Detecting deposition in conduits by thermal energy harvesting

Abstract

A deposition detection device is configured to be installed on a conduit. The deposition detection device includes: a thermal energy harvesting assembly including a thermo-electric generator (TEG) configured to be positioned with a first side of the TEG proximate an outer wall of the conduit and a second side of the TEG facing away from the conduit; and an indicator packaged with and electrically coupled to the thermal energy harvesting assembly, the indicator configured to output a visible or audible indication representative of an amount of material deposition inside the conduit based on an electrical output of the thermal energy harvesting assembly.

Description

TECHNICAL FIELD

[0001] The present disclosure is directed to methods and devices for detecting material deposition in conduits, and more particularly, to a thermal energy harvesting system and method for monitoring and detecting the extent of material deposition inside conduits. BACKGROUND

[0002] In the activity of transporting produced oil and gas via a pipeline, deposits may accumulate on the internal surfaces of the pipeline. Over time, the deposition of materials (e.g., sand, inorganic scales, asphaltenes, hydrates, and / or waxes) may hinder flow or completely block the flow path through the pipeline. Deposits may develop over a short period (e.g., unintended production of sand could impact production within hours) or over a longer period (e.g., the impact of gradual wax deposition may be undetectable for months).

[0003] Monitoring the internal state of the pipeline involves the measurement of key parameters (e.g., pressures, temperatures, flow rates) and observing the progression of measured values in time. Monitoring is performed to identify conditions that may hinder production. Detection involves determining the location of a deposit that is hindering production.

[0004] Few methods exist for monitoring and detecting the extent of deposition within offshore oil and gas production lines. Of the conventional methods of interrogating the internal state of a pipeline, pigging operations are the most used method for purging, cleaning, and inspecting pipelines. In a typical pigging operation, a physical device is placed within the pipe of interest. The mechanical device is designed to maintain a seal with the pipe wall and is forced through the pipe by a difference in fluid pressure. Unfortunately, in pigging operations, mechanical devices can stop moving or become stuck in the pipeline. Stopped or stuck devices will block the flow path and must be removed from the pipeline before flow may resume.

[0005] Alternatively, external devices may be used to detect the internal state of the pipeline. For example, computed tomographic (CT) imaging has been used to detect deposits in pipelines in cases where the density differences between deposit and surrounding materials (e.g., various phases of fluid or pipe wall) are significant enough to enable the detection of these differences in pipeline. However, CT devices are normally transported to a location where deposition is suspected, and images of pipeline cross-sections are created by moving the CT device from one location to another. This is a time intensive and costly process. 2024372805   25 Jun 2026 [0005A] Reference to any prior art in the specification is not an acknowledgement or suggestion that this prior art forms part of the common general knowledge in any jurisdiction or that this prior art could reasonably be expected to be combined with any other piece of prior art by a skilled person in the art. SUMMARY [0005B] According to a first aspect of the invention there is provided a deposition detection device configured to be installed on a conduit, the deposition detection device comprising: a thermal energy harvesting assembly comprising a thermo-electric generator (TEG) configured to be positioned with a first side of the TEG proximate an outer wall of the conduit and a second side of the TEG facing away from the conduit; and an indicator packaged with and electrically coupled to the thermal energy harvesting assembly, the indicator configured to output a visible or audible indication representative of an amount of material deposition inside the conduit based on an electrical output of the thermal energy harvesting assembly. [0005C] According to a second aspect of the invention there is provided a system, comprising: a conduit configured to transport fluid between a first location and a second location; a deposition detection device coupled to the conduit, the deposition detection device comprising: a thermal energy harvesting assembly comprising a thermo-electric generator (TEG) with a first side proximate an outer wall of the conduit and a second side facing away from the conduit; and an indicator configured to output a visible or audible indication representative of an amount of material deposition inside the conduit based on an electrical output of the thermal energy harvesting assembly; and an external recorder configured to capture and record the visible or audible indication output from the deposition detection device. [0005D] According to a third aspect of the invention there is provided a method of operation of a deposition detection device, comprising: transferring heat across a thermo-electric generator (TEG) of a thermal energy harvesting assembly, wherein the TEG is positioned with a first side of the TEG proximate an outer wall of a conduit and a second side of the TEG facing away from the conduit; generating an electrical output via the thermal energy harvesting assembly in response to the heat transferred across the TEG; and outputting, via an indicator packaged with and electrically coupled to the thermal energy harvesting assembly, a visible or audible indication representative of an amount of material deposition inside the conduit based on the electrical output of the thermal energy harvesting assembly. [0005E] By way of clarification and for avoidance of doubt, as used herein and except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additions, components, integers or steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] 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.

[0007] FIG. 1 is a schematic top view of a system in which deposition detection devices are installed along a conduit, in accordance with an embodiment of the present disclosure.

[0008] FIG. 2A is a schematic diagram illustrating certain components of a deposition detection device, in accordance with an embodiment of the present disclosure.

[0009] FIG. 2B is a schematic diagram illustrating internal components of another deposition detection device, in accordance with an embodiment of the present disclosure.

[0010] FIG. 3 is a side cross-sectional schematic diagram illustrating a deposition detection device, in accordance with an embodiment of the present disclosure.

[0011] FIG. 4 is a side partial cross-sectional view of a deposition detection device attached to a conduit in a permanent installation, in accordance with an embodiment of the present disclosure.

[0012] FIG. 5 is a side partial cross-sectional view of a deposition detection device attached to a conduit in a temporary or semi-permanent installation, in accordance with an embodiment of the present disclosure.

[0013] FIG. 6 is a side partial cross-sectional view of a deposition detection device attached to a conduit in a portable installation, in accordance with an embodiment of the present disclosure.

[0014] FIG. 7 is a process flow diagram illustrating a method for detecting material deposition inside a conduit, in accordance with an embodiment of the present disclosure.

[0015] FIG. 8 is a process flow diagram illustrating a method for detecting material deposition inside a conduit, in accordance with an embodiment of the present disclosure.

[0016] FIG. 9 is a schematic diagram illustrating an example layout of positions for deposition detection devices to be placed around a circumference of a conduit, in accordance with an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE DRAWINGS

[0017] The example embodiments discussed herein are directed to systems, apparatus, and methods related to monitoring and detecting depositions (e.g., wax or other materials) inside conduits (e.g., pipelines). In particular, the disclosed systems, apparatus, and methods provide a low-cost method of detecting wax or other material deposition using a device placed external to a conduit. The device harvests conduit / ambient water or ambient air heat exchange to generate electrical power. The amount of electrical power generated by the device corresponds to the local temperature difference between fluid flowing through the conduit and ambient seawater (for subsea conduit) or ambient air (for onshore conduit).

[0018] The accumulation of wax or other solids inside a conduit (e.g., a pipeline or jumper) can be detected by monitoring temperature on the external surface of the conduit. The fluid being transported inside the subsea conduit typically exhibits significantly higher temperatures compared to the surrounding seawater. This temperature differential is particularly pronounced in deepwater applications, where the seawater temperature remains relatively constant in close proximity to the pipeline or jumper. The disclosed systems, apparatus, and methods may harvest the energy due to heat flux, accumulate the energy as electric potential on a capacitor, and discharge the capacitor on an indicator when electric potential reaches a certain level on the capacitor, thereby outputting an indication of temperature difference between the pipeline / jumper surface and the seawater for an external device to record. In some embodiments, the indicator may be an LED, and the time duration between the LED flashes provides a visible indication of the differential temperature for the external device in the vicinity. In other embodiments, the indicator may be a speaker (e.g., piezoelectric crystal that vibrates) or other sound source, and the time duration between modulated sound pulses output from the speaker provides an audible indication of the differential temperature for the external device in the vicinity. The indicator modulated sound frequency may indicate device location or another sensor value.

[0019] The terms “conduit,” “pipeline” and “pipe” are used herein interchangeably and may refer to a pipeline. The “conduit” is configured to communicate fluids (e.g., production fluid) from a first location to a second location. The disclosed systems and methods may be applied to subsea conduits located and / or configured to be positioned subsea, or land-based conduits located and / or configured to be positioned on land. A “subsea conduit” may refer to a subsea pipeline or a subsea jumper. The term “subsea conduit” refers to any conduit (e.g., pipeline, pipe, or jumper) that is either located subsea or configured to be positioned subsea. The “subsea conduit” is configured to communicate fluids (e.g., production fluid) from a subsea location to another location (e.g., another subsea location or a surface location). While the certain parts of the following description may describe the deposition detection device(s) as being used with subsea conduits, it should be noted that the same deposition detection device(s) or similar device(s) may be used similarly with landbased conduits.

[0020] The use of the terms "about", “approximately”, and similar terms applies to all numeric values, whether or not explicitly indicated. These terms generally refer to a range of numbers that one of ordinary skill in the art would consider as a reasonable amount of deviation to the recited numeric values (i.e., having the equivalent function or result). For example, this term may be construed as including a deviation of ±10 percent of the given numeric value provided such a deviation does not alter the end function or result of the value. Therefore, a value of about 1% may be construed to be a range from 0.9% to 1.1%. Furthermore, a range may be construed to include the start and the end of the range. For example, a range of 10% to 20% (i.e., range of 10%-20%) includes 10% and also includes 20%, and includes percentages in between 10% and 20%, unless explicitly stated otherwise herein. Similarly, a range of between 10% and 20% (i.e., range between 10% - 20%) includes 10% and also includes 20%, and includes percentages in between 10% and 20%, unless explicitly stated otherwise herein.

[0021] It is understood that when combinations, subsets, groups, etc. of elements are disclosed (e.g., combinations of components in a composition, or combinations of steps in a method), that while specific reference of each of the various individual and collective combinations and permutations of these elements may not be explicitly disclosed, each is specifically contemplated and described herein. By way of example, if an item is described herein as including a component of type A, a component of type B, a component of type C, or any combination thereof, it is understood that this phrase describes all of the various individual and collective combinations and permutations of these components. For example, in some embodiments, the item described by this phrase could include only a component of type A. In some embodiments, the item described by this phrase could include only a component of type B. In some embodiments, the item described by this phrase could include only a component of type C. In some embodiments, the item described by this phrase could include a component of type A and a component of type B. In some embodiments, the item described by this phrase could include a component of type A and a component of type C. In some embodiments, the item described by this phrase could include a component of type B and a component of type C. In some embodiments, the item described by this phrase could include a component of type A, a component of type B, and a component of type C. In some embodiments, the item described by this phrase could include two or more components of type A (e.g., Al and A2). In some embodiments, the item described by this phrase could include two or more components of type B (e.g., Bl and B2). In some embodiments, the item described by this phrase could include two or more components of type C (e.g., Cl and C2). In some embodiments, the item described by this phrase could include two or more of a first component (e.g., two or more components of type A (Al and A2)), optionally one or more of a second component (e.g., optionally one or more components of type B), and optionally one or more of a third component (e.g., optionally one or more components of type C). In some embodiments, the item described by this phrase could include two or more of a first component (e.g., two or more components of type B (B1 and B2)), optionally one or more of a second component (e.g., optionally one or more components of type A), and optionally one or more of a third component (e.g., optionally one or more components of type C). In some embodiments, the item described by this phrase could include two or more of a first component (e.g., two or more components of type C (Cl and C2)), optionally one or more of a second component (e.g., optionally one or more components of type A), and optionally one or more of a third component (e.g., optionally one or more components of type B).

[0022] If a component of a figure is described but not expressly shown or labeled in that figure, the label used for a corresponding component in another figure may be inferred to that component. Conversely, if a component in a figure is labeled but not described, the description for such component may be substantially the same as the description for the corresponding component in another figure. For any figure shown and described herein, one or more of the components may be omitted, added, repeated, and / or substituted. Accordingly, embodiments shown in a particular figure should not be considered limited to the specific arrangements of components shown in such figure.

[0023] Further, a statement that a particular embodiment (e.g., as shown in a figure herein) does not have a particular feature or component does not mean, unless expressly stated, that such embodiment is not capable of having such feature or component. For example, for purposes of present or future claims herein, a feature or component that is described as not being included in an example embodiment shown in one or more particular drawings is capable of being included in one or more claims that correspond to such one or more particular drawings herein.

[0024] Terms such as “first”, “second”, “primary,” “secondary,” “above”, “below”, “inner”, “outer”, “distal”, “proximal”, “end”, “top”, “bottom”, “upper”, “lower”, “side”, “left”, “right”, “front”, “rear”, and “within”, when present, are used merely to distinguish one component (or part of a component or state of a component) from another. This list of terms is not exclusive. Such terms are not meant to denote a preference or a particular orientation, and they are not meant to limit embodiments of earth penetrating tools. In the following detailed description of the example embodiments, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0025] Turning now to the drawings, FIG. 1 is a top view (i.e., viewed from an overhead perspective) of a system in which at least one deposition detection device 100 is installed on a conduit 102. In the embodiment illustrated in FIG. 1, the conduit 102 is a subsea conduit. However, as mentioned above, the deposition detection device(s) 100 may be similarly installed on a conduit located on land, rather than subsea. The subsea conduit 102 may include a subsea pipeline, a subsea jumper, or a combination thereof. The subsea conduit 102 may be located on the seabed or above the seabed. Three deposition detection devices 100 are installed in the system shown. The system illustrated further includes a pipeline end termination (PLET) 104. Each deposition detection device 100 is attached to the outer surface of a conduit wall 106, as shown.

[0026] The deposition detection devices 100 may each use thermal energy harvesting to generate and output an indication of the amount of material deposition inside the conduit 102 at the location of the detection device 100. The deposition detection device 100 described herein utilizes a Seebeck device and an energy harvesting circuit to generate electrical power. The amount of electrical power per unit time is proportional to the temperature difference between the external conduit wall 106 and ambient seawater 108. In one embodiment, the electrical power is used to generate a signal that can be detected by a passing remotely operated vehicle (ROV) 110 or autonomous underwater vehicle (AUV), though other embodiments could enable communication with other external devices. For example, the signal output from the indicator on the detection device 100 could be detected by a stationary, permanently installed subsea receiver 112. In embodiments where the deposition detection device 100 is positioned on a land-based conduit, the external recorder configured to detect the signal(s) output from the deposition detection device 100 may include a stationary or mobile recorder located on land.

[0027] In some embodiments, the electrical power may be utilized to generate a signal that is communicated to an external observer (e.g., ROV 110, AUV, or receiver 112) in pulses of visible light by a light emitting diode (LED). To that end, the ROV 110, AUV, and / or receiver 112 may be equipped with a camera to receive the output visual signal(s) from the deposition detection device(s) 100. In other embodiments, the electrical power may be utilized to generate a signal that is communicated to the external observer in pulses of modulated sound waves by one or more speakers. To that end, the ROV 110, AUV, and / or receiver 112 may be equipped with a hydrophone to receive the output audible signal(s) from the deposition detection device(s) 100.

[0028] The frequency of pulsing LED light or pulsing modulated sound waves corresponds to the amount of generated electrical power and serves as an indication of the temperature difference between conduit wall 106 and ambient seawater 108. A passing ROV 110 or AUV or stationary receiver 112 may record the pulsing signal frequency, and an analysis may be performed on the recorded signal to determine the local temperature difference between the measured conduit wall location and the ambient seawater.

[0029] The heat flow through the deposition detection device 100 may be impacted by an internal deposit layer (e.g., wax, scale, or other material deposit inside the conduit 102). Deposits will hinder the heat flow due to their insulating properties, and the hindered heat flow would thereby reduce the available heat flow through the conduit wall 106 for energy harvesting. A passing ROV 110 or AUV or stationary receiver 112 would detect the frequency of the pulsing LED or modulated sound signal, and thereby, changes in heat flow may be monitored over time and over a span of locations (e.g., circumferential locations and / or axial locations) along the conduit 102 to detect an indication of deposit absence or presence of a deposition in the conduit 102 and / or the extent of deposition in the conduit 102. Further, this method may be used to measure deposit characteristics (e.g., position in axial direction, position in circumferential direction, relative shape of deposit, estimated thickness of deposit, etc.). The measurements may enable quantitative and / or qualitative analysis of deposit characteristics.

[0030] A detection device 100 or multiple detection devices 100 may be placed near a conduit wall 106. The detection device(s) 100 may be placed at different axial locations along the conduit 102 in a manner to enable axial detection of a deposit, as shown in FIG. 1. Additionally, or alternatively, the detection device(s) 100 may be placed at different circumferential locations along the conduit 102 in a manner to enable circumferential detection of a deposit, as shown in FIG. 6. A signal generated by the detection device 100 may be communicated to a passing device (e.g., a detector placed on an ROV 110 or AUV) or to a permanently installed receiver 112. A decrease in electrical power and the resulting attenuation of signal from an expected value at a single position can be translated to a relative thickness of deposit within the conduit 102 at that position. The expected signal value may be obtained from an analysis of historical data, simulation, or analogs. Multiple signal attenuations may be monitored to improve the resolution of the detection method.

[0031] While the seawater temperature remains somewhat constant in deepwater applications, it can be valuable for the ROV 110, AUV, or receiver 112 to also record and monitor the ambient temperature of the seawater 108. Existing flow assurance analysis may provide a reasonably accurate estimation of the flow temperature inside the conduit 102. When both the flow temperature and conduit surface temperatures are known, it becomes possible to calculate wax (or other deposit) thickness inside of the conduit 102.

[0032] This method of collecting and processing generated signals enables the construction of a model for the deposit-effected region of the conduit 102. The level of signal attenuation may be correlated to deposit characteristics. The deposition detection device(s) 100 can be installed temporarily or permanently, and methods of installation may enable the deposition detection device(s) 100 to be placed circumferentially, placed axially, and / or incorporated into a clamp (shown in FIG. 6).

[0033] FIG. 2A is a schematic diagram illustrating the main components of the disclosed deposition detection device 100. As illustrated, the deposition detection device 100 may include five stages: a thermo-electric generator 200, a low voltage booster 202, energy accumulation 204, a voltage trigger 206, and an indicator 208 (e.g., LED or speaker). These components of the deposition detection device 100 and their function will be described below with reference to headings and subheadings.

[0034] Thermo-electric generator (TEG)

[0035] As mentioned above, the deposition detection device 100 includes a thermo-electric generator 200. Thermo-electric generators (TEGs) 200, also known as thermo-electric modules or thermo-electric power generators, are devices that convert heat energy directly into electrical energy using a phenomenon called the Seebeck effect. They are particularly useful in situations where there is a temperature difference between two points, such as in subsea pipelines and jumpers in production where waste heat can be collected for electric generation. Different parts and functions of the TEG 200 will be described below with reference to the following subheadings. The TEG 200 may be any thermoelectric device that operates in a Seebeck mode under the conditions of the environment in which the TEG 200 is used. For example, some thermo-electric coolers (TEC) may operate in a Seebeck mode under certain environmental conditions (e.g., within certain temperature ranges) and so would qualify as a TEG 200 for the purposes of the present disclosure when operating under those conditions.

[0036] (1) Seebeck Effect

[0037] The fundamental principle behind the TEG 200 is the Seebeck effect, which is based on the fact that when you connect two dissimilar materials or semiconductors in a closed circuit and there is a temperature gradient across them, an electric voltage is generated. This voltage can drive an electric current if a load is connected.

[0038] (2) Thermo-electric materials

[0039] The TEG 200 may be made from special materials known as thermo-electric materials or thermo-electric semiconductors. These materials have unique properties that make them suitable for this application. They have a high Seebeck coefficient, which means they generate a significant voltage when subjected to a temperature difference. Additionally, they have low thermal conductivity to maintain the temperature gradient.

[0040] (3) Module Structure

[0041] The TEG 200 may consist of multiple thermo-electric materials (thermocouples) connected in series and / or parallel to form a module. The module typically has a hot side and a cold side. The hot side is exposed to a heat source, while the cold side is kept at a lower temperature. The temperature gradient across the thermo-electric materials generates an electric voltage.

[0042] (4) Heat Source

[0043] The TEG 200 may require a heat source to function. This heat source could be a pipe or jumper in production, another heat-producing process, or relatively a hotter seawater or ambient air temperature. The hot side of the TEG 200 is placed in close proximity to this heat source (e.g., against a conduit wall).

[0044] (5) Heat Sink

[0045] The cold side of the TEG 200 is connected to a heat sink, which may be a finned radiator or some other cooling system. The heat sink is responsible for dissipating the heat absorbed by the cold side and maintaining the temperature difference.

[0046] (6) Electric Generation

[0047] As heat flows from the hot side to the cold side of the TEG 200, it generates a voltage across the thermo-electric materials. This voltage can be used to power electrical devices or charge batteries. The efficiency of the TEG 200 may depend on various factors, including the temperature difference across the TEG 200, the materials used in the TEG 200, and the design of the TEG module.

[0048] Advantages of using the TEG 200 include the device simplicity, reliability, and the fact that there are no moving parts, making the TEG 200 suitable for remote or harsh environments. Researchers are continually working on developing more efficient thermo-electric materials to enhance the performance of TEGs for various applications.

[0049] The voltage needed to operate the deposition detection device 100 may be entirely provided via the TEG 200, so that no battery or external power source is needed to operate the device. As such, the deposition detection device 100 does not require any external connections, which can be a liability underwater.

[0050] Low Voltage Booster

[0051] As mentioned above, the deposition detection device 100 may include a low voltage booster 202. The low voltage booster 202, often referred to as a voltage booster or voltage regulator, is an electronic device or circuit designed to increase a low or insufficient input voltage to a higher and more stable output voltage. The low voltage booster 202 may be especially useful when dealing with power sources that provide lower voltage levels than required for specific applications. The low voltage booster 202 performs the opposite function of voltage regulators that step-down or reduce voltage. The low voltage booster 202 used in the disclosed detection device may be a generic, off-shelf voltage booster. Different parts and functions of the low voltage booster 202 will be described below with reference to the following subheadings.

[0052] It should be noted that the low voltage booster 202 is optional. In some embodiments, the low voltage booster may be omitted when there are multiple TEGs connected in series to provide an increased voltage (e.g., as shown in FIG. 2B).

[0053] (1) Input Voltage

[0054] The input voltage to the low voltage booster 202 is lower than the desired output voltage of the low voltage booster 202. This can occur in various scenarios, such as when using a TEG (200) with varying output. In the disclosed detection device 100, the input voltage to the low voltage booster 202 is the voltage generated by and output from the TEG 200. In one embodiment, the input voltage to the low voltage booster 202 may be around 0.2 V, although the input voltage may vary based on the temperature gradient experienced across the TEG 200.

[0055] (2) Boosting Circuit

[0056] Inside the low voltage booster 202, there is a boosting circuit 210 that employs various components like transistors, inductors, capacitors, and sometimes transformers. These components work together to increase the input voltage to a desired level. For example, as illustrated in FIG. 2A, the boosting circuit 210 may include an inductor 212, a switching device 214, and a diode 216. Other components not shown may be included in the boosting circuit 210 as well.

[0057] (3) Switching Operation

[0058] The boosting circuit 210 of the low voltage booster 202 may operate using a switching technique (214), often at a high frequency, such as tens or hundreds of kHz. This high-frequency switching allows for efficient energy transfer and voltage transformation through the low voltage booster 202.

[0059] Energy Accumulator

[0060] As mentioned above, the deposition detection device 100 may include an energy accumulator 204. When the boosting circuit 210 of the low voltage booster 202 is turned on, energy from the input voltage source (TEG 200) is stored in the inductor 212 or other energy storage component(s) of the boosting circuit 210. When the boosting circuit 210 is switched off, this stored energy may be released and transferred to the energy accumulator 204. The energy accumulator 204 may take the form of a capacitor 218, as shown. As the switching operation (214) of the boosting circuit 210 continues, the voltage across the output capacitor 218 increases, resulting in a higher output voltage compared to the input voltage.

[0061] Voltage Trigger

[0062] As mentioned above, the deposition detection device 100 may include a voltage trigger 206. The voltage trigger 206 may include a 1381 voltage trigger circuit 220, or some other type of voltage trigger circuit. The 1381 voltage trigger circuit 220 is a specific type of voltage-triggered switching device, often referred to as a voltage detector or voltage supervisor. The “1381” designation refers to a family of voltage trigger circuits made by various manufacturers, and it is commonly associated with the SE1381, which is a popular variant. These circuits are designed to monitor an input voltage and trigger an action when the voltage crosses a predefined threshold. The primary purpose of a 1381 voltage trigger circuit 220 is to provide voltage-based control. Other types of voltage trigger circuits may be used in other embodiments.

[0063] In one embodiment, the voltage trigger 206 may trigger once the voltage across the capacitor 218 reaches 1.95 V. In other embodiments, the voltage trigger 206 may trigger once the voltage across the capacitor 218 reaches 2.2 V, 2.5 V, or another value. The filling time for the capacitor 218 to reach the voltage trigger amount varies based on the temperature difference across the TEG 200.

[0064] Indicator

[0065] As discussed above, the indicator 208 may be a visual indicator (e.g., an LED 222) or an audible indicator (e.g., speaker). In the illustrated embodiment, the indicator 208 is an LED 222. An LED 222, or light emitting diode, is commonly used as an indicator in various electronic devices and systems. LEDs 222 are small semiconductor devices that emit light when an electric current passes through them. They are popular for indicator applications due to their energy efficiency, long lifespan, compact size, and ease of use. An LED 222 may require 1.8 V to operate. The LED 222 will flash each time the voltage trigger 206 is triggered by the voltage stored across the capacitor 218. The LED 222 may be specifically chosen to be visible in a particular environment (e.g., a subsea environment) by a particular recorder (e.g., ROV, AUV, etc.) using a relatively low amount of power. For example, the color of the LED 222 and the amount of ON-time in which the LED 222 will pulse or blink during its operation may be chosen to reduce an amount of power required to operate the indicator while ensuring that the light output is visible to the camera of the external recorder.

[0066] In other embodiments, the indicator 208 may include a speaker that emits modulated sound waves when an electric current passes therethrough. The speaker will sound each time the voltage trigger 206 is triggered by the voltage stored across the capacitor 218. In embodiments where multiple detection devices 100 are used in close proximity and they each have a speaker as the indicator 208, the speakers for the devices may be set to output modulated sound waves at different frequencies. That way, a hydrophone may pick up multiple modulated sound waves output from different speakers, and the sounds from each individual speaker may be separated during subsequent analysis. The use of speakers may be beneficial in cases where a portion of a subsea conduit may be buried by sand or other material at the seabed such that an LED indicator might not be feasible. In embodiments where multiple detection devices are arranged circumferentially about the subsea conduit, it may be desirable to modulate the frequency of the sound output from the device closest to the bottom of the subsea conduit at a lower frequency (in case the conduit is buried), since lower frequency sound waves travel better through solids than higher frequency sound waves.

[0067] In other embodiments, the indicator 208 may include a speaker that emits modulated sound waves whose frequency corresponds to a sensor value, such as the frequency or amplitude of the attached structure's dominant vibration, or electrical resistance between the attached structure's surface and seawater to determine cathodic protection integrity.

[0068] It may be undesirable for an LED 222 to flash (or speaker to sound) continuously, or too infrequently, as the camera (or hydrophone) on the external recorder needs to be able to pick up the individual flashes (or sounds) so that the frequency of these indications can be measured. As such, it may be desirable to balance the size of the TEG 200 and the storage capacity of the capacitor 218 to output the indication within this desired time period range.

[0069] Additional Explanation regarding the Seebeck Effect

[0070] The Seebeck effect, a specific type of thermo-electric effect, is a phenomenon in physics and thermodynamics that describes the generation of an electromotive force (EMF) or voltage in a conductor when there is a temperature difference between two points along the conductor. This effect is the basis for the operation of thermo-electric devices, which can convert heat energy into electrical energy and vice versa.

[0071] Key points about the Seebeck effect include the following, under subheadings.

[0072] (1) Temperature gradient

[0073] The Seebeck effect occurs when there is a temperature gradient along a conductor or semiconductor material. In other words, one end of the material is hotter than the other.

[0074] (2) Electron diffusion

[0075] At the hot end of the material, electrons gain kinetic energy and move more vigorously, while at the cold end, they have lower kinetic energy. This temperature difference causes electrons to diffuse from the hot end to the cold end.

[0076] (3) Charge accumulation

[0077] As electrons diffuse, they carry their electric charge with them. This movement of charge results in the accumulation of positive and negative charges at the hot and cold ends of the conductor, respectively.

[0078] (4) Generation of voltage

[0079] The accumulation of charges at the ends of the conductor creates a voltage potential difference, or electromotive force (EMF), between the two ends. This voltage can be measured and used to power electronic circuits or devices.

[0080] (5) Dependence on material

[0081] The magnitude of the Seebeck effect depends on the material properties of the conductor or semiconductor. Some materials exhibit a stronger Seebeck effect than others, making them more suitable for thermo-electric applications.

[0082] FIG. 2A provides only one example of electrical components that may make up the energy harvesting circuit in the deposition detection device, and other embodiments may be possible. For example, the components shown in FIG. 2A may be arranged in different orders in other embodiments. In one example, the energy harvesting circuit of the deposition detection device 100 may include a voltage booster located between the voltage trigger 206 and the indicator 208, instead of or in addition to a voltage booster between the TEG and the energy accumulator. In addition, certain elements of the deposition detection device 100 may be duplicated and / or not present in the system. For example, FIG. 2B illustrates an example energy harvesting circuit of the deposition detection device 100 in which multiple TEGS 200A and 200B are electrically coupled in series and configured to output a DC voltage to the energy accumulator 204, without the use of any low voltage boosters between the TEGS 200A / B and the accumulator 204. Other variations of the energy harvesting circuitry may be apparent to those of ordinary skill in the art. In each case, at least one TEG 200, an accumulator 204, a voltage trigger 206, and an indicator 208 may be present.

[0083] FIG. 3 is a side cross-sectional schematic diagram illustrating a deposition detection device 100. As illustrated, the detection device 100 may include a thermo-electric generator (TEG) 200 disposed between a heat sink 300 and a magnet 302, an electronic module 304, and an indicator 208 (e.g., indicator LED 222), all securely assembled using an adhesive 306 (e.g., high-strength epoxy). As illustrated, the TEG 200, which may be an off-shelf device, is fully enclosed by the heat sink 300, the magnet 302, and the adhesive 306, so that it is not exposed to seawater. In the illustrated embodiment, the magnet 302 acts as the “heat source” for the detection device 100. Both the heat sink 300 and the magnet 302 may be made from high thermal conductivity materials. The adhesive 306 may have relatively much less thermal conductivity than the magnet 302 and the heat sink 300. The electronics module 304 may contain one or more of the low voltage booster 202, the energy accumulator 204, and the voltage trigger 206 described above with reference to FIG. 2A.

[0084] The magnet 302 may include any desired magnetic material. In embodiments where the magnet 302 will be used in a subsea environment, the magnet 302 may be a neodymium magnet, a samarium-cobalt magnet, or any other type of magnet appropriate for a subsea or onshore environment. A samarium-cobalt magnet may be particularly suitable for use in high-temperature applications, because samarium-cobalt magnets offer better thermal stability and can withstand higher temperatures than neodymium magnets. In addition, samarium-cobalt magnets have a higher resistance to demagnetization, which can be useful particularly when deployed in a subsea environment.

[0085] When dispatched at a location along a subsea conduit where production fluid in the conduit is a higher temperature than the surrounding seawater, the heat sink 300 may be in direct contact with the seawater and the cold side (308) of the thermo-electric generator 200; and the magnet 302 may be in direct contact with the subsea conduit and the hot side (310) of the thermoelectric generator 200. The magnet 302 may be used to attach, directly or indirectly, the deposition detection device 100 to the outside wall of the conduit.

[0086] In some embodiments, the deposition detection device 100 may be attached directly to an outer wall of the conduit via the magnet 302. In other embodiments, the deposition detection device 100 may be attached to an outer protection layer that is surrounding the conduit. This outer protection layer may include, for example, any thermally conductive material. In some embodiments, the outer protection layer may include a thin cushion of water (e.g., sea water) trapped between the conduit and the deposition detection device 100 using a seal.

[0087] In certain embodiments, the heat sink 300 may also be a magnet (like 302). This allows for the selective reversal of the orientation of the TEG 200 with respect to the conduit for cases where the temperature of fluid flowing through the conduit is lower than the temperature of the surrounding seawater.

[0088] The magnet surface(s) 302 may be machined in such a way that they would make a large or maximum area of direct contact with both the conduit and the thermo-electric generator 200. For example, the magnet surface(s) 302 may be machined with a concave section 312 on the side opposite from the TEG 200. The curvature of the concave section 312 may be chosen to match an outer contour of the conduit (or of a protective surface located around the conduit). The heat sink 300 should make maximum area of direct contact with the TEG 200. In embodiments where only one side of the detection device 100 has a magnet 302 for interfacing with a subsea conduit, the opposing heat sink side (300) may be shaped with fins or other features to maximize contact with the seawater.

[0089] The seawater contact surface 314 (e.g., on the magnet 302, the heat sink 300, or both) may be optimized to minimize marine growth. For example, the contact surface(s) 314 may be coated with a zinc coating, a fluorocarbon or fluoropolymer-based coating, or any other coating with a high thermal conductivity but that is not suitable for marine growth and calcareous deposits.

[0090] In locations along the conduit where conduit wall temperatures are expected to be higher than ambient temperatures (i.e., conduit contents are hotter than ambient seawater or air surrounding the conduit), the detection device 100 may be oriented with the TEG 200 in a position that enables the electrical conversion of heat flowing from the conduit wall to the ambient seawater. In locations along the conduit where heat flow is in the reverse direction (e.g., in locations where Joule-Thomson effects produce cooler than ambient conduit wall temperatures), the device may be oriented with the TEG 200 in a position that enables the electrical conversion of heat energy flowing from the ambient seawater to the conduit wall. At locations near a subsea manifold where the production fluid first begins flowing through a subsea jumper or pipeline, the subsea ambient seawater temperatures may be approximately 10-15 degrees Celsius, while the production fluid in the conduit may be approximately 80-85 degrees Celsius. The TEG 200 and the electronics in module 304 may be configured such that a difference between the conduit and seawater temperatures of at least 5 degrees Celsius will trigger the indicator 208 (e.g., LED 222) to flash or sound.

[0091] FIGS. 4-6 show different ways in which the deposition detection device 100 may be attached to a conduit 102. The method of device attachment may be a permanent installation (e.g., integrated into a conduit insulation as shown in FIG. 4), a semi-permanent installation (e.g., a leave-in-place magnetic attachment as shown in FIG. 5), or portable (e.g., integrated into a moveable clamp as shown in FIG. 6). The variety of methods for device attachment enable deployments with new construction and retro fits of existing construction.

[0092] FIG. 4 is a side partial cross-sectional view of a deposition detection device 100 attached to a conduit 102 in a permanent installation. The detection device 100 may be integrated into a surface protection 400 and an insulation 402 of the conduit 102. The placement of the detection device 100 may enable heat conduction through the TEG (e.g., 200 of FIGS. 2 and 3) of the detection device 100. The Seebeck components (e.g., TEG, heat source component, etc.) of the detection device 100 may be placed against the surface protection 400 of the conduit 102. Other components of the detection device 100, such as the energy harvesting circuitry (e.g., low voltage booster 202, energy accumulator 204, and voltage trigger 206 of FIG. 2 A), may be packaged and integrated into the conduit insulation 402. These non-Seebeck components do not require direct exposure to the conduit wall 106 and / or seawater.

[0093] FIG. 5 is a side partial cross-sectional view of a deposition detection device 100 attached to a conduit 102 in a semi-permanent installation. The conduit wall 106 may be coated (e.g., using fusion bonded epoxy) to protect the external surface, and the detection device 100 may be attached to (e.g., via a magnet of the detection device 100) and in contact with the external surface protection. The placement of the detection device 100 may enable heat conduction through the TEG (e.g., 200 of FIGS. 2 and 3) of the detection device 100.

[0094] FIG. 6 is a side partial cross-sectional view of a deposition detection device 100 attached to a conduit 102 in a portable installation. Seamlessly integrating multiple devices 100 within a semi-flexible clamp 600, this adaptable system efficiently covers several designated sections of the conduit 102. The placement of the clamp 600 with multiple detection devices 100 enables heat conduction through the Seebeck component of each detection device 100. The attachment of the clamp 600 may be facilitated by magnets situated on the underside of the detection devices 100. In some embodiments, the clamp 600 may include ROV handles 602 to allow for convenient manipulation of the clamp 600 into a desired location along the conduit 102. The flashing frequency of the indicator LEDs 222 may provide an inferred measurement of the deposition thickness directly beneath the detection devices 100. This clamp embodiment may be similarly implemented with speaker indicators that output modulated sound waves from each speaker.

[0095] FIG. 9 is a schematic diagram illustrating an example layout of positions for multiple deposition detection devices 100 to be placed around a circumference of the conduit 102. As shown in FIG. 9, the buildup of material (e.g., wax) inside a conduit 102 may be substantially symmetrical, often with the thickest portion of material buildup toward the bottom of the conduit 102 and the least amount of material buildup toward the top of the conduit 102. It may be desirable to position multiple deposition detection devices 100 along one half of the conduit 102, as shown. This half represents one vertical side of the conduit 102, and the material buildup along this half may be substantially similar to the material buildup along the opposite side of the conduit 102 due to the symmetry in material deposition. As illustrated, the deposition detection devices 100 may be positioned such that they are not all equally spaced around the circumference of the conduit 102. For example, as shown, six deposition detection devices 100 may be positioned at about 90° (at the top point of the conduit 102), about 180°, about 203°, about 225°, about 248°, and about 270° from horizontal. Other arrangements (equidistant or non-equidistant from each other) of multiple deposition detection devices 100 may be used in other embodiments.

[0096] FIG. 7 is a process flow diagram illustrating a method 700 for detecting a deposition inside a conduit. The usage of the method 700 may be independent of duration of installation (i.e., whether permanent or temporary) and independent of installation period (e.g., new pipeline or jumper, used pipeline or jumper, etc.). The method 700 enables both monitoring (i.e., observing the progression of deposition) and detection (i.e., determining the location of a deposit) of material deposited inside the conduit. Certain steps shown in the blocks of method 700 in FIG. 7 may be repeated, performed in different orders than shown, or omitted in other embodiments without departing from the scope of the present disclosure.

[0097] At block 702, the method 700 may include generating a first DC voltage via a thermoelectric generator (TEG) located between a conduit on one side and seawater or ambient air on an opposite side. The TEG may be located such that it is connected to both the conduit and the seawater or ambient air by different thermally conductive materials (e.g., magnet(s), heat sink, etc.). At block 704, the method 700 may include receiving the first DC voltage at a low voltage booster circuit coupled to the TEG and outputting a second DC voltage higher than the first DC voltage from the booster circuit. In other embodiments, the boosting step of block 704 may be omitted. For example, as described above with reference to FIG. 2B, the method may include using multiple TEGs electrically coupled in parallel to output a higher DC voltage. In still other embodiments, a single TEG may supply the entire useable / desired voltage. At block 706, the method 700 may include storing electrical energy from the second DC voltage in an energy accumulator coupled to the low voltage booster. At block 708, the method 700 may include, upon the electrical energy stored in the energy accumulator reaching a threshold, triggering a discharge of the electrical energy to an indicator via a voltage trigger coupled to the energy accumulator. At block 710, the method 700 may include outputting an indication (e.g., light or sound) from the indicator using the electrical energy discharged from the energy accumulator. The discharged electrical energy may power the indicator to output the indication, as described above.

[0098] FIG. 8 is a process flow diagram illustrating a method 800 for detecting the deposition inside a conduit based on indications output from a detection device. At block 802, the method 800 includes positioning a deposition detection device proximate a conduit. The deposition detection device may be permanently or temporarily installed on the conduit. At block 804, the method 800 includes generating an electrical output via a thermal energy harvesting assembly of the deposition detection device in response to heat transferred through a thermo-electric generator (TEG) of the thermal energy harvesting assembly. At block 806, the method 800 includes outputting, via an indicator on the deposition detection device, a pulsing signal of a visible or audible indication based on the electrical output from the energy harvesting assembly. At block 808, the method 800 includes recording the pulsing signal via an external recorder. At block 810, the method 800 may include analyzing a frequency of the pulsing signal to identify a deposit present inside the conduit. At block 812, the method 800 may include estimating one or more physical properties of the deposit within the conduit based at least on the pulsing signal. Estimating the one or more physical properties may include determining a relative thickness of the deposit based on a local temperature difference calculated between the ambient seawater temperature and the outer wall of the conduit. The method 800 may also include generating a map of the deposit in an axial direction and a circumferential direction along the conduit based on pulsing signals recorded for multiple detection devices positioned at different locations on the conduit.

[0099] In some embodiments, the method 800 may include designing a treatment for the conduit based on the estimated one or more physical properties of the deposit. The estimated physical properties of the deposit may include type or density of the deposit as well as thickness of the deposit at different locations within the conduit. This information is useful in designing a proper treatment (e.g., chemical treatment program, or mechanical removal procedure) to remove the deposit. The method 800 may include performing a treatment (e.g., the designed treatment) on the conduit and repeating at least steps 804, 806, 808, and 812 while performing the treatment to monitor the physical properties of the deposit within the conduit in response to the treatment. In particular, the method 800 may include performing a treatment on the conduit; recording the pulsing signal output from the indicator while performing the treatment; and monitoring the one or more physical properties of the deposit within the conduit while performing the treatment. In this way, the deposition detection device may be used to confirm the efficacy of the treatment.

[0100] In some embodiments, a method may include sensing signals (i.e., light or sound indications) output from the indicator and the frequency with which the signals are output from the indicator. The method may include analyzing the frequency of signals output from a single indicator along with other sensor measurements (e.g., ambient seawater temperature measurement(s), production fluid temperature measurement(s)) to determine an amount of material deposition inside the conduit proximate the location of the detection device. In some embodiments, the method may include sensing signals output from multiple indicators of multiple detection devices located along the conduit to generate a map of material deposition inside the conduit. Such a map of material deposition in the conduit may be used to inform on mitigation and / or remediation operations.

[0101] The disclosed systems, apparatus, and methods enable real-time monitoring of deposition in a conduit. Unlike inspection of deposition by pigging, the disclosed detection method does not place flow paths at risk from a stopped or stuck object. Unlike other external measurements, the disclosed systems, apparatus, and methods offer a low-cost solution that can be permanently installed. The disclosed deposition detection does not require a radioactive source like external densitometer measurements that require a gamma ray source and detector. The disclosed systems, apparatus, and methods enable real time monitoring and early detection of deposition and support evaluations of the effectiveness of mitigation and remediation efforts. The disclosed systems, apparatus, and methods offer improved operational awareness and flexibility in detecting deposition within conduits.

[0102] Certain illustrative embodiments are described below:

[0103] Embodiment 1: A deposition detection device configured to be installed on a conduit, the deposition detection device including: a thermal energy harvesting assembly including a thermo-electric generator (TEG) configured to be positioned with a first side of the TEG proximate an outer wall of the conduit and a second side of the TEG facing away from the conduit; and an indicator packaged with and electrically coupled to the thermal energy harvesting assembly, the indicator configured to output a visible or audible indication representative of an amount of material deposition inside the conduit based on an electrical output of the thermal energy harvesting assembly.

[0104] Embodiment 2: The deposition detection device of Embodiment 1, wherein the thermal energy harvesting assembly further includes an energy harvesting circuit configured to receive a voltage output from the TEG and to generate electrical outputs for powering the indicator.

[0105] Embodiment 3: The deposition detection device of Embodiment 2, wherein the energy harvesting circuit includes a low voltage booster configured to boost the voltage output from the TEG, an energy accumulator configured to store electrical energy output from the low voltage booster, and a voltage trigger circuit configured to trigger a release of the stored electrical energy from the energy accumulator to the indicator when the stored electrical energy reaches a predetermined threshold.

[0106] Embodiment 4: The deposition detection device of Embodiment 3, wherein the low voltage booster includes a boosting circuit having an inductor and a switching device, and wherein the energy accumulator includes a capacitor.

[0107] Embodiment 5: The deposition detection device of Embodiment 1, further including a heat sink coupled to the second side of the TEG.

[0108] Embodiment 6: The deposition detection device of Embodiment 5, wherein the heat sink includes fins.

[0109] Embodiment 7: The deposition detection device of Embodiment 5, wherein the heat sink includes a magnet.

[0110] Embodiment 8: The deposition detection device of Embodiment 1, further including a magnet coupled to the first side of the TEG.

[0111] Embodiment 9: The deposition detection device of Embodiment 8, further including a heat sink coupled to the second side of the TEG.

[0112] Embodiment 10: The deposition detection device of Embodiment 9, wherein the TEG is fully enclosed by the magnet, the heat sink, and an adhesive material.

[0113] Embodiment 11: The deposition detection device of Embodiment 9, wherein the heat sink, the magnet, or both, are coated with a zinc coating, a fluorocarbon-based coating, or a fluoropolymer-based coating.

[0114] Embodiment 12: The deposition detection device of Embodiment 8, further comprising a heat sink coupled to the second side of the TEG.

[0115] Embodiment 13: A system, including: a conduit configured to transport fluid between a first location and a second location; a deposition detection device coupled to the conduit, the deposition detection device including: a thermal energy harvesting assembly including a thermoelectric generator (TEG) with a first side proximate an outer wall of the conduit and a second side facing away from the conduit; and an indicator configured to output a visible or audible indication based on an electrical output of the thermal energy harvesting assembly; and an external recorder configured to capture and record the visible or audible indication output from the deposition detection device.

[0116] Embodiment 14: The system of Embodiment 13, further including multiple deposition detection devices including the deposition detection device coupled to the conduit, each of the multiple deposition detection devices having a thermal energy harvesting assembly and an indicator.

[0117] Embodiment 15: The system of Embodiment 14, wherein at least two deposition detection devices of the multiple deposition detection devices are located at different axial locations along a length of the conduit.

[0118] Embodiment 16: The system of Embodiment 14, wherein at least two deposition detection devices of the multiple deposition detection devices are located at different circumferential locations around the conduit.

[0119] Embodiment 17: The system of Embodiment 14, wherein the indicator on each deposition detection device is a speaker configured to output an audible indication, and wherein each speaker of the multiple deposition detection devices is configured to output an audible indication at a different frequency from any other speaker of the multiple deposition detection devices.

[0120] Embodiment 18: The system of Embodiment 17, wherein the multiple deposition detection devices are arranged circumferentially around the conduit, and wherein the speaker of the deposition detection device at the lowest position in a vertical direction around the conduit is configured to output an audible indication at a frequency lower than any other speaker of the multiple deposition detection devices.

[0121] Embodiment 19: The system of Embodiment 14, wherein the multiple deposition detection devices are integrated into a clamp that is removably disposed around the conduit.

[0122] Embodiment 20: The system of Embodiment 19, wherein the multiple deposition detection devices are arranged circumferentially around the conduit via the clamp.

[0123] Embodiment 21: The system of Embodiment 19, wherein the clamp includes one or more remote operated vehicle (ROV) handles for selective positioning of the clamp around the conduit.

[0124] Embodiment 22: The system of Embodiment 13, wherein the indicator includes an LED configured to output light pulses, and the external recorder includes a camera to detect the light pulses.

[0125] Embodiment 23: The system of Embodiment 13, wherein the indicator includes a speaker configured to output modulated sound pulses, and the external recorder includes a hydrophone to detect the modulated sound pulses.

[0126] Embodiment 24: The system of Embodiment 13, wherein the external recorder further includes a temperature sensor to detect an ambient seawater temperature.

[0127] Embodiment 25: The system of Embodiment 13, wherein the deposition detection device is magnetically coupled to an outer wall of the conduit.

[0128] Embodiment 26: The system of Embodiment 25, wherein the deposition detection device includes a magnet having a concave surface matching a contour of the outer wall of the conduit.

[0129] Embodiment 27: The system of Embodiment 13, wherein the TEG is oriented with respect to the conduit such that the TEG generates a voltage via heat flowing from the conduit through the TEG to ambient seawater.

[0130] Embodiment 28: The system of Embodiment 13, wherein the TEG is oriented with respect to the conduit such that the TEG generates a voltage via heat flowing from ambient seawater through the TEG to the conduit.

[0131] Embodiment 29: The system of Embodiment 13, wherein the conduit is a subsea conduit and includes a subsea pipeline, a subsea jumper, or both.

[0132] Embodiment 30: The system of Embodiment 13, wherein the conduit is configured to transport fluids produced from a well therethrough.

[0133] Embodiment 31: The system of Embodiment 13, further including: a processor configured to be communicatively coupled to the external recorder; and a memory communicatively coupled to the processor, the memory storing instructions that, when executed by the processor, cause the processor to: receive, from the external recorder, an output indicative of signals measured by the external recorder; identify a deposit present inside the conduit based on the output from the external recorder; and estimate one or more physical properties of the deposit within the output from the external recorder.

[0134] Embodiment 32: A method of operation of a deposition detection device, including: transferring heat across a thermo-electric generator (TEG) of a thermal energy harvesting assembly, wherein the TEG is positioned with a first side of the TEG proximate an outer wall of a conduit and a second side of the TEG facing away from the conduit; generating an electrical output via the thermal energy harvesting assembly in response to the heat transferred across the TEG; and outputting, via an indicator packaged with and electrically coupled to the thermal energy harvesting assembly, a visible or audible indication representative of an amount of material deposition inside the conduit based on the electrical output of the thermal energy harvesting assembly.

[0135] Embodiment 33: The method of Embodiment 32, further including: generating a first DC voltage via the TEG in response to the heat transferred across the TEG; receiving the first DC voltage at a low voltage booster circuit of the thermal energy harvesting assembly and outputting a second DC voltage higher than the first DC voltage from the low voltage booster circuit; storing electrical energy from the second DC voltage in an energy accumulator of the thermal energy harvesting assembly; upon the electrical energy stored in the energy accumulator reaching a predetermined threshold, triggering a discharge of the electrical energy to the indicator via a voltage trigger of the thermal energy harvesting assembly; and outputting the visible or audible indication via the indicator using the electrical energy discharged from the energy accumulator.

[0136] Embodiment 34: The method of Embodiment 33, further including: increasing a voltage of the electrical energy discharged from the energy accumulator via a second voltage booster prior to the electrical energy reaching the indicator.

[0137] Embodiment 35: The method of Embodiment 33, further including repeating storing electrical energy in the energy accumulator, triggering the discharge of the electrical energy upon the electrical energy stored in the energy accumulator reaching the predetermined threshold, and outputting the visible or audible indication.

[0138] Embodiment 36: The method of Embodiment 32, further including: generating a DC voltage via the TEG and a second TEG electrically coupled in series to the TEG, in response to heat transferred across the TEG and across the second TEG; storing electrical energy from the DC voltage in an energy accumulator of the thermal energy harvesting assembly; upon the electrical energy stored in the energy accumulator reaching a predetermined threshold, triggering a discharge of the electrical energy to the indicator via a voltage trigger of the thermal energy harvesting assembly; and outputting the visible or audible indication via the indicator using the electrical energy discharged from the energy accumulator

[0139] Embodiment 37: The method of Embodiment 32, including operating the thermal energy harvesting assembly and the indicator entirely using voltage generated by the TEG.

[0140] Embodiment 38: A conduit monitoring and detection method, including: positioning a deposition detection device proximate a conduit; generating an electrical output via a thermal energy harvesting assembly of the deposition detection device in response to heat transferred through a thermo-electric generator (TEG) of the thermal energy harvesting assembly; outputting, via an indicator on the deposition detection device, a pulsing signal of a visible or audible indication based on the electrical output from the energy harvesting assembly; recording the pulsing signal via an external recorder located; analyzing a frequency of the pulsing signal to identify a deposit present inside the conduit; and estimating one or more physical properties of the deposit within the conduit based at least on the pulsing signal.

[0141] Embodiment 39: The method of Embodiment 38, further including: receiving additional sensor measurements including an ambient seawater temperature measurement and / or a production fluid temperature measurement; and estimating the one or more physical properties of the deposit within the conduit based on the pulsing signal and the additional sensor measurements.

[0142] Embodiment 40: The method of Embodiment 38, including: positioning multiple deposition detection devices proximate the conduit at different locations along the conduit; recording pulsing signals output from the multiple deposition detection devices via the external recorder; and analyzing frequencies of the pulsing signals to identify a deposit present inside the conduit; and estimating one or more physical properties of the deposit within the conduit based at least on the pulsing signals.

[0143] Embodiment 41: The method of Embodiment 40, further including generating a map of the deposit in an axial direction and a circumferential direction along the conduit based on the pulsing signals.

[0144] Embodiment 42: The method of Embodiment 38, further including determining a local temperature difference between an outer wall of the conduit and ambient seawater based on the frequency of the pulsing signal.

[0145] Embodiment 43: The method of Embodiment 42, wherein estimating the one or more physical properties of the deposit includes determining a relative thickness of the deposit based on the local temperature difference.

[0146] Embodiment 44: The method of Embodiment 38, further including: performing a treatment on the conduit; recording the pulsing signal output from the indicator while performing the treatment; and monitoring the one or more physical properties of the deposit within the conduit while performing the treatment.

[0147] Embodiment 45: The method of Embodiment 38, wherein the deposit detection device is permanently installed on the conduit.

[0148] Embodiment 46: The method of Embodiment 38, wherein the deposit detection device is temporarily installed on the conduit.

[0149] Although embodiments described herein are made with reference to example embodiments, it should be appreciated by those skilled in the art that various modifications are well within the scope and spirit of this disclosure. Those skilled in the art will appreciate that the example embodiments described herein are not limited to any specifically discussed application and that the embodiments described herein are illustrative and not restrictive. From the description of the example embodiments, equivalents of the elements shown therein will suggest themselves to those skilled in the art, and ways of constructing other embodiments using the present disclosure will suggest themselves to practitioners of the art. Therefore, the scope of the example embodiments is not limited herein.

Claims

1. A deposition detection device configured to be installed on a conduit, the deposition detection device comprising:a thermal energy harvesting assembly comprising a thermo-electric generator (TEG) configured to be positioned with a first side of the TEG proximate an outer wall of the conduit and a second side of the TEG facing away from the conduit; andan indicator packaged with and electrically coupled to the thermal energy harvesting assembly, the indicator configured to output a visible or audible indication representative of an amount of material deposition inside the conduit based on an electrical output of the thermal energy harvesting assembly.

2. The deposition detection device of claim 1, wherein the indication output from the indicator comprises a series of light or modulated sound pulses, wherein a frequency of the light or modulated sound pulses corresponds to the amount of material deposition inside the conduit.

3. The deposition detection device of any one of claims 1-2, wherein the indicator comprises an LED configured to output pulses of light based on the electrical output of the thermal energy harvesting assembly.

4. The deposition detection device of any one of claims 1-2, wherein the indicator comprises a speaker configured to output modulated pulses of sound based on the electrical output of the thermal energy harvesting assembly.

5. The deposition detection device of any one of claims 1-4, wherein the thermal energy harvesting assembly further comprises an energy harvesting circuit configured to receive a voltage output from the TEG and to generate electrical outputs for powering the indicator.

6. The deposition detection device of claim 5, wherein the energy harvesting circuit comprises a low voltage booster configured to boost the voltage output from the TEG, an energy accumulator configured to store electrical energy output from the low voltage booster,2024372805   25 Jun 2026and a voltage trigger circuit configured to trigger a release of the stored electrical energy from the energy accumulator to the indicator when the stored electrical energy reaches a predetermined threshold.

7. The deposition detection device of claim 6, further comprising a second voltage booster disposed between the voltage trigger circuit and the indicator to increase a voltage of the electrical energy released from the energy accumulator to the indicator.

8. The deposition detection device of any one of claims 5-7, further comprising a second TEG electrically coupled in series with the TEG, wherein the energy harvesting circuit comprises:an energy accumulator configured to store electrical energy output from the TEG and the second TEG; anda voltage trigger circuit configured to trigger a release of the stored electrical energy from the energy accumulator when the stored electrical energy reaches a predetermined threshold.

9. The deposition detection device of any one of claims 1-8, further comprising a heat sink coupled to the second side of the TEG.

10. The deposition detection device of any one of claims 1-9, further comprising a magnet coupled to the first side of the TEG.

11. The deposition detection device of claim 10, wherein the magnet has a concave surface on a side of the magnet facing away from the TEG.

12. A system, comprising:a conduit configured to transport fluid between a first location and a second location;a deposition detection device coupled to the conduit, the deposition detection device comprising:a thermal energy harvesting assembly comprising a thermo-electric generator (TEG) with a first side proximate an outer wall of the conduit and a second side facing away from the conduit; and2024372805   25 Jun 2026an indicator configured to output a visible or audible indication representative of an amount of material deposition inside the conduit based on an electrical output of the thermal energy harvesting assembly; andan external recorder configured to capture and record the visible or audible indication output from the deposition detection device.

13. The system of claim 12, further comprising multiple deposition detection devices including the deposition detection device coupled to the conduit, each of the multiple deposition detection devices having a thermal energy harvesting assembly and an indicator.

14. The system of claim 13, wherein the indicator on each deposition detection device is a speaker configured to output an audible indication, and wherein each speaker of the multiple deposition detection devices is configured to output an audible indication at a different modulated frequency from any other speaker of the multiple deposition detection devices.

15. The system of any one of claims 13-14, wherein the multiple deposition detection devices are integrated into a clamp that is removably disposed around the conduit.

16. The system of any one of claims 12-15, wherein the conduit is located subsea, and the external recorder comprises a remote operated vehicle (ROV), an autonomous underwater vehicle (AUV), or a stationary subsea receiver.

17. The system of any one of claims 12-16, wherein the conduit is located on land, and the external recorder comprises a stationary or mobile receiver.

18. The system of any one of claims 12-17, wherein the deposition detection device is magnetically coupled to an outer wall of the conduit.

19. The system of any one of claims 12-17, wherein the deposition detection device is integrated into a surface protection and / or an insulation layer of the conduit.

20. A method of operation of a deposition detection device, comprising:2024372805   25 Jun 2026transferring heat across a thermo-electric generator (TEG) of a thermal energy harvesting assembly, wherein the TEG is positioned with a first side of the TEG proximate an outer wall of a conduit and a second side of the TEG facing away from the conduit;generating an electrical output via the thermal energy harvesting assembly in response to the heat transferred across the TEG; andoutputting, via an indicator packaged with and electrically coupled to the thermal energy harvesting assembly, a visible or audible indication representative of an amount of material deposition inside the conduit based on the electrical output of the thermal energy harvesting assembly.

Images