Pipeline monitoring systems and methods for marine currents

Abstract

A pipeline monitoring system for a subsea pipe includes a current sensor that collects marine current data proximate the subsea pipe and a pipe response sensor system that measures response data of the subsea pipe. A pipeline loading service compares the marine current data and the response data to determine whether a correlation exists. Where a correlation exists, the pipeline loading service can determine a current loading attributable to the marine current data and can update a pipeline loading with the current loading. Where no correlation exists, the pipeline loading service can determine an intrinsic loading attributable to the response data and can update the pipeline loading with the intrinsic loading. The pipeline loading service provides maintenance recommendations for the subsea pipe based upon the current loading and the intrinsic loading.

Description

PIPELINE MONITORING SYSTEMS AND METHODS FOR MARINE CURRENTSTECHNICAL FIELD

[0001] Embodiments of the technology relate generally to a monitoring system for measuring marine currents to determine stress on pipelines.BACKGROUND

[0002] Pipelines are commonly used to transport fluids, including water, gasses, and petroleum products on land as well as undersea. Pipelines include tubular pipe components that can include straight and bent sections of pipe, as well as sections with more complex geometries such as reducers, expanders, elbow joints, and tee joints. In subsea pipelines that transport hydrocarbons, a variety of pipe sections and types may be employed. Flow lines can be used transport fluids along or near the bed of a body of water as well as across subsea canyons and escarpments. Jumpers are tubular sections that connect to manifolds. Risers are pipe components engineered to transport fluids vertically between subsea equipment and facilities at the water’s surface such as drilling or production facilities.

[0003] Pipelines typically are manufactured from steel and are subject to wear, stress, and fatigue. Sources of wear, stress, and fatigue on a pipeline can include erosion and corrosion of the pipe wall, vibrations and loads from a variety of sources, and thermal and pressure cycling. In the production of hydrocarbons, pipelines are critical infrastructure components. Therefore, the ability to regularly monitor and inspect the integrity of pipelines improves the process of producing hydrocarbons and reduces safety hazards. However, because subsea pipelines are often located at significant depths, inspecting and monitoring pipelines to assess wear, stress, and fatigue is an expensive and challenging task. When accurate assessment and monitoring of pipelines is not possible, pipeline operators generally rely on overly conservative estimates as to when pipe sections must be maintained or replaced. Interrupting the operation of a pipeline to perform maintenance or to replace a section of subsea pipe can be hazardous and expensive.

[0004] Marine currents are one type of load that causes stress in subsea pipelines. The highly variable nature of marine currents makes it particularly challenging to monitorthe loads they impose on subsea pipelines. It also can be challenging to discern loads caused by marine currents from loads imposed on the pipeline from other sources. Accordingly, improved systems for monitoring the stresses that marine currents cause on pipelines would be beneficial.SUMMARY

[0005] The present disclosure is directed to apparatus and methods for monitoring subsea pipelines. One example embodiment is directed to a pipeline monitoring system. The pipeline monitoring system may comprise: (a) an attachment device for attaching the pipeline monitoring system to a subsea pipe; (b) a power source that supplies power to the pipeline monitoring system; (c) a pipe response sensor system that measures response data of the subsea pipe; (d) a current sensor that collects marine current data from a region proximate the subsea pipe; (e) a controller that supplies power from the power source to the pipe response sensor system and to the current sensor; and (f) a data storage device that stores the marine current data measured by the current sensor and the response data measured by the pipe response sensor system.

[0006] Another example embodiment is directed to a method for monitoring a subsea pipe. The method may comprise: (a) installing a pipeline monitoring system on the subsea pipe, the pipeline monitoring system comprising a current sensor and a pipe response sensor system; (b) measuring, by the current sensor, marine current data from a region proximate the subsea pipe; (c) measuring, by the pipe response sensor system, response data of the subsea pipe; (d) determining, by a pipeline loading service executing on a computing device, whether a correlation exists between the marine current data and the response data; (e) if the correlation exists, calculate, by the pipeline loading service, a current loading attributable to the marine current data and updating a pipeline loading with the current loading; and (f) if the correlation does not exist, calculate, by the pipeline loading service, an intrinsic loading attributable to the response data and updating a pipeline loading with the intrinsic loading

[0007] The foregoing embodiments are non-limiting examples and other aspects and embodiments will be described herein. The foregoing summary is provided to introduce various concepts in a simplified form that are further described below in thedetailed description. This summary is not intended to identify required or essential features of the claimed subject matter nor is the summary intended to limit the scope of the claimed subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The accompanying drawings illustrate only example embodiments of a pipe monitoring systems and methods and therefore are not to be considered limiting of the scope of this disclosure. The principles illustrated in the example embodiments of the drawings can be applied to alternate methods and apparatus. Additionally, 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. Certain dimensions or positions may be exaggerated to help visually convey such principles. In the drawings, the same reference numerals used in different embodiments designate like or corresponding, but not necessarily identical, elements.

[0009] Figure 1 illustrates a subsea pipeline with multiple pipeline monitoring systems attached to the exterior of the pipeline in accordance with an example embodiment of the disclosure.

[0010] Figure 2 illustrates a pipeline monitoring system with an acoustic current sensor attached to the exterior of a pipe in accordance with an example embodiment of the disclosure.

[0011] Figure 3 illustrates a pipeline monitoring system with a propeller current sensor attached to the exterior of a pipe in accordance with an example embodiment of the disclosure.

[0012] Figure 4 illustrates a pipeline monitoring system with an electromagnetic current sensor attached to the exterior of a pipe in accordance with an example embodiment of the disclosure.

[0013] Figure 5 illustrates the components of a sensor housing of a pipeline monitoring system in accordance with an example embodiment of the disclosure.

[0014] Figure 6 illustrates the components of another example of a sensor housing of a pipeline monitoring system in accordance with an example embodiment of the disclosure.

[0015] Figure 7 illustrates a pipeline monitoring network in accordance with an example embodiment of the disclosure.

[0016] Figure 8 illustrates current data and response data measured with a pipeline monitoring system in accordance with an example embodiment of the disclosure.

[0017] Figure 9 is a flowchart illustrating a method of using a pipeline monitoring system in accordance with an example embodiment of the disclosure.DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0018] The example embodiments discussed herein are directed to systems and methods for monitoring marine currents around subsea pipelines and for assessing the loading on the pipelines caused by the marine currents. The example systems and methods described herein are particularly beneficial in the oil and gas industry where fluids are often transported through lengthy subsea pipelines. The examples described herein improve upon existing monitoring devices that are placed on subsea pipelines, but only measure certain limited characteristics about the pipeline. Existing monitoring devices fail to incorporate sensors for monitoring marine currents. Existing monitoring systems also fail to discern whether the loads on a subsea pipeline are caused by marine currents or by another source such as other equipment or temperature or pressure changes.

[0019] The example embodiments described herein provide an improved approach that simplifies the measurement of marine currents along a subsea pipeline. This improved approach places pipeline monitoring systems that include current sensors along a pipeline. The pipeline monitoring systems facilitate placement of current sensors at many locations along a pipeline and also allows for focusing on locations along a pipeline that may be particularly susceptible to loading from marine currents. The improved approach described herein also facilitates leaving current sensors in place on a pipeline for an extended period of time for continued monitoring of the pipeline. The example embodiments described herein use the current sensor measurements in combination with other measurements to discern the source of a load on a section of pipe in a pipeline. The example embodiments described herein also use the analysis of the data collected from sensors to track loading and fatigue on the pipeline over time so that maintenance recommendations can be made that optimize efficiency and reduce hazards. Accordingly, the embodiments describedherein address one or more of the shortcomings in existing approaches to monitoring subsea pipelines.

[0020] In the following paragraphs, particular embodiments will be described in further detail by way of example with reference to the drawings. In the description, well- known components, methods, and / or processing techniques are omitted or briefly described. Furthermore, reference to various feature(s) of the embodiments is not to suggest that all embodiments must include the referenced feature(s).

[0021] Figure 1 illustrates a subsea environment in which a pipeline is located. The terms “subsea” and “marine” are used herein to broadly encompass any body of water in which a pipeline may be located, including but not limited to an ocean, a sea, a bay, a lake, and a river. Additionally, as used herein, a “pipeline” typically comprises sections of pipe and the terms “pipeline” and “pipe” as used herein broadly encompass any tubular equipment placed in a body of water that may be subj ected to loading from marine currents, including but not limited to flow lines, jumpers, risers, canyon and escarpment crossing lines, pipe fittings, pipe elbows, pipe connectors, cables, and umbilicals.

[0022] Figure 1 illustrates an example of a subsea pipeline 101 that extends along a seabed and terminates at subsea equipment. A riser 103 portion of the pipeline 101 connects the pipeline 101 to a platform located at the surface of the sea. In accordance with the embodiments described herein, pipeline monitoring systems 110, 120, 130, and 140 are placed at positions along the pipeline 101. As will be described further below, each pipeline monitoring system can include a current sensor that gathers marine current data for currents flowing proximate to the pipeline monitoring system. Each pipeline monitoring system also can include other sensors, such as sensors that measure response data indicating the pipelines response to various conditions, including temperature and pressure conditions as well as loads imposed on the pipeline. In certain examples, the pipeline monitoring systems can communicate among each other which can be used to transfer data along the length of the pipeline 101. The marine current data and the response data can be used to analyze loads placed on the pipeline by the marine currents and to make recommendations regarding the maintenance of pipeline.

[0023] The pipeline monitoring systems can be attached to the pipe sections of the pipeline before the pipe is placed underwater. Alternatively, the pipeline monitoringsystems can be placed on a pipe after the pipe is in position in the water. As examples, the pipeline monitoring systems can be placed on a pipe in the water by a subsea vehicle or by a diver. Figure 1 illustrates a subsea vehicle 160 which can be used to place pipeline monitoring systems at various positions along the pipeline and remove pipeline monitoring systems from the pipeline. In some applications, the subsea vehicle 160 also can remove components of the pipeline monitoring systems and communicate with the pipeline monitoring systems. The subsea vehicle 160 can be an undersea remotely operated vehicle (ROV) or an autonomous undersea vehicle (AUV). The example subsea vehicle 160 includes a communication system 162 that allows data signals, including control commands, to be communicated between the subsea vehicle 160 and other equipment located at the surface or undersea. The communication system 162 can support communications of a variety of types, including optical signals, radio signals, and audio signals. A remote data collection device 163 onboard the subsea vehicle 160 can store data collected from the pipeline monitoring systems as will be described further below. The subsea vehicle 160 also includes a navigation system 164 used to direct the subsea vehicle 160 in the desired direction and a propulsion system 166 that drives the subsea vehicle 160 towards the desired destination. Lastly, the subsea vehicle 160 includes a manipulator 167 that can be controlled with the received control commands and that can be used to actuate other devices, including lifting and turning other devices. In the example of Figure 1, the subsea vehicle’s manipulator 167 can be used to place the pipeline monitoring systems on the pipe 102, remove pipeline monitoring systems from the pipe 102, and to manipulate components of the pipeline monitoring systems.

[0024] Figures 2, 3, and 4 illustrate examples of pipeline monitoring systems attached to an exterior of a pipe. The configurations of the pipeline monitoring systems shown in Figures 2, 3, and 4 are illustrative examples and in other embodiments the pipeline monitoring systems can have other configurations or components. In each of the examples of Figures 2, 3, and 4, the pipeline monitoring systems are attached to a pipe using a clamping device. In other example embodiments, the pipeline monitoring systems can be attached to the pipe using other means, such as straps, magnetic attachment devices, or adhesive materials. The components of the pipeline monitoring systems can be made from a variety of materials. In certain examples, components can be made from materialsthat are not ferromagnetic so as to minimize interference with the sensors onboard the pipeline monitoring system. For example, materials such as titanium and polymers can be used for some or all of these components.

[0025] Referring to Figure 2, an example pipeline monitoring system 210 is shown attached to a section of pipe 202 that can make up part of a longer subsea pipeline. The pipe 202 has a central axis of symmetry passing along the longitudinal center of the pipe. The pipeline monitoring system 210 includes an attachment device 212 in the form of a clamp. The clamp includes opposing arms that extend around opposite sides of the pipe 202 and that secure the pipeline monitoring system 210 to the pipe 202. The opposing arms of the clamp can pivot about a pivot rod and can be biased to a closed position by a spring or other device. The clamp can be opened and closed by a diver or undersea vehicle to install and remove the pipeline monitoring system 210 with respect to the pipe 202.

[0026] The pipeline monitoring system 210 also comprises a sensor housing 214. In the example of Figure 2, the sensor housing 214 is located between the two opposing arms of the clamp that extend around the pipe 202. However, in other embodiments, the sensor housing can be at other positions on the pipeline monitoring system. For example, in certain embodiments it may be advantageous for the sensor housing to extend around portions of the circumference of the pipe or to project outward and away from the exterior of the pipe. The sensor housing can comprise one or more vessels designed to withstand the effects of hydrostatic pressure encountered at subsea depths. As one example, the sensor housing 214 can have a cylindrical shape that is sealed to withstand large hydrostatic pressures.

[0027] The example sensor housing 214 comprises an acoustic current sensor 216 that uses acoustic signals to measure marine currents proximate to the pipeline monitoring system 210. The acoustic current sensor 216 typically has a cylindrical shape that extends from the sensor housing 214. The acoustic current sensor 216 can be an integrated component of the sensor housing 214 or can be attached to the sensor housing as an accessory component. The acoustic current sensor 216 includes one or more windows for transmitting acoustic signals and detecting reflected acoustic signals to collect data about proximate marine currents. Acoustic current sensors typically have a range of up to 10 meters from the sensor within which marine current data can be collected. The sensorhousing 214 and / or the acoustic current sensor 216 can be oriented at any position around the circumference of the pipe 202 to gather marine current data in any direction around the pipe 202. Incorporating the current sensor into the pipeline monitoring system with other sensors avoids the need to deploy separate current sensors on buoys or other equipment.

[0028] The example sensor housing 214 also includes a pipe response sensor system 218. The pipe response sensor system 218 can comprise one or more sensing devices that detect characteristics of the pipe in response to various conditions. As one example, the pipe response sensor system 218 can include an accelerometer that detects motion or vibrations in the pipe 202, for example, in response to marine currents or other loads applied to the pipe 202. As another example, the pipe response sensor system 218 can include one or more strain gauges that measure strains in the pipe 202 caused by one or more loads applied to pipe 202. Other types of sensors, such as temperature or pressure sensors can be included in the pipe response sensor system 218. As will be described further below, the pipe response sensor system is used in tandem with the current sensor to determine the effect of marine currents on the pipe 202.

[0029] Figure 3 illustrates another example of a pipe monitoring system 310 attached to a pipe 302. Pipeline monitoring system 310 is similar in many respects to pipeline monitoring system 210 and it can be assumed that the descriptions of pipeline monitoring system 210 apply equally to pipeline monitoring system 310, except as noted in the following description. As with pipeline monitoring system 210, pipeline monitoring system 310 includes an attachment device 312 in the form of a clamp with opposing arms that secure the pipeline monitoring system 310 to the pipe 302. Pipeline monitoring system 310 also includes a sensor housing 314 comprising sensors for collecting data related to the pipe 302. As in the sensor housing 214, sensor housing 314 includes a pipe response sensor system 318 that comprises one or more sensing devices for measuring characteristics of the pipe in response to various conditions. As examples, the pipe response sensor system 318 can include one or more of an accelerometer, a strain gauge, a pressure sensor, or a temperature sensor.

[0030] The current sensor of pipe monitoring system 310 differs from that of Figure 2 in that it is a propeller current sensor 316. The propeller current sensor 316 includes a propeller at its end that measures the marine current passing by the sensor 316. To avoiddistortions in the marine current flowing along the surfaces of the pipe 302 and the pipeline monitoring system 310, the propeller current sensor 316 extends outward from the sensor housing 314 so that the propeller can obtain more accurate marine current data. The propeller current sensor 316 can be an integrated component of the sensor housing 314 or can be attached to the sensor housing as an accessory component. The sensor housing 314 and / or the propeller current sensor 316 can be oriented at any position around the circumference of the pipe 302 to gather marine current data in any direction around the pipe 302.

[0031] Figure 4 illustrates another example of a pipe monitoring system 410 attached to a pipe 402. Pipeline monitoring system 410 is similar in many respects to pipeline monitoring system 210 and it can be assumed that the descriptions of pipeline monitoring system 210 apply equally to pipeline monitoring system 410, except as noted in the following description. As with pipeline monitoring system 210, pipeline monitoring system 410 includes an attachment device 412 in the form of a clamp with opposing arms that secure the pipeline monitoring system 410 to the pipe 402. Pipeline monitoring system 410 also includes a sensor housing 414 comprising sensors for collecting data related to the pipe 402. As in the sensor housing 214, sensor housing 414 includes a pipe response sensor system 418 that comprises one or more sensing devices for measuring characteristics of the pipe in response to various conditions. As examples, the pipe response sensor system 418 can include one or more of an accelerometer, a strain gauge, a pressure sensor, or a temperature sensor.

[0032] The current sensor of pipe monitoring system 410 differs from that of Figure 2 in that it is an electromagnetic current sensor 416. The electromagnetic current sensor 416 includes one or more induction circuits that measure the marine current passing by the sensor 416. To avoid distortions in the marine current flowing along the surfaces of the pipe 402 and the pipeline monitoring system 410, the electromagnetic current sensor 416 extends outward from the sensor housing 414 so that the sensor can obtain more accurate marine current data. The electromagnetic current sensor 416 can be an integrated component of the sensor housing 414 or can be attached to the sensor housing as an accessory component. The sensor housing 414 and / or the electromagnetic current sensor416 can be oriented at any position around the circumference of the pipe 402 to gather marine current data in any direction around the pipe 402.

[0033] Referring now to Figures 5 and 6, two different example embodiments for a sensor housing of a pipeline monitoring system are illustrated. In the example of Figure 5, the current sensor is an integrated component of the pipeline monitoring system. In contrast, in the example of Figure 6, the current sensor is an accessory that attaches to the pipeline monitoring system. Incorporating the current sensor into the pipeline monitoring system, either as an integrated component or as an attached accessory, is advantageous because it eliminates the need to deploy separate current sensors on buoys or other equipment. Moreover, as will be described further, collecting marine current data allows for a more accurate assessment of the loads applied to a subsea pipeline, which allows for improved maintenance of the pipeline.

[0034] Figure 5 illustrates components of a sensor housing 514 that can be incorporated into a pipeline monitoring system 510 that can be attached to a subsea pipe. The sensor housing 514 includes a power source in the form of a battery and power supply 520. The battery and power supply provide power to the components of the sensor housing 514. The battery and power supply 520 can take a variety of forms and in other embodiments can be other types of power sources, such as a fuel cell, a thermoelectric generator, or a kinetic power source that relies upon motion such as the motion of the sea to drive a turbine. Advances in the miniaturization and power consumption of electronic components as well as the capacity of batteries enable sensors to be deployed and to operate for years before requiring maintenance or replacement. Appropriate electrical connectors and interfaces can provide power from the battery and power supply to the other components of the sensor housing 514.

[0035] The sensor housing 514 includes sensors such as those described previously for collecting data pertaining to the pipe. A current sensor 530 can be any one of the previously described acoustic current sensor, propeller current sensor, or electromagnetic current sensor. Although illustrated in Figure 5 as internal to the sensor housing 514 for simplicity, it should be understood that the current sensor typically would extend from the sensor housing 514 as described previously to collect accurate marine current data. A pipeline response sensor system 532 can include one or more of the previously describedsensors that measure characteristics of the pipe in response to various phenomena, including loads applied to the pipe and temperature and pressure changes. As described previously, an accelerometer can be used to detect motion or vibrations in the pipe. As another example, a strain gauge can detect strain in the pipe. When implemented, a strain gauge typically would include a portion of the gauge that is outside the sensor housing and attached directly to the outer surface of the pipe.

[0036] The sensor housing 514 further includes a data storage device 528 that can store data and / or algorithms and a controller 526 that can execute based upon the data and / or algorithms in the data storage device 528. As examples, the controller 526 can store data collected by the current sensor 530 and the pipe response sensor system 532 in the data storage device 528. The controller also can execute instructions in the form of algorithms to manage the operation of the components of the sensor housing 514. In certain embodiments, the controller can perform certain initial processing on the data collected by the sensors in order to reduce the amount of data that must be transmitted from the pipeline monitoring system 510 and, thereby, reduce power consumption. The controller can be implemented as one or more processors, including but not limited to a multicore processor, a system-on-a-chip, or a multichip module.

[0037] As indicated by the broken line, in an example embodiment, the data storage device 528 can be located in a sealed subcomponent housing that can be easily removed from the sensor housing 514. Such a subcomponent housing allows a subsea vehicle, a diver, or another piece of equipment to remove the data storage device 528 while leaving the remainder of the sensor housing 514 and the pipeline monitoring system 510 in place on a subsea pipe. The ability to remove the subcomponent housing containing the data storage device 528 provides one method for collecting data from the pipeline monitoring system 510 that has been gathered over time by the sensors. In such a case, the removed data storage device 528 could be replaced with a new data storage device that will store data that is newly collected by the sensors.

[0038] The sensor housing 514 also can include an optional communications signal interface 522. The communications signal interface allows for wireless communication between the pipeline monitoring system 510 and other equipment. Such wireless communication can use any wireless communication method, such as optical signals, radiosignals, acoustic signals, magnetic pulse signals, or magneto-quasi static signals, as indicated by representative signals 524. Accordingly, the sensor housing 514 does not require any wires extending outside the sealed sensor housing. Eliminating wires that might extend from the sensor housing eliminates challenges presented by large hydrostatic pressures and facilitates the insertion and removal of the sensor housing 514 with respect to the pipeline monitoring system 510. As examples, the communication signal interface 522 allows the sensor housing 514 to transmit data collected by the sensors to other subsea equipment, to a subsea vehicle passing in proximity to the pipeline monitoring system 510, or to equipment at the water’s surface such as a floating platform.

[0039] Referring now to Figure 6, as referenced previously, an alternate embodiment of a sensor housing 614 of a pipeline monitoring system 610 is illustrated. Pipeline monitoring system 610 is similar in many respects to pipeline monitoring system 510 and it can be assumed that the descriptions of the components of pipeline monitoring system 510 apply equally to pipeline monitoring system 610, except as noted in the following description. As with pipeline monitoring system 510, pipeline monitoring system 610 includes a battery and power supply 620 that provides power for the components of the pipeline monitoring system 510. Similarly, a data storage device 628 stores data and algorithms that are executed upon by a controller 626. The sensor housing 614 also can include an optional communication signal interface 622 enable wireless communication of data and commands between the sensor housing 614 and other equipment.

[0040] The sensor housing 614 includes sensors similar to those described previously for collecting data pertaining to the pipe. A pipe response sensor system 632 can include one or more sensors, such as an accelerometer or strain gauge, that collect characteristics of the pipe in response to various phenomena, including loads applied to the pipe and temperature and pressure changes. The current sensor 630 of sensor housing 614 can be one of the previously described acoustic current sensors, propeller current sensors, or electromagnetic current sensors. However, current sensor 630 is different from the current sensor 530 of Figure 5 in that current sensor 630 is attached as an accessory to the outside of sensor housing 614. Attaching the current sensor 630 as an accessory to the sensor housing 614 can facilitate deployment of current sensors on existing pipelinemonitoring systems. In one example embodiment, the current sensor 630 can have its own wireless communication signal interface that can communication data, such as measured current data, with the controller 626 via the communication signal interface 622.

[0041] Referring now to Figure 7, a simplified pipeline monitoring network 700 is illustrated for monitoring loading on an undersea pipe 702 due to marine currents. Example pipeline monitoring systems 710 and 711 are shown installed on the undersea pipe 702. Each of the pipeline monitoring systems 710 and 711 can include the current sensors and the pipe response sensor systems consistent with the descriptions of the previous embodiments. Data gathered by the current sensors and the pipe response sensor systems can be transmitted to network 745 via one of the previously described methods. For example, the gathered data may be transmitted directly from the pipeline monitoring systems 710 and 711 via wireless communication methods to the network 745. Alternatively, a subsea vehicle can travel in proximity to each of the pipeline monitoring systems 710 and 711 where it collects the data from the sensors via wireless communication methods. In yet another example, a subsea vehicle may remove the data storage device or the entire pipeline monitoring system in order to collect the data gathered by the sensors. As further illustrated in Figure 7, the collected sensor data can be stored in a pipeline loading database 750. Pipeline loading database 750 can store current data collected by current sensors and response data collected by pipe response sensor systems.

[0042] The pipeline monitoring network 700 also can include a computing system 770 for analyzing the current data and the response data. As is commonly known for computing systems, computing system 770 includes one or more processors 772, memory 774, and input / output interfaces 776. The storage device 778 can be an integrated component of the computing system 770, as illustrated in Figure 7, or it can be external to the computing system. In addition to an operating system, the storage device can include a pipeline loading service (“PLS”) 780. The PLS 780 can receive data from the pipeline loading database 750 via network 745 and analyze the data to determine what loading has been applied to the pipeline and the accumulated fatigue on the pipeline. The PLS 780 also can generate recommendations for optimizing the maintenance of the pipeline based upon the determined loading and accumulated fatigue. The PLS includes computer executable instructions that perform methods for determining current loading from the collectedmarine current data and for determining intrinsic loading from other types of loads as detected by the response data. The PLS further includes computer executable instructions that perform methods for determining loading on the pipeline from the current loading and the intrinsic loading and for determining accumulated fatigue on the pipeline due to the various load. Lastly, the PLS includes computer executable instructions that perform methods for generating maintenance recommendations for the pipeline.

[0043] The computing components illustrated in Figure 7 are merely illustrative examples and in alternate embodiments certain of the computing components can be combined, simplified, or distributed in a different manner. While the PLS 780 is illustrated in Figure 7 as one or more software modules stored in storage device 778 of computing system 770, the PLS 780 also can be implemented as a service available on remote computing devices, such as the cloud, which service can be accessed to analyze pipeline loading and fatigue data and provide recommendations for managing the operation of the pipeline. Additionally, while the PLS 780 is described herein as an integrated software service, in other embodiments the service can be distributed across multiple services or computing systems. Furthermore, in certain embodiments the PLS 780 can include a machine learning model that is trained using historical measured loading and fatigue data for pipelines to estimate loading and fatigue on the monitored pipe 702. The operation of the PLS 780 will be described in further detail below in connection with the example methods of Figures 8 and 9.

[0044] Referring now to Figures 8 and 9, an example method for implementing the previously described systems is illustrated. Figure 9 illustrates a method 900 for using current loading data to generate recommendations for maintaining a pipeline. As explained further below, Figure 8 illustrates how a portion of the analysis is performed. It should be understood that method 900 is a non-limiting example and in alternate embodiments certain steps of method 400 may be modified, combined, performed in parallel, or omitted.

[0045] Beginning with operation 905 of method 900, a pipeline monitoring system is installed on a section of pipe in a subsea pipeline. The installed pipeline monitoring system can be one of many that are installed along the length of the pipeline. The pipeline monitoring system can be installed using the subsea vehicle 160 or using other equipment. As described previously in connection with Figures 1-4, the pipeline monitoring systemcan be installed on the pipe, in the case of a clamping system, by placing the opposing arms of the clamp on opposite sides of the pipe. A spring can bias the arms to close against the sides of the pipe. The current sensor and the pipe response sensor system can be powered on to collect data relating to the pipe. The sensors can be configured to collect data continuously over a period of time or at designated intervals.

[0046] In operation 910, the current sensor of the pipeline monitoring system can measure current data (also referred to as marine current data) proximate to the pipeline monitoring system. In some embodiments, the marine current data can include both the speed and direction of the current. The marine current data can be collected over a period of time so that it can be averaged to filter out transient currents or anomalous data. The controller of the pipeline monitoring system can store the marine current data in a data storage device onboard the pipeline monitoring system.

[0047] In operation 915, the pipe response sensor systems can measure the pipe’s response to various phenomena, including motion of the pipe and strain in the pipe, and collect such data as response data. The response data should be collected at the same time or during the same intervals that the current data is collected so that the two data sets can be compared. The controller can store the response data in the data storage device onboard the pipeline monitoring system.

[0048] Periodically, the current data and the response data can be transmitted to a database for analysis by a pipe loading service. As described previously in connection with Figures 5, 6, and 7, the current data and the response data can be transmitted to the database by a subsea vehicle, by wireless communication, or by a combination of those methods. In some embodiments, the controller onboard the pipeline monitoring system will perform pre-processing on the current data and the response data before it is transmitted for analysis by the pipe loading service.

[0049] In operation 920, the pipe loading service analyzes the marine current data and the response data to determine whether a correlation exists between the two data sets. Specifically, the pipe loading service can determine whether a motion or strain in the pipe indicated by the response data is attributable to the measured marine current. In one embodiment, this determination can include estimating a marine current load that would be applied to the pipe based upon the speed and / or direction of the current as indicated bythe marine current data. Figure 8 provides a graph of a sample data plot to illustrate the presence or absence of this correlation between the two data sets. The right hand side of the graph illustrates the existence of a correlation between the current speed, as indicated by the measured marine current data, and the response data measured by the pipe response sensor system. In contrast, the left hand side of the graph illustrates a response in the pipe that is not due to the current and, therefore, is attributable to other phenomenon, such as loading from other sources (referred to as intrinsic loading to distinguish from current loading) or changes in temperature or pressure.

[0050] If the pipe loading service determines there is a correlation between the marine current data and the response data, the method can proceed to operation 925. In operation 925, the pipe loading service calculates the marine current loading on the pipe from the measured marine current data. In some instances, some or all of these marine current loading calculations may have already been performed in operation 920 in determining whether there is a correlation between the two data sets. Once the current loading has been calculated, the pipe loading service can store this marine current loading data in the database 750. The pipe loading service also can use the calculated marine current loading to update the total pipe loading on the pipe, which also can be stored in the database 750. The total pipe loading is an accumulation of all the loads applied to the pipe that have been detected by the current sensor and by the pipe response sensor system.

[0051] On the other hand, if the pipe loading service determines there is no correlation between the marine current data and the response data, method 900 proceeds to operation 930. In operation 930, the pipe loading service uses the response data to calculate the intrinsic loading on the pipe. The intrinsic loading is loading on the pipe from sources other than the current such as other equipment, seismic vibrations, or changes in temperature or pressure. Once the intrinsic loading has been calculated, the pipe loading service can store this intrinsic loading data in the database 750. The pipe loading service also can use the calculated intrinsic loading to update the total pipe loading on the pipe, which also can be stored in the database 750. In other words, the calculated intrinsic loading is combined with the current loading to arrive at the total pipe loading.

[0052] In operation 935, the pipe loading service analyzes the total pipe loading to generate a maintenance recommendation for the pipeline. The marine current loading,intrinsic loading, and total pipe loading data in the database 750 can include data collected from multiple pipeline monitoring systems along the length of the pipeline. The pipe loading service can analyze the total pipe loading over a particular interval of time or for the entire time period for which loading data is available for the pipeline. Additionally, the pipe loading service can examine the pipe loading data for particular sections of pipe or for the entire pipeline. Moreover, the pipe loading service can consider the type of loading, either current loading or intrinsic loading, in generating a maintenance recommendation. For example, the presence of current loading applied to a section of pipe for a prolonged period of time may require maintenance on the pipe sooner in contrast to temporary intrinsic loading due to an interval of increased pressure within the pipeline. The types of maintenance recommendations that the pipe loading service outputs can include but are not limited to inspection of the pipeline or a pipe segment; reinforcement of a pipeline or pipe segment, or replacement of a pipeline or pipe segment. The pipeline operator can use the maintenance recommendations output by the pipe loading service to execute maintenance operations. The maintenance recommendations allow the pipeline operator to avoid unnecessary hazardous shutdowns of the pipeline and to make more efficient decisions about when to perform maintenance and what type of maintenance on the pipeline.

[0053] Operation 940 includes an optional step offered by the pipe loading service. Specifically, the pipe loading service can calculate an accumulated fatigue for the pipeline and for individual pipe sections of the pipeline. The pipe loading service can use the marine current loading data and the intrinsic loading data to determine an accumulated fatigue for the pipeline and the individual pipe sections of the pipeline. The accumulated fatigue can take other factors into consideration such as the material with which the pipeline is made and the expected lifecycle of the pipeline material. The pipe loading service can output updated maintenance recommendations based upon the calculated accumulated fatigue on the pipeline.

[0054] The current sensors, accelerometers, strain gauges, and other sensors described herein are commercially available devices. As one example, the sensors can have low power requirements that maximizes the life of the battery in the sensor housing. Similarly, the processor(s) described herein can be commercially available hardwareprocessors such as an integrated circuit, a central processing unit, a multi-core processing chip, an SoC, a multi-chip module including multiple multi-core processing chips, or another hardware processor as known to those of skill in this field. The transmitters and receivers described herein can include signal transfer links that transmit and receive communications via known communication protocols. Lastly, the data storage devices described herein can be persistent storage devices, such as flash memory, that can store software instructions and data.

[0055] For any figure shown and described herein, one or more of the components may be omitted, added, repeated, and / or substituted. Additionally, it should be understood that in certain cases components of the example systems can be combined or can be separated into subcomponents. Accordingly, embodiments shown in a particular figure should not be considered limited to the specific arrangements of components shown in such figure. Further, 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 can be inferred to that component. Conversely, if a component in a figure is labeled but not described, the description for such component can be substantially the same as the description for the corresponding component in another figure.

[0056] With respect to the example methods described herein, it should be understood that in alternate embodiments, certain steps of the methods may be performed in a different order, may be performed in parallel, or may be omitted. Moreover, in alternate embodiments additional steps may be added to the example methods described herein. Accordingly, the example methods provided herein should be viewed as illustrative and not limiting of the disclosure.

[0057] Terms such as “first”, “second”, “top”, “bottom”, “side”, “distal”, “proximal”, and “within” are used merely to distinguish one component (or part of a component or state of a component) from another. Such terms are not meant to denote a preference or a particular orientation, and are not meant to limit the embodiments described herein. In the example embodiments described herein, 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 indetail to avoid unnecessarily complicating the description.

[0058] The terms “a,” “an,” and “the” are intended to include plural alternatives, e.g., at least one. The terms “including”, “with”, and “having”, as used herein, are defined as comprising (i.e., open language), unless specified otherwise.

[0059] When Applicant discloses or claims a range of any type, Applicant's intent is to disclose or claim individually each possible number that such a range could reasonably encompass, including end points of the range as well as any sub-ranges and combinations of sub-ranges encompassed therein, unless otherwise specified. Numerical end points of ranges disclosed herein are approximate, unless excluded by proviso.

[0060] Values, ranges, or features may be expressed herein as “about”, from “about” one particular value, and / or to “about” another particular value. When such values, or ranges are expressed, other embodiments disclosed include the specific value recited, from the one particular value, and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood that there are a number of values disclosed therein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. In another aspect, use of the term “about” means ±20% of the stated value, ±15% of the stated value, ±10% of the stated value, ±5% of the stated value, ±3% of the stated value, or ±1% of the stated value.

[0061] 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 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

CLAIMSWhat is claimed is:

1. A pipeline monitoring system comprising: an attachment device for attaching the pipeline monitoring system to a subsea pipe; a power source that supplies power to the pipeline monitoring system; a pipe response sensor system that measures response data of the subsea pipe; a current sensor that collects marine current data from a region proximate the subsea pipe; a controller that supplies power from the power source to the pipe response sensor system and to the current sensor; and a data storage device that stores the marine current data measured by the current sensor and the response data measured by the pipe response sensor system.

2. The pipeline monitoring system of claim 1, wherein the current sensor is one of an acoustic current sensor, a propeller current sensor, and an electromagnetic current sensor.

3. The pipeline monitoring system of claim 1, wherein the pipe response sensor system comprises at least one of an accelerometer and a strain gauge.

4. The pipeline monitoring system of claim 1, wherein the current sensor and the pipe response sensor system are contained within a sensor housing.

5. The pipeline monitoring system of claim 1, wherein a pipeline loading service compares the marine current data and the response data, determines whether a correlation exists between the marine current data and the response data, and outputs a maintenance recommendation based upon a determination that the correlation exists.

6. The pipeline monitoring system of claim 5, wherein the marine current data and the response data are received by a computing system and the pipeline loading service executes on the computing system.

7. The pipeline monitoring system of claim 6, wherein the computing system receives marine current data and response data from a plurality of pipeline monitoring systems located along the subsea pipe.

8. The pipeline monitoring system of claim 1, further comprising a communication signal interface that transmits the marine current data and the response data to a receiver.

9. The pipeline monitoring system of claim 8, wherein the receiver is located on one of a subsea vehicle or a floating platform.

10. The pipeline monitoring system of claim 1, wherein the data storage device is contained in a subcomponent housing that is removable from the pipeline monitoring system.

11. A method for monitoring a subsea pipe, the method comprising: installing a pipeline monitoring system on the subsea pipe, the pipeline monitoring system comprising a current sensor and a pipe response sensor system; measuring, by the current sensor, marine current data from a region proximate the subsea pipe; measuring, by the pipe response sensor system, response data of the subsea pipe; determining, by a pipeline loading service executing on a computing device, whether a correlation exists between the marine current data and the response data; if the correlation exists, calculate, by the pipeline loading service, a current loading attributable to the marine current data and updating a pipeline loading with the current loading; andif the correlation does not exist, calculate, by the pipeline loading service, an intrinsic loading attributable to the response data and updating a pipeline loading with the intrinsic loading.

12. The method of claim 11, further comprising: outputting, by the pipeline loading service, a maintenance recommendation based upon the updating of the pipeline loading.

13. The method of claim 12, further comprising: determining, by the pipeline loading service, an accumulated fatigue of the subsea pipe based upon the updating of the pipeline loading; and outputting, by the pipeline loading service, an updated maintenance recommendation based upon the accumulated fatigue of the subsea pipe.

14. The method of claim 11, further comprising transmitting, by a communications signal interface of the pipeline monitoring system, the marine current data and the response data to a receiver.

15. The method of claim 14, wherein the receiver is located on one of a subsea vehicle or a floating platform.

16. The method of claim 11, further comprising: storing the marine current data and the response data in a data storage device of the pipeline monitoring system.

17. The method of claim 16, further comprising removing the data storage device from the pipeline monitoring system with a subsea vehicle.

18. The method of claim 11, wherein the current sensor is one of an acoustic current sensor, a propeller current sensor, and an electromagnetic current sensor.

19. The method of claim 1, wherein the pipe response sensor system comprises at least one of an accelerometer and a strain gauge.

20. The method of claim 1, wherein the current sensor and the pipe response sensor system are contained within a sensor housing of the pipeline monitoring system.

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