System and method for assessing performance and / or life of subsea conduits

Abstract

A system includes: a conduit configured to extend from a surface location to a subsea location; an end termination located at an upper end of the conduit; a support assembly positioned at the surface location and configured to support the end termination such that a load transfer interface of the end termination with the support assembly transfers loads from the conduit to the support assembly; at least two load cells disposed within a load path of the support assembly; and a communication system coupled to the load cells and configured to communicate signals based on measurements from the load cells to a location away from the end termination and / or to a local receiver.

Description

SYSTEM AND METHOD FOR ASSESSING PERFORMANCE AND / OR LIFE OFSUBSEA CONDUITSFIELD OF THE INVENTION

[0001] The present disclosure is directed generally to subsea conduits such as risers, pipes, control umbilicals, and power umbilicals and, more particularly, to measurement techniques for assessment of performance and / or life of such subsea conduits.BACKGROUND

[0002] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and / or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

[0003] Various conduits are used in subsea environments to provide transmission of fluids, power, and communications between surface locations and subsea locations. Such conduits can include flexible risers, power cables / umbilicals, control umbilicals, and / or flexible pipes used, for example, in offshore oil and gas operations. Performance assessment of conduits such as these depends on the measurement of tensile stresses on each element within the crosssection of the conduit. Since it is impractical and nearly impossible to directly measure these stresses, suppliers and engineering contractors have developed numerical models that rely heavily on assumptions for offshore loads. Since there are many uncertainties regarding environmental loading, the common practice is to make conservative assumptions, which can significantly overestimate the stress loads, leading to reduced calculations of fatigue life. This leads to overly conservative system design and higher costs. These over-design challenges are exacerbated by larger water depths as the conduits get heavier, imposing higher loads and more complex designs. It is now recognized that a need exists for a low cost system and method for assessing performance and / or life of conduits based on actual sensor measurements.

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

[0005] In accordance with aspects of the disclosure, a system includes: a conduit configured to extend from a surface location to a subsea location; an end termination located at an upper end of the conduit; a support assembly positioned at the surface location and configured to support the end termination such that a load transfer interface of the end termination with the support assembly transfers loads from the conduit to the support assembly; at least two load cells disposed within a load path of the support assembly; and a communication system coupled to the load cells and configured to communicate signals from the load cells to a location away from the end termination and / or to a local receiver.

[0006] In accordance with aspects of the disclosure, a method includes: supporting an end termination located at an upper end of a conduit from a support assembly, the conduit extending from a surface location to a subsea location; transferring loads from the conduit to the support assembly via a load transfer interface of the end termination with the support assembly; measuring loads on the conduit via at least two load cells disposed within a load path of the support assembly; and communicating signals indicative of measurements taken by the at least two load cells to a location away from the end termination via a communication system.

[0007] In accordance with aspects of the disclosure, a method for retrofitting a system including a conduit extending from a surface location to a subsea location, an end termination located at an upper end of the conduit, and a support assembly supporting the end termination such that loads on the conduit are transferred to the support assembly, includes: positioning at least two load cells within a load path of the support assembly; and coupling a communication system to the load cells, the communication system being configured to communicate signals from the load cells to a location away from the end termination.BRIEF DESCRIPTION OF DRAWINGS

[0008] The drawings illustrate only example embodiments and are therefore not to be considered limiting in scope, as the example embodiments may admit to other equally effective embodiments. The elements and features shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the exampleembodiments. Additionally, certain dimensions or positions may be exaggerated to help visually convey such principles. In the drawings, reference numerals designate like or corresponding, but not necessarily identical, elements.

[0009] FIG. l is a schematic illustration of a flexible conduit extending from a surface location to a subsea location, in accordance with an embodiment of the present disclosure.

[0010] FIGS. 2 A and 2B are a partial cutaway view and an above view, respectively, of an end termination of a flexible conduit supported by a split flange, in accordance with an embodiment of the present disclosure.

[0011] FIG. 3 is a partial cross-sectional view of a system including an end termination supported by a support structure having at least two load cells, in accordance with an embodiment of the present disclosure.

[0012] FIGS. 4A-4F are schematic top views of arrangements of load cells disposed on a split flange, in accordance with an embodiment of the present disclosure.

[0013] FIG. 5 is a partial cross-sectional view of another system including an end termination supported by a support structure having at least two load cells, in accordance with an embodiment of the present disclosure.

[0014] FIG. 6 is a partial cross-sectional view of another system including an end termination supported by a support structure having at least two load cells, in accordance with an embodiment of the present disclosure.

[0015] FIGS. 7A-7F are schematic top views of arrangements of load cells disposed on a flange joint, in accordance with an embodiment of the present disclosure.

[0016] FIG. 8 is a partial cross-sectional view of another system including an end termination supported by a support structure having at least two load cells, in accordance with an embodiment of the present disclosure.

[0017] FIG. 9 is a partial cross-sectional view of another system including an end termination supported by a support structure having at least two load cells, in accordance with an embodiment of the present disclosure.

[0018] FIGS 10A-10D are schematic diagrams illustrating systems for powering load cells on a support structure, in accordance with an embodiment of the present disclosure.

[0019] FIGS. 11 A and 1 IB are schematic block diagrams illustrating communication systems, in accordance with an embodiment of the present disclosure.

[0020] FIG. 12 is a process flow diagram illustrating a method for assessing performance and / or life of a flexible subsea conduit, in accordance with an embodiment of the present disclosure.

[0021] FIG. 13 is a process flow diagram illustrating a method for retrofitting a system with load cells for assessment of performance and / or life of the flexible conduit, in accordance with an embodiment of the present disclosure.DETAILED DESCRIPTION OF THE INVENTION

[0022] The present disclosure is directed to systems and methods for assessing performance and / or life of conduits (such as flexible risers, power umbilicals / cables, control umbilicals, and flexible pipes) extending from a surface location to a subsea location. As offshore oil and gas assets age and come toward the end of their design life, a renewed assessment is needed to ensure the remaining life of risers, flexible pipes, umbilicals, and power cables can be safely extended. Understanding the performance and life expectations of such conduits involves inputting data regarding environmental loads into models for analysis. However, current models rely on several assumptions (which are often very conservative) embedded in them, and the conservative assumptions can result in performance / life evaluations where a replacement is recommended earlier than necessary.

[0023] To overcome the deficiencies with existing performance / life assessment techniques, the present disclosure provides systems and methods to accurately measure stresses on the conduit in an inexpensive and, in some instances, retrofittable way. The measured stress data can then be input into models directly, instead of relying on inferred information / data from conservative assumptions in the model. Upon directly measuring certain forces acting on the conduit, the measurements can be converted quickly and easily into the model to provide more accurate property calculations (e.g., stress / force calculations on individual riser components, etc.). Using accurately measured stress data input to the model can provide large gains in terms of the safe extension of life of old producing assets and optimizing the life of new assets.

[0024] In presently disclosed systems and methods, the systems and methods involve placement of load cells within a load path of the support assembly supporting the end termination at an upper (surface) end of the conduit. The load cells can measure the total tension exerted on the end termination from the weight of the conduit and other forces on the conduit. Once the total tension at the top of the conduit is measured, the measured stresses can be input to a model for easily deriving the tensile stresses distributed in a cross section and oneach element of the conduit. Using the high fidelity measurement data, instead of data inferred using conservative assumptions, can significantly reduce the uncertainty and overestimation / underestimation of stresses with the existing model. Thus, the model can produce a more accurate understanding of performance and remaining field life of the conduit. The measurement data can be locally recorded and transmitted to a control station of the platform and become a valuable, higher quality input for integrity management, life extension, monitoring of extreme events (e.g., storms, hurricanes, 100-1000 year recurring events), and fitness assessment, among others.

[0025] The disclosed methodology may be incorporated into new conduits prior to or during their deployment. In addition, the disclosed methodology may be retrofittable to older conduits that are already deployed and in use, bringing benefits in life extension assessments of the existing equipment.

[0026] The disclosed methodology may be used with flexible conduits. The term “flexible conduit” used in the present disclosure is any flexible conduit extending from a surface to at least partially subsea. The flexible conduit may generally extend from a surface location (e.g., at or above the surface of water) to a subsea location (e.g., below the surface of water). The term “flexible conduit” may encompass a flexible riser, any other flexible pipe or pipeline, an umbilical such as a power umbilical, a control umbilical, or an umbilical having both power and control cabling, or subsea power cables, among others. Importantly, the “flexible conduit” extends downward from a surface location to a subsea location and has a degree of flexibility allowing the conduit to bend at one or more points along its length.

[0027] The use of the terms "about", “approximately”, and similar terms applies to all numeric values, whether or not explicitly indicated. These terms generally refer to a range of numbers that one of ordinary skill in the art would consider as a reasonable amount of deviation to the recited numeric values (i.e., having the equivalent function or result). For example, this term may be construed as including a deviation of ±10 percent of the given numeric value provided such a deviation does not alter the end function or result of the value. Therefore, a value of about 1% may be construed to be a range from 0.9% to 1.1%. Furthermore, a range may be construed to include the start and the end of the range. For example, a range of 10% to 20% (i.e., range of 10%-20%) includes 10% and also includes 20%, and includes percentages in between 10% and 20%, unless explicitly stated otherwise herein. Similarly, a range of between 10% and 20% (i.e., range between 10% - 20%) includes 10% and also includes 20%, and includes percentages in between 10% and 20%, unless explicitly stated otherwise herein.

[0028] Turning now to the drawings, FIG. 1 illustrates an example system 100 including a flexible conduit 102 in accordance with the present disclosure. As discussed above, the flexible conduit 102 may include a flexible riser, umbilical(s), power cable(s), or any other flexible conduit extending at least partially subsea.

[0029] A flexible riser can be a multilayered flexible pipe, with each layer of the pipe having a specific function to ensure the riser’s integrity and performance. Such layers may include, but are not limited to, an inner carcass, an internal pressure sheath, multiple armor layers, an anti-wear layer, and an external pressure sheath. Flexible risers can be used to transport production fluids from the seabed to surface facilities. Flexible risers connect subsea production equipment such as, for example, wellheads and manifolds, to surface processing facilities, which can be located on platforms, ships, or floating production storage and offloading units (FPSOs). Flexible risers are engineered to handle the complex dynamic motions of the surface facilities while maintaining a secure and reliable flow path under various conditions, including temperature changes, pressures, and ocean currents.

[0030] Power cables can include electrical power cables that are specifically designed to withstand harsh conditions of the subsea environment and provide a reliable connection between surface facilities and subsea equipment. One or more power cables may be bundled together within a power umbilical.

[0031] Umbilicals typically contain a set of tubes, electrical cables, and / or fiber optic cables that are bundled together to supply control and / or power from a power source to subsea oil and gas operations and transmit information between a control station and subsea oil and gas operations. Umbilicals are characteristically very long, and can connect a surface level substation to electrical machines or another undersea substation. Umbilical tubes can be used for injection of fluid, such as hydraulic fluid or chemical inhibitors, to operate subsea equipment and improve flow assurance for oil and gas applications. Umbilicals often include cables which conduct electricity over long distances. Umbilicals also often include fiber-optic cables for transmitting data, control signals and sensing signals.

[0032] As shown, the flexible conduit 102, when deployed and operational, extends from a surface location 104 to a subsea location 106. The surface location 104 may include a portion of a topside structure 108 at or above a surface 110 of the water. The topside structure 108 can be, for example, a floating vessel, a floating platform, a FPSO, a semi-submersible vessel, or a fixed platform. The subsea location 106 may be the location of a subsea component 112 to which the flexible conduit 102 is coupled. The subsea component 112 can be, for example, a subsea fluid handling component (e.g., a flowline, a pipeline end termination, a manifold, asubsea tree, an umbilical termination assembly, or a combination thereof) or other subsea operation equipment (e.g., a subsea pump, a subsea compressor, a control or distribution module, a lower marine riser package and blow-out preventer, an electrically submersible pump, a subsea separator, or various types of sensors and communication devices).

[0033] The flexible conduit 102 may take different forms in different embodiments. For example, the flexible conduit 102 may include a flexible riser extending from a fluid handling component on the topside structure 108 to a subsea fluid handling component (112) at the subsea location 106 for transporting production fluids. As another example, the flexible conduit 102 may include a power cable extending from a power source located on the topside structure 108 to subsea operation equipment (112) at the subsea location 106 for providing power to operate the subsea equipment. As another example, the flexible conduit 102 may include an umbilical (e.g., a control umbilical) extending from a control center located on the topside structure 108 to subsea operation equipment (112) at the subsea location 106 for outputting control signals to control the operation of the subsea equipment.

[0034] Regardless of the exact type and layout of the flexible conduit 102 with respect to its connection at the surface location 104 and its connection at the subsea location 106, the flexible conduit 102 includes an end termination located at an upper end of the flexible conduit 102. The end termination may be supported by a support assembly 114 (e.g., which may include a flange) positioned at the surface location 104 such that a load transfer interface of the end termination with the support assembly 114 transfers loads from the flexible conduit 102 to the support assembly 114. In accordance with the present disclosure, at least two load cells are disposed within a load path of the support assembly 114. A communication system may be coupled to the load cells and configured to communicate signals from the load cells to a location away from the end termination and / or to a local receiver. The flexible conduit 102 and its support assembly 114 may be part of a new installation having the load cells and communication system incorporated therein. In other embodiments, the flexible conduit 102 and its support assembly 114 may be part of an existing installation to which the load cells and communication system are later added.

[0035] Over the life of the system 100, the flexible conduit 102 can experience high levels of mechanical stress and strain at certain locations during installation and operation stages. For instance, stresses due to fatigue are particularly high at the hang off point and at the touchdown point. It can be important to monitor and analyze the stresses on the flexible conduit 102 to ensure that the flexible conduit 102 is operating within design limits and to determine a remaining life of the flexible conduit 102. The load cells described herein provide a directmeasurement that can be input to a model used for monitoring and analyzing the stresses on the flexible conduit 102 for performance and life assessment.

[0036] FIGS. 2 A and 2B show an example end termination 200 of a flexible conduit 102 supported by a support assembly 114, in accordance with an embodiment of the present disclosure. As described above, the support assembly 114 is configured to support the end termination 200 such that a load transfer interface 201 of the end termination 200 with the support assembly 114 transfers loads from the flexible conduit 102 to the support assembly 114.

[0037] As illustrated, the support assembly 114 may include a split flange 202. The end termination 200 may have a groove 204 specifically machined therein, and the split flange 202 may be received into the groove 204 for locking the end termination 200 to the support assembly 114. The split flange 202 may include two plate pieces 206A and 206B that come together and slot into the groove 204 in the end termination 200, and then are connected (e.g., via bolts 208) onto another structure (e.g., the flange of an I-tube 210) of the support assembly 114. The split flange 202 can hold the end termination 200 in place at the surface location (e.g., 104 of FIG. 1). The split flange 202 may hold the entire weight of the flexible conduit 102 extending from the end termination 200, as well as the tensile load from any loads acting on the flexible conduit 102.

[0038] It should be noted that other types, relative sizes, shapes, dimensions, components, and connecting mechanisms of a support assembly 114 and end termination 200 may be used in other embodiments, and the present disclosure is not limited to the embodiment shown specifically in FIGS. 2 A and 2B. For example, the split flange 202 may have a different shape when viewed from above (e.g., circular shape, etc.) than the shape (substantially square with rounded comers) shown in FIG. 2B. As another example, the end termination 200 may include a circumferential projection (instead of a groove) configured to fit into a groove formed in the split flange 202. One or more additional components may be structurally coupled between the split flange 202 and the I-tube 210 and within the load path of the support assembly 114 in certain embodiments. Different coupling mechanisms other than bolts 208 may be used to connect the split flange 202 to one or more other components (e.g., I-tube 210), as would be apparent to one of ordinary skill in the art. In still other embodiments, a split flange 202 may not be used at all. Rather, the support assembly 114 may include another structure that can be coupled in a load-bearing manner to the end termination 200 to support the weight of the flexible conduit 102. Any desired type of support assembly 114 that is configured to supportthe weight and tensile load of the flexible conduit 102 may be used without departing from the scope of the present disclosure.

[0039] FIGS. 3-9 illustrate different potential configurations of load cells 300 within the load path of a support assembly 114 like the one shown in FIGS. 2 A and 2B having a split flange 202. In each of FIGS. 3-9, the load cells 300 may be strain gauges, hydraulic, pneumatic, capacitive, or piezoelectric load cells, or any other type of load cells. It should be noted that similar configurations of load cells 300 may be provided within the load path of support assemblies 114 having different types, relative sizes, shapes, dimensions, components, and connecting mechanisms than those shown in the figures. Regardless of the exact details of the support assembly 114, multiple load cells 300 may be placed within the load path of the support assembly 114 to provide direct measurements of the total tension exerted on the end termination 200 from the flexible conduit 102.

[0040] FIG. 3 shows an end termination 200 for a flexible conduit 102 having a groove 204 configured to receive a split flange 202, and at least two load cells 300 incorporated into the split flange 202. The two load cells 300 visible in FIG. 3 are located within the split flange 202 on opposite sides of the end termination 200. As illustrated in FIG. 3, the load cells 300 may be disposed on and / or coupled to an upper surface 302 of the split flange 202. The load cells 300 are coupled to the upper surface 302 at locations where the end termination 200 overlaps the split flange 202 when the split flange 202 is received into the groove 204. That is, the load cells 300 are in vertical alignment with the “ring” of the end termination 200 where it overlaps the split flange 202. From this location, the load cells 300 can measure the load being transferred in a downward direction directly from the downward facing surface 304 of the end termination 200 to the upper surface 302 of the split flange 202. As such, the load cells 300 can be used to measure a total tension on the flexible conduit 102 terminating at the end termination 200. Once the total tension is measured, the measurement data can be input to a model to derive or estimate the tensile stresses distributed in the cross section of the flexible conduit 102 and / or on each element of the flexible conduit 102. Using actual measurements from the load cells 300 in the model to derive or estimate these stresses can significantly reduce the uncertainty and overestimation / underestimation of the model outputs, compared to using the model with conservative assumptions and no load cell measurements.

[0041] The two or more load cells 300 may be built into the split flange 202. For example, as shown in FIG. 3 the load cells 300 may be positioned within small hollowed out sections 306 of the split flange 202 along the upper surface 302 to provide a continuous surface on which the downward facing surface 304 of the end termination 200 is supported. In another example,the load cells 300 may be relatively thin components that are positioned directly atop a continuous upper surface 302 of the split flange 202. In still other examples, the two or more load cells 300 may be built into or coupled directly to the downward facing surface 304 of the end termination 200 and used to capture the reaction force transferred from the split flange 202 to the end termination 200 at the load transfer interface of the end termination 200 with the split flange 202.

[0042] FIGS. 4A-4F schematically illustrate different placements and configurations for the load cells 300 in a support assembly 114 (e.g., on an upper surface 302 of a split flange 202 as in FIG. 3). As shown, when viewed from above the load cells 300 may be positioned adjacent a bore 400 extending through the support assembly 114 (e.g., forming a radially inner edge of the split flange 202 of FIG. 3). The support assembly 114 includes at least two load cells 300 (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or more load cells 300). As shown in FIGS. 4A-4D, the load cells 300 may be discrete and positioned in various patterns or configurations. As shown in FIGS. 4E and 4F, the load cells 300 may be incorporated into one or more continuous load cell arrangements 402 that take load cell measurements at multiple positions within each continuous load cell arrangement 402. FIG. 4F only has one continuous load cell arrangement 402 that extends around the entire circumference of the bore 400 to take multiple load cell measurements at different positions around the bore 400.

[0043] The support assembly 114 may include any desired number of load cells 300 disposed at different locations around the support assembly 114. For example, FIG. 4A has four load cells 300, FIG. 4B has two load cells 300, FIG. 4C has eight load cells 300, and FIG. 4D has five load cells 300. As shown in FIGS. 4A-4C, the at least two load cells 300 may be positioned equidistant from each other circumferentially around the bore 400 extending through the support assembly 114. For example, in FIG. 4A, the four load cells 300 are located 90 degrees apart from each other around the bore 400. In FIG. 4B, the two load cells 300 are located 180 degrees apart from each other, on opposite sides of the bore 400. In FIG. 4C, the eight load cells 300 are located 45 degrees apart from each other around the bore 400. As shown in FIG. 4D, the at least two load cells 300 may be positioned at random distances from each other around the circumference of the bore 400.

[0044] Having more than one load cell 300 is beneficial because there may not always be 100% full overlapping contact of the groove (e.g., 204 of FIG. 3) with the load cell(s) 300 / split flange (e.g., 202 of FIG. 3) on all sides of the bore 400, depending on the stresses acting on the flexible conduit (e.g., 102 of FIG. 3). Having more than one load cell 300 provides redundancyto the measurements and can help with proper calibration of the total tensile measurement, particularly in case there is a gap or movement on any side of the bore 400.

[0045] In the embodiment illustrated in FIG. 5, at least two load cells 300 are incorporated into a continuous piece 500 that is separate from the split flange 202. FIG. 5 shows an end termination 200 for a flexible conduit 102 having a groove 204 configured to receive the split flange 202 and the continuous piece 500 having the at least two load cells 300. The groove 204 is sized to receive both the split flange 202 and the separate piece 500 together. The two load cells 300 visible in FIG. 5 are in the continuous piece 500 above the split flange 202 on opposite sides of the end termination 200. The continuous piece 500 is positioned on the upper surface 302 of the split flange 202 where the end termination 200 overlaps the split flange 202 when the split flange 202 is received into the groove 204. As such, the load cells 300 are in vertical alignment with the “ring” of the end termination 200 where it overlaps the continuous piece 500 / split flange 202. From this location, the load cells 300 can measure the load being transferred in a downward direction directly from the downward facing surface 304 of the end termination 200 to the continuous piece 500 and the split flange 202. As such, the load cells 300 can be used to measure a total tension on the flexible conduit 102 terminating at the end termination 200. Once the total tension is measured, the measurement data can be input to a model to derive or estimate the tensile stresses distributed in the cross section of the flexible conduit 102 and / or on each element of the flexible conduit 102. Using actual measurements from the load cells 300 in the model to derive or estimate these stresses can significantly reduce the uncertainty and overestimation / underestimation of the model outputs, compared to using the model with conservative assumptions and no load cell measurements.

[0046] The two or more load cells 300 may be built into the continuous piece 500. For example, the load cells 300 may be positioned within small hollowed out sections of the continuous piece along an upper surface of the continuous piece to provide a continuous surface on which the downward facing surface 304 of the end termination 200 is supported. In another example, the load cells 300 may together form the entirety of the continuous piece 500 positioned atop the split flange 202. In still other examples, the two or more load cells 300 may be built into or coupled directly to a lower surface of the continuous piece 500 and used to measure a reaction load being transferred in an upward direction from the split flange 202 to the continuous piece 500.

[0047] Any of the different placements and configurations for the load cells 300 in a support assembly 114 shown in FIGS. 4A-4F may be used with the load cells 300 incorporated into the continuous piece 500 of FIG. 5 that is separate from the split flange 202.

[0048] FIG. 6 shows another embodiment of a support structure 114 in which the at least two load cells 300 are incorporated into the split flange 202. The two load cells 300 visible in FIG. 6 are located within the split flange 202 on opposite sides of the end termination 200. As illustrated in FIG. 6, the load cells 300 may be disposed on and / or coupled to a lower surface 600 of the split flange 202. The load cells 300 are coupled to the lower surface 600 at locations where the split flange 202 overlaps another structure (e.g., flange of I-tube 210) of the support structure 114 when the split flange 202 is received into the groove 204. That is, the load cells 300 are in vertical alignment with the ring-shaped portion of the split flange 202 overlapping the flange of the I-tube 210. From this location, as load is transferred in a downward direction directly from the lower surface 600 of the split flange 202 to an upper surface of the I-tube, the load cells 300 can capture the reaction force on the split flange 202 from the I-tube 210 at the load transfer interface. As such, the load cells 300 can be used to measure a total tension on the flexible conduit 102 that is transferred through the end termination 200 and the split flange 202 to the I-tube 210. Once the total tension is measured, the measurement data can be input to a model to derive or estimate the tensile stresses distributed in the cross section of the flexible conduit 102 and / or on each element of the flexible conduit 102. Using actual measurements from the load cells 300 in the model to derive or estimate these stresses can significantly reduce the uncertainty and overestimation / underestimation of the model outputs, compared to using the model with conservative assumptions and no load cell measurements.

[0049] The two or more load cells 300 may be built into the split flange 202. For example, as shown in FIG. 6 the load cells 300 may be positioned within small hollowed out sections 604 of the split flange 202 along the lower surface 600 to provide a continuous surface to be supported by the I-tube 210. In another example, the load cells 300 may be relatively thin components that are coupled directly to a continuous lower surface 600 of the split flange 202. In still other examples, the two or more load cells 300 may be built into or coupled directly to the upper surface 602 of the I-tube 210 and used to measure the load being transferred in a downward direction from the split flange 202 to the flange of the I-tube 210.

[0050] FIGS. 7A-7F schematically illustrate different placements and configurations for the load cells 300 in a support assembly 114 (e.g., above the flange of an I-tube 210 as in FIG. 6). As shown, when viewed from above the load cells 300 may be positioned adjacent a bore 700 extending through the support assembly 114 (e.g., forming a radially inner edge of the flange of the I-tube 210 of FIG. 6). The support assembly 114 includes at least two load cells 300 (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or more load cells 300). As shown in FIGS. 7A-7D, the load cells 300 may be discrete and positioned in various patterns or configurations. As shownin FIGS. 7E and 7F, the load cells 300 may be incorporated into one or more continuous load cell arrangements 702 that take load cell measurements at multiple positions within each continuous load cell arrangement 702. FIG. 7F only has one continuous load cell arrangement 702 that extends around the entire circumference of the bore 700 to take multiple load cell measurements at different positions around the bore 700.

[0051] The support assembly 114 may include any desired number of load cells 300 disposed at different locations around bore 700. For example, FIG. 7A has four load cells 300, FIG. 7B has two load cells 300, FIG. 7C has eight load cells 300, and FIG. 7D has five load cells 300. As shown in FIGS. 7A-7C, the at least two load cells 300 may be positioned equidistant from each other circumferentially around the bore 700 extending through the support assembly 114. For example, in FIG. 7A, the four load cells 300 are located 90 degrees apart from each other around the bore 700. In FIG. 7B, the two load cells 300 are located 180 degrees apart from each other, on opposite sides of the bore 700. In FIG. 7C, the eight load cells 300 are located 45 degrees apart from each other around the bore 700. As shown in FIG. 7D, the at least two load cells 300 may be positioned at random distances from each other around the circumference of the bore 700 and / or at random distances radially away from the bore 700 within the plane of the load transfer interface.

[0052] Having more than one load cell 300 is beneficial because there may not always be the same stresses acting on the support assembly 114 at every position around the bore 700 from the flexible conduit (e.g., 102 of FIG. 6). Having more than one load cell 300 provides redundancy to the measurements and can help with proper calibration of the total tensile measurement, particularly in case there is an uneven distribution of the tensile forces on the support structure 114.

[0053] As shown in FIG. 8, the support assembly 114 may further include a flange joint 800 that is disposed between the split flange 202 and the flange of the I-tube 210 when the split flange 202 is received into the groove 204 of the end termination 200. In the support structure 114 of FIG. 8, the at least two load cells 300 are incorporated into the flange joint 800, rather than the split flange 202 or the I-tube 210. As illustrated in FIG. 8, the load cells 300 may be disposed on and / or coupled to an upper surface 802 of the flange joint 800. The load cells 300 are coupled to the upper surface 802 at locations where the split flange 202 overlaps the flange joint 800 when the flange joint 800 is connected to the split flange 202 (e.g., via bolts 208). That is, the load cells 300 are in a load transfer interface of the split flange 202 with the flange joint 800. From this location, the load cells 300 can measure the load being transferred in a downward direction directly from the lower surface 600 of the split flange 202 to the uppersurface 802 of the flange joint 800. As such, the load cells 300 can be used to measure a total tension on the flexible conduit 102 that is transferred through the end termination 200 and the split flange 202 to the flange joint 800. Once the total tension is measured, the measurement data can be input to a model to derive or estimate the tensile stresses distributed in the cross section of the flexible conduit 102 and / or on each element of the flexible conduit 102. Using actual measurements from the load cells 300 in the model to derive or estimate stresses can significantly reduce the uncertainty and overestimation / underestimation of the model outputs, compared to using the model with conservative assumptions and no load cell measurements.

[0054] The two or more load cells 300 may be built into the flange joint 800. For example, as shown in FIG. 8 the load cells 300 may be positioned within small hollowed out sections 804 of the flange joint 800 along the upper surface 802 to provide a continuous surface on which the lower surface 600 of the split flange 202 is supported. In another example, the load cells 300 may be relatively thin components that are positioned directly atop a continuous upper surface 802 of the flange joint 800. In still other examples, the two or more load cells 300 may be built into or coupled directly to the lower surface 600 of the split flange 202 and used to capture the reaction force from the flange joint 800 to the split flange 202 at the load transfer interface of the split flange 202 with the flange joint 800. In further embodiments, the load cells 300 may be positioned along the load transfer interface of the flange joint 800 with the flange of the I-tube 210 below, similar to the arrangement of load cells 300 described with reference to FIG. 6 (with the flange joint 800 taking the place of the split flange 202 of FIG. 6).

[0055] Any of the different placements and configurations for the load cells 300 in a support assembly 114 shown in FIGS. 7A-7F may be used with the load cells 300 incorporated into the flange joint 800 of FIG. 8.

[0056] In the embodiment illustrated in FIG. 9, at least two load cells 300 are incorporated into bolts 208 used to couple the split flange 200 to another flange portion of the support assembly 114. In the illustrated embodiment, the load cells 300 are incorporated into bolts 208 used to connect the split flange 202 to the flange portion of the I-tube 210. In other embodiments, the bolts may pass through additional components (e.g., flange joint, etc.) as well. The two load cells 300 visible in FIG. 9 are in different bolts 208 extending through the split flange 202 and the I-tube 210 on opposite sides of the end termination 200. The load cells 300 may be incorporated into the bolts 208 at any desired position along the bolt length, as long as it is exposed to the stresses being transferred through the bolt 208. From this location, the load cells 300 can measure the load being transferred in a downward direction from the split flange202 through the bolts 208 and ultimately to the I-tube 210. As such, the load cells 300 can be used to measure a total tension on the flexible conduit 102 terminating at the end termination 200. Once the total tension is measured, the measurement data can be input to a model to derive or estimate the tensile stresses distributed in the cross section of the flexible conduit 102 and / or on each element of the flexible conduit 102. Using actual measurements from the load cells 300 in the model to derive or estimate these stresses can significantly reduce the uncertainty and overestimation / underestimation of the model outputs, compared to using the model with conservative assumptions and no load cell measurements.

[0057] Each load cell 300 may be incorporated into a different bolt 208 of the support assembly 114. Any desired number and pattern or arrangement of bolts 208 (e.g., every bolt, every other bolt in a circumferential direction, a random arrangement of bolts) in the support assembly 114 may be equipped with load cells 300. Incorporating the load cells 300 into bolts 208 provides an easy method by which to retrofit existing assets with load cells 300 for measuring the total tension on a flexible conduit 102 that has already been deployed. Existing bolts can simply be removed and replaced with bolts having load cells 300, one at a time, while the connection is still maintained between the support assembly 114 and the end termination 200.

[0058] Although not shown in FIGS. 3-9, the load cells 300 may require power to operate. FIGS. 10A-10D illustrate examples of how the load cells 300 incorporated into the support assembly 114 may be powered.

[0059] In some embodiments, the load cells 300 may be battery powered. FIG. 10A shows one such embodiment where a load cell 300 is coupled to a surface of a structural component 1000 of the support assembly 114. The structural component 1000 may be, for example, a split flange (e.g., 202), a flange of an I-tube (e.g., 210), a flange joint (e.g., 800), or any other structure within the support assembly 114. FIG. 10A shows a battery 1002 operably coupled to the load cell(s) 300. As shown, the battery 1002 may be disposed in a recess 1004 formed in the structural component 1000 of the support assembly 114. Such batteries can be relatively large compared to the load cells 300 they are powering, so positioning the battery 1002 in a recess 1004 as shown can save space within the support assembly 114 and not disrupt the physical connections / load transfer taking place within the support assembly 114. The battery 1002 may be rechargeable.

[0060] In other embodiments, the load cells 300 may be powered from a link to topsides equipment. As shown in FIG. 10B, for example, the load cell(s) 300 may be powered via one or more electrical cables 1050 extending from a topside system 1052 to the support assembly114. The cable(s) 1050 can extend from a junction box of the topside system 1052 to power the sensors 300 in the support assembly 114.

[0061] In other embodiments, a power generation system incorporated into the support assembly 114 may provide power to the load cells 300. In FIG. 10C, for example, the system includes a power generation component 1070 coupled to the support assembly 114 and operably coupled to the load cell(s) 300. The power generation component is configured to generate electrical power from compressive dynamic motion of the end termination (e.g., 200) due to movement and changing of loads on the flexible conduit (e.g., 102). For example, in a support assembly 114 having a split flange (e.g., as shown in FIGS. 2A-9), the split flange (e.g., 202) is subject to cyclic loading, compression loading, and so forth. The power generation component 1070 may be coupled to a portion of the support assembly 114 that is subject to cyclic movement due to the cyclic loading of the split flange, and may use the cyclic loading to create electrical energy for powering the load cell(s) 300. The power generation component 1070 may provide the electrical energy to charge a battery 1002 used to power the load cell(s) 300, as shown in FIG. 10C. In some embodiments, the split flange (or another structure of the support assembly 114) may be divided into different segments that support load cells 300 and power generation components 1070, as shown in FIG. 10D.

[0062] Although not shown in FIGS. 3-9, the disclosed systems include a communication system used to communicate signals indicative of the measurements obtained by the load cells 300 to a processor for further analysis. FIGS. 11A and 11B illustrate examples of different communication systems 1100 A and 1100B that may be used to communicate the measurements from the load cells 300.

[0063] In FIG. 11 A, the communication system 1100A includes a transmission interface 1102 capable of transmitting signals from the at least two load cells 300 to a location away from the end termination (e.g., a topside location 1104) in real time or near-real time. The transmission interface 1102 may be a wired (e.g., digital communication cable, fiber optic cable, etc.) or wireless (e.g., Bluetooth, etc.) transmission interface 1102 for communicating measurement signals from the load cells 300 on the support assembly 114 to the topside location 1104. If the transmission interface 1102 is wireless, the transmissions may occur as soon as possible once a connection is established. The communication system 1100A may communicatively couple the load cells 300 to a processor 1106 at the topside location 1104. The processor 1106 may be part of an information handling system 1108 having at least the processor 1106 and a memory 1110 at the topside location 1104. The information handling system 1108 may include many other features as well, such as input / output devices and storage components, amongothers. The memory 1110 may store instructions that, upon execution by the processor 1106, cause the processor 1106 to perform certain tasks in accordance with the present disclosure. These instructions may include, for example, instructions to receive signals indicative of load cell measurements, analyze the measurement data retrieved from the load cells 300, store the measurement data retrieved from the load cells 300, and / or perform various estimations based on the measurement data.

[0064] In FIG. 1 IB, a data storage / analysis component 1130 is coupled to the load cell(s) 300 and the communication system 1100B. The data storage / analysis component 1130 may include one or more data storage components, one or more data analysis components, one or more combined data storage and analysis components, or a combination thereof. A data storage component (1130) may be configured to store measurements received from the load cell(s) 300. The measurements may be associated with a time stamp and stored with the time stamp in the data storage component (1130). A data analysis component (1130) may be configured to generate certain key indicator parameters based on measurements received from the load cell(s) 300. These key indicator parameters may include, for example, maximum tension, minimum tension, average tension, standard deviation of the tension, or others. The data analysis component (1130) may perform statistical assessment of the measurements received from the load cell(s) 300, either directly or accessed from the data storage component (1130).

[0065] The communication system 1100B is a communication interface 1132 that may be periodically accessed. The communication interface 1132 is configured to communicate measurement signals from the load cell 300 on the support assembly 114 to a local receiver 1134 once the receiver 1134 is connected. In some embodiments, the communication system 1100B may communicate all measurements obtained from the load cell(s) 300 (e.g., accessed from the data storage component (1130) to a receiver 1134. In some embodiments, the communication system 1100B may communicate the key indicator parameters calculated by the data analysis component (1130) to the receiver 1134. The data storage / analysis component 1130 may store measurements taken by the load cell(s) 300 in real time or near-real time. The receiver 1134 (which may be a probe, a cellular device, or another local receiver) may periodically connect to the communication interface 1132 to access and retrieve the stored load cell measurements and / or calculated parameters. Once the receiver 1134 is connected, the communication interface 1132 outputs transmissions 1135 (e.g., wired or wireless) of the stored measurements or calculated parameters to the receiver 1134. The data storage / analysis component 1130 and wireless communication interface 1132 may be incorporated into aprinted circuit board attached to a structure (e.g., split flange) of the support assembly 114, or in wiring that is printed directly onto the surface of structure of the support assembly 114.

[0066] The receiver 1134 may be part of an information handling system 1138 that also includes a processor 1136 and a memory 1140. The information handling system 1138 may include other features as well, such as input / output devices and storage components, among others. The memory 1140 may store instructions that, upon execution by the processor 1136, cause the processor 1136 to perform certain tasks in accordance with the present disclosure. These instructions may include, for example, instructions to receive signals indicative of load cell measurements, analyze the measurement data retrieved from the load cells 300, store the measurement data retrieved from the load cells 300, display the measurements in real time or near-real time on a user display, and / or perform various estimations based on the measurement data.

[0067] FIG. 12 is a process flow diagram of an example method 1200 for using a support assembly with multiple load cells to assess performance and / or life of a flexible conduit, in accordance with the present disclosure. It should be noted that the method 1200 shown in FIG. 12 is merely an example and other embodiments may include additional steps not shown, have one or more illustrated steps removed, or have certain illustrated steps performed in different orders than shown, without departing from the scope of the present disclosure.

[0068] At block 1202, the method 1200 includes supporting an end termination located at an upper end of a flexible conduit from a support assembly, the flexible conduit extending from a surface location to a subsea location. At block 1204, the method 1200 includes transferring loads from the flexible conduit to the support assembly via a load transfer interface of the end termination with the support assembly. At block 1206, the method 1200 includes measuring loads on the flexible conduit via at least two load cells disposed within a load path of the support assembly. At block 1208, the method 1200 includes communicating signals indicative of measurements taken by the at least two load cells to a location away from the end termination via a communication system. The location away from the end termination may include a processor at a topsides location, a processor within a local receiver that is brought into proximity with the communication system, or some other location.

[0069] At block 1210, the method 1200 may include receiving, at a processor, the signals from the communication system. At block 1212, the method 1200 may include deriving, via the processor, tensile stresses distributed across a section of the flexible conduit based on the signals. At block 1214, the method 1200 may include estimating, via the processor, a remaining field life of the flexible conduit based on the signals. By using the measurementstaken directly from the support assembly, the processor can input the measurement data to a simplified model, which can be used to perform the steps of blocks 1212 and 1214. The simplified model does not include the conservative assumptions (e.g., from earlier models) for determining the tensile loads on the flexible conduit. As such, the simplified model can provide more accurate estimations of tensile stresses distributed across the flexible conduit, from which the life expectancy of those components and the entire flexible conduit can be extrapolated.

[0070] FIG. 13 is a process flow diagram of an example method 1300 for retrofitting a system to provide more accurate assessments of performance and / or life of a flexible conduit. The method 1300 shown in FIG. 13 is merely an example and other embodiments may include additional steps not shown, have one or more illustrated steps removed, or have certain illustrated steps performed in different orders than shown, without departing from the scope of the present disclosure.

[0071] At block 1302, the method 1300 includes providing a flexible conduit extending from a surface location to a subsea location, an end termination located at an upper end of the flexible conduit, and a support assembly supporting the end termination such that loads on the flexible conduit are transferred to the support assembly. At block 1304, the method includes positioning at least two load cells within a load path of the support assembly. In some embodiments, positioning the load cells within the load path (1304) may include: at block 1306, removing at least two bolts from a load transfer interface of the end termination with the support assembly while maintaining the connection between the end termination and the support assembly via at least one additional bolt; and at block 1308, replacing the at least two bolts with new bolts having the at least two load cells incorporated therein. At block 1310, the method 1300 includes coupling a communication system to the load cells, the communication system being configured to communicate signals from the load cells to a location away from the end termination.

[0072] It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of example embodiments. For example, the functions described above and implemented as the best mode for operating the present invention are for illustration purposes only. Other arrangements and methods may be implemented by those skilled in the art without departing from the scope and spirit of this invention. Moreover, those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

CLAIMSWhat is claimed is:

1. A system, comprising: a conduit configured to extend from a surface location to a subsea location; an end termination located at an upper end of the conduit; a support assembly positioned at the surface location and configured to support the end termination such that a load transfer interface of the end termination with the support assembly transfers loads from the conduit to the support assembly; at least two load cells disposed within a load path of the support assembly; and a communication system coupled to the load cells and configured to communicate signals based on measurements by the load cells to a location away from the end termination and / or to a local receiver.

2. The system of claim 1, wherein the conduit comprises a flexible riser, a power cable, an umbilical, a thermoplastic composite pipe (TCP), or a carbon steel pipe.

3. The system of claim 1, wherein the support assembly comprises a split flange and the end termination comprises a groove formed therein, wherein the split flange is configured to be received into the groove4. The system of claim 3, wherein the at least two load cells are incorporated into the split flange.

5. The system of claim 4, wherein at least one of the load cells is coupled to an upper surface of the split flange at a location where the end termination overlaps the split flange when the split flange is received into the groove.

6. The system of claim 4, wherein at least one of the load cells is coupled to a lower surface of the split flange at a location where the split flange overlaps another structure of the support assembly when the split flange is received into the groove.

7. The system of claim 3, wherein the at two load cells are incorporated into a continuous piece separate from the split flange and configured to be received into the groove with the split flange.

8. The system of claim 3, wherein the support assembly further comprises a flange joint configured to be disposed between the split flange and an I-tube located beneath the split flange when the split flange is received into the groove, wherein at least one load cell is incorporated into the flange joint.

9. The system of claim 3, wherein the split flange is coupled to another flange portion of the support assembly via multiple bolts, wherein at least one load cell is incorporated into at least one of the bolts.

10. The system of claim 1, wherein the at least two load cells are positioned equidistant from each other circumferentially around a bore extending through the support assembly.

11. The system of claim 1, further comprising a battery operably coupled to the at least two load cells and disposed in a recess formed in a component of the support assembly.

12. The system of claim 1, wherein the at least two load cells are powered via one or more electrical cables extending from a topside system to the support assembly.

13. The system of claim 1, further comprising a power generation component coupled to the support assembly and configured to generate electrical power from compressive dynamic motion of the end termination, the power generation component operably coupled to the at least two load cells.

14. The system of claim 1, wherein the communication system comprises a wired or wireless transmission interface for transmitting signals from the at least two load cells to a topside location in real time or near-real time.

15. The system of claim 1, further comprising a data storage component and / or a data analysis component coupled to the at least two load cells and to the communication system.

16. A method, comprising: supporting an end termination located at an upper end of a conduit from a support assembly, the conduit extending from a surface location to a subsea location; transferring loads from the conduit to the support assembly via a load transfer interface of the end termination with the support assembly; measuring loads on the conduit via at least two load cells disposed within a load path of the support assembly; and communicating signals indicative of measurements taken by the at least two load cells to a location away from the end termination via a communication system.

17. The method of claim 16, further comprising: receiving, at a processor, the signals from the communication system; and deriving, via the processor, tensile stresses distributed across a section of the conduit based on the signals.

18. The method of claim 16, further comprising: receiving, at a processor, the signals from the communication system; and estimating, via the processor, a remaining field life of the conduit based on the signals.

19. A method for retrofitting a system comprising a conduit extending from a surface location to a subsea location, an end termination located at an upper end of the conduit, and a support assembly supporting the end termination such that loads on the conduit are transferred to the support assembly, comprising: positioning at least two load cells within a load path of the support assembly; and coupling a communication system to the load cells, the communication system being configured to communicate signals from the load cells to a location away from the end termination.

20. The method of claim 19, wherein positioning the at least two load cells comprises: removing at least two bolts from a load transfer interface of the end termination with the support assembly while maintaining the connection between the end termination and the support assembly via at least one additional bolt; and replacing the at least two bolts with new bolts having the at least two load cells incorporated therein.

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