frame 160 is lowered further relative to the subsea equipment module 150, the support beam 400 for the foldable resonator array 220 remains in place on top of the subsea equipment module 150 (as shown in FIG. 27F). The support frame 160 eventually lands on one or more landing profiles (e.g., comer pins 235) of the subsea equipment module 150. This lowers the support frame 160 (and the attached resonator arrays) around the subsea equipment module 150, as shown in FIG. 27G. Movable guides 402 on the support frame 106 may be configured to move upward with respect to the rest of the support frame 160. These movable guides 402 may land on catchers 404 of the installed subsea equipment modules while the rest of the support frame 160 is being lowered. Eventually, receivers on the support frame 160 may rest on the landing profiles of the subsea equipment modules to halt the relative movement of the support frame 160 with respect to the subsea equipment modules. Once the support frame 160 is landed, the installation sequence may include a subsequent operation to deploy the foldable resonator array 220 on a backside of the subsea equipment module 150, as shown in FIG. 27H. The unfolding process may be actuated using an ROV bucket 236 on top of the support frame 160, which rotates a cam to lower the central beam and gas manifold 222 of the resonator array 220 downward relative to the support frame 160, thus deploying the resonator array 220 from a collapsed configuration to an expanded / deployed configuration. After this, the guide pins 230 may be removed and re-used to deploy a noise mitigation system on another subsea equipment module.

[0096] The roof-mounted resonator arrays 56 may then be independently lowered onto the support frame 160 of the noise mitigation system 54, as shown in FIG. 271. The roof of thesupport frame 160 may include guide pins 238 located at one or more comers thereof. The roof frame 206 may land on the guide pin profiles 238 of the support frame 160. As such, the complete roof section may be filled with resonator panels. The external placement of guide pins 238 minimizes risk of damage of the resonator array assemblies 56 during installation of the roof structure.

[0097] A method of operating a noise mitigation system in accordance with present embodiments will now be described. The method may include delivering a working gas at a gas inlet area located proximate a first (lowest) longitudinal end of a panel of a deepwater resonator array, the panel extending along a longitudinal axis and having a plurality of resonator cups that are open along a downward facing surface of the panel. The method may include directing the working gas in the direction of the longitudinal axis via one or more gutters formed in the downward facing surface of the panel. As described above, the one or more gutters may extend from the gas inlet area to a gas outlet area proximate a second longitudinal end of the panel. The method may include filling the plurality of resonator cups with the working gas as the working gas moves from the gas inlet area toward the gas outlet area. The method may include filling the plurality of resonator cups sequentially along the longitudinal axis of the panel. The one or more gutters may provide a laminar flow of the working gas to fill the resonator cups. The method may include directing the working gas from the gas outlet area of the panel to a subsequent panel located above the panel via a port fluidly coupled to the gas outlet area. The filling may continue until it is determined that all resonator cups of the resonator array have been filled to at least a preselected capacity with gas. In some embodiments, the noise mitigation system may include one or more sensors and a control system configured to control output of working gas from a gas source to fill the resonator cups. The sensor(s) may be passive sensors or active sensors.

[0098] Indirect sensors (which may also be referred to as “passive” sensors) are sensors configured to track an attributable overall noise level from the subsea processing system, and the signals from these sensor(s) can be used to monitor performance degradation of the noise mitigation system. When the emitted sound reaches a high enough level according to the passive sensor signals, the control system may output signals to open one or more solenoid(s) of the gas distribution system to provide a working gas to the resonator panels. Similarly, as the working gas is filling the resonator cups via gravity distribution, the passive sensors may continue to monitor the sound level. When the sound level reaches a low enough level to confirm that the resonator cups have been refilled, or a timed release of a specific volume ofgas has been delivered, the control system may output signals to close the actuated valves of the gas distribution system to stop the refilling process.

[0099] Direct sensors (which may also be referred to as “active” sensors) are sensors configured to monitor an amount of gas in one or more resonator cups. For example, the active sensors may include conductivity probes located at a preselected level less than 100% (e.g. a 50% fill level) in a resonator cup and at or near a 100% fill level of the cup. The active sensors may be placed within a last resonator cup in the filling sequence of a resonator array. The active sensors may be placed in other resonator cups as well. When the probe identifies that water has reached the preselected fill level in the resonator cup, the control system may output signals to open the actuated valves of the gas distribution system to provide a working gas to the resonator panels. Similarly, as the working gas is filling the resonator cups via gravity distribution, the active sensors may continue to measure at or near the 100% fill level. When the probe identifies that gas has reached the 100% fill level in the resonator cup, the control system may output signals to close the remotely actuated valves of the gas distribution system to stop the refilling process.

[0100] In some embodiments, the noise mitigation system may use sensor signals to determine both when to initiate filling / re-filling and when to stop filling / re-filling the resonator cups in a resonator array. In other embodiments, the noise mitigation system may be configured to initiate re-filling of the cups at a set frequency, such as once a week, once a month, or some other frequency, and the sensor signals are only used to determine when to stop filling / re-filling the resonator cups. In still other embodiments, the noise mitigation system may use sensor signals to initiate re-filling of the cups, and the noise mitigation system may be configured to execute the re-filling process for a predetermined amount of time for each re-fill indicating a specific gas volume has been released (not based on additional sensor signals).

[0101] The sensor signals may be used to validate an effective filling / re-filling process for the resonator arrays of the noise mitigation system. The sensor signals may also be used to provide information to troubleshoot issues (e.g., scaling, fouling, bio-organisms, etc.) with the noise mitigation system, for example, if the sensor signals indicate the cups have not been refilled after a predetermined time has passed.

[0102] It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of example embodiments. For example, the functions described above and implemented as the best mode for operating the present invention are for illustration purposes only. Other arrangements and methods may be implemented by those skilled in theart without departing from the scope and spirit of this invention. Moreover, those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

CLAIMS1. A deepwater noise mitigation system, comprising: a support frame configured to be deployed in a deepwater environment to surround at least a portion of equipment located subsea and configured for subsea use; a first elongated panel extending along a first longitudinal axis, the first panel configured for deepwater use and coupled to the support frame, wherein the support frame is configured to hold the first panel such that the first longitudinal axis is inclined with respect to a horizontal plane, the first panel comprising: a plurality of resonator cups formed therein, the plurality of resonator cups being open along a lower surface of the first panel to receive a working gas; a first gas inlet area located proximate a first longitudinal end of the first panel; a first gas outlet area located proximate a second longitudinal end of the first panel opposite the first longitudinal end of the first panel; and at least one gutter formed in the lower surface of the first panel and extending along the surface from the first gas inlet area to the first gas outlet area.

2. The deepwater noise mitigation system of claim 1, wherein the support frame is configured to hold the first panel such that the first longitudinal axis is at an inclination of less than about 3 degrees with respect to the horizontal plane.

3. The deepwater noise mitigation system of claim 1, further comprising: a second elongated panel extending along a second longitudinal axis, the second panel comprising: a plurality of resonator cups formed therein, the plurality of resonator cups being open along a lower surface of the second panel to receive a working gas; a second gas inlet area located proximate a first longitudinal end of the second panel; a second gas outlet area located proximate a second longitudinal end of the second panel opposite the first longitudinal end of the second panel; and at least one inverted gutter formed in the surface of the second panel and extending along the surface from the second gas inlet area to the second gas outlet area.

4. The deepwater noise mitigation system of claim 3, further comprising at least one connector coupling the second longitudinal end of the first panel to the first longitudinal end of the second panel.

5. The deepwater noise mitigation system of claim 4, wherein the at least one connector comprises a port formed therethrough, the port connecting the first gas outlet area to the second gas inlet area.

6. The deepwater noise mitigation system of claim 4, wherein the first longitudinal axis is inclined in a first direction and the second longitudinal axis is angled in a second direction opposite the first direction.

7. The deepwater noise mitigation system of claim 3, wherein the first longitudinal axis is parallel to the second longitudinal axis.

8. The deepwater noise mitigation system of claim 3, further comprising a gas manifold fluidly coupled to the first gas inlet area and the second gas inlet area to enable parallel filling of the resonator cups of the first and second panels with gas.

9. The deepwater noise mitigation system of claim 3, wherein the first panel and the second panel are connected side by side to each other.

10. The deepwater noise mitigation system of claim 3, wherein the first panel and the second panel are stacked one over the other.

11. A deepwater noise mitigation system, comprising: a structural support frame configured to be deployed in a deepwater environment to be positioned around subsea equipment located at or proximate the seafloor; a deepwater resonator array movably connected to the structural frame, the deepwater resonator array comprising a plurality of elongated panels connected to a central beam / gas manifold, each elongated panel having a plurality of inverted resonator cups formed therein; wherein the deepwater resonator array is configured to be selectively transitioned between a collapsed configuration and an expanded / deployed configuration, wherein in the collapsed configuration the plurality of elongated panels are collapsed toward the central beam / gas manifold, wherein in the expanded configuration the plurality of elongated panels are expanded in a direction away from the central beam / gas manifold for use.

12. The deepwater noise mitigation system of claim 11, wherein each elongated panel comprises at least one inverted gutter formed therein to direct gas flow from the central beam / gas manifold toward an extended end of the elongated panel to fill the plurality of resonator cups.

13. The deepwater noise mitigation system of claim 11, wherein in the expanded configuration each elongated panel is inclined with respect to a horizontal plane.

14. A deepwater subsea oil and / or gas facility comprising: subsea equipment configured for deepwater use positioned at or proximate the seafloor; and a deepwater noise mitigation system, comprising: a structural support frame positioned around the subsea equipment; and a deepwater resonator array coupled to the support frame and comprising at least a first elongated panel and a second elongated panel, each of the first and second elongated panels being inclined with respect to a horizontal plane, wherein each of the first and second panels comprises: a plurality of inverted resonator cups formed therein and open along a surface of the panel to receive a working gas; a gas inlet area located proximate a first end of the panel; a gas outlet area located proximate a second end of the panel opposite the first end of the panel; and at least one inverted gutter formed in the surface of the panel and extending along the surface from the gas inlet area to the gas outlet area.

15. A method, comprising: delivering a working gas at a gas inlet area located proximate a first longitudinal end of a panel of a deepwater resonator array configured for deepwater use, the panel extending along a longitudinal axis that is inclined relative to a horizontal plane and having a plurality of resonator cups that are open along a downward facing surface of the panel;directing the working gas in a direction of the longitudinal axis via one or more gutters formed in the downward facing surface of the panel, the one or more gutters extending from the gas inlet area to a gas outlet area proximate a second longitudinal end of the panel, the second longitudinal end located vertically higher than the first longitudinal end; and filling the plurality of resonator cups with the working gas as the working gas moves from the gas inlet area toward the gas outlet area via gravity.

16. The method of claim 15, comprising filling the plurality of resonator cups sequentially along the longitudinal axis of the panel.

17. The method of claim 15, wherein the one or more gutters provide a laminar flow of the working gas to fill the inverted resonator cups.

18. The method of claim 15, further comprising directing the working gas from the gas outlet area of the panel to a subsequent panel located above the panel via a port fluidly coupled to the gas outlet area.

19. A method of installing a deepwater noise mitigation system, comprising: providing the deepwater noise mitigation system comprising: a structural support frame; and a deepwater resonator array movably coupled to the structural frame, the deepwater resonator array comprising a plurality of elongated panels connected to a gas manifold, each elongated panel having a plurality of resonator cups formed therein; positioning the structural frame of the deepwater noise mitigation system over subsea equipment located at or proximate the seafloor with the deepwater resonator array being in a collapsed configuration in which the plurality of elongated panels are collapsed toward the central beam / gas manifold; lowering the deepwater resonator array in the collapsed configuration with respect to the subsea equipment so the deepwater resonator array passes between two components of the subsea equipment; and transitioning the deepwater resonator array from the collapsed configuration to an expanded / deployed configuration in which the plurality of elongated panels are expanded in a direction away from the central beam / gas manifold.

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