PULL-IN BUOY
Technical Field
[0001 ] The present invention relates to the use of a loading hose for transferring fluids between a first and second reservoir offshore. Typically, the loading hose is used to transfer hydrocarbons to a tanker from a loading buoy, from a floating production and/or storage unit (FPSO / FSO), or from a loading unit (e.g. cargo transfer vessel - CTV).
Background Art
[0002] When transferring fluids to a tanker at sea, it is known to use a floating loading hose, which typically extends from a loading buoy. The end of the loading hose is provided with a loading hose coupling and is lifted onto the tanker, where a connection is made between the loading hose coupling and a receiving connection flange on the tanker.
[0003] In order to hoist the end of the floating loading hose onto the tanker, a crane arranged on the tanker is used. To do this, the crane hook must be connected to the floating hose. This connection is typically made manually with personnel on a tug or a workboat. The personnel must typically get hold of a lifting chain arranged on the floating hose end, and connect the lifting chain to the crane hook.
[0004] Since this operation is done at sea and with heavy equipment, it is not without risk. Typically, the maximum wave height for performing such operation is between 2 and 2,5 meters (Hs = 2,0 - 2,5 m).
[0005] Patent application publication WO2014083056 discloses a solution for connecting a mooring line from a floating structure, such as a ship, to a structure situated on the seabed, typically an anchor installed in the seabed. A guideline extends from the ship down to a wire tackle attached to the anchor, and back up to the ship. One end of the guideline is connected to a winch on the ship for pulling in the guideline, while the other end connects to a mooring line. The mooring line is paid out while the guideline is pulled in. At the intersection between the guideline and the mooring line, there is an upper connection element that is configured to connect with a lower connection element attached to the anchor. When the upper connection element has been pulled into engagement with the lower connection element, they are attached to each other, thereby connecting the mooring line to the subsea anchor. With this solution, the operator is enabled to connect to a remote, not visible connection point at the subsea location without the use of an ROV (remotely operated vehicle) or a diver. Once the mooring line has been connected to the anchor, the operation is completed.
[0006] GB2461713 discloses a marine connection system that includes a floating winch structure with a winch line that is suspended in a floating member adjacent the winch structure. A surface cable is to be connected to a cable on the seabed. The which line is connected to a further line that extends from a buoy and down to the
cable on the subsea. By pulling the winch line, the subsea cable is lifted up to the surface cable.
[0007] US20140034137 presents an offshore fluid transfer system on a ship, and thus relates to the same field as the present invention. In this solution, a pulling line and an overhanging crane beam are used to move the end of an articulated fluid pipe into engagement with the fluid interface of an adjacent ship. The articulated fluid pipe absorbs mutual movement between the two ships. Notably, except for the two ships themselves, no part of the fluid transfer system is in contact with the seawater.
[0008] An object of the present invention may be to present equipment and a method that may reduce the risk for personnel injuries and/or to increase the operational limits.
Summary of invention
[0009] According to a first aspect of the present invention, there is provided a loading hose connection assembly having a pull-in line, a floating part, and a connecting part. The floating part comprises a buoyant body configured to make the floating part float in a body of water, a connecting part reception interface, a first locking element, a pull-in line guide element, and a loading hose connection interface. The connecting part comprises a second locking element configured to enter into locking engagement with the first locking element, a pull-in line connection interface, a crane string connection interface. According to the invention, the pull-in line extends from the pull-in line connection interface to the pull-in line guide element, and further to a pull-in section of the pull-in line, such that a pull in the pull-in section pulls the connecting part into the connecting part reception interface, thereby enabling a locking engagement with the floating part.
[0010] It will be understood that the pull-in section of the pull-in line, which is pulled, is a portion of the pull-in line, which is outside the floating part and the connecting part. Typically, the pull-in section can be on a tanker or another ship.
[001 1 ] In some embodiments, the connecting part reception interface can be arranged in a receiving body with an entrance aperture, wherein the first locking means is arranged between the entrance aperture and the pull-in line guide element.
[0012] Advantageously, the first locking element and the second locking element can in some embodiments be configured to automatically enter into a locking engagement when the connecting part is pulled into the connecting part reception interface. This means that no other actuation of the locking elements will be necessary in order to establish the locked connection between the floating part and the connecting part. In other words, the connecting part is pulled into the locking engagement by means of the pull-in line.
[0013] Advantageously, in some embodiments the floating part may further comprise a pull-in line return channel. In such embodiments, the pull-in line may
enter the floating part through an entrance aperture, and exit the floating part through the pull-in line return channel.
[0014] In such embodiments, the connecting part reception interface and the pull-in line return channel may both have a straight, elongated extension, wherein the mutual angle between their respective axially extending center axes may be less than 30 degrees.
[0015] In some examples of such embodiments, the pull-in line return channel may have a return channel aperture and the floating part may further comprise an auxiliary return aperture, which is configured to guide the pull-in line out of the floating part.
[0016] In such embodiments, the pull-in line may be returned out from the assembly without extending through the pull-in line return channel. As will be shown with the more detailed discussion further below, the use of the auxiliary return aperture will typically be used when the pull-in of the connecting part is performed from a tug. In such situations, there may be a significant angle between the portion of the pull-in line extending into the assembly and the portion that returns out from the assembly.
[0017] According to a second aspect of the present invention, there is provided a method of providing, by using the loading hose connection assembly according to the first aspect of the invention, a connection between a crane hook of a ship crane and a floating loading hose floating in the sea, and lifting the loading hose onto a ship. The method comprises the following steps:
a) connecting a connecting part of a connection assembly to the crane hook; b) connecting an end of a pull-in line of the connection assembly to the connecting part;
c) pulling in the opposite end or in a pull-in section of the pull-in line and paying out crane wire from the crane, thereby pulling the connecting part towards a floating part of the connection assembly, which is connected to the floating loading hose, as the pull-in line runs freely into and out of the floating part;
d) locking the connecting part to the floating part by pulling the pull-in line, as the connecting part and the floating part comprises locking elements configured to automatically establish a locked connection when the connecting part is pulled into a connecting part reception interface;
e) lifting the loading hose onto the ship by transmission of lifting force from the crane hook to the loading hose, as the locked connection between the floating part and the connecting part is configured to transmit said lifting force.
[0018] In some embodiments of the method according to the second aspect of the invention, step c) may comprise pulling the pull-in section from a position on the same ship as on which the ship crane is mounted. That is, in such embodiments, the part of the pull-in line that extends out from the connection assembly and which is pulled, is pulled from a position on a ship, on which the crane is positioned. Such a ship may typically be a tanker, onto which fluid shall be loaded through the loading hose.
[0019] Moreover, step c) may alternatively comprise pulling the pull-in section from a position on another ship than the ship on which the ship crane is mounted. Such an embodiment will be discussed in one the examples below.
[0020] By automatically establishing a locked connection between the floating part and the connecting part of the connection assembly, it is herein meant that the actuation of the locking function may take place by operation of the pull-in line. I.e. by a pull in the pull-in line, so that the two parts are mated together into a locked position.
Brief description of drawings
[0021 ] While the present invention has been presented in general terms above, some examples of embodiment will be given in the following with reference to the drawings, in which
Fig. 1 is a view illustrating a typical situation before connecting a crane hook to a floating hose floating in the sea;
Fig. 2 is a cross section view of an embodiment of the connection assembly
according to the invention, in a non-connected state;
Fig. 3 is a cross section view of the assembly shown in Fig. 2, in a connected state;
Fig. 4 is a view corresponding to Fig. 1 , illustrating however application of a
connection assembly according to the invention;
Fig. 5 is a view corresponding to Fig. 4, illustrating another application of
connection assembly according to the invention;
Fig. 6a to Fig. 6e depict step by step application of the connection assembly
according to the application shown in Fig. 4;
Fig. 7a to Fig. 7e depict step by step application of the connection assembly
according to the application shown in Fig. 5;
Fig. 8 depict a part of the connection assembly, when used according to the
application shown in Fig. 4 and Fig. 6a to Fig. 6e;
Fig. 9 depict a part of the connection assembly, when used according to the
application shown in Fig. 5 and Fig. 7a to Fig. 7e;
Fig. 10 depict an alternative embodiment of the connection assembly according to the invention in a non-connected state;
Fig. 1 1 depict the embodiment shown in Fig. 10 in a connected state;
Fig. 12 depict another embodiment of the connection assembly in a non-connected state; and
Fig. 13 depict the embodiment of Fig. 12 in a connected state.
[0022] Fig. 1 shows a typical situation before a floating loading hose 1 is connected to a tanker 3. The tanker 3 is positioned adjacent the floating loading hose 1 , which floats in the sea and which is connected to a fluid reservoir, such as a floating buoy (not shown). The tanker 3 is provided with a crane 5. The crane 5 has a crane hook 7 at the end of a crane wire 9.
[0023] The end of the loading hose 1 is provided with a coupling 1 1 configured for connection to a connection flange (not shown) on the tanker 3. Also arranged on the end of the loading hose 1 is a lifting chain 13, which is used to lift the end of the loading hose.
[0024] Adjacent the tanker 1 and the floating hose 3 is a tug 15. In the situation shown in Fig. 1 , personnel on the tug 15 control the end of the loading hose 1 with a towing line 17 connected to the lifting chain 13. As discussed above, with operations according to the prior art, the personnel on the tug 15 will manually connect the lifting chain 13 to the crane hook 7. Since the floating hose will move and the tug 15 may roll and heave due to waves, this operation may be hazardous and cannot be performed during excessive wave heights.
[0025] Fig. 2 and Fig. 3 show a connection assembly 10 according to the present invention, the use of which makes it possible to reduce hazard during the connection of the crane hook 7 to the floating hose 1 .
[0026] The connection assembly 10 comprises a floating part 50, a connecting part 70, and a pull-in line 20. The connecting part 70 is configured to be locked to the floating part 50 when pulled towards the floating part by means of the pull-in line 20. The pull-in line 20 can typically be a rope or any other suitable string.
[0027] Fig. 2 depicts the assembly in a non-connected state. The floating part has a buoyant body 51 , which has such a weight and volume that it makes the assembly 10 float in a body of water. The buoyant body 51 can advantageously comprise a hardening foam, giving both low weight and robustness. The floating part 50 will float in water when the connecting part 70 is not connected to the floating part 50.
However, the floating part 50 may advantageously also be made to float in water when the connecting part 70 is connected.
[0028] Fig. 2 and Fig. 3 depict the connection assembly 10 with cross section side views. In the shown embodiment, the buoyant body 51 has a circular shape with a centrally arranged opening 53. The buoyant body 51 is attached to the upper portion of a sleeve 55, which extends through the opening 53.
[0029] The lower end of the sleeve 55 comprises a loading hose connection interface, here shown in the form of a chain connection 57. The loading hose connection interface 57 is configured to be connected to the floating loading hose 1 (Fig. 1 ) for hoisting the end of the hose onto the tanker 3.
[0030] The upper end of the sleeve 55 comprises a guide funnel 59. The guide funnel is arranged at the upper end of a connecting part reception interface 61 , which
in the shown embodiment is inside the sleeve 55. In this embodiment, the guide funnel 59 constitutes an entrance aperture 52 of the connecting part reception interface 61 .
[0031 ] In a wall portion of the sleeve 55 and positioned at a lower section of the sleeve, there is a pull-in line guide element 63. In this embodiment, the pull-in line guide element is in form of a sheave 63 on which the pull-in line 20 is guided. As can be seen with the cross section view of Fig. 2, the pull-in line 20 enters the sleeve 55 at an upper portion of the sleeve, through the guide funnel 59. The pull-in line 20 extends downward to the pull-in line guide element 63, at which position it exits the sleeve 55 through an aperture 65 in the sleeve wall. The pull-in line 20 then extends back upwards along the sleeve 55, on the external part of the sleeve, and through a pull-in line return channel 67.
[0032] The pull-in line 20 is at one end attached to the connecting part 70, via a pull- in line connection interface 71 at a lower end of the connecting part. When pulling in the part of the pull-in line 20 that extends out of the floating part 50, and which is opposite the end of the pull-in line connected to the connecting part 70, the
connecting part 70 will be pulled towards the floating part 50. Such a pull is indicated with the arrow 20b, and this part of the pull-in line 20 is termed a pull-in section 20a. Eventually, the connecting part 70 will be pulled into engagement with the floating part 50, as is shown with Fig. 3. In this position, the connecting part 70 has been pulled into the connecting part reception interface 61 , namely inside the sleeve 55. When being pulled into this position, the connecting part 70 is guided by means of the guide funnel 59.
[0033] In the embodiment shown in Fig. 2 and Fig. 3, the connecting part 70 has a central stem 73. The pull-in line connection interface 71 is arranged at a lower portion of the central stem 73. At an upper portion, the connecting part 70 is provided with a crane string connection interface 75. The crane string connection interface is attached to a crane wire 9 (cf. Fig. 1 ).
[0034] The connecting part 70 further comprises a second locking element, which in the shown embodiment is in form of a radially compressible locking sleeve 77. The locking sleeve 77 may comprise axially extending slits at its upper portion, which make the upper portion of the sleeve radially compressible. When pulled into the sleeve 55 of the floating part 50, the second locking element 77 is configured to make a locking engagement with a first locking element 69. In the shown
embodiment, the first locking element is in the form of an axially facing locking shoulder inside the bore of the sleeve 55. Thus, when pulled into the sleeve 55, the axially and upwardly facing edges 77a of the second locking element 77 are moved past the axially and downwardly facing locking shoulder 69 of the floating part 50.
[0035] The sleeve 55 forms a receiving body, configured to receive at least a portion of the connecting part 70, wherein the said portion is pulled beyond the entrance aperture 52.
[0036] When the connecting part 70 has been locked to the floating part 50, the crane 5 (Fig. 1 ) may hoist the connection assembly 10 and the end of the floating loading hose 1 onto the tanker, as the floating part 50 is attached to the loading hose. This attachment may be provided with a connection between the floating part 50 and the lifting chain 13 (Fig. 1 ).
[0037] Thus, in order to connect the crane hook 7 to the coupling 1 1 at the end of the loading hose 7, the operator employs a pull-in line 20 that extends to the connecting part 70, via the floating part 50. The floating part 50 is attached to the end of the loading hose 7, such as with the lifting chain 13 (Fig. 1 ). The pull in the pull-in line 20 and the paying out of the crane wire 9, will move the connecting part 70 into a locked engagement with the floating part 50. Since the connecting part 70 is attached to the crane hook 7, the operator may lift the loading hose end once the locking engagement between the connecting part 70 and the floating part 50 has been made.
[0038] Notably, this operation may be performed without any personnel being close to the crane hook 7 or the end of the loading hose 1 (e.g. the coupling 1 1 ), when the connection is made between the crane and the loading hose 1 . Consequently, the operator has reduced risk for injuries and the operation is less limited by wave heights.
[0039] Advantageously, between loading operations, i.e. when the connection assembly 10 according to the invention is not in use, it should be stored in a dry state in order to prevent fouling. If for instance being used in a situation involving a CALM (catenary anchor leg mooring) buoy, the loading hose will typically be floating at sea all the time. In such a situation, one may advantageously store the connection assembly 10 on board a workboat between the operations.
[0040] If for instance being used in a situation involving a CTV (cargo transfer vessel), the connection assembly 10 may be connected to the floating hose end before the floating hose is reeled out from the storage reel. When the loading operation is finished, the loading hose is reeled back onto the reel on the ship, and the connection assembly 10 will be disconnected.
[0041 ] Fig. 4 schematically depicts a situation where the operator is in the process of pulling the connecting part 70 towards the floating part 50. A person on the tug 15 controls the pulling of the pull-in line 20 by using a winch 19 on the tug, which provides the pulling force in the pull-in line. Also connected to the lifting chain 13 and/or the floating part 50 is the towing line 17.
[0042] Fig. 5 schematically depicts a situation similar to that in Fig. 4, however where the operator pulls the pull-in line 20 from a position on the tanker 3.
[0043] Fig. 6a to Fig. 6e illustrate the process of connecting the crane hook 7 to the floating hose 1 , via the connection assembly 10 according to the invention. As with the situation discussed above with reference to Fig. 4, the personnel handling the pull-in line 20 is on the tug 15.
[0044] In Fig. 6a, the connecting part 70 has been connected to the crane hook 7. One end of the pull-in line 20 has been hoisted to personnel on the tanker 3. The personnel connects that end to the pull-in line connection interface 71 of the connecting part 70, cf. Fig. 6b.
[0045] In the situation shown in Fig. 6c, the operator pays out the crane wire 9, while simultaneously pulling in the pull-in line 20 from the tug (not shown), making the connecting part 70 approach the floating part 50. In Fig. 6d, the connecting part 70 has been pulled into locking engagement with the floating part 50, thus providing a robust connection between the crane hook 7 and the end of the floating hose 1 , via the lifting chain 13.
[0046] In the situation shown in Fig. 6e, the operator lifts up the loading hose 1 by means of the crane 5.
[0047] Fig. 7a to Fig. 7e correspond to Fig. 6a to Fig. 6e discussed above, except that the operator pulls the pull-in line 20 from a position on the tanker 3 and not from a position on the tug 15.
[0048] Fig. 8 depicts a cross section view through a floating part 50 having a slightly different design compared to the one shown in Fig. 2 and Fig. 3. In the embodiment shown in Fig. 8, the buoyant body 51 extends along more than half of the axial extension of the sleeve 55. Furthermore, the lower part of the buoyant body 51 is positioned at the axial position of the pull-in line guide element 63.
[0049] In the situation shown in Fig. 8, the pull-in line 20 does not extend through the pull-in line return channel 67. Instead, it extends laterally out to the side of the floating part 50. This situation will typically be the case when the operator pulls the pull-in line 20 from the tug 15, as illustrated in Fig. 4. In such cases, the parts of the pull-in line 20 extending into and out from the floating part 50 will have substantially different directions. The floating part 50 has a cutout 62 in the buoyant body 51 to give space for the pull-in line 20 in such situations.
[0050] Referring now to Fig. 9, which depicts the same floating part 50 as Fig. 8. The pull-in line return channel 67 is arranged in the buoyant body 51 , and extends substantially or almost in parallel with the sleeve 55. Notably, between the position of the entrance aperture 52 and the position of the pull-in line guide element 63, the pull-in line 20 extends down and back up in a substantially parallel or almost parallel fashion.
[0051 ] The pull-in line return channel 67 has a return channel aperture 68, out of which the pull-in line 20 extends (i.e. out of which the pull-in section 20a of the pull-in line 20 extends). In the embodiment shown in Fig. 9, the return channel aperture 68 faces substantially in the same direction as the entrance aperture 52 of the connecting part reception interface 61 .
[0052] In the embodiment shown in Fig. 9, both the connecting part reception interface 61 and the pull-in line return channel 67 have a straight, elongated extension. The mutual angle between their respective center axes may typically be
less than 30 degrees, and advantageously less than 20 degrees. This may also apply to other embodiments within the scope of the invention.
[0053] Notably, letting the buoyant body extend downwards on the sleeve 55, to the position of the pull-in line guide element 63, and arranging the cutout 62 in this position, provides some protection for the pull-in line guide element 63 against impacts.
[0054] While the pull-in line guide element 63 shown in the embodiment discussed herein is in the form of a sheave, other embodiments may involve another type of pull-in line guide element. For instance, the pull-in line guide element 63 may merely comprise a curved, smooth edge, about which the pull-in line 20 may curve.
[0055] Fig. 10 and Fig. 1 1 depict an alternative embodiment of the connection assembly 10 according to the invention, in a non-connected and connected state, respectively. In this embodiment, the locking engagement between the floating part 50 and the connecting part 70 is provided with means different from the embodiment discussed with reference to Fig. 2 and Fig. 3.
[0056] As with the previously discussed embodiment, the connecting part 70 has a central stem 73 configured to be pulled into a sleeve 55 of the floating part 50. On the central stem 73, the second locking engagement 77 is arranged. In this embodiment, the second locking engagement 77 is in the form of a connection system
commercially marketed under the name Ballgrab from the company First Subsea Ltd. The central stem 73 is provided with a plurality of aperture in outer face, out of which apertures a plurality of balls partly extend. When the central stem 73 has been pulled into the connecting part reception interface 61 , inside the sleeve 55, the Ballgrab system forces the balls radially outwards and into engagement with the inner wall of the sleeve. This provides a locking engagement between the floating part 50 and the connecting part 70. Such a connected state is shown in Fig. 1 1 . In this embodiment, the first locking element 69 of the floating part 50 may be the radially inwardly facing wall of the sleeve 55, against which the balls 77 of the connecting part 70 are forced when in the connected state.
[0057] Fig. 12 and Fig. 13 depict yet another alternative embodiment of the connection assembly 10 according to the invention. In this embodiment, the second locking element 77 is in form of three sliding elements. The sliding elements 77 are configured to slide in an axial direction on the central stem 73. Furthermore, the central stem 73 is provided with a tapered outer face, which will force the sliding elements 77 radially outwards when being pulled with the crane wire 9.
[0058] Fig. 12 shows the connection assembly 10 in a non-connected state. In Fig. 13, the central stem 73 and the sliding elements 77 have been pulled into the connecting part reception interface 61 , i.e. within the sleeve 55. When a pulling force is exerted onto the central stem 73 from the crane string connection interface 75, the tapered design of the central stem 73 will force the sliding elements 77 to expand radially. This radial expansion will provide mechanical engagement between the
connecting part 70 and the floating part 50, making the operator able to hoist the end of the loading hose 1 onto the tanker 3.
[0059] Fig. 14a, Fig. 14b, and Fig. 14c illustrate the connecting part 70 of the embodiment shown in Fig. 12 and Fig. 13 with three cross sections views along three different portions of the connecting part 70. Fig. 14a is a cross section view along a horizontal plane at a bottom part of the stem 73. Fig. 14b is a corresponding view at a mid-portion, while Fig. 14c is a cross section view along an upper portion. Each of the three sliding elements 77 is provided with a protrusion 77b that is received in a groove 73b in the central stem 73. The protrusion 77b and the groove 73b retains the sliding elements 77 in place on an outer inclined face 73c of the central stem 73. An inner face 77c of the sliding elements abuts the inclined face 73c.
[0060] Hence, by pulling the central stem 73 upwards, the sliding elements 77 will be forced radially outwards when sliding against the outer inclined faces 73 of the central stem 73. This radially outward movement / force, will secure the connecting part 70 to the floating part 50.
[0061 ] Notably, each of the three drawings of Fig. 14a, Fig. 14b, and Fig. 14c are depicting the same situation, wherein the outer faces of the three sliding elements 77 have the same radial position. As the central stem 73 is pulled upwards, the diameter constituted by the outer faces of the three sliding elements 77 will increase.