Marine riser management system including subsea acoustic monitoring platform and an associated method

A system and method for monitoring a condition of a marine riser including at least one subsea sensing and acoustic platform mechanically coupled to a riser joint of the marine riser. The at least one platform includes one or more sensors mechanically coupled to the riser joint and including plug-and-play sensor interface technology. The platform further includes a microprocessor configured to receive and analyze sensor data from the one or more sensors and provide pre-processed data representative of a determination of a condition of the riser joint. A memory module is provided including one or more software modules executable by the microprocessor and configured to provide data storage. The platform further includes an acoustic modem configured to receive the pre-processed data, communicate the condition to a topside acoustic transceiver in real-time and provide remote command configuration in response to the condition. An included power module provides power to the platform components.

BACKGROUND

The subject matter disclosed herein generally relates to a marine riser management system. More specifically, the subject matter relates to a platform based system coupled to a marine riser and a method for analyzing sensor data received from sensors disposed on the platform and transmitting the sensor data via acoustic telemetry to an on-vessel monitor.

Marine risers are components used in offshore drilling of hydrocarbons and production operations conducted from a vessel on the ocean surface. Marine risers are vertical structures that extend miles in length connecting the vessel and a well head on the ocean floor. The marine riser needs to be successfully deployed into the ocean and maintained over their lifespan (e.g., 20 years) in challenging environments while meeting safety and regulatory requirements.

Existing riser management systems include sensors that are coupled to a marine riser. Such systems have numerous operational challenges due to limitations in the retrieval of sensor data by monitors deployed on the vessel. For example, the monitor receives sensor data from loggers coupled to the sensors. Such systems are disadvantageous as the loggers include large amounts of non-readily interpreted sensor data. Moreover, the retrieval of sensor data from the loggers typically occurs post-process, i.e., after the drilling or production operation is complete. In another example, the monitor receives sensor data via data transmission systems (e.g., acoustic data transmission) that are coupled to the sensors. Such systems are disadvantageous as the sensor data received by the monitor is semi real-time (e.g., once a day, once in 12 hours, and the like) due to low transmission rates and high power constraints of the data transmission system. In another example, a remotely operated vehicles (ROVs) may be used to retrieve data with short range acoustic telemetry.

Thus, there is a need for an enhanced marine riser management system.

BRIEF DESCRIPTION

In accordance with one aspect of the present technique, a system includes at least one subsea sensing and acoustic platform mechanically coupled to a first riser joint of a marine riser. The at least one subsea sensing and acoustic platform including, one or more sensors mechanically coupled to the first riser joint, a microprocessor, a memory module, an acoustic modem and a power module. The one or more sensors include plug-and-play sensor interface technology. The microprocessor is configured to receive and analyze sensor data from the one or more sensors and provide pre-processed data representative of a determination of a condition of the first riser joint and whether the condition satisfies transmission criterion. The memory module includes one or more software modules executable by the microprocessor and configured to provide data storage. The acoustic modem is configured to receive the pre-processed data, communicate the condition to a topside acoustic transceiver in real-time, and at least one of send and receive one or more remote command configurations in response to the condition. The power module is configured to provide power to the one or more sensors, the microprocessor, the memory module and the acoustic modem.

In accordance with one aspect of the present technique, a marine riser management system is provided. The marine riser management system includes at least one subsea sensing and acoustic platform coupled to a riser joint of a marine riser. The at least one subsea sensing and acoustic platform including one or more sensors mechanically coupled to the riser joint, a microprocessor, a memory module, an acoustic modem and a power module. The marine riser management system further including a topside acoustic transceiver and an on-vessel monitor. The one or more sensors include plug-and-play sensor interface technology. The microprocessor is configured to receive and analyze sensor data from the one or more sensors and provide pre-processed data representative of a determination of a condition of the riser joint and whether the condition satisfies transmission criterion. The microprocessor comprises a software platform/operating system (OS) configured to provide interfacing with one or more components of the system. The memory module includes one or more software modules executable by the microprocessor and including data storage. The acoustic modem is configured to receive the pre-processed data, communicate the condition in real-time and at least one of send and receive one or more remote command configurations in response to the condition. The power module is configured to provide power to the one or more sensors, the microprocessor, the memory module and the acoustic modem. The topside acoustic transceiver is configured to receive the communicated condition from the acoustic modem and transmit the remote command configurations to the at least one subsea sensing and acoustic platform. The on-vessel monitor is configured to process the communicated condition and generate the remote command configurations.

In accordance with one aspect of the present technique, a method is disclosed. The method including receiving sensor data from one or more sensors disposed on a subsea sensing and acoustic platform mechanically coupled to a riser joint of a marine riser, analyzing the sensor data to determine a condition of the riser joint, determining whether the condition satisfies a transmission criterion, sending a notification including the condition via an acoustic modem disposed on the subsea sensing and acoustic platform to a topside acoustic transceiver in real-time in response to determining that the condition satisfies the transmission criterion and at least one of sending one or more remote command configurations via the acoustic modem to at least one of a power module, a sensor interface, a memory module and a microprocessor disposed on the subsea sensing and acoustic platform and receiving one or more remote command configurations via the topside acoustic transceiver in response to the condition.

DETAILED DESCRIPTION

As used herein, the terms “software” and “firmware” are interchangeable, and may include any computer program stored in memory for execution by devices that include, without limitation, mobile devices, clusters, personal computers, workstations, clients, and servers.

As used herein, the term “computer” and related terms, e.g., “computing device”, are not limited to integrated circuits referred to in the art as a computer, but broadly refers to at least one microcontroller, microcomputer, programmable logic controller (PLC), application specific integrated circuit, and other programmable circuits, and these terms are used interchangeably herein.

A system and method for transmitting sensor data of a marine riser is described herein. More particularly, a platform based system that is capable of collecting data from sensors installed on subsea structures, processing the sensor data on demand, and communicating (two-way) with top side transceiver in real time (for data transmission, control command, etc.) via acoustic telemetry is described.FIG. 1illustrates a block diagram of a riser management system100according to one embodiment. In the illustrated embodiment, the riser management system100includes a vessel110, a marine riser120, and a well head140. The vessel110may be any type of ship or platform floating on the ocean surface configured to perform and/or monitor offshore drilling of hydrocarbons and production operations. In the illustrated embodiment, the vessel110further includes an on-vessel monitor112configured to receive a condition and/or sensor data of the marine riser120via an acoustic transceiver114. The on-vessel monitor112may include a processor, a memory, and a display device for further processing and displaying the condition and/or sensor data to, for example, a drilling contractor, an administrator of the riser management system100, and the like. In one embodiment, the on-vessel monitor112may be further configured to send the condition and/or sensor data to an on-shore monitor (not shown) for further analytics of, for example, an oil leak situation, a riser replacement requirement, riser string motion due to inadequate tension on drilling rig tensioner system or strong loop currents, lack of riser motion, and the like. The subsea sensing and acoustic platform and integrated components, the sensor data and the condition are described below in further detail with reference toFIG. 2.

As illustrated inFIG. 1, the marine riser120may be a vertical structure that acts as a sealed pathway between the vessel110and the well head140on the ocean surface. In one embodiment, the marine riser120may be a drilling riser that is used for, for example, pumping down lubricants, extracting drilling mud and drill cuttings, and the like, during drilling operations. In another embodiment, the marine riser120may be a production riser that is used for, for example, extracting hydrocarbons from the ocean floor. In the illustrated embodiment, the marine riser120includes a plurality of riser joints122,124and126that are connected to each other by, for example, bolted flanges. Each riser joint122,124and126is mechanically coupled to a subsea sensing and acoustic platform130,132and134for sending a condition and/or sensor data of the riser joint122,124and126, and thus a condition of the marine riser120, to the on-vessel monitor112.

FIG. 2illustrates the subsea sensing and acoustic platform132mechanically coupled to the riser joint126according to the embodiment ofFIG. 1. The subsea sensing and acoustic platform132includes one or more sensors150, a sensor interface152, a microprocessor156, a memory module156, an acoustic modem159and an acoustic transducer160for communication and networking, and a power module162, such as a battery. In an embodiment, the one or more sensors150may be communicatively coupled to each other via a network, such as a wired or wireless communication type, and may have any number of configurations such as a star configuration, token ring configuration, or other known configurations. Furthermore, the network may include a local area network (LAN), a wide area network (WAN) (e.g., the Internet), a peer-to-peer network, and/or any other interconnected data path across which multiple devices may communicate. The sensor interface152enables raw sensor data to be collected from the one or more sensors150and processed by the microprocessor154. In an embodiment, the sensor interface152may include IO's, UART, Ethernet, USB, or the like. In an embodiment, the sensor interface152is a standard plug-and-play interface module and includes both the necessary hardware that allows easy sensor connection and the software layer that handles the sensor data acquisition, conversion (e.g., data range, unit, etc.) based on the connected one or more sensors150and types of sensors.

During operation, processed data may be stored via the memory module156and/or transmitted wirelessly via the acoustic modem158and the acoustic transducer160to the topside acoustic transceiver, and more particularly the acoustic transceiver114(FIG. 1) in real-time or near real-time. The acoustic modem158may implement advanced data delivery algorithms and support addressing and networking to provide acoustic telemetry. In addition, the acoustic modem158is easy to control with a comprehensive set of commands and software-configurable settings.

The one or more sensors150may include any type of sensors that are configured to measure one or more physical parameters of the riser joint126. In one embodiment, the one or more sensors150include one or more strain gauges configured to measure the strain of the riser joint126. In another embodiment, the one or more sensors150include an angular rate sensor, such as a motion sensor configured to measure, for example, displacement, velocity, acceleration, and the like, of the riser joint126, described presently. In yet another embodiment, the one or more sensors150include a curvature sensor or inclinometer configured to measure a roll and pitch angle of the riser joint126. The one or more sensors150is further configured to send the sensor data (i.e., strain data, displacement data, pitch angle data, and the like) to the microprocessor154via the sensor interface152. Although in the illustrated embodiment, a plurality of sensors150are shown, in other embodiments, a single sensor may be included in the subsea sensing and acoustic platform132and coupled to the riser joint126.

As previously indicated, the sensor interface152may be any device that is configured to collect raw sensor data for subsequent processing by the microprocessor154. The microprocessor154is configured to provide sensor data signal pre-processing. In an embodiment, the microprocessor154calculates basic statistics from raw sensor data received via the sensor interface152. Logic in the microprocessor154may be configured to detect normal versus abnormal behavior of the riser string120or detect unusual change in motion of riser string120. In an embodiment, the microprocessor154is configured with an open architecture operating system (OS), thereby allowing customized software application development for various sensor types, signal processing, local analytics, etc. The software platform/OS provides basic and standard application interface for interfacing with other component/functions of the subsea sensing and acoustic platform132, e.g. acoustic modem158, sensor interface152, etc. In addition, users can develop customized software applications in the OS. In an embodiment, remote command configuration of the microprocessor154from the topside, i.e. on-vessel monitor112, is provided. More particularly, remote command configuration of the power model, acoustic data rate, sensor type, etc. via an acoustic link, and more particularly, via the acoustic modem158, are provided.

Subsequent to pre-processing of the sensor data and calculation of basic statistics by the microprocessor154, the acoustic modem158and the acoustic transducer160transmit the sensor data and/or a condition of the riser joint126to the on-vessel monitor112via the top-side transceiver114. In an embodiment, the microprocessor154, the memory module156, the acoustic modem158and the acoustic transducer160may be coupled to a bus (not shown) for communication with additional subsea sensing and acoustic platforms, such as the subsea sensing and acoustic platforms130and134. Although in the illustrated embodiment, the subsea sensing and acoustic platform132is shown coupled to the riser joint126, in other embodiments, a plurality of subsea sensing and acoustic platforms may be coupled to each riser joint, such as the riser joints122,124and126.

The microprocessor154may include at least one arithmetic logic unit, general purpose controller or other processor arrays to perform computations, and/or retrieve data stored on the memory module156. In another embodiment, the microprocessor154is a multiple core processor. The microprocessor154processes data signals and may include various computing architectures including a complex instruction set computer (CISC) architecture, a reduced instruction set computer (RISC) architecture, or an architecture implementing a combination of instruction sets. The processing capability of the microprocessor154in one embodiment may be limited to supporting the retrieval of data and transmission of data. The processing capability of the microprocessor154in another embodiment may also perform more complex tasks, including various types of feature extraction, modulating, encoding, multiplexing, and the like. In other embodiments, other type of processors, operating systems, and physical configurations are also envisioned.

The memory module156may be a non-transitory storage medium configured as an onboard module or plug in memory module, e.g. micro SD card. For example, the memory module156may be a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device, flash memory or other memory devices. In one embodiment, the memory module156also includes a non-volatile memory or similar permanent storage device, and media such as a hard disk drive, a floppy disk drive, a compact disc read only memory (CD-ROM) device, a digital versatile disc read only memory (DVD-ROM) device, a digital versatile disc random access memory (DVD-RAM) device, a digital versatile disc rewritable (DVD-RW) device, a flash memory device, or other non-volatile storage devices.

The memory module156stores data that is required for the pre-processing and computing of basic statistics from the raw sensor data received via the sensor interface152. In one embodiment, the memory module156stores one or more software modules157(e.g., an analysis module, a communication module, a decisioning module, a notification module, and the like) that are executed under the control of the microprocessor154. In another embodiment, the memory module156stores transmission criteria (e.g., a stress threshold value, a criterion mode shape, a fatigue threshold value, and the like) that are defined by, for example, a drilling operator, an administrator of the subsea sensing and acoustic platform132or the riser management system100. The transmission criteria are described below in further detail with reference to the acoustic modem158.

The acoustic modem158and the acoustic transducer160include any device configured to receive any sensor data from the one or more sensors150, via the sensor interface152and the microprocessor154, and send the sensor data and/or condition of the riser joint126to the on-vessel monitor112via acoustic transmission. The acoustic modem158includes transmission criteria in the form of codes and routines configured to handle communications between the one or more sensors150and the on-vessel monitor112. In one embodiment, the acoustic modem158includes a set of instructions executable by the microprocessor154to provide the functionality for handling communications between the one or more sensors150and the on-vessel monitor112. In another embodiment, the set of instructions is stored in the memory module156and is accessible and executable by the microprocessor154. In either embodiment, the acoustic modem158is adapted for communication and cooperation with the microprocessor154, the acoustic transducer160, the acoustic transceiver114and the on-vessel monitor112.

In one embodiment, the acoustic modem158receives sensor data from the one or more sensors150via the microprocessor154. For example, the acoustic modem158receives the sensor data in real-time or near real-time at a data sampling rate of at least 10 hertz. In another example, the acoustic modem158receives the sensor data in response to sending a request for sensor data to the one or more sensors150. As previously indicated, the sensor data received from the one or more sensors150may include, for example, strain data, displacement data, velocity data, acceleration data, roll angle data and pitch angle data of the riser joint126. In another example, the acoustic modem158further receives sensor data associated with one or more neighboring riser joints122and124of the marine riser120. In such an embodiment, the sensor interface152sends the received sensor data to the microprocessor154and the acoustic modem158. The acoustic modem158may also perform analog to digital conversion, noise filtering, and the like, prior to sending the sensor data to the acoustic transceiver114. In another embodiment, the acoustic modem158receives a notification including, for example, a condition of the riser joint126from the microprocessor154. In such an embodiment, the acoustic modem158sends the notification to the on-vessel monitor via the acoustic transceiver114.

Referring now toFIGS. 3 and 4, illustrated are embodiments of a marine riser management system, generally similar to system100ofFIGS. 1 and 2, including a plurality of subsea sensing and acoustic platforms as disclosed herein. Referring more specifically toFIG. 3, illustrated is an embodiment of a marine riser management system200for use in determining the status of a tensioner system of a drilling rig202. Due to manual error or miscalculation, drilling rig tensioner systems often may not put adequate tension on a deployed riser string, such as deployed riser string204inFIG. 3, extending from the drilling rig202to a well head206. This lack of adequate tensioning on the riser string204often causes the riser string204to bend, as illustrated at208, in response to ocean currents210. The marine riser management system200includes a plurality of subsea sensing and acoustic platforms212each located at a riser joint214. As previously described, each subsea sensing and acoustic platforms212includes one or more sensors, previously described with regard toFIGS. 1 and 2. In this particular embodiment, each of the subsea sensing and acoustic platforms212includes one or more motion sensors to detect motion of riser string204over a set time interval. Sensor data, such as displacement data, velocity data and/or acceleration data, obtained by the one or more motion sensors in each of the plurality of subsea sensing and acoustic platforms212is calculated by a microprocessor, generally similar to the microprocessor154previously described with regard toFIGS. 1 and 2, and contained therein each of the plurality of subsea sensing and acoustic platforms212. More particularly, the microprocessor is configured to calculate basic statistics from raw sensor data. In an embodiment, the microprocessor calculates bending and/or motion of the riser joint314based on the displacement data, velocity data and acceleration data. Logic in the microprocessor detects unusual change in motion of riser string204. An acoustic modem in each of the plurality of subsea sensing and acoustic platforms212, generally similar to the acoustic modem158previously described with regard toFIGS. 1 and 2, transmits the preprocessed sensor data to a topside acoustic transceiver216in real time, alerting crew to take action from high stress (calculated from additional topside vibration analysis) e.g. place additional tension on the riser string204.

Referring more specifically toFIG. 4, illustrated is another embodiment of a marine riser management system300for use in addressing strong loop currents impacting a drilling rig302. In the presence of strong loop currents311, drilling rig tensioner systems often do not put adequate tension on a deployed riser string, such as deployed riser string304inFIG. 4, extending from the drilling rig302to a well head306. This lack of adequate tensioning on the riser string304often causes the riser string304to drift, as illustrated in a top view at308, in response to ocean currents310that create the loop currents311. The marine riser management system300includes one or more subsea sensing and acoustic platforms312each located at a riser joint314. As previously described, each subsea sensing and acoustic platforms312includes one or more sensors. In this particular embodiment, each of the subsea sensing and acoustic platforms312includes one or more motion sensors to detect motion of riser string304over a set time interval. Sensor data, such as displacement data, velocity data and/or acceleration data, obtained by the one or more motion sensors in each of the plurality of subsea sensing and acoustic platforms312is calculated by a microprocessor, generally similar to the microprocessor154previously described with regard toFIGS. 1 and 2, and contained therein each of the plurality of subsea sensing and acoustic platforms312. More particularly, the microprocessor is configured to calculate basic statistics from raw sensor data. In an embodiment, the microprocessor calculates movement of the riser joint314in response to the strong loop currents311based on the displacement data, velocity data and acceleration data. Logic in the microprocessor detects unusual change in movement of riser string304. An acoustic modem in each of the plurality of subsea sensing and acoustic platforms312, generally similar to the acoustic modem158previously described with regard toFIGS. 1 and 2, transmits the preprocessed sensor data to a topside acoustic transceiver316in real time, alerting crew to take action from high stress (calculated from additional topside vibration analysis) e.g. place additional tension on the riser string304in light of the strong loop currents311. In the event of an extreme event in response to strong loop currents311, the programmed inspection interval of the riser joints214may be shortened via the platform based acoustic modem158.

In yet another alternate embodiment, where no extreme events (hurricane), strong currents or operator error occurs while exploring field (and drilling wells) over an extended period of time, the motion sensors on a subsea sensing and acoustic platform as disclosed herein may detect motion of riser string over an extended set time interval. A microprocessor included in the subsea sensing and acoustic platform is configured to calculate basic statistics from raw sensor data. Logic in the microprocessor detects normal behavior in motion of the riser string. An acoustic modem transmits preprocessed sensor data to topside acoustic transceiver in real time, alerting crew that no action is needed (calculated from additional topside vibration analysis). In the event of normal behavior, an opportunity to lengthen inspection interval for specific riser joints may be initiated due to extended life prediction.

As previously indicated, each of the one or more subsea sensing and acoustic platforms is based on a modular approach, integrating sensors, such as motion sensors (accelerometer, gyroscope, etc.), a plug-and-play interface for sensor data acquisition, processing, wireless acoustic communication, data storage, power module, and the like. Acoustic telemetry provides real-time or near real-time condition monitoring and alerts. In addition, plug-and-play technology may be implemented with respect to any of the platform based components to minimize and/or eliminate any requirement of auxiliary cabling with minimal impact on existing operations. The open architecture operating system (OS) of the microprocessor allows for customized software application development for sensor types, signal processing, local analytics, etc.

As described, in an embodiment, the memory module156stores one or more software modules157(e.g., an analysis module, a communication module, a decision module, a notification module, and the like) that are executed under the control of the microprocessor154. As best illustrated inFIG. 4, in an embodiment, the subsea sensing and acoustic platform132, and more particularly the memory154includes the one or more software modules157, and more particularly, may include an analysis module350, a communication module352, a decision module354and a notification module356.

In a specific embodiment of the subsea sensing and acoustic platform132, the software modules157may include the analysis module352, including codes and routines configured to determine a condition of the riser joint126based on the received sensor data. The analysis module350includes a set of instructions executable by the microprocessor154to provide the functionality for determining a condition of the riser joint126. The analysis module350is stored in the memory module156and is accessible by the microprocessor154. The analysis module350is adapted for communication and cooperation with the microprocessor154and other modules of the software modules157.

The analysis module350analyzes the sensor data received from the one or more sensors150to determine a condition of the riser joint126. In one embodiment, the analysis module350is further configured to remove noise from the received sensor data prior to determining a condition of the riser joint126. As previously described with regard toFIGS. 3 and 4, in an embodiment, the analysis module350may be configured to analyze the sensor data to determine motion or displacement of the riser string in response to ocean currents. In another embodiment, the analysis module350may be configured to analyze the sensor data to determine a stress level as a condition of the riser joint132. For example, the analysis module350calculates the stress level of the riser joint126based on the strain data received from the communication module352. In another example, the analysis module350calculates the stress level of the riser joint126based on the strain data, the curvature (i.e., the roll and the pitch angle) of the riser joint126. In a further example, the analysis module350calculates the stress level of the riser joint126based on a stress amplification factor. In such an embodiment, the analysis module350retrieves the stress amplification factor from the memory module156. The stress amplification factor is dependent on the position/depth of the riser joint126in the ocean and is defined by, for example, an administrator of the riser management system.

In another embodiment, the analysis module350may be configured to analyze the sensor data to determine a vibrational characteristic as the condition of the riser joint126. The analysis module350determines the vibrational characteristic based on at least one of the displacement, the velocity, the acceleration, and the strain data of the riser joint126. The vibrational characteristic of the riser joint126includes, for example, a vibrational frequency, a vibrational mode shape, and the like. For example, the analysis module350determines the vibrational frequency and the vibrational mode shape of the riser joint126based on the strain data, using finite element analysis.

In yet another embodiment, the analysis module350may be configured to analyze the sensor data to determine a fatigue level as the condition of the riser joint126. The analysis module350calculates the fatigue level of the riser joint126based on at least one of the strain data, the stress level, and the vibrational characteristic of the riser joint132. In yet another embodiment, the analysis module350receives additional sensor data from one or more sensors150disposed within one or more subsea sensing and acoustic platforms130and134(FIG. 1) coupled to one or more neighboring riser joints122,124, respectively. In such an embodiment, the analysis module130analyzes the additional sensor data and the sensor data received from the one or more sensors150of the subsea sensing and acoustic platform132to determine a condition of the riser joint126. For example, the analysis module350calculates the strain level of the riser joint126based on the strain data received from the one or more sensors150and the strain data received from the one or more sensors150coupled to the riser joints122,124. In the above described embodiments, the analysis module350is further configured to send the condition and the sensor data used to determine the condition, to the decision module354.

The decision module354includes codes and routines configured to determine whether a condition of the riser joint126satisfies a transmission criterion. In one embodiment, the decision module354includes a set of instructions executable by the microprocessor154to provide the functionality for determining whether the condition of the riser joint126satisfies the transmission criterion. In another embodiment, the decision module354is stored in the memory module156and is accessible and executable by the microprocessor154. In either embodiment, the decision module354is adapted for communication and cooperation with the microprocessor154and other modules of the software modules157.

The decision module354receives the condition of the riser joint126and determines whether the received condition satisfies the transmission criterion. The decision module354retrieves the transmission criterion from the memory module156. The transmission criterion is defined by, for example, a drilling contractor, an administrator of the riser management system100, and the like. If the decision module354determines that the condition satisfies the transmission criterion, the decision module354sends a message to the notification module356for sending a notification to the on-vessel monitor112(FIG. 1) via the acoustic modem158. The message includes the condition and the sensor data used by the analysis module354to determine the condition.

In one embodiment, the decision module354receives the displacement data of the riser joint126and determines whether the received displacement exceeds a threshold value (i.e., the transmission criterion). For example, the decision module354receives the displacement amount of the riser joint126relative to a home position. In such an example, the decision module354determines that the received displacement amount exceeds a threshold value and sends a message to the notification module356.

In another embodiment, the decision module354receives a vibrational characteristic of the riser joint126and determines whether the vibrational characteristic satisfies a transmission criterion. For example, the decision module354receives the vibrational frequency as 0.5 hertz. In such an example, the decision module354determines that the received vibrational frequency is within a frequency threshold range of 0.2 hertz-1.5 hertz and sends a message to the notification module356. In another example, the decision module354receives the vibrational mode shape of the riser joint126. In such an example, if the received vibrational mode shape does not match the criterion mode shape, the decision module354does not send a message to the notification module356.

In yet another embodiment, the decision module354receives the fatigue level of the riser joint126and determines whether the received fatigue level satisfies a transmission criterion. For example, the decision module354receives a fatigue level of the riser joint126as 80%. In such an example, the decision module354determines that the received fatigue level exceeds a fatigue threshold value of 50% and sends a message to the notification module356.

The notification module356includes codes and routines configured to send a notification to the on-vessel monitor112. In one embodiment, the notification module356includes a set of instructions executable by the microprocessor154to provide the functionality for sending the notification to the on-vessel monitor112. In another embodiment, the notification module356is stored in the memory module156and is accessible and executable by the microprocessor154In either embodiment, the notification module356is adapted for communication and cooperation with the microprocessor154and other modules of the software modules157.

The notification module356receives a message from the decision module354and sends a notification to the on-vessel monitor112via the acoustic modem158and the acoustic transducer160. In one embodiment, the notification includes the condition (e.g., displacement from a home position, and the like) of the riser joint126that satisfies the transmission criterion. In another embodiment, the notification includes the condition of the sensor data and the sensor data used by the analysis module350to determine the condition. In yet another embodiment, the notification includes an instruction based on the condition of the riser joint126. For example, if the decision module354determines that the displacement of the riser joint126exceeds the threshold value (i.e., transmission criteria), the notification module356sends a notification including the displacement amount of the riser joint126, the sensor data, and an instruction to the on-vessel monitor112. In such an example, the instruction instructs the on-vessel monitor112to adjust the tension of the marine riser120in light of present ocean currents, as previously described with regard toFIGS. 3 and 4.

In yet another embodiment, the notification module356generates data for providing a user interface including the condition of the riser joint126to, for example, a drilling contractor. In such an embodiment, the notification module356(FIG. 5) sends the notification to a display device included in the on-vessel monitor112. The display device renders the data and graphically displays actionable information to the user interface.

FIG. 6illustrates a flow diagram400of a method for transmitting sensor data of a riser joint according to one embodiment. The communication module receives sensor data from one or more sensors disposed on a subsea sensing and acoustic platform coupled to a first riser joint of a marine riser402. For example, the communication module352(FIG. 5) receives displacement data of the riser joint126(FIG. 1) from the one or more sensors in real-time at a data sampling rate of at least 10 hertz. In an embodiment, the communication module may also receive additional data from one or more sensors coupled to a second riser joint of the marine riser. For example, the communication module352(FIG. 5) receives displacement data of the riser joint122(FIG. 1) in real-time.

The analysis module analyzes at least one of the sensor data and the additional data to determine a condition of the riser joint404. In the above example, the analysis module350(FIG. 5) calculates a degree of displacement of the riser joint126(FIG. 1) in real-time based on the received sensor data and the additional data. The decision module determines whether the condition of the riser joint satisfies a transmission criterion406. In the above example, the decision module354(FIG. 5) determines whether the calculated amount of displacement of the riser joint126(FIG. 1) exceeds a threshold stress value. The notification module sends a notification, via the acoustic modem158(FIG. 5), including the condition to an on-vessel monitor communicatively coupled to the marine riser in response to determining that the condition satisfies the transmission criterion408. In the above example, the notification module356(FIG. 5) sends a notification to the on-vessel monitor112(FIG. 1) as the decision module354determines that the calculated displacement of the riser joint126(FIG. 1) exceeds the threshold criterion.

In response to the received condition, remote command/configuration modifications may be acoustically transmitted to components of the subsea sensing and acoustic platform410and/or the topside acoustic transceiver114(FIG. 1).

Drilling risers are a critical infrastructure component in offshore drilling and production operations. These vertical structures extend miles in length and must be successfully deployed and maintained over their 20+ year lifespan in increasingly challenging environments while meeting safety and regulatory needs. Accordingly, disclosed herein is a sophisticated and effective tool to manage such drilling risers. Such tool can be used to better understand riser health and structural integrity in order to avoid potential events, and reduce unscheduled down time, particularly in hostile, inaccessible and remote locations.

The above described riser management system is advantageous compared to conventional riser management systems, as the sensor data is analyzed in real-time for determining a condition of each riser joint of a marine riser. Additionally, instead of sending large amounts of non-interpreted sensor data to the on-vessel monitor, transmitting the condition that satisfies a transmission criterion and the sensor data used to determine the condition, is advantageous due to the low data transmission rates and high power consumption of the existing data transmission systems. Furthermore, the riser management system disclosed herein includes one or more plug-and-play components and includes an open architecture operating system (OS) and is thus easily customizable with no requirement of auxiliary cabling. Such risk management systems can be used to better understand riser health and structural integrity in order to avoid potential events, and reduce unscheduled down time, particularly in hostile, inaccessible and remote locations

It is to be understood that not necessarily all such objects or advantages described above may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the systems and techniques described herein may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

While the subject matter has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the inventions are not limited to such disclosed embodiments. Rather, the subject matter can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the inventions. Additionally, while various embodiments of the subject matter have been described, it is to be understood that aspects of the inventions may include only some of the described embodiments. Accordingly, the inventions are not to be seen as limited by the foregoing description, but are only limited by the scope of the appended claims.