WO2016059446A1

WO2016059446A1 - Apparatus and system for restoring fluid flow within a subsea pipe segment

Info

Publication number: WO2016059446A1
Application number: PCT/IB2014/002833
Authority: WO
Inventors: Tamas BOZSO; Robert BOZSO; Gabor Molnar; Peter BAJCSI
Original assignee: Zerlux Hungary Kft.
Priority date: 2014-10-13
Filing date: 2014-10-13
Publication date: 2016-04-21

Abstract

An apparatus and system for removing at least a portion of a hydrate deposit within a subsea pipe segment (91) includes a submersible remotely-operated plurality of and inter-coupled modules (20), each module having a laser emitting element (25). A power conduit (21) is provided to supply one of an electrical current source and laser light to the apparatus. Each module further comprises at least one magnet for securing the module to an exterior surface of a subsea pipe segment A flexible coupling (45) secures each module to at least one adjacent module. The plurality of modules are deployable on the exterior surface of the subsea pipe segment and the modules are activatable to impinge laser light from the laser emitting elements onto the exterior surface of the subsea pipe segment. A hydrophone (49) and/or a temperature sensor may be provided on the apparatus. A remotely operated vehicle may be used to deploy and recover the apparatus.

Description

APPARATUS AND SYSTEM FOR RESTORING

FLUID FLOW WITHIN A SUBSEA PIPE SEGMENT

BACKGROUND

Field of the Invention

[0001] The present invention relates to an apparatus for restoring flow within a subsea pipe segment blocked by an accumulation or deposit of a solid material. For example, but not by way of limitation, hydrate deposits, asphalt deposits or paraffin deposits may impair the flow capacity of a subsea pipe segment. Specifically, this invention relates to an apparatus and a system that can be used to restore flow capacity by providing a channel through a solid deposit through which fluid flow can be restored.

Background of the Related Art

[0002] Subsea pipe systems are widely used to transport fluids from one place, such as a subsea wellhead or a marine production platform, to another place, such as a marine production platform or a terrestrial facility. Hydrates, particularly gas hydrates, are a common problem encountered by operators of subsea pipe systems. The formation of hydrates within a subsea pipe system generally occurs as a result of the presence of sufficient amounts of hydrocarbon gas, usually methane and/or ethane, in the presence of water under conditions including low temperature and high pressure. The formation of hydrates is widespread in subsea pipes that are deep within the sea where temperatures can fall to 4 °C (39 °F) or lower. Hydrates may also form in and on subsea pipes and other subsea assets in waters near the poles where seawater can remain in a liquid state at temperatures below 0 °C. Any water-containing solution with a saline concentration that is lower than the seawater may potentially freeze within the pipeline under these conditions. In addition to hydrates, other solids may also be deposited within an interior bore of a pipe segment and impair the flow capacity of the pipe segment. Paraffin, asphalt, ice and other solids may also accumulate within the interior bore of a pipe segment. [0003] Embodiments of the apparatus and system of the present invention may be used to dissolve or melt blockages and/or deposits hydrates, ice, asphalt, which is a mixture of longer-chain hydrocarbons, and paraffin, which is often included within recoverable oil within the earth's crust.

[0004] An operator of a subsea pipe system that has impaired flow capacity due to the formation of solids within the interior bore of a pipe segment of the pipe system can implement remedies for the loss in flow capacity. For example, but not by way of limitation, the operator may remediate the problem by flowing warm fluids through the pipe segment. It will be understood that warm fluids may be redirected to the affected pipe segment for the purpose of thawing or melting the hydrate deposit. Alternately, a chemical solvent that melts a hydrate blockage or that impairs the growth or formation of hydrates or other solid materials may be introduced into the pipe segment or upstream from the pipe segment to remediate the blockage. However, in order to implement these or other methods to remediate hydrate blockages, it is important to first restore at least a reduced flow capacity so that warmer fluids can be moved through the affected pipe segment to melt and remove the solid deposit. An additional benefit to the restoration of flow is the reduction of static pressure on the blockage. High pressure and lower temperatures promote the formation of hydrates, and the restoration of flow will reduce the pressure on the blockage.

BRIEF SUMMARY

[0005] One embodiment of the present invention provides an apparatus for being magnetically secured to a subsea pipe segment and for thereafter irradiating a portion of an exterior surface of the subsea pipe segment with laser light to heat the portion of the exterior surface adjacent to the apparatus and to melt or dislodge at least a portion of the solid blockage or deposit within the bore of the pipe segment. The application of heat by the apparatus forms a channel through the blockage through which fluid flow may be restored, thereby lowering the pressure to further promote removal of the blockage.

[0006] An embodiment of the apparatus comprises at least one module having an activatable laser light emitting element. The laser light emitting element is activatable to irradiate a portion of an exterior surface of the subsea pipe segment proximal to the at least one module to heat the portion of the exterior surface of the pipe segment and to transfer heat across a pipe wall to an interior bore of the pipe segment. A solid material adhered to the interior bore wall will melt and/or become dislodged as a result of the heat transfer.

[0007] An embodiment of the apparatus may additionally include a hydrophone disposed on the at least one module to detect an acoustic signal produced as a result of the transfer of heat to the solid material and to generate a signal corresponding to the detected acoustic signal. Another embodiment of the apparatus may additionally include a temperature sensor disposed on the at least one module to detect a temperature of the exterior surface of the pipe segment to which the apparatus is magnetically secured. Another embodiment of the apparatus may additionally include a photo-sensor disposed on the at least one module to detect the presence or absence of a laser light beam emitted by the module.

[0008] An embodiment of this apparatus may additionally include an umbilical having a first end coupled to the at least one module and a second end coupled to one of a marine vessel and a submersible and remotely operated vehicle. The umbilical may include an electrical conductor to provide electrical current to the at least one module of the apparatus to power the at least one laser light emitting element therein, which includes an electrically-powered laser light generator. Alternately, the umbilical may provide an optical conductor to provide laser light to the at least one module to power the at least one laser light emitting element, which may be optical in nature and does not include a laser light generator. It will be understood that, for this latter embodiment, a laser light generator will be required at the input end of the optical conduit that delivers the laser light to the at least one laser light emitting element in the at least one module of the apparatus.

[0009] An embodiment of a system that includes an embodiment of the apparatus may additionally include a first umbilical, having a first end coupled to the at least one module and a second end coupled to a submersible and remotely operated vehicle, and a second umbilical having a first end coupled to the remotely operated vehicle and a second end coupled to a marine vessel at or near the surface of the sea in which the subsea pipe segment lies. This embodiment of a system provides for electrical current generation onboard the marine vessel and electrical current transmission through the second umbilical from the marine vessel to the remotely operated vehicle. Electrical current may then be transmitted from the submerged and remotely operated vehicle to the at least one module on the blocked or partially blocked pipe segment to power the laser light emitting element of the at least one module. The first umbilical may provide electrical current from the remotely operated vehicle to the at least one module to power the laser light emitting element, which includes an electrically-powered laser light generator. In this embodiment, the first umbilical includes an electrically conductive cable and the second umbilical also includes an electrically conductive cable.

[0010] It will be understood that electrical current conditioning devices, such as transformers, may be employed with this embodiment to minimize resistance heating losses in the transmission of electrical current. For example, but not by way of limitation, the electrical current generated onboard the marine vessel and transmitted to the remotely operated vehicle may be of a high voltage and a low amperage pairing to minimize electrical resistance losses in the second umbilical, and the submerged and remotely controlled vehicle may include a transformer to "step-down" the voltage (and "step-up" the amperage) of the electrical current then transmitted through the first umbilical to the laser light emitting elements of the apparatus to a voltage and amperage pairing that is more useful for activating the laser light emitting elements of the at least one module of the apparatus. It will be understood that the second umbilical, from the marine vessel at the surface of the sea to the submerged and remotely operated vehicle, will likely be much longer than the first umbilical, from the remotely operated vehicle to the at least one module on the blocked or partially blocked pipe segment, due to the proximity of the remotely operated vehicle to the blocked or partially blocked subsea pipe segment.

[0011] In a different embodiment, the electrical current delivered from the marine vessel at the surface to the remotely operated vehicle at a high voltage and low amperage pairing may be transmitted without conditioning to one or more current conditioning devices, such as a transformer, coupled directly to and positioned adjacent to at least one of the plurality of modules magnetically secured on the pipe segment. This embodiment reduces electrical resistance losses in both the second umbilical (from the marine vessel to the remotely operated vehicle) and in the first umbilical (from the remotely operated vehicle to the transformer adjacent to at least one module on the pipe segment), while still providing conditioned current that is suitable for powering the laser light emitting elements of the modules on the pipe segment.

[0012] An embodiment of the system and apparatus of the present invention may further include a hydrophone disposed on a remotely operated vehicle to detect acoustic signals emerging from within the heat pipe segment. The embodiment of the system and apparatus may further include a data storage medium on the remotely operated vehicle, wherein one or more acoustic signals detected by the hydrophone are stored on the data storage medium. Similarly, in an embodiment of a system and apparatus having a temperature sensor on at least one of the modules of the apparatus, the temperature reading(s) may be stored on a data storage medium on the remotely operated vehicle. Alternately, either a hydrophone signal or a temperature signal, or both, can be transmitted from the at least one module through the first umbilical to the remotely operated vehicle, and then through the second umbilical to the marine vessel, to be used in operating the apparatus.

[0013] It will be understood that the term "pipe segment," as that term is used herein, refers to a segment of a pipe system. Pipe segment may refer to a conventional length of pipe, or to assemblies that would ordinarily be connected to and/or made a part of a pipe system. These assemblies include, but are not limited to, valves, pipe fittings, blowout preventer stacks, Christmas trees, and branches that are fabricated and connected to the pipe system to control the flow of fluids, as with a valve or blowout preventer, or to transport fluids to, or to remove fluids from, the pipe system.

[0014] It will be understood that the term "laser target," as that term is used herein, may be any portion of the exterior surface of the pipe segment that is targeted for irradiation using laser light beams emitted by the laser light emitting elements of one or more modules of an apparatus of the present invention.

[0015] In one embodiment of the present invention, an apparatus comprises a module having a laser light emitting element supported by a case of the module, a plurality of legs on the module, at least one magnetic foot coupled to an end of at least one of the plurality of legs and a power supply conduit coupled to the module to provide power to the laser light emitting element, wherein the module is magnetically securable at the at least one magnetic foot to an exterior surface of a subsea pipe segment comprising a magnetic material, and wherein the laser light emitting element is energizable to impinge a laser light beam on a portion of the exterior surface to heat a solid material deposited on an interior bore of the pipe segment opposite a pipe wall from the portion of the exterior surface. The apparatus may further comprise at least one spring element disposed intermediate the at least one magnetic foot and the at least one leg wherein the at least one spring element is deformable to provide for alignment of the at least one magnetic foot with a curvature of the exterior surface of the pipe segment. The apparatus may further comprise a skirt surrounding a substantial portion of the laser light beam intermediate the module and the exterior surface of the pipe segment to which the module is magnetically secured, wherein the skirt at least partially isolates a space intermediate the module and the exterior surface of the pipe segment from surrounding seawater to conserve heat produced by the laser light beam.

[0016] An embodiment of a system of the present invention comprises a plurality of intercoupled modules having a laser light emitting element supported by a case of each module, a plurality of legs on each module, at least one magnetic foot coupled to an end of at least one of the plurality of legs of each module and a power supply conduit coupled to each module to provide power to the laser light emitting element of the module, wherein each module is magnetically securable at the at least one magnetic foot to an exterior surface of a subsea pipe segment comprising a magnetic material, and wherein the laser light emitting element is energizable to impinge a laser light beam on a portion of the exterior surface to heat a solid material deposited on an interior bore of the pipe segment opposite a pipe wall from the portion of the exterior surface, and wherein the system further comprises a submersible and remotely operated vehicle and a first umbilical having a first end coupled to the remotely operated vehicle and a second end coupled to the plurality of intercoupled modules, wherein the first umbilical includes an electrically conducting conduit to power the laser emitting element. Alternately, instead of an electrically conductive conduit provided to power a plurality of laser light emitting elements that include electrically powered laser light generators, the plurality of intercoupled modules may be powered by laser light provided from a submersible and remotely operated vehicle, and a first umbilical having a first end coupled to the remotely operated vehicle and a second end coupled to the plurality of intercoupled modules, wherein the first umbilical includes an optically conducting conduit to power the laser emitting element. In an optional embodiment, the remotely operated vehicle of the system includes a camera for generating a signal corresponding to an image of the pipe segment. The optional embodiment may further include a remotely operated vehicle having lights to enable the camera to better capture images of the pipe segment and the module. Another optional embodiment may further include a remotely operated vehicle having a storage member for storing the intercoupled modules during submersion of the remotely operated vehicle from a marine vessel at a surface of the sea to a position proximal to the pipe segment, and a movable arm activatable for deploying the intercoupled modules from the storage member on the remotely operated vehicle onto the exterior surface of the pipe segment. Optionally, the movable arm is activatable to retrieve the apparatus from the exterior surface of the pipe segment. Optionally, the movable arm of the remotely operated vehicle is activatable to retrieve the apparatus module from the exterior surface of the pipe segment, wherein the apparatus is activatable to restore the apparatus to the storage member of the remotely operated vehicle. Optionally, the intercoupled modules may further include a temperature sensor disposed on at least one module to contact the exterior surface of the pipe segment to which the module is magnetically secured, wherein the temperature sensor generates a signal corresponding to a detected temperature of the pipe segment.

[0017] In another embodiment of the apparatus of the present invention, the apparatus comprises a plurality of intercoupled modules, each module having an energizable laser light emitting element coupled to a case and a plurality of legs extending from the case, a plurality of magnetic feet, at least one magnetic foot coupled to each of the plurality of legs, a plurality of flexible couplings, at least one flexible coupling disposed intermediate each of the modules and at least one other adjacent module to intercouple the plurality of modules into a string of modules, wherein the intercoupled modules are magnetically securable at the plurality of magnetic feet to an exterior surface of a subsea pipe segment comprising a magnetic material, and wherein the laser light emitting elements of the plurality of modules are together energizable to heat with laser light beams an elongate portion of an exterior surface of the pipe segment to which the apparatus is magnetically secured. The apparatus may further include a skirt extending from at least one of the intercoupled modules to surround at least some of the plurality of legs, wherein the skirt at least partially isolates at least one laser light beam from surrounding seawater proximal to the pipe segment. Optionally, the skirt surrounds all of the legs of the intercoupled modules to at least partially isolate a plurality of laser light beams from surrounding seawater proximal to the pipe segment. The apparatus may further include a plurality of spring elements disposed intermediate the plurality of magnetic feet and the plurality of legs of each module, wherein the plurality of spring elements are each deformable to provide for alignment of the plurality of magnetic feet with a portion of the exterior surface of the pipe segment to which the plurality of magnetic feet are magnetically secured.

[0018] An embodiment of a system of the present invention comprises a plurality of intercoupled modules, each module having an energizable laser light emitting element coupled to a case and a plurality of legs extending from the case, a plurality of magnetic feet, at least one magnetic foot coupled to each of the plurality of legs, a plurality of flexible couplings, at least one flexible coupling disposed intermediate each of the modules and at least one other adjacent module to intercoupled the plurality of modules into a string of modules, wherein the intercoupled modules are magnetically securable at the plurality of magnetic feet to an exterior surface of a subsea pipe segment comprising a magnetic material, and wherein the laser light emitting elements of the plurality of modules are together energizable to heat with laser light beams an elongate portion of an exterior surface of the pipe segment to which the plurality of intercoupled modules is magnetically secured. The embodiment of the system further includes a submersible and remotely operated vehicle and a first umbilical having a first end coupled to the intercoupled modules and a second end coupled to the remotely operated vehicle, the first umbilical including an electrical conduit to conduct power from the remotely operated vehicle to the laser emitting elements of the intercoupled modules. In an optional embodiment, the remotely operated vehicle further includes a movable arm for positioning the plurality of intercoupled modules in a magnetically secured condition on an exterior surface of a subsea pipe segment to together impinge laser light emitted by the laser emitting elements onto the exterior surface of the pipe segment. In another optional embodiment, at least one of the intercoupled modules includes a temperature sensor disposable in contact with the exterior surface of the pipe segment to detect a temperature of the exterior surface and to generate a signal corresponding to a detected temperature. Optionally, the temperature sensor can be disposed within a magnetic foot that engages the exterior surface of the pipe segment to which the apparatus is magnetically secured. Optionally, at least one of the intercoupled modules may include at least one hydrophone to detect acoustic signals generated as a result of heat imparted to the pipe segment by the laser light beams emitted by the plurality of intercoupled modules.

[0019] Another embodiment of a system of the present invention comprises a plurality of intercoupled modules, each module having an energizable laser light emitting element coupled to a case and a plurality of legs extending from the case, a plurality of magnetic feet, at least one magnetic foot coupled to each of the plurality of legs, a plurality of flexible couplings, at least one flexible coupling (45) disposed intermediate each of the modules and at least one other adjacent module to intercouple the plurality of modules into a string of modules, and a storage unit for storing the intercoupled modules, the storage unit including a storage reel about which the plurality of intercoupled modules is disposed for submersion and transport to the proximity of the pipe segment, wherein the intercoupled modules are magnetically securable at the plurality of magnetic feet to an exterior surface of a subsea pipe segment comprising a magnetic material, and wherein the laser light emitting elements of the plurality of modules are together energizable to heat with laser light an elongate portion of an exterior surface of the pipe segment to which the plurality of intercoupled modules is magnetically secured. Optionally, the storage unit further comprises a first set of rolling elements for engaging the pipe segment wherein the first set of rolling elements enable the storage unit to move along the pipe segment as the plurality of intercoupled modules is reeled out from the storage reel. In a related optional embodiment, the storage unit may further include a motor on the storage unit coupled to drive a second set of rolling elements, wherein operation of the motor moves the storage unit along the pipe segment as the storage reel rotates.

BRIEF DESCRIPTION OF THE APPENDED DRAWINGS

[0020] FIG. 1 is a perspective view of an embodiment of a laser light emitting module that can be used to assemble a string and an array of the apparatus of the present invention.

[0021] FIG. 2 is a perspective view of an alternate embodiment of a laser light emitting module that can be used to assemble an apparatus of the present invention.

[0022] FIG. 3 is an elevation view of an embodiment of an apparatus of the present invention magnetically secured to a subsea pipe segment blocked by a solid material deposited within the bore of the pipe segment.

[0023] FIG. 4 is an elevation view of an alternate embodiment of the apparatus of FIG. 3 magnetically secured to a subsea pipe segment blocked by a solid material deposited within the bore of the pipe segment.

[0024] FIG. 5 is an elevation view of an embodiment of the apparatus of the present invention magnetically secured to a curved subsea pipe segment blocked by a solid material deposited within the bore of the pipe segment.

[0025] FIG. 6 is an illustration of how the laser light beams emitted by the plurality of modules of an embodiment of an apparatus of the present invention together overlap to provide a continuous laser light exposure onto the exterior surface of a pipe segment blocked by a solid material deposited within the bore of the pipe segment.

[0026] FIG. 7 is an illustration of the power density of the laser light delivered onto the pipe segment of FIG. 6 by each of the modules of the apparatus.

[0027] FIG. 8 is an illustration of the cumulative power density of laser light together delivered onto the pipe segment of FIG. 6 by the collection of modules of the apparatus.

[0028] FIG. 9 is a plan view of a pair of modules intercoupled using a flexible coupling to form an embodiment of the apparatus of the present invention having a short string of modules.

[0029] FIG. 10 is the plan view of FIG. 9 after the rightmost module is repositioned relative to the leftmost module.

[0030] FIG. 11 is the plan view of the modules of FIG. 9 intercoupled using a pair of flexible couplings. [0031] FIG. 12 is the plan view of FIG. 11 after the rightmost module is repositioned relative to the leftmost module.

[0032] FIG. 13 is the plan view of the modules of FIG. 9 after an additional two modules are intercoupled with the original two modules to form an embodiment of the apparatus of the present invention having an array of modules.

[0033] FIG. 14 is the plan view of the modules of FIG. 13 after an additional flexible coupling is added to further intercouple the modules.

[0034] FIG. 15 is an end view of an embodiment of the apparatus of the present invention magnetically secured to a subsea pipe segment and including a transformer to condition the voltage to the plurality of modules of the apparatus.

[0035] FIG. 16 is a sectional elevation view of an optional magnetic foot connected to a leg of a module of an embodiment of an apparatus of the present invention to provide a signal corresponding to the temperature of the exterior surface of the pipe segment to which the module is magnetically secured.

[0036] FIG. 17 is an illustration of a marine vessel being used to deploy an embodiment of an apparatus of the present invention onto a subsea pipe segment blocked by a solid material deposited within the bore of the pipe segment.

[0037] FIG. 18 is an illustration of a marine vessel and a plurality of submersible shuttle vehicles being used to deploy an embodiment of an apparatus of the present invention onto a subsea pipe segment blocked by a solid material deposited within the bore of the pipe segment.

[0038] FIG. 19 is an elevation view of a first embodiment of an apparatus of the present invention magnetically secured to a subsea pipe segment blocked by a solid material deposited within the bore of the pipe segment and a second embodiment of the apparatus being positioned for docking with the first embodiment to form an extended string of modules magnetically secured to the pipe segment.

[0039] FIG. 20 is a perspective view of a large subsea asset to which an embodiment of an apparatus of the present invention including an array of modules is magnetically secured to the asset. [0040] FIG. 21 is an elevation view of a magnetic foot of a module of an embodiment of an apparatus of the present invention equipped with an electromagnetic device for impairing the magnetic field of the magnetic foot.

[0041] FIG. 22 is a perspective view of a receptacle coupled to an first apparatus of the present invention and a stabber coupled to a second apparatus of the present invention for the purpose of being inserted into the receptacle on the first apparatus for the purpose of coupling the first apparatus and the second apparatus into an extended string of modules, each having a laser light emitting element for irradiating a portion of the exterior surface of the pipe segment.

DETAILED DESCRIPTION

[0042] FIG. 1 is a perspective view of an embodiment of a submersible laser light emitting module 20 that can be used to assemble a string 60 and an array 93 of the apparatus of the present invention. The module 20 includes a top 34, a first electrical terminal 29 and a second electrical terminal 42, with an electrically powered laser light emitting element 25 disposed conductively intermediate the first electrical terminal 21, supported by electrical riser 43, and the second electrical terminal 42, supported by electrical riser 44, to convert electrical current delivered through the first and second electrical terminals 29 and 42 to a laser light beam SO. The module 20 further includes one or more heat dissipation fins 26 to remove heat from the laser light generator 25 and a case 24 to surround and to isolate the laser light generator 25 from surrounding seawater (not shown). The module 20 further includes a lens 28 to optically condition the laser light 50 into an impingement pattern that is suitable for the application.

[0043] The module 20 of FIG. 1 further includes a plurality of legs 30 coupled to the case 24 and extending in a direction opposite to the electrical riser 43 that supports the first electrical terminal 29 and electrical riser 44 that supports the second electrical terminal 42. In the embodiment of the module 20 of FIG. 1, the legs 30 each include a spring 31 biasing a magnetic foot 23 distally to the case 24. The magnetic feet 23 are adapted for magnetically engaging an exterior surface 90 of a subsea pipe segment 91 (not shown in FIG. 1) and for securing the module 20 to the pipe segment 91. The spring 31 is deformable to allow movement of the magnetic foot 23 to misalign, to at least a degree, relative to the other magnetic feet 23 coupled to other legs 30 to promote flush engagement with a generally flattened magnetic foot 23 with a curved exterior surface 90 of the pipe segment 91.

[0044] The case 24 of the module 20 includes an aperture (not shown) disposed intermediate the laser light emitting element 25 and the pipe segment 91 to which the module 20 is magnetically securable. The aperture is covered and sealed by a pressure resistant transparent member 27 which allows the laser light beam 50 emerging from the lens 28 to pass through.

[0045] The module 20 of FIG. 1 further includes a skirt 32 that surrounds the legs 30 and springs 31 to thereby surround the laser light beam 50 from the surrounding seawater and to thereby at least partially isolate the water within the laser light beam 50 from the surrounding seawater. Portions of the skirt 32 of the module 20 in FIG. 1 are not shown in FIG. 1 to reveal the legs 30 and springs 31. It will be understood that the skirt 32 will, by isolating the laser light beam 50 from the surrounding seawater, minimize heat loss from the water within the skirt 32 and maximize the heat delivered by the laser light beam 50 to the pipe segment 91.

[0046] FIG. 2 is a sectioned and perspective view of an alternate embodiment of a laser light emitting module 20 that can be used to assemble an apparatus of the present invention. The sectioned view of FIG. 2 eliminates two of four legs 30 along with the near portion of the skirt 32, a portion of the case 24, and one of the second electrical terminal 42 from the view provided by the drawing. FIG. 2 better reveals the position of the laser light generator 25 relative to the aperture 52 through which the optically conditioned laser light beam 50 passes. The skirt 32 structure is flexible for partially collapsing upon engagement with the exterior surface 90 of the pipe segment 91 (not shown in FIG. 2). The legs 30 include a spring element 32 and a magnetic foot 23 for magnetically securing the module 20 to the exterior surface 90 of the pipe segment 91 (not shown). The top 34 of the module 20 includes a plurality of heat dissipation fins 26 and the electrical riser 43 that supports the electrical terminal 21 and the seal 29.

[0047] FIG. 3 is an elevation view of an embodiment of an apparatus 60 of the present invention magnetically secured to a subsea pipe segment 91 having an interior bore 94 that is blocked by a solid material 92 deposited within the bore 94 of the pipe segment 91. The apparatus 60 comprises a plurality of intercoupled modules 20, each module 20 comprising a plurality of legs 30 with spring elements 31 and magnetic feet 23 for magnetically securing the modules 20 to the pipe segment 91. The modules 20 of the apparatus 60 are intercoupled using flexible couplings 45 that flexibly connect adjacent modules 20. The modules 20 each further comprise a laser light generator 25 to generate a laser light beam 50 impinging on the exterior surface 90 of the pipe segment 91. The modules 20 of the apparatus 60 of FIG. 3 are connected in series for providing electrical power to the laser light generator 25. The leftmost module 20 in FIG. 3 receives electrical current through electrical conduit 21, which goes through the laser light generator 25 of the leftmost module 20. Electrical current continues from the laser light generator 25 of the leftmost module 20 in FIG. 3 through jumper conduit 42 that is supported, in part, by electrical riser 44. The jumper conduit 42 supplies electrical current to the second module 20 to the right of the leftmost module 20 in FIG. 3, and the electrical current passes through the laser light generator 25 of the second module 20 to the right of the leftmost module 20 and through the middle jumper conduit 42 of FIG. 3 to the adjacent module 20 to the left of the rightmost module 20 in FIG. 3.

[0048] It will be understood that, like other electrical current consuming devices connected in series, the number of modules 20 that can be connected in a string of modules 20, as are the four modules 20 illustrated in the example of FIG. 3 depends on the power consumption demands of the electrically-powered laser light generator 25. The electrical conduits 21 and the jumper conduits 42 in FIG. 3 are selected to meet or exceed the current demands of the laser light generators 25 for the voltage and amperage of the current at which those devices are designed to operate.

[0049] Optionally, a shunt 79 may be provided on each module 20 to remove the laser light generator 25 of any given module 20 from the series circuit illustrated in FIG. 3 in the event that the laser light generator 25 pulls an excessive amount of current or otherwise malfunctions. This optional safety feature enables the string 60 of modules 20 to continue to function at a lesser capacity notwithstanding the malfunction of one of a plurality of modules 20.

[0050] The skirts 32 surrounding the legs 30, spring elements 31 and magnetic feet 23 of each module 20 of the string 60 of modules 20 of FIG. 3 are provided for engaging the exterior surface 90 of the pipe segment 91 to partially isolate the laser light beam 50 emitted by that module 20 from the surrounding seawater. The skirt 32 preserves heat and promotes heating of the adjacent portion of the pipe segment 31. It will be understood that other embodiments of the apparatus 60 comprising the string of modules 20 may employ skirts 32 having a varied configuration.

[0051] FIG. 4 is an elevation view of an alternate embodiment of the apparatus 60 of FIG. 3 magnetically secured to a subsea pipe segment 91 blocked by a solid material 92 deposited within the bore 94 of the pipe segment 91. As in FIG. 3, the modules 20 of the apparatus 60 of FIG. 4 are intercoupled using the flexible couplings 45. The skirt 32 of the apparatus 60 surrounds all of the legs 30, the spring elements 31, the magnetic feet 23 and the laser light beams 50 of the plurality of modules 20 of the apparatus 60. The skirt 32 of FIG. 4 also partially collapses upon engagement with the exterior surface 90 of the pipe segment 91.

[0052] The plurality of intercoupled modules 20 illustrated in FIG. 4 further includes a photo-sensor 100 to detect irradiation of the exterior surface 90 of the pipe segment 91 by laser light beam 50 emitted by the laser light emitting element 25 of a module 20 of the intercoupled plurality of modules 20 of FIG. 4. The photo-sensor 100 generates a signal to a processor 101 provided on the module 20. The processor 101 may also be coupled to receive a signal generated by the peripheral device 49 such as, for example, a hydrophone. It will be understood that conductive conduits, such as wires, that connect the photo-sensor 100 to the processor 101, or that connect the peripheral device 49 (hydrophone) to the processor 101, are not shown in FIG. 4 for purposes of clarity of the drawing.

[0053] FIG. 4 also illustrates the inclusion of a photo-sensor 100 disposed on each module 20 of the apparatus 60. The photo-sensor 100 is positioned to detect the laser light beam 50 emitted by the laser light emitting element 25 of the module 20. The photo-sensor 100 generates a signal to a processor 100 on the module 20. The processor 100 may relay the signal, or a loss of a signal, through a first umbilical 21 to a remotely operated vehicle 74 and/or to a marine vessel 70.

[0054] FIG. 5 is an elevation view of an embodiment of the apparatus 60 of the present invention magnetically secured to a curved subsea pipe segment 91 having an interior bore 94 that is blocked by a solid material 92 deposited within the bore 94 of the pipe segment 91. FIG. 5 better illustrates the function of the spring elements 31 intermediate the magnetic feet 23 and the legs 30 of each module 20 of the apparatus 60. It will be understood that the magnetic feet 23 of each module 20 of the apparatus 60 of FIG. 5 are misaligned to a greater extent with the apparatus 60 secured to a curved pipe segment 91 that they would be with the apparatus 60 secured to a straighter pipe segment 91 like those of FIGs. 3 and 4. The spring elements 31 provide the flexibility for the magnetic feet 23 to provide optimal magnetic securement by allowing the magnetic feet 23 to engage the exterior surface 90 of the pipe segment 91 in a flush manner rather than remaining in a fixed and inflexible relationship with the legs 30.

[0055] FIG. 5 also illustrates the utility of the flexible couplings 45 that secure each module 20 of the apparatus 60 with at least one other adjacent module 20. It will be noted that the curvature of the pipe segment 91 causes a greater separation 46 between adjacent modules 20 near the tops 34 of the modules 20 than at the magnetic feet 23. The flexible couplings 45 allow for this separation 46 without releasing any module 20 from the intercoupled relationship with the one or more adjacent modules 20.

[0056] FIG. 5 also illustrates an apparatus 60 including a plurality of intercoupled modules 20, each module 20 having a temperature sensor 102 to sense a temperature within the skirt 32 surrounding the legs 30 of the module 20. The temperature sensor 102 generates a signal to a processor 101 on the module 20 for storing or for further transmission to a remotely operated vehicle or to a marine vessel at the surface of the sea.

[0057] FIGs. 6-8 illustrate how the laser light beams 50A, 50B, 50C and 50D emitted by the plurality of modules 20 of an embodiment of an apparatus 60 of the present invention may together overlap one with one or more others to provide a continuous laser light exposure onto the exterior surface 90 of a pipe segment 91 having an interior bore 94 that is blocked by a solid material 92 deposited within the bore 94 of the pipe segment 91. The aggregated laser light beams 50A, 50B, 50C and SOD emitted by the plurality of modules 20 together provide continuous laser light exposure over a length L as illustrated in FIG. 6. FIG. 7 illustrates the power density of the individual laser light beams 50A, 50B, 50C and 50D emitted by the plurality of modules 20. FIG. 8 illustrates the cumulative power density of laser light beams 50A, 50B, SOC and SOD together delivered onto the pipe segment of FIG. 6 by the collection of modules 20 of the apparatus 60.

[0058] FIG. 9 is a plan view of a pair of modules 20A and 20B intercoupled using a flexible coupling 45 to form an embodiment of the apparatus 60 of the present invention having a short string (two) of the modules 20A and 20B. The electrical terminals, electrical risers and heat dissipation fins are excluded from FIGs. 9-14 to better illustrate the benefits provided by the flexible couplings 45. The flexible coupling 45 flexibly c connecting the leftmost module 20A to the rightmost module 20B can accommodate at least some separation 46 of the rightmost module 20B from an adjacent (leftmost) module 20A, as illustrated in FIG. 5. FIG. 10 is the plan view of the apparatus 60 of FIG. 9 after the rightmost module 20B is repositioned relative to the leftmost module 20A. FIG. 10 illustrates an additional degree of freedom of limited movement of a module 20B relative to the adjacent module 20A in the apparatus 60 of the present invention. In FIG. 10, the rightmost module 20B is rotated slightly counterclockwise relative to the leftmost module 20A to the position shown in dotted lines as module 20B' It will be understood that this additional degree of flexibility of the apparatus 60 enables the apparatus 60 to be more readily securable to a pipe segment 91 due to the adaptability and malleability of the apparatus 60.

[0059] FIG. 11 is the plan view of the modules 20A and 20B of FIG. 9 intercoupled using a pair of flexible couplings 45 in a spaced apart configuration one relative to the other. This configuration limits movement of the rightmost module 20B in the manner illustrated in FIG. 12. FIG. 12 is the plan view of FIG. 11 after the rightmost module 20B is repositioned relative to the leftmost module 20A so that the angles of the flexible couplings 45 are congruent and the modules 20A and 20B' remain parallel but offset by an amount depending on the dimensions of the modules 20A and 20B', the distance between the couplings 45 and the effective length of the couplings 45.

[0060] FIG. 13 is the plan view of the modules 20A and 20B of FIG. 9 after an additional two modules 20C and 20C are intercoupled, using flexible couplings 45, and the newly introduced modules 20C and 20D intercoupled one with the other and each with one of the original two modules 20A and 20B to form an embodiment of the apparatus 60 of the present invention having an array of modules 20. It will be understood that the term "array," as it is used herein, means a plurality of intercoupled modules 20 having a plurality of rows and a plurality of columns.

[0061] FIG. 14 is the plan view of the modules 20A, 20B, 20C and 20D of FIG. 13 after an additional flexible coupling 45 is added to further intercouple the diagonally opposed modules 20A and 20C. It will be understood that the addition of the fifth flexible coupling 45 present in FIG. 14 and not present in FIG. 13 will substantially prevent movement of the modules 20A, 20B, 20C and 20D one relative to the others.

[0062] The embodiments of the apparatus of FIGs. 9 and 11 include modules 20A and 20B that are coupled using flexible couplings 45 in a manner that enables an extended string and\or an extended array of a larger plurality of modules 20 to misalign to a limited extent and to thereby wrap circumferentially about an axis of a pipe segment 91. It will be understood that the combined freedom of limited misalignment, in multiple modes (circumferentially and elevationally) provided by the combination of the flexible couplings 45 in a favorable configuration will enable an extended string and/or array to conform to the exterior surface 90 of a pipe segment 91 and to prevent unwanted complications in securing the strings and/or arrays to a pipe segment using robotic machines. For example, but not by way of limitation, the capacity to misalign in an offset manner or in a circumferentially shifted manner as illustrated in FIGs. 9-14 enables an extended string and/or array of modules 20 to accommodate and conform to the curvature, bends and other features of the exterior surface 90 of the pipe segment 91. Similarly, the capacity to misalign in an offset manner or in a elevationally shifted manner as illustrated in FIG. 5 enables an extended string 60 and/or array 93 of modules 20 to accommodate and conform to the curvature, bends and other features of the exterior surface 90 of the pipe segment 91.

[0063] FIG. 15 is an end view of an alternate embodiment of the apparatus of the present invention magnetically secured to an exterior surface 91 of a subsea pipe segment 91 and including a transformer 56 to condition a voltage of electrical current provided to the plurality of modules 20 of the apparatus. It will be understood that the transmission of electrical current over extended lengths of transmission cable causes power loss due to resistance of the cable. The resistance losses are minimized by transmitting the current at a high voltage and low amperage pairing. The transformer 56 receives current through a conductive umbilical conduit 53, at a first voltage and amperage pairing, and conditions the current to a second voltage and amperage pairing that is more suitable for powering the laser light generators 25 of the modules 20. The module 20, visible underneath the transformer 56, receives the conditioned current through the electrical terminal 21 on the riser 43. The other modules 20, and the second electrical terminal 42 of the module 20, are hidden from view in FIG. 15 as the modules 20 are disposed on the pipe segment 91 in a linear configuration.

[0064] FIG. 15 illustrates the transformer 56 disposed atop the end module 20 of the apparatus and magnetically secured to the pipe segment 91 in a manner similar to the manner in which the modules 20 are secured to the pipe segment 91. The transformer 56 is magnetically secured to the pipe segment 91 with magnetic feet 59 coupled to legs 57 and having spring elements 58 intermediate the magnetic feet 59 and the legs 57 to provide for a small amount of misalignment of the rightmost magnetic foot 59 with the leftmost magnetic foot 59 due to the curvature of the exterior surface 90 of the pipe segment 91.

[0065] FIG. 16 is a sectional elevation view of an optional magnetic foot 23 that is coupled to a leg 30 of a module 20 (not shown) or a transformer 56 (not shown) of an embodiment of an apparatus of the present invention to provide, through a signal conduit 40, a signal corresponding to the temperature of the exterior surface 90 of the pipe segment 91 to which the module 20 is magnetically secured. The magnetic foot 23 of FIG. 16 comprises a cavity 97 within the magnetic foot 23 having a highly conductive plunger 46 movably received within a channel 97 and biased by a plunger spring 41. A contact end 47 of the plunger 46 is disposed to engage the exterior surface 90 of the pipe segment 91 as the magnetic foot 23 is magnetically engaged with the pipe segment 91. Engagement of the contact end 47 of the plunger 46 with the pipe segment 91 depresses the plunger 46 and the spring 41, and brings the plunger 46 into engagement with a temperature sensor 39, which may be a thermistor, that is coupled to the signal conduit 40. It will be understood that the magnetic foot 23 of FIG. 16 may be provided on one or a plurality of modules 20 and transformers 56 to provide temperature readings as needed to monitor the warming of the targeted portion of the pipe segment 91. It will be understood that the magnetic foot 23 that includes the temperature sensor 39 may be positioned either inside the skirt 32, as are the legs 30 that support the module 20 and that are coupled to the magnetic feet 23 that secure the module 20 to the exterior surface 90 of the pipe segment 91, or the magnetic foot 23 that includes the temperature sensor 39 may be disposed outside the skirt 32 and apart from the legs 30 that are interior to the skirt 32. It will be understood that the highly conductive nature of the pipe segment 91 will cause the temperature of the exterior surface 90 of the pipe segment 91 to be generally within a range of temperatures at all locations within close proximity to the module 20.

[0066] FIG. 17 is an illustration of a marine vessel 70 at the surface of a sea being used to deploy an embodiment of an apparatus of the present invention onto an exterior surface 90 of a subsea pipe segment 91 blocked by a solid material 92 deposited within the bore 94 of the pipe segment 91. FIG. 17 illustrates the usage of a storage unit 77 having rolling elements 78 and 79 and a rotatable reel 76 onto which an elongated string 60 of modules 20 can be wrapped for convenient storage of the string 60 of modules 20 for submersion and transportation to the blocked pipe segment 91. The storage unit 77 may be descended from the marine vessel 70 using a cable 71 and positioned proximal to the pipe segment 91. The marine vessel 70 may also submerge and lower a shuttle base 73 having a remotely operated shuttle 74 with a robotic arm 75 for manipulating and installing on the pipe segment 91 the string 60 of modules 20. The remotely operated shuttle 74 retrieves the string 60 of modules 20 from the reel 76 as the reel 76 rotates in the direction indicated by the arrow 80 on the reel 76. A motor 95 is coupled through a drive chain 96 to rotate a powered rolling elements 78 in a clockwise direction to assist in moving the storage unit 77 as the string 60 is reeled out and into magnetic engagement with the blocked pipe segment 91. The shuttle 74 is used to deposit the string 60 of modules 20 onto the pipe segment 91 as illustrated in FIG. 17 for use in heating the pipe segment 91 and removing at least a portion of the blockage 92.

[0067] FIG. 18 is an illustration of a marine vessel 70 and a plurality of submersible shuttle vehicles 74 being used to deploy embodiments of apparatuses 60 consisting of strings of modules 20 of the present invention onto a subsea pipe segment 91 blocked by a solid material 92 deposited within the bore of the pipe segment 91. FIG. 18 illustrates the usage of an alternate storage unit 77 for storing a plurality of apparatuses 60 of the present invention consisting of strings of modules 20. The storage unit 77 is illustrated as having been submerged and lowered into the sea using a cable 71. A plurality of shuttles 74 are provided for retrieving the apparatuses and depositing them on the exterior surface 90 of the pipe segment 91. The leftmost shuttle 74 in FIG. 18 is illustrated as having deposited a string 60 of modules 20 onto the exterior surface 90 of the pipe segment 91, the middle shuttle 74 is illustrated as approaching the pipe segment 91 and supporting another string 60 of modules 20 with robotic arms 75, and the rightmost shuttle 60 is illustrated as approaching the storage unit 77 to use the robotic arms 75 to retrieve another string 60 of modules 20 for deposit onto the pipe segment 91. Images of the operation of the shuttles 74 and the apparatus 60 may be provided by a camera 82 disposed on a remotely operated vehicle 73.

[0068] It will be understood that the flexible couplings 45 illustrated in FIGs. 3-5 and 9- 14 allow movement of one module 20 relative to an adjacent and intercoupled module 20 as described above in relation to these same figures. It will further be understood that the limited movement of adjacent modules 20 provided by the flexible couplings 45 can cause the extended strings 60 of modules 20 to become unwieldy and difficult to deposit and position on the pipe segment 91.

[0069] FIG. 19 is an elevation view of a leftmost and first embodiment of an apparatus 60A of the present invention magnetically secured to a subsea pipe segment 91 blocked by a solid material 92 deposited within the bore 94 of the pipe segment and a rightmost and second embodiment of the apparatus 60B being positioned for docking with the leftmost and first embodiment 60 to form an extended string of modules 20 magnetically secured to the pipe segment 91. The leftmost apparatus 60A includes a transformer 56, similar to that discussed above in connection with FIG. 15, and the leftmost apparatus 60A includes a string coupling receptacle 85 having an upwardly open cavity (not shown). The receptacle 85 is connected to an end of a support rod 86 that is received through a plurality of support rings 87 connected to individual modules 20 of the apparatus 20A. It will be understood that the support rod 86 and the support rings 87 enable supporting and positioning of the apparatus 20A for being deposited onto the exterior surface 90 of the pipe segment 91.

[0070] The rightmost apparatus 20B in FIG. 19 is being positioned for docking with the leftmost apparatus 20A. The rightmost apparatus 20B includes a support rod 86 received through a plurality of support rings 87 connected to individual modules 20 of the apparatus 20B. The rightmost apparatus 20B further includes a string coupling stabber 84 shaped for being received into the string coupling receptacle 85 of the leftmost apparatus 60A. The string coupling receptacle 85 of the leftmost apparatus 60A may further include a docking slot 89 into which a portion of the stabber 84 of the rightmost apparatus 60 is receivable to secure the leftmost apparatus 60A and the rightmost apparatus 60B one to the other to together form a longer apparatus.

[0071] FIG. 20 is a perspective view of a large subsea asset 69 to which an embodiment of an apparatus of the present invention is magnetically secured. The apparatus in FIG. 20 includes an array 93 of modules 20 magnetically secured to the vessel 69 to engage and to heat, through the impingement of a laser light beam 50 (not shown in FIG. 20) from each module 20 of the array 93 onto the vessel 69. The vessel 69 may be supported on the seafloor or on a subsea platform 64 by a plurality of legs 65. The vessel 69 may include a feed pipe 67 and a drain pipe 68 to together move liquid though the vessel 69. The array 93 of modules 20 of FIG. 20 may be powered through an umbilical 94 that includes an electrical current conductor.

[0072] It will be understood that the magnetic foot 23 of the modules 20 of embodiments of the present invention may be difficult to disengage after the blocked vessel 69 and/or pipe segment 91 are heated as described herein above. It is desirable to recover from the vessel 69 and/or the pipe segment 91 the embodiment of the string 60, array 93 or module 20 of the present invention for later use.

[0073] FIG. 21 is an elevation view of an alternate magnetic foot 23 of a module 20 (not shown) of an embodiment of an apparatus of the present invention equipped with an electromagnetic device 59 for impairing the magnetic field 54 of the magnetic foot 23. The embodiment of the magnetic foot 23 of FIG. 21 includes a first portion 23A having a first polarity and a second portion 23B having a second, opposite polarity. The magnetic foot 23 generates a magnetic field 54 that secures the magnetic foot 23, along with any module 20 (not shown) coupled to the leg 30 to which the magnetic foot 23 is connected, to the exterior surface 90 of a pipe segment 91. The alternate embodiment of the magnetic foot 23 illustrated in FIG. 21 includes a coiled conductor 61 through which a current can be passed to produce a second magnetic field to disrupt and/or impair the magnetic field 54 produced by the magnetic polarity of the first portion 23A and the second portion 23B. It will be understood that disruption and/or impairment of the magnetic field 54 that magnetically secures the magnetic foot 23 and the module 20 to which the magnetic foot 23 is connected will reduce the force required to remove the module 20 from the pipe segment 91.

[0074] FIG. 22 is a perspective view of a receptacle 85 coupled to an first apparatus 60A (not shown - see FIG. 19) of the present invention and a stabber 84 coupled to a second apparatus 60B of the present invention for the purpose of being inserted into the receptacle 85 on the first apparatus 20A for the purpose of coupling the first apparatus 20A and the second apparatus 20B into an extended string of modules 20, each having a laser light emitting element 25 (not shown) for irradiating a portion of the exterior surface 90 (not shown) of the pipe segment 91 (not shown).

[0075] A variety of peripheral devices and optional systems may be used with embodiments of the modules 20, strings 60 and arrays 93 of the present invention. For example, but not by way of limitation, a peripheral device 49 may be provided on one or more modules 20 of a string 60 or array 93. For example, but not by way of limitation, the peripheral device 49 (see FIG. 3) may, in one embodiment, comprise a hydrophone to detect acoustic signals generated during heating of the pipe segment 91 with laser light emitted from the modules 20. A solid gas hydrate, such as methane hydrate or ethane hydrate, disassociates, upon a sufficient decrease in pressure and/or a sufficient increase in temperature, into water and hydrocarbon gas. While decreasing pressure within a pipe segment may not always be feasible, embodiments of the present invention induce hydrate disassociation into water and hydrocarbon gas by heating a laser target on the exterior of the pipe segment using a laser. The heating of the laser target transfers heat to a portion of the interior bore of the pipe segment and to a solid deposit adhered to or formed on the interior bore of the pipe segment to disassociate the hydrate into water and gas. The resulting formation of gas bubbles such as, for example, methane gas bubbles and/or ethane gas bubbles, occurs as a result of the disassociation of a portion of the hydrate deposit proximal to the heated portion of the interior bore wall of the pipe segment. The gas bubbles escape the wall surface and/or the hydrate deposit and the formation of gas bubbles from the disassociating hydrate creates a pressure transient within the pipe segment. The change in the physical state of the solid hydrate as it disassociates into a gas phase and a liquid phase (water) creates an acoustic signal that is primarily the result of the liberation of the gas bubbles from the hydrate. Some of these bubbles quickly collapse as they contact surrounding fluid within the pipe segment and cool. The formation of the gas bubbles, and the subsequent collapse of at least some of the gas bubbles, generates acoustic waves in the interior bore of the pipe segment. The acoustic waves penetrate the pipe wall and can be detected by an peripheral device 49 such as a hydrophone disposed without, but proximal to, the pipe segment 91 as illustrated in FIG. 3. It will be understood that the peripheral device 49, such as a hydrophone, may be disposed on each module 20, on a string 60 of modules 60 (see FIGs. 3-6 and 17-19) or on an array 93 (see FIG. 20) of modules 20.

[0076] It should be noted that other physical changes occur as a result of the disassociation of the gas from the hydrate solid. As gas hydrates are solids that strongly resemble ice, stresses are initially produced inside the ice matrix as it is heated and as it expands. These stresses often result in audible acoustic waves caused by the physical and structural changes within the gas hydrate resulting from temperature changes induced by impingement of the laser light on the laser target on the pipe segment of interest.

[0077] Other acoustic waves may be generated as a result of the loosening of a hydrate blockage and physical displacement of a loosened blockage subject to a pressure differential. Upon initial heating by laser light impingement on the laser target on the pipe segment, a thin layer of liquid forms between the warmed pipe wall and the blockage due to the rapid dissipation of heat through the metal of the pipe wall and the localized onset of phase transition that starts along the interior bore wall of the pipe segment as a result of the laser impingement. It will be understood that a pressure differential across the gas hydrate blockage would result in a sudden displacement which can generate acoustic waves.

[0078] It will be understood that the term "intercoupled," as that term is used herein, is used to indicate that each module of a plurality of modules that form a string, or of a plurality of modules that form an array, is "coupled" to at least one other adjacent module. It will be clear that an interior module of a string, that is, a module that is not at the end of a string, will be coupled to two adjacent modules, and that an interior module within an array, that is, a module that is not along an edge of a module, may be coupled to four, five or even six other modules, depending on the positions of the flexible couplings that intercouple the modules.

[0079] It will be understood that, for electrical power supplied to a module, a string of modules and/or to an array of modules to be magnetically secured to a subsea pipe segment, submersible electrical connectors may be used to prevent unwanted water intrusion into electrical connectors. Inductive couplings may be used or, to prevent unwanted power losses associated with inductive couplings, water-tight electrical connectors available from "wet-mateable" connectors, a part of the Nautilus™ Series of electrical connectors made by Teledyne Oil & Gas Online - ODI Product Line of Thousand Oaks, California, USA and/or Teledyne ODI, Inc. of Daytona Beach, Florida, USA.

[0080] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components and/or groups, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The terms "preferably," "preferred," "prefer," "optionally," "may," and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.

[0081] The corresponding structures, materials, acts, and equivalents of all means or steps plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but it is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

27

We claim:

1. An apparatus (20), comprising;

a module (20);

a laser light emitting element (25) supported by a case of the module (20); and a plurality of legs (30) on the module (20);

at least one magnetic foot (23) coupled to an end of at least one of the plurality of legs (30); and

a power supply conduit coupled to the module (20) to provide power to the laser light emitting element (25);

wherein the module (20) is magnetically securahle at the at least one magnetic foot (23 ) to an exterior sur face (90) of a subsea pipe segment (91) comprising a magnetic material; and

wherein the laser light emitting element (25) is energizable to impinge a laser light beam (50) on a portion of the exterior surface (90) to heat a solid material (92) deposited on an interior bore (94) of the pipe segment (91 ) opposite a pipe wall (91) from the portion of the exterior surface (90).

2. The apparatus (20) of claim 1 , further comprising:

at least one spring element (31 ) disposed intermediate the at least one magnetic foot (23) and the at least one leg ( 30);

wherein the at least one spring element (31 ) is deformable to provide for alignment of the at least one magnetic foot (31 ) with a curvature of the exterior surface (90) of the pipe segment (91 ).

3. The apparatus (20) of claim 1, further comprising:

a skirt (32 ) surrounding a substantial portion of the laser light beam (50) intermediate the module (20) and the exterior surface (90) of the pipe segment (9.1 ) to which the module (20) is magnetically secured; wherein the skirt (32) at least partially isolates a space intermediate the module (20) and the exterior surface (90) of the pipe segment (91) from surrounding seawater to conserve heat produced by the laser light beam (50).

4. The apparatus (20) of claim 1 , further comprising".

a submersible and remotely operated vehicle; and

a first umbilical (21) having a first end coupled to the remotely operated vehicle and a second end coupled to the apparatus;

wherein the first umbilical (21) includes an electrically conducting conduit to power the laser emitting element (25).

5. The apparatus (20) of claim 1 , further comprising:

a submersible and remotely operated vehicle; and

a first umbilical (21 ) having a first end coupled to the remotely operated vehicle and a second end coupled to the apparatus (60);

wherein the first umbilical includes an optically conducting conduit to power the laser emitting element (25).

6. The apparatus (20) and system of claim 4, wherein the remotely operated vehicle (74) further includes a camera for generating a signal corresponding to an image of the pipe segment (91 ).

7. The apparatus (20) and system (103) of claim 6, wherein the remotely operated vehicle (73) further includes lights to enable the camera (82) to better capture images of the pipe segment (91) and the modules (20).

8. The apparatus (20) and system of claim 7, wherein the remotely operated vehicle (73) further includes:

a storage member (77) for storing the apparatus (60) during submersion of the remotely operated vehicle from a marine vessel (70) at a surface of the sea to a position proximal to the pipe segment (91); and a movable arm (75) activatable for deploying the apparatus (60) from die storage member (77) onto the exierior surface (90) of the pipe segment (91).

9. The apparatus (20) and system (103) of claim 8, wherein the movable arm (75 ) is activatabie to retrieve the apparatus (60) from the exterior surface (90) of the pipe segment (91).

10. The apparatus (20) and system (103) of claim 8, wherein the movable arm (75) of the remotely operated vehicle (74) is activatable to retrieve the apparatus (60) from the exterior surface (90) of the pipe segment (91): and

wherein the apparatus (60) is activatable to restore the apparatus (60) to the storage member (77).

.1 1. The apparatus (20) and system (103) of claim 7, further comprising:

a temperature sensor (39) disposed on the module (20) to contact the exterior surface (90) of the pipe segment (91) to which the module (20) is magnetically secured; wherein the temperature sensor (39) generates a signal corresponding to a detected temperature of the pipe segment. (91).

12, An apparatus (60), comprising:

a plurality of intercoupled modules (20), each module (20) having an energizahle laser Sight emitting element (25) coupled to a case (24) and a plurality of legs (30) extending from the case;

a plurality of magnetic feet (23), at least one magnetic foot (23) coupled to each of the plurality of legs (30); and

a plurality of flexible couplings (45), at least one flexible coupling (45) disposed intermediate each of the modules (20) and at least one other adjacent module (20) to interconnect the plurality of modules (20) into a siring of modules (20);

wherein the intercoupled modules (20) are magnetically securable at the plurality of magnetic feet (23) to an exterior surface (91 ) of a subsea pipe segment (91) comprising a magnetic material; and wherein the laser light emitting elements (25) of the plurality of modules (20) are together energizable to heat with laser light (50) an elongate portion of an exterior surface (91) of the pipe segment (91 ) to which the apparatus (60) is magnetically secured ,

13. The apparatus (60) of claim 12, further comprising:

a skirt (32) extending from at least one of the intercoupled modules (20) to surround at least some of the plural ity of legs (30);

wherein the skirt (32) at least partially isolates at least one laser light beam (50) from surrounding seawater proximal to the pipe segment (91).

14. The apparatus (60) of claim 33, wherein the skirt (32) surrounds all of the legs (30) of the intercoupled modules (20) to at least partially isolate a plurality of laser light beams (50) from surrounding seawater proximal to the pipe segment (91).

15. The apparatus (60) of claim 14, further comprising:

a plurality of spring elements (31) disposed intermediate the plurality of magnetic feet (23) and the plurality of legs (30) of each module (20);

wherein the plurality of spring elements (31 ) are each deforraable to provide for alignment of the plurality of magnetic feet (23) with a portion of the exterior surface (90) of the pipe segment (91) to which the plurality of magnetic feet (23) are magnetically secured.

16. The apparatus (60) of claim 15, further comprising:

a submersible and remotely operated vehicle (73); and

a first umbilical (21. S3) having a first end coupled to the apparatus (60) and a second end coupled to the remotely operated vehicle (73 k the first umbilical (21 , 53} including an electrical conduit (21) to conduct power from the remotely operated vehicle (73) to the laser emitting elements (25) of the apparatus (60).

1.7. The apparatus (60) of claim 16, wherein the remotely operated vehicle (73) former includes; a movable arm (75) for positioning the plurality of intercoupled modules (20) in a magnetically secured condition on an exterior surface (90) of a subsea. pipe segment (91 ) to together impinge laser light (50) emitted by the laser emitting elements (25) onto the exterior surface (90) of the pipe segment (91).

18. The apparatus (60) of claim 12, further comprising:

a tempera tare sensor (39) disposable in contact with the exterior surface (90) of the pipe segment (91) to detect a temperature of the exterior surface (90 ) and to generate a. signal (40) corresponding to a detected temperature.

19. The apparatus (60) of claim 18, wherein the temperature sensor (39) is disposed within a magnetic foot (23) that engages the exterior surface (90) of the pipe segment (91) to which the apparatus (60) is magnetically secured.

20. The apparatus (60) of claim 12, further comprising:

at least one hydrophone (49) coupled to at least one of the modules (20) of the apparatus (60) to detect acoustic signals generated as a result of heat imparted to the pipe segment (91) by the laser light beams (50) emitted by the modules (20) of the apparatus (60).

21. A system (103), comprising:

an apparatus (60) having a plurality of intercoupled modules (20), each module (20) of the apparatus (60) having an energizable laser light emitting element (25) coupled to a case (24) and a plurality of legs (30) extending from the case (24);

a plurality of magnetic feet (23), at least one magnetic foot (23) coupled to each of the plurality of legs (30) of each module (20) of the apparatus (60);

a plurality of flexible couplings (45), at least one flexible coupling (45) disposed intermediate each of the mod uies (20) and at least one other adjacent module (20) of the apparatus (60) to interconnect the plurality of modules (20) into a siring of modules (20); and a storage unit (77) for storing the plurality of intercoupled modules (20), the storage unit (77) including a storage reel (76) about which the plurality of intercoupled modules (20) is disposed for submersion and transport to the proximity of the pipe segment (91 );

wherein the plurality of intercoupled modules (20) is magnetically secnrable at the plurality of magnetic feet (23) to an exterior surface (91) of a subsea pipe segment (91) comprising a magnetic material; and

wherein the laser light emitting elements (25) of the plurality of modules (20) of the apparatus (60) are together energizable to heat with laser light beams (50) an elongate portion of an exterior surface (91) of the pipe segment (91 ) to which the plurality of intercoupled modules (60) is magnetically secured.

22. The system of claim 21 , wherein the storage unit (77) further comprises:

a first set of roll ing elemen ts (79) for engaging the pipe segment (91):

wherein the first set of rolling elements (79) enable the storage unit (77) to move along the pipe segment (91) as the plurality of intercoupled modules (20) of the apparatus

(60) is reeled out from the storage reel (76).

23. The system of claim 22, further comprising:

a motor (95) on the storage unit (77) coupled, to drive a second set of rolling elements (78);

wherein operation of the motor (95) moves the storage unit (77) along the pipe segment (91) as the storage reel (76) rotates.