MECHANICALLY LINED PIPE

BACKGROUND

Field

[0001] Aspects of the present disclosure generally relate to apparatus and methods for reeling and unreeling mechanically lined pipe (MLP).

Description of the Related Art

[0002] There are many methods of laying deep water pipelines, such as reel- laying. The pipe for performing such laying operations is generally stored on large reels. The reeling and unreeling of MLP from large reels is prone to problems like liner wrinkling.

[0003] Therefore, what is needed is an improved apparatus for and method of loading pipe on to a vessel from shore and laying the pipe from the vessel into a target location.

SUMMARY

[0004] Aspects of the present disclosure generally relate to apparatus, systems, and methods for reeling and unreeling mechanically lined pipe.

[0005] In one implementation, a method of reeling a pipeline includes positioning a friction seal at a predetermined distance from an end of a first stalk, and coupling one or more additional stalks to the end of the first stalk to form a pipeline section. The coupling of the one or more additional stalks includes, for each one of the one or more additional stalks coupled, moving the friction seal to the predetermined distance from an end of the respective one of the one or more additional stalks. The method also includes maintaining a predetermined pressure in an internal volume of the pipeline section during the coupling of the one or more additional stalks and loading of the pipeline section onto a reel.

[0006] In one implementation, a method of reeling a pipeline includes coupling a first end of a first stalk to a manifold disposed concentrically on a reel. The method also includes disposing, in the first end of the first stalk, a friction seal in a first location. The method also includes applying pressure to an internal volume of the first stalk to move the friction seal to a predetermined distance from a second end of the first stalk. The method also includes pressurizing the first stalk to a predetermined pressure after moving the friction seal to the predetermined distance from the second end of the first stalk. The method also includes loading the first stalk onto the reel while the first stalk is at the predetermined pressure, and coupling a first end of a second stalk to a second end of the first stalk. The first stalk and the second stalk form at least part of the pipeline. The method also includes applying pressure to the internal volume of the first stalk to move the friction seal to a predetermined distance from a second end of the second stalk. The method also includes pressurizing the second stalk to the predetermined pressure after moving the friction seal to the predetermined distance from the second end of the second stalk. The method also includes loading the second stalk onto the reel while the second stalk is at the predetermined pressure.

[0007] In one implementation, a system for reeling pipelines includes a reel, and a manifold coupled to the reel. The manifold includes a plurality of pressure pump connections. The system also includes a pressure pump removably coupled to at least one connection of the plurality of pressure pump connections via a pressure line. The system also includes a coupling coupled to the at least one connection of the plurality of pressure pump connections. The coupling is fluidly connected to the pressure pump through the manifold to pressurize a pipe stalk upon supply of a pressurized fluid from the pressure pump to the coupling.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, as the disclosure may admit to other equally effective embodiments. [0009] Figure 1 is a partial schematic illustration of a reeling system, according to one implementation.

[0010] Figure 2 is a partial schematic illustration of a system for reeling pipelines from on-shore locations to vessels, according to one implementation.

[0011] Figure 3A is a partial schematic isometric view of a circular manifold assembly, according to one implementation.

[0012] Figure 3B is a partial schematic isometric view of a circular manifold disposed on a reel, according to one implementation.

[0013] Figure 3C is an enlarged schematic view of the circular manifold and the reel illustrated in Figure 3B, according to one implementation.

[0014] Figure 3D is a side schematic view of the circular manifold and the reel illustrated in Figure 3C, according to one implementation.

[0015] Figure 4 is a schematic flow chart of a method of reeling and laying pipe, according to one implementation.

[0016] Figures 5A-5F include a series of partial schematic illustrations of a friction seal during reeling of pipeline, according to one implementation.

[0017] Figure 6A illustrates a pressurized pipeline, according to one implementation.

[0018] Figure 6B illustrates the pressurized pipeline shown in Figure 6A, according to one implementation.

[0019] Figure 7 is a partial schematic illustration of a tower on an offshore vessel, according to one implementation.

[0020] Figure 8 is a partial schematic illustration of a pressurized pipeline, according to one implementation.

[0021] Figure 9 is a partial schematic illustration of a weld location of a pipeline 1101 , according to one implementation. [0022] Figure 10A is an illustration of pipe segment cutting and removal, according to one implementation.

[0023] Figure 10B illustrates the pipeline after the pipe segment is removed as shown in Figure 10A, according to one implementation.

[0024] Figure 11 illustrates a pipeline configuration according to one implementation.

[0025] Figure 12 illustrates winch removal from a pipeline according to one implementation.

[0026] Figure 13 illustrates a pipeline after the winch is removed according to one implementation.

[0027] Figure 14 illustrates a pipeline payout operation, according to one implementation.

[0028] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

DETAILED DESCRIPTION

[0029] Aspects of the present disclosure generally relate to apparatus, systems, and methods for reeling and unreeling mechanically lined pipe. Exemplary aspects relate to methods of assembling and transferring a plurality of pipe stalks (“stalks”). The stalks are welded together to form a pipeline or a portion of a pipeline. The welding, referred to herein as tying-in, is done in an on-shore location and the stalk(s) are transferred from this on-shore location to a reel on a vessel location and subsequently transferred from the reel on the vessel to the ocean floor. There are numerous challenges presented by this transfer process and by laying pipeline on or underneath the ocean floor, including kinking, and buckling.

[0030] One of the challenges with using a reel barge is that the pipe may kink, buckle, misalign, or otherwise fail to properly load on to the reel from the shore location where the stalks are welded. Similar problems may be experienced during unloading of mechanically lined pipe, with the additional challenge of liner wrinkling.

[0031] Using the apparatus, systems and/or methods herein, a plurality of stalks is assembled on-shore and loaded on to a laying vessel or on a reel of a transport vessel while pressurized. The plurality of stalks is assembled by welding the plurality of stalks together. In one example, the plurality of stalks are then unloaded from the reel into a seabed or other location while remaining at a predetermined pressure. The plurality of stalks may be maintained at a constant pressure. Maintaining the plurality of stalks at a nearly constant pressure reduces or eliminates the probability of kinking or buckling of the reeled/unreeled pipeline. In one example, the plurality of stalks is depressurized to an ambient pressure and then unloaded from the reel into a seabed or other location while remaining at the ambient pressure.

[0032] In one example, a friction seal is employed in the assembly of pipe stalks on shore, such that the friction seal is moved from stalk to stalk. The friction seal is held in place by pressure in the pipe that is maintained during loading of the plurality of stalks on to the reel.

[0033] In one example, a first end of a first stalk is loaded on to a reel, and a friction seal is disposed in the first stalk. The reel is located on a vessel. The reel includes a circular manifold (discussed below) that is employed to generate pressure inside of a plurality of stalks (such as the first stalk, and a second stalk— discussed below) as the stalks are welded together on-shore. The reel and the circular manifold discussed herein may be located on-shore while the plurality stalks are welded together, and later transferred to a laying vessel or transport vessel. The friction seal is moved to a position of a distance“X” from a second end of the first stalk, and when the second end of the first stalk is at the tie-in station, the second end is welded to a first end of a second stalk and the friction seal is subsequently moved through the second stalk to a predetermined distance from a second end of the second stalk. The friction seal is adjacent a terminal end (e.g., the end not coupled to the circular manifold) of the reeled pipeline. The friction seal prevents pressure from escaping the terminal end of the pipeline and towards the first end that is coupled to the circular manifold, facilitating the terminal end to remain pressurized. [0034] The distance“X” discussed herein is a distance engineered to reduce the likelihood the friction seal inadvertently exits the pipeline in the event the friction seal releases and the pressure behind the friction seal pushes the friction seal. In one example, the“X” distance is calculated based on an amount of additional volume of fluid to be inserted in the pipeline section in order to reach the target pressure during pipeline pressurization. In an example where there are no locks on the friction seal, the friction seal will move inside the pipe until the applied pressure is no longer able to move the friction seal against frictional forces. The friction seal moves until the applied pressure that is applied to a first side of the friction seal is unable to overcome the frictional forces of the frictional seal and the pressure applied to a second side (e.g., an opposite side) of the friction seal (for example, ambient pressure). In such an example, the pressure applied on each side of the friction seal may be equal. The friction seal is designed to move when the differential pressure applied to the first side of the friction seal exceeds a predetermined value.

[0035] In one embodiment, which can be combined with other embodiments, the distance“X” is at least 25 percent of a length of the stalk being tied-in to the pipeline. In one embodiment, which can be combined with other embodiments, the distance “X” is 1.0 m or more, such as 10.0 m or more.

[0036] Subsequent tie-ins of stalks may be performed in a similar manner until the last stalk in the pipeline or pipeline section is loaded. In one example, a friction seal receiver is coupled to the inside of the last stalk in a section of the last stalk in an unpressurized state, e.g., at an ambient pressure side of the friction seal. The friction seal is then moved through the last stalk and caught by the friction seal receiver. The friction seal receiver may be configured with a valve for maintaining pressure within the pipeline including the plurality of stalks once the friction seal is removed from the pipeline. Thus, the reel, when loaded, includes a plurality of pressurized pipe stalks, and, during fabrication of the pipeline portion, a predetermined pressure is maintained in the pipeline as it is formed via the tie-ins of stalks. Optionally, prior to removal of the friction seal, it is contemplated that a sacrificial length of unpressurized stalks may be used to facilitate adjustment of vessel equipment, including tensioners or straighteners. In such an example, the unpressurized stalks are sacrificially removed after adjustment of the vessel hardware, and then the friction seal is removed. In one example, the sacrificial section is about 12 joints of pipeline in length.

[0037] In one embodiment, which can be combined with other embodiments, the predetermined pressure within the pipeline having the plurality of stalks is from 0 bar to 50 bar, such as 5 bar to less than 30 bar, for example 5 bar to 25 bar. In one example, the predetermined pressure is maintained until the last stalk of the pipeline is reeled onto the reel.

[0038] The pipeline, after being loaded onto the reel, can be unloaded and the pipe laid on the seabed while the pipe is pressurized, which reduces the likelihood of liner wrinkling, buckling, or other undesirable results during the laying process. In one example, a pressure (such as the predetermined pressure) is maintained during reeling, transportation of the reel to an offshore location, and unreeling. An optional cap may be attached to the terminal end of the pipeline after the friction seal is removed to facilitate maintaining the predetermined pressure in the pipeline. In one example, the predetermined pressure is maintained during reeling, the pressure is then relieved, and the reel is transported to an offshore location. The pipeline is then re-pressurized for deployment. In one example, the predetermined pressure is maintained during reeling and then the pipeline is depressurized to an ambient pressure. The reel is then transported to an offshore location with the pipeline at the ambient pressure with or without water inside the pipeline. The pipeline is then unloaded toward a seafloor at the ambient pressure (with or without water inside the pipeline).

[0039] An accumulator is not necessary for the systems and methods herein to facilitate pressurization of the pipeline. Accumulators may be employed in some systems to store energy or dampen pressure fluctuations, but are not required for the systems and methods disclosed herein. Rather, pressure within the pipeline may be constantly monitored, and adjusted on the fly to maintain a predetermined pressure. Examples which do not utilize accumulators avoid the expenses associated with accumulators.

[0040] Figure 1 is a partial schematic illustration of a reeling system 100, according to one implementation. The reeling system 100 includes at least two regions, a first on-shore region 100A and a second, adjacent, on-board region 100B. The on-board region 100B is on-board an offshore vessel 190. The first on-shore region 100A includes a tie-in module 102 (which includes a pig location 104) adjacent to an onshore tensioner 106 which is adjacent to a joint coating station 110. One or more on-shore rollers 112 (two are shown) may be employed to advance the stalk 108 from the tie-in module 102, the onshore tensioner 106, and the joint coating station 110 and toward one or more on-board rollers 114 that are part part of the on- board region 100B. The on-board region 100B includes a tower 116 that supports a winch wire 118 and a crane 120 that is removably coupled to a reel 122 that is loaded with pressurized pipeline coiled on the reel 122. A working basket 188 is coupled to the reel 122 and one or more reel walkers 186 are configured to walk the reel 122. The reel 122 is configured to rotate to reel the stalk 108 (and additional stalks of the pipeline) onto the reel 122. A crane line 184 is removably coupled to the reel 122.

[0041] Figure 2 is a partial schematic illustration of a system 200 for reeling pipelines from on-shore locations to vessels, according to one implementation. The system 200 includes equipment in different, distinct locations. A first location 202 is an on-shore location. The on-shore location 202 may be, for example, quayside or dockside at a fabrication facility or dock, and may be used to load stalks of pipe on to a vessel to form at least part of a pipeline. The on-shore location 202 includes at least one tie-in station 202A, tensioner 202B, field joint coating station 202C, and one or more rollers 202D.

[0042] A second location 204 that is an on-board location is positioned adjacent the on-shore location 202. In one example, the on-board location is on-board a vessel, such as an offshore oil and gas vessel. The on-board location 204 includes one or more rollers 204A that receive pressurized pipeline from the on-shore location 202, such as from the one or more rollers 202D of the on-shore location 202. The on-board location 204 includes a tower 204B, one or more winches 204C, a crane 204D, and a reel 204E. The reel 204E includes a frame that defines a center of the reel 204E. A circular manifold 204F is disposed on the reel 204E and concentrically to the center of the reel 204E. The circular manifold 204F is removably coupled to the reel 204E, and a pipe initiation head is connected to the manifold 204F as discussed in detail in Figures 3A and 3B in order to maintain a predetermined pressure in the pipeline as the pipeline is formed via tying in additional stalks at the tie-in station 202A.

[0043] Figure 3A is a partial schematic isometric view of a circular manifold assembly 300A, according to one implementation. The circular manifold assembly 300A in Figure 3A includes a circular manifold 302. The circular manifold 302 is a continuous, connected, hollow structure having an interior diameter 312 and an outside diameter 310. The circular manifold 302 may be used as the circular manifold 204F described above. The circular manifold 302 includes a plurality of inlets and outlets that may collectively be referred to as a plurality of pressure pump connections 304. The plurality of pressure pump connections 304 is disposed around an exterior 314 of the circular manifold 302. The pressure pump connections 304 are evenly spaced from each other. The pressure pump connections 304 may be patterned or otherwise irregularly spaced. In one example, the circular manifold assembly 300A includes a single pressure pump connection 304. A pressure pump 390 is connected to at least one of the pressure pump connections 304 via a pressure line 306. A coupling 308 is included for connecting the circular manifold 302 to a stalk of a pipeline to be reeled and/or unreeled. The coupling 308 may be a rigid or semi-rigid. The pressure pump 390 is in fluid communication with a pipe stalk (such as the stalk 108 of Figure 1 ) of the pipeline to facilitate pressurization of the pipeline during reeling/unreeling of the pipeline. Fluid, such as liquid water, is pumped from the pressure pump 390 through the pressure line 306 and the circular manifold 302, through the coupling 308, and into the pipeline connected to the coupling 308. As additional stalks are added to the terminal end of the pipeline, additional fluid is pumped through the circular manifold 302 so that pressure at a predetermined pressure as each additional stalk is added and reeled.

[0044] Figure 3B is a partial schematic isometric view of a circular manifold 302 disposed on a reel 316, according to one implementation. The reel 316 having the circular manifold 302 may be used as the reel 122 illustrated in Figure 1 and/or the reel 204E illustrated in Figure 2. The reel 316 includes a first side 318 and a second side 320 that are separated by and disposed on either side of a center portion 322. During operation of the reel 316, a plurality of pressurized or unpressurized pipe may be disposed around the center portion 322. Each of the first and second sides 318, 320 includes a plurality of spokes 324 extending from a reel coupling mechanism 330 (e.g., axle) extending beyond each of the first side 318 and the second side 320. The plurality of spokes 324 form a plurality of reel pockets 326 in which the circular manifold 302 is disposed. The plurality of spokes 324 are each coupled to a first outer edge 318A and a second outer edge 320A of each side 318 and 320, respectively. Each spoke 324 is additionally coupled to the reel coupling mechanisms 330 in a radially-extending configuration. One or more reel supports 320B, 320C may be positioned concentrically about the reel coupling mechanism 330, and may be coupled to the spokes 324 to impart rigidity to the reel 316. Each reel pocket 326 is disposed between two adjacent spokes 324 that extend radially from the reel coupling mechanism 330 to meet at one of the respective first or second outer edges 318A or 320A. In one example, the reel pockets 326 are at least partially formed by intersections between the plurality of spokes 324 and one of the reel supports 320B, 320C.

[0045] In one example, the reel 316 is driven by one or more actuators that are configured to rotate the reel 316 in one or more of a loading direction 328A and/or an unloading direction 328B to load and/or unload pipelines. The loading direction 328A is opposite of the unloading direction 328B.

[0046] Figure 3C is an enlarged schematic view of the circular manifold 302 and the reel 316 illustrated in Figure 3B, according to one implementation. Figure 3D is a side schematic view of the circular manifold 302 and the reel 316 illustrated in Figure 3C, according to one implementation. The coupling 308 connects to an initiation head 388, fluidly connecting the circular manifold 302 to the initiation head 388. The initiation head 388 is coupled to a pipe head of a pipeline 386. The pipe head may be disposed at a first end of a first stalk of the pipeline 386. The initiation head 388 is mounted on a mount plate 384. The mount plate 384 is coupled to one of the first or second sides 318, 320 using for example one or more bolts 382. In one example, the mount plate 384 is a clevis plate. When pressurized fluid is supplied from the pressure pump 390, pressurized fluid flows into the circular manifold 302 from the pressure line 306, into the coupling 308 from the circular manifold 302, and into the initiation head 388 from the coupling 308. The pressurized fluid flows into the pipeline 386 from the initiation head 388 to pressurize the pipeline 386 and/or to move a friction seal disposed in the pipeline 386.

[0047] Figure 4 is a schematic flow chart of a method 400 of reeling and laying pipe, according to one implementation. At block 404, a first stalk of pipe is coupled to a circular manifold located on a reel. At block 406, a friction seal is disposed in a first end of the first stalk. While the first stalk is maintained in a substantially linear configuration (e.g., not wrapped around the reel), one or more additional stalks of pipe may be coupled to the first stalk. Once an operator makes a determination to wrap the joined stalks (e.g., the pipeline) around the reel, pressure is first applied to the stalk(s) via the manifold. The applied pressure is applied behind the friction seal and in a direction from the first end of the first stalk to a terminal end of the stalk(s). The first end is connected to a coupling of the circular manifold for receiving pressurized fluid. The applied pressure pushes the friction seal in a direction from the first end toward the terminal end and positions the friction seal at a distance“X” from the terminal end of the pipeline. The distance “X” may vary among and between stalk interior diameters, exterior diameters, wall size, stalk length, or other factors or combinations of factors. In one example, the friction seal stops short of the terminal end at the distance“X” from the terminal end. In one example, it is contemplated that the additional stalks may be coupled to the first stalk prior to insertion of the friction seal. In such an example, the length of travel of the friction seal is reduced during pressurization.

[0048] At block 408, the pipeline is pressurized. The pressurization at block 408 includes pressurizing the pipeline to an internal pressure (e.g., a predetermined pressure) from 0 bar to 50 bar, such as 5 bar to less than 30 bar, for example 5 bar to 25 bar. At block 410, while the pressure is maintained at the predetermined pressure, the pipeline is reeled onto the reel until a terminal end of the pipeline is in position at the tie-in station.

[0049] During the reeling at block 410, the internal pressure of the internal volume of the pipeline is monitored and, in an optional block 412, the pipeline is re- pressurized as needed if the pressure drops below a predetermined threshold. In one example, one or more pressure gauges connected to the circular manifold monitor an operating pressure (such as an internal pipe pressure of the pipeline having one or more stalks) at block 410. The one or more pressure gauges transmit an indication to a controller if the internal pipe pressure falls below the predetermined threshold. In one example, the predetermined threshold is set to be at or within a range of the predetermined pressure. In an example where the predetermined pressure is from 5 bar to 25 bar, the predetermined threshold is set to be within 5 bar to 25 bar. The one or more pressure gauges transmit an indication to the controller for the controller to cause re-pressurization of the pipeline at block 412 to cause the internal pipe pressure to be above the predetermined threshold and/or within a range of the predetermined pressure. Once the first stalk is pressurized and has been reeled towards the vessel at block 410 such that the second end of the first stalk reaches a tie-in station on-shore, the pressure pump line may optionally be disconnected from the manifold.

[0050] At block 416, an additional stalk of pipe is coupled to the pipeline at the tie- in station by coupling a first end of the additional stalk of pipe to the terminal end of the first stalk of pipe. As illustrated at block 420, one or more of blocks 406-416 may be repeated for each additional stalk of pipe tied into the pipeline until the last stalk is tied into the pipeline using welding. For example, subsequent to the tie-in of one or more additional stalks, the pipeline is pressurized as described above to move the friction seal to a distance of“X” from the terminal end of the pipeline having the one or more additional stalks. The pressure pump may be reconnected, if need be, to facilitate pipeline pressurization. In examples where the friction seal is moved to the distance“X” from the terminal end of the pipeline, the movement may be executed by monitoring the movement of the friction seal using a beacon from a location co-located or remote from the tie-in station. The friction seal is moved to each new stalk as stalks are tied-in to the pipeline, which maintains the pressure in the pipeline as the pipeline is reeled. Maintaining pressure in the pipeline during reeling reduces or eliminates kinks in the pipeline and other challenges presented by reeling long lengths of pipeline.

[0051] After a final stalk is tied-in to the pipeline at block 420, and the pressure pump is reconnected to the reel manifold, the friction seal is moved using the pressurization to a final position at block 424. This final position of the friction seal may be referred to as a Ύ” distance, and may comprise a range in distance from 100 m - 200 m from the terminal end of the pipeline. Therefore, the length of pipe along the Ύ” distance is not pressurized. The length Ύ” may be used for adjusting equipment on the vessel, and as such, may be sacrificial. Because the stalks are sacrificial, kinks within the sacrificial stalks will not affect the final laid pipeline. Additionally, the length of sacrificial joints may be selected such that the length is equal to or less than a length of stalks which may be joined onshore (e.g., may be accommodated on shore without reeling). Subsequently, after removing the sacrificial joint (and thus repositioning the friction seal a distance X from the terminal end of the pipeline), at block 426 a friction seal receiver is coupled to the terminal end of the final stalk, and the line is pumped until the friction seal is disposed into the friction seal receiver at block 428.

[0052] At block 430, a receiver valve is closed to maintain the pressure in the pipeline and to jack down a tower on the vessel until the vessel is at a predetermined location, such as a predetermined offshore location. Subsequently, once the vessel reaches the predetermined offshore location, the tower is jacked back up. During operations at blocks 424, 426, 428, and 430, the pipeline remains pressurized between 5 bar and 25 bar, e.g., at the predetermined pressure. At block 432, subsequent to the tower being jacked down into a laying location where the pipe is to be disposed from the vessel on to or beneath the ocean floor or other location, the pipeline is depressurized and the length of the pipe containing the friction seal receiver, which is now coupled to or including the friction seal, is removed.

[0053] In one example, at block 434, a pipeline end termination (PLET) comprising a pressure cap is welded to the pipeline on the tower. The pipeline is subsequently re-pressurized at block 436 to be between about 5 bar and 25 bar (e.g., the predetermined pressure) and subsequently payed out off of the reel (laid on or beneath the ocean floor or other target location) at block 438 while remaining at the constant pressure (for example the predetermined pressure) established during the loading of the stalks on to the reel. During the pipe laying at block 438, the pressure is monitored at block 440 and the line is re-pressurized at block 442 if the pressure gauges determine that the internal pipeline pressure has fallen below a predetermined target or a low end of a target range. [0054] In one example, at block 432, an internal volume of the pipeline on the reel is depressurized to an ambient pressure prior to transporting the pipeline on the reel to an offshore location. The ambient pressure can be an atmospheric pressure, such as an atmospheric pressure at sea level. At block 444, the pipeline on the reel is transported on a vessel to an offshore location while the internal volume of the pipeline is at the ambient pressure. The transportation of the pipeline at block 444 occurs subsequently to the depressurization to the ambient pressure at block 432. At block 446, the pipeline is unloaded from the reel and toward a seafloor at the offshore location. The unloading at block 446 occurs while the pipeline is at the ambient pressure. The present disclosure contemplates that portions of the internal volume of the pipeline that are deployed below a sea level may rise above the ambient pressure due to water from the sea entering the internal volume. In one embodiment, which can be combined with other embodiments, an end of the pipeline unloaded at block 446 includes a pressure cap, PLET, installation head, and/or a seal that facilitates preventing sea water from entering the internal volume of the pipeline as the pipeline is unloaded toward the seafloor. Preventing sea water from entering the pipeline facilitates maintaining the internal volume of the pipeline at the ambient pressure. The unloading of the pipeline at block 446 includes using a tensioner of a tower to move the pipeline through one or more straighteners on the tower.

[0055] At block 446, the pipeline is maintained during unloading at the same bend direction as a bend direction that was applied to the pipeline during loading of the pipeline onto the reel at block 410. The same bend direction may be established, for example, by loading the pipeline onto the reel using a loading direction (such as the loading direction 328A described above) that is opposite of an unloading direction (such as the unloading direction 328B described above).

[0056] In one embodiment, which can be combined with other embodiments, at least a portion of the pipeline is re-loaded (re-reeled) back onto the reel after being unloaded at block 446. The pipeline is re-loaded while the pipeline is at the ambient pressure. The one or more straighteners of the tower or set to be fully open while the pipeline is re-loaded onto the reel to facilitate maintaining the same bend direction for the pipeline. [0057] Transporting the pipeline at the ambient pressure (such as at block 444) and/or unloading the pipeline from the reel at the ambient pressure (such as at 446) facilitates several benefits such as weight savings, time savings, operational cost savings, and/or increased pipeline carrying capacity for the reel and vessel. Reels and/or vessels have weight carrying capacities in regard to the size and/or length of pipeline that may be carried in a single trip. The absence of a pressurized fluid (such as water) from a pipeline facilitates enabling a given reel and vessel to carry more pipeline in a single trip. Carrying more pipeline in a given trip of a vessel facilitates reducing the number of trips during an oil and gas operation. Reducing the number of trips can save millions of dollars in operation costs. Maintaining an internal volume of a pipeline at an ambient pressure also saves time that would be spent on pressurizing or depressurizing the pipeline to a certain pressure for a particular operation. Maintaining the pipeline at the ambient pressure also facilitates efficient and effective transportation, maneuvering, and/or cutting of the pipeline.

[0058] Maintaining the pipeline at the same bend direction facilitates reducing or eliminating wrinkling and/or kinking of the pipeline, such as wrinkling of a liner of the pipeline, when the pipeline is unloaded at the ambient pressure.

[0059] Figures 5A-5F include a series of partial schematic illustrations of a friction seal 508 during reeling of pipeline, according to one implementation. Figures 5A-5F are described with respect to a reel 502 and an tie-in 504, each representing a“side” of the process of using a friction seal 508 in a plurality of pipe stalks that form a pipeline. One or more of the reel 503 or the tie-in 504 may be on-shore or offshore, such as on a vessel. In the example illustrated, the reel 503 is an on-shore reel and the tie-in 504 is an on-shore tie-in. FIG. 5A illustrates a first end 522 of a first stalk 506 and a friction seal 508 disposed in the first stalk 506 and adjacent to the first end 522 of the first stalk 506. Subsequently, as shown in FIG. 5B, the first stalk 506 is pressurized using applied pressure, as illustrated by arrows 510. Pressure is applied to an internal volume 509 of the first stalk 506. The applied pressure moves the friction seal 508 (as indicated by arrows 514) to a position located at a distance 512 from a second end 536 of the first stalk 506. The friction seal 508 moves in a direction from the first end 522 of first stalk 506 toward the second end 536 of the first stalk 506. The friction seal 508 is moves to the distance 512 from a terminal end of the pipeline that is defined by the second end 536 of the first stalk 506 in Figure 5B.

[0060] The distance 512 is measured from the second end 536 of the first stalk 506 that defines the terminal end, and may be calculated based on a stalk interior diameter, exterior diameter, pipe material(s), pipe wall thickness, overall length of stalk, or combinations of those or other factors. It is appreciated that the overall lengths of each stalk (such as the first stalk 506 and the second stalk 516 discussed below) may be from 30 feet to 90 feet or more. The distance 512 is equal to the distance“X” discussed above.

[0061] The friction seal 508 may be inserted from a tie-in side of the first stalk 506 that is disposed at the on-shore tie-in 504, and positioned at the distance“X”, or greater than the distance“X”, from the terminal end of the pipeline. For example, the friction seal 508 may be inserted into the first stalk 506 from the second end 536 and positioned at the distance 512 from the second end 536 (such as the distance“X” from the second end 536). One or more of the operations illustrated in Figures 5A and 5B may be included in block 406 discussed in Figure 4.

[0062] Figure 5C illustrates first stalk 506 being tied in at location 524 to a second (e.g., additional) stalk 516 having a first end 540 and a second end 538. The first stalk 506 and the second stalk 516 form at least a part of a section of a pipeline 500. The second end 538 defines the terminal end of the pipeline in Figure 5C. Subsequently, as shown in Figure 5D, the friction seal 508 is moved (as illustrated by arrow 518) using applied pressure (as illustrated by arrows 526) from the first stalk 506 into the second stalk 516 to a distance 520 from the second end 538 of the second stalk 516. The applied pressure 526 is applied to the internal volume 509 of the first stalk 506. The distance 520 may be the same as, similar to, or different than the distance 512 discussed in Figure 5B. The applied pressure is applied behind the friction seal 508, on a side of the friction seal facing the first end 522 of the first stalk 506. The applied pressure is applied to the friction seal 508 in a direction Di from the first end 522 of the first stalk 506 and toward the first end 540 of the second stalk 516 to move the friction seal 508 in the direction Di. [0063] Figure 5E illustrates disposal of a friction seal receiver 530 on a second end 560 of a last stalk 528 in a pipeline section of the pipeline 500. The second end 560 of the last stalk 528 is opposite of a first end 558 of the last stalk 528. The last stalk 528 as discussed herein defines the terminal end of the pipeline 500, after removal of any sacrificial length of pipeline.

[0064] Subsequently, as shown in Figure 5F, the friction seal 508 is moved (as illustrated by arrows 534) into the friction seal receiver 530. The friction seal 508 is moved using applied pressure (as illustrated by arrows 532). Subsequent to the friction seal receiver 530 capturing the friction seal 508, a section of the last stalk 528 is removed that includes the friction seal receiver 530 and the friction seal 508.

[0065] Deployment of the terminal end may include transporting the reeled pipeline 500 to an offshore location, and then depressurizing the pipeline 500 to remove the friction seal receiver 530 and replace with a desired fixture, such as a cap. In one example, the pipeline is then re-pressurized to a desired pressure (such as the same predetermined pressure used for reeling the pipeline on the reel), and the pipeline is unreeled to a desired lay location in a pressurized state while maintaining an internal volume of the pipeline 500 at the predetermined pressure.

[0066] In one example, deployment of the terminal end includes depressurizing an internal volume of the reeled pipeline 500 to an ambient pressure prior to transporting the reeled pipeline 500 to an offshore location while the reeled pipeline 500 is at the ambient pressure. After transportation, the pipeline 500 is unloaded from the reel and toward a seafloor while the internal volume of the pipeline 500 is at the ambient pressure.

[0067] The friction seal 508 facilitates pressurization of the pipeline 500 during loading on to a reel on a vessel and/or during subsequent unloading on to a seabed from the reel on the vessel. In an embodiment, which can be combined with other embodiments, the friction seal 508 engages with an inner surface of the pipeline 500 without the use of a mechanical, magnetic, or other type of lock or locking feature. The friction seal 508 is instead held in place via pressure on either side of the friction seal. In one example, the friction seal 508 moves if a threshold amount of a differential pressure, such as 20 bar, is applied to the friction seal 508. In an example where the friction seal 508 engages the pipeline 500 without locks, friction is created between the inner surface of the pipeline 500 and an exterior of the friction seal 508 to position the friction seal 508. In such an example, not using locks on the friction seal 508 facilitates durability and longevity, ease of manufacturability, ease of replacement, reduced risk of rusting, and reduced operating costs.

[0068] In one embodiment, which can be combined with other embodiments, the friction seal 508 uses one or more locks to engage the inner surface of the pipeline 500 and be positioned at the distance 512 between the friction seal 508 and the second end 536 of the first stalk 506. The one or more locks engage the inner surface of the pipeline 500 when actuated. The one or more locks may be remotely monitored and/or remotely actuated, such as by using sensors. In one example, a magnetic ring uses magnetic force to actuate one or more locks and engage the inner surface of the pipeline 500 to stop the friction seal 508 for example at the distance 512. The magnetic ring is disposed on the friction seal 508 and/or about the pipeline 500. In one example, the one or more locks include mechanical locks. In one example, a single friction seal 508 is used.

[0069] In one embodiment, which can be combined with other embodiments, the friction seal 508 includes a pig and the friction seal receiver 530 includes a pig receiver. The friction seal 508 includes a monitoring module for remotely monitoring the friction seal 508, such as a position of the friction seal 508 in relation to the second end 536 of the first stalk 506 and/or a position of the friction seal 508 in relation to the friction seal receiver 530. The monitoring module can be used to remotely operate the friction seal 508, such as remotely actuate one or more locks on the friction seal 508. The monitoring module includes a pinger (beacon).

[0070] One or more of the aspects, features, components, and/or properties described for the friction seal 508 may be combined with and/or included for one or more of the friction seals 602 and/or 802, and/or the friction seal described in reference to the method 400.

[0071] Figure 6A illustrates a pressurized pipeline 600, according to one implementation. In one example of a pressurized pipeline 600, a first internal pipeline target pressure is about 10 bars. A volume of fluid is pumped to reach 10 bars, which in one example is 0.28 m ³ of fluid, but may vary depending on internal dimensions of the pipeline 600. When 0.28 m ³ of fluid is pumped into a first stalk 601 of the pipeline 600, a friction seal 602 moves about 11.4 m. Thus, a distance“X” between the friction seal 602 and an end 603 of the first stalk 601 is greater than 11.4 m so that the seals of the friction seal 602 hold the first internal pipeline target pressure. In one example, a second internal pipeline target pressure is about 10 bars (e.g., the predetermined pressure to be maintained within the pipeline during reeling and/or unreeling). The friction seal 602 is illustrated as a pig in Figures 6A- 6B

[0072] The friction seal 602 is designed to move in response to a differential pressure applied to the friction seal 602, such as a differential pressure resulting from pressure applied to a pressurized section 605 of the pipeline 600. The differential pressure is applied to the friction seal 602 when a pressure acting on a first side 602a of the seal is greater than a pressure acting on a second side 602b of the friction seal 602. In one example, the differential pressure is about 20 bar of differential pressure. The friction seal does not move when the applied pressure within the pressurized section 605 of the pipeline 600 is maintained at a pressure less than the differential pressure that moves pressure seal. The pressure pump described above, which is connected to the pipeline 600 through a circular manifold and an initiation head, may supply a pressurized fluid that applies pressure to the pressurized section 605 of the pipeline 600. The pressurized section 605 of the pipeline 600 can be pressurized to a predetermined pressure of about 5 bar to about 20 bar.

[0073] Figure 6B illustrates the pressurized pipeline 600 shown in Figure 6A, according to one implementation. A first end 609 of a second stalk 607 is welded to the end 603 of the first stalk 601. The second stalk 607 includes a second end 610 after welding the second stalk 607 to the first stalk 601 , pressure is applied to the pressurized section 605 of the pipeline 600. The applied pressure moves the friction seal 602 from a first position to a second position, as indicated by arrow 608. The friction seal 602 includes a pinger (beacon) that is monitored, and movement of the friction seal 602 is monitored using the pinger (beacon). Pumping of a pressurized fluid is also monitored as discussed above. The pumping can be ceased when the friction seal is at a distance“X” before a terminal end of the pipeline 600, such as the second end 610 of the second stalk 607. The tie-in and friction seal moving operations can be repeated for a plurality of stalks until a last stalk is welded to form the pipeline 600. Once the last tie in is performed to weld the last stalk, the pressure pump can be connected to the reel manifold (if not already connected) and pumping can be initiated. The movement of the friction seal 602 is monitored using the pinger, and the movement of the friction seal 602 is stopped once the friction seal is a predetermined distance, such as about 12 joints (144m) from the end of the last stalk. In one example, the last 12 joints are sacrificial joints and they may be used for achieving the straightening setting. Thus, the pipeline section including the last 12 joints may not be pressurized. The head is then welded to the end of the last stalk, which is trailed (moved) to the reel and over an aligner.

[0074] Figure 7 is a partial schematic illustration of a tower 700 on an offshore vessel, according to one implementation. The tower 700 may be used as part of the tower 116 illustrated in Figure 1. The tower 700 includes a tensioner 702 and one or more straighteners, such as one or more top straighteners 703 and one or more lower straighteners 704. Once a head is welded to a pipeline 701 as discussed above, a tensioner 702 such as an LV 105 tensioner can be closed, and the top straighteners 703 and/or lower straighteners 704 can be employed to perform straightening trials on the pipeline 701. Once an appropriate straightening setting is determined, payout and joint cutting are repeated until the joint that contains the friction seal reaches a worktable. The friction seal receiver is then welded to the pipeline end and pumping is initiated and continued until the friction seal is moved into and secured in the friction seal receiver. The receiver main valve is then closed in order to maintain the pressure in the pipeline and the tower 700 is lowered (jacked down) to prepare the vessel for transit.

[0075] The following description relates to deployment of the reeled pipeline from the vessel, once the vessel has reached a predetermined offshore location.

[0076] Figure 8 is a partial schematic illustration of a pressurized pipeline 800, according to one implementation. Once the vessel is in a predetermined offshore location, the tower (such as the tower 116) is raised (jacked up) while the pipeline

800 remains pressurized, such as in a pressurized section 805. The pipeline 800 can be depressurized to remove (cut out) a friction seal receiver 804 having a friction seal 802 while the vessel is at the desired offshore location. In one example, the removal of the friction seal 802 can be executed by making a cut of the pipeline 800 at a predetermined distance, for example, 300mm, below the tensioner in order to insert a first end pipeline end termination (PLET) in the firing line and weld the PLET to the pipeline 800. The friction seal 802 is illustrated as a pig in Figure 8, and the friction seal receiver 804 is illustrated as a pig receiver having a valve 807.

[0077] Figure 9 is a partial schematic illustration of a weld location 900 of a pipeline 901 , according to one implementation. A weld, at the weld location 900, of the first end PLET 903 to the pipeline 901 is performed, and a pressure in the pipeline 901 can be adjusted via the reel and manifold as discussed above to a gauge pressure within a range of 5 bar to 25 bar. The first end PLET 903 has a pressure cap in order to withstand the pipeline internal pressure. Subsequently, the pipeline 901 can be reeled out, and the internal pressure of the pipeline 901 can be monitored. Depending upon the results of the monitoring during reeling out of the pipeline 901 , the pipeline can be re-pressurized. To facilitate reeling and re- pressurization, a pressure pump may remain connected to the circular manifold of the reel during reeling, or the pressure pump may be disconnected for reeling and reconnected for re-pressurization, if re-pressurization occurs. For pipeline with in- line skids (ILT), once the cut to length location for ILT reaches a predetermined point, the pipeline is clamped, and the pipeline is depressurized to ambient pressure.

[0078] Figure 10A is an illustration of pipe segment cutting and removal, according to one implementation. In one example, two cuts are made in the pipeline 1001 in order to remove a pipe segment 1002 that will be replaced with a blind flange 1003 and a valve 1004. The remaining pipeline 1001 is pressurized on the reel.

[0079] Figure 10B illustrates the pipeline 1001 after the pipe segment 1002 is removed as shown in Figure 10A, according to one implementation. A winch 1007, such as a 50mT winch, is connected to the blind flange 1003 and recovers the pipeline 1001 in order to clear the firing line of the pipeline 1001 and to deploy the A/R wire for torsion release. [0080] Figure 11 illustrates a pipeline configuration according to one implementation. A torsion release head 1103 is welded to a bottom section of the pipeline 1001 , and torsion release is performed with the A/R wire. The torsion release head is cut and the pipeline 1001 is pulled down from the hang-off beam until the blind flange 1003 is out of the tensioner, as illustrated in Figure 12.

[0081] Figure 12 illustrates winch removal from a pipeline according to one implementation. As shown in Figure 12, tension is applied to the pipeline (e.g., the pipeline is squeezed) using the tensioner, and the winch is removed. The pipeline is subsequently depressurized, and the pipeline is cut to just below the tensioner in order to insert the ILT.

[0082] Figure 13 illustrates a pipeline after the winch is removed according to one implementation. A top ILT weld and a bottom ILT weld are performed in a top gap region 1301 and a bottom gap region 1302, respectively.

[0083] Figure 14 illustrates a pipeline payout operation, according to one implementation. A pipeline 1401 is re-pressurized to pay out the pipeline 1401 toward an oil and gas operations location, such as an oil and gas operations location on a seafloor 1409. The operations discussed herein can be repeated for a second end PLET if subsequent pipelines are to be installed from the reel. The pipeline 1401 is paid out by unloading (or unreeling) the pipeline 1401 from a reel 1402 disposed on a vessel 1403. The pipeline 1401 is unloaded from the reel 1402 and fed through a tower 1406 that includes one or more tensioners and one or more straighteners, such as those illustrated in Figure 7.

[0084] The aforementioned description explains several aspects of the disclosure. Exemplary, but non-limiting, examples of methods and systems are further described below.

[0085] In one example, a method comprises: (a) coupling a first end of a first stalk of pipe to a manifold circumferentially disposed on a reel, wherein the manifold comprises a plurality of pressure gages and the reel; (b) disposing, in the first end of the first stalk, a friction seal in a first location; (c) relocating, via pressure applied to an interior of the first stalk, the friction seal to a predetermined distance from a second end of the first stalk, wherein relocating the friction seal removably couples the friction seal inside the first stalk at the predetermined distance from the second end of the first stalk; (d) subsequent to removably coupling the friction seal in the first stalk, pressurizing the first stalk to a predetermined pressure; (e) transferring the first stalk to the reel while the first stalk is at the predetermined pressure; (f) coupling a first end of a second stalk to a second end of the first stalk; (g) relocating, via pressure applied to the interior of the first stalk, the friction seal to a predetermined distance of a second end of the second stalk, wherein relocating the friction seal removably couples the friction seal inside the first stalk at the predetermined distance from the second end of the second stalk; (h) subsequent to (g), pressurizing the second stalk to the predetermined pressure; and (i) while the second stalk is pressurized at (g), transferring the second stalk to the reel.

[0086] Optionally, in the example, the predetermined pressure is from about 5 bar to about 25 bar.

[0087] Optionally, the example may also further comprise transferring the first stalk while the first stalk remains pressurized by (j) monitoring, via the plurality of pressure gages on the manifold, a pressure of the interior of the first stalk.

[0088] Optionally, the example may also further comprise (k) re-pressurizing, in response to a determination based on the monitoring at (j) that a monitored interior pressure is below the predetermined pressure.

[0089] Optionally, the example may also further comprise repeating (e) - (i) for a predetermined number of stalks until an overall pipeline length is reached.

[0090] Optionally, in the example, the reel is located on a vessel.

[0091] Optionally, the example may also further comprise: (k) disposing a friction seal receiver in the pipeline; and (I) receiving the friction seal in the friction seal receiver; and subsequent to (I), (m) removing a portion of the pipeline containing the friction seal and the friction seal receiver.

[0092] In a second example, a system comprises: a pressure pump; a reel; a manifold coupled to the reel, wherein the manifold comprises a plurality of pressure pump connections, wherein the pressure pump is removably coupled to at least one connection of the pressure pump connections via a pressure line; a connector coupled to the pressure pump connection and configured, in a first state of the system to further couple to a pipe stalk to pressurize the pipe stalk upon activation of the pressure pump.

[0093] Optionally, in the second example, in the first state of the system, at least a portion of the pipe stalk is disposed on the reel and is pressurized.

[0094] Optionally, in the second example, the manifold comprises a circular shape and is coupled to and circumferentially disposed around the reel via a plurality of pockets formed by an intersection of a reel support and a plurality of spokes.

[0095] Optionally, in the second example, the reel is located on a vessel.

[0096] Optionally, in the second example, further in the first state of the system, a friction seal is coupled to an interior of the pipeline section and operable to move, in response to pressure generated by the pressure pump, inside the pipeline through each of a plurality of serially connected stalks to maintain the constant pressure in the pipeline section during the loading of each stalk of the plurality of serially connected stalks.

[0097] Optionally, in the second example, in a second state of the system, a friction seal receiver is coupled to the interior of the pipeline section to secure the friction seal subsequent to a last stalk of the plurality of stalks being coupled to the pipeline section and pressurized to the constant pressure.

[0098] Optionally, in the second example, in a third state of the system, the reel is configured to lay the pipeline section in a seabed location while the constant pressure is maintained in the pipeline section.

[0099] In a third example, a method of reeling pipeline, comprises coupling a friction seal to a predetermined location from an end of a first stalk; loading a plurality of stalks on to a loading reel by coupling the plurality of stalks in series to form a pipeline section, wherein, during the loading, the friction seal is moved to a predetermined location in each subsequent stalk in sequence of assembly after each stalk is coupled to an adjacent stalk; and during the loading, maintaining a constant pressure in the pipeline section.

[0100] Optionally, the third example further comprises maintaining the constant pressure in the pipeline section via a circular manifold removably coupled to the reel.

[0101] Optionally, the third example further comprises: disposing, at an unpressurized end of the pipeline section opposite the reel, a friction seal receiver; subsequently, applying pressure to move the friction seal into the friction seal receiver; and removing at least some of the unpressurized end of the pipeline section that comprises the friction seal disposed in the friction seal receiver.

[0102] Optionally, in the third example, the constant pressure is between 5 bar and 25 bar.

[0103] Optionally, the third example further comprises: unloading the pipeline from the reel while maintaining the constant pressure.

[0104] In a fourth example, a method comprises pressurizing a pipe; reeling the pressurized pipe; moving a friction seal within the pipe; and attaching an additional stalk of pipe to the pressurized pipe.

[0105] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The present disclosure also contemplates that one or more aspects of the embodiments described herein may be substituted in for one or more of the other aspects described. The scope of the disclosure is determined by the claims that follow.