PRIORITY CLAIM

This application claims priority from Italian Patent Application No. 102017000019527 filed on February 21, 2017 the disclosure of which is incorporated by reference

TECHNICAL FIELD

The present invention relates to a launching system for inserting a vehicle in a pipeline in a body of water.

In general, the term "vehicle" within the scope of the present disclosure refers to any device configured to be advanced into the pipeline to convey tools, such as scrapers for cleaning the inner surface of the pipeline and/or selectively expandable gaskets which allow the pipeline to be temporarily blocked and/or dynamic gaskets which allow the vehicle to drain the water from the pipe. Moreover, the term "vehicle" within the scope of the present disclosure refers to a single module equipped with at least one of the aforesaid tools or with a plurality of modules connected to each other. In the "oil & gas" industry, each module is defined with the term "pig".

STATE OF THE ART The well-known systems generally comprise a cylinder, which has an open end and is configured to house a vehicle to be inserted into the pipeline; and an aligning structure, which is configured to be clamped to the pipeline so as to align the cylinder with the pipeline and to tightly couple the cylinder onto the outside of the pipeline after removal of any coating on the outside of said pipeline. Pumping a pressurized fluid into the cylinder causes transfer of the vehicle from the cylinder to the pipeline, and subsequently, the advancement thereof along the pipeline.

Launching systems of the type identified above are described in documents US 2002/0059687, US 6,533,032, and US 6,022,421. Launching operations are generally performed in a body of water and involve the use of ROVs .

One of the major problems of the above-mentioned launching systems is achieving a tight coupling between the cylinder and the pipeline. In some cases, the pipeline is provided with an outer coating and it is necessary to remove the outer coating along the end section and to finish off the end section so as to provide an effective tight coupling with the cylinder.

OBJECT OF THE INVENTION

The object of the present invention is to provide a launching system for inserting a vehicle in a pipeline in a body of water, which is capable of obviating the drawbacks of the prior art.

In accordance with the present invention, there is provided a launching system for inserting a vehicle in a pipeline in a body of water, the launching system comprising:

- a cylinder, which extends along a first axis, has an open end, and is configured for housing a vehicle to be inserted in the pipeline;

- an aligning structure, which is connected to the cylinder and is configured to be clamped to the pipeline so as to align the cylinder with the pipeline; and

- a piston, which is housed in the cylinder, and is configured to push the vehicle into the pipeline in a first direction .

Thanks to the present invention, the transfer can be accomplished without the need to provide a tight coupling between the cylinder and the pipeline in which the cylinder is clamped to the outside of the pipeline.

In particular, the cylinder comprises a pipe; a blind flange; and at least one connector, through which a pressurized fluid can be fed into the cylinder.

The fluid used is normally water, which is brought to a higher pressure than the pressure in the body of water in the areas surrounding the pipeline and the launching system. In particular, the launching system comprises a restoring device associated with the cylinder and connected to the piston for pulling the piston in a second direction opposite to the first direction.

In this way, the piston is returned to the initial position and is ready to insert a new vehicle.

In particular, the aligning structure comprises a frame, which is mounted on the cylinder and defines a housing space for housing the pipeline; at least three guiding devices; and a plurality of clamping devices.

In practice, the aligning structure is rigidly connected to the cylinder and can be clamped to the pipeline so that the cylinder is rigidly connected to the pipeline .

In particular, the launching system comprises at least one floating device for reducing its weight and facilitating its installation. The floating device is preferably tubular in shape, is arranged around the cylinder and supported by the aligning structure.

The floating device provides greater manoeuvrability, in the body of water, of the assembly formed by the cylinder, the aligning structure, the piston, and the vehicle to be fitted on the end section of the pipeline.

In particular, the piston comprises a module; and an annular gasket mounted on the module and configured to seal the space between the module and the cylinder.

The annular gasket allows the piston to be moved in the first direction.

In particular, the piston comprises a further annular gasket mounted on the module and configured to seal the space between the module and the cylinder and/or the pipeline .

The additional gasket increases the effectiveness of the seal between the piston and the cylinder.

Alternatively, and according to one embodiment of the present invention, the additional annular gasket serves the purpose of sealing the space between the module and the pipeline, whereas the other annular gasket is arranged between the module and the cylinder.

In accordance with this embodiment, the piston is positioned partly inside the cylinder and partly inside the pipeline. The piston also comprises a conduit, which is configured for fluidically connecting the space upstream of the piston to the space downstream of the piston; and a remotely controlled valve for selectively opening and closing the conduit.

In this way, the piston practically seals the connection between the cylinder and the pipeline and allows the pressurized fluid to directly push the vehicle into the pipeline. In particular, the piston comprises a spacer for pushing the vehicle. The spacer allows the vehicle to be fully inserted in the pipeline while keeping the piston completely inside the cylinder.

In particular, the piston comprises a connecting member for connecting the piston to a restoring device so as to return the piston to the initial position.

The present invention also relates to a launching method for inserting a vehicle in a pipeline, which is free from the drawbacks of the prior art.

In accordance with the present invention, there is provided a launching method for inserting a vehicle in a pipeline in a body of water, the method comprising the steps of:

- housing a vehicle in a cylinder, which extends along a first axis and has an open end;

- aligning the cylinder with a pipeline, which extends along a second axis and has a respective open end;

- arranging the open end of the cylinder so that it faces the open end of the pipeline; and

- pushing a piston housed in the cylinder in a first direction for transferring the vehicle from the cylinder to the pipeline.

Thanks to the present method, it is not necessary to provide a tight coupling between the cylinder and the pipeline, whose free ends can also be arranged at a given distance one from the other.

In greater detail, the method comprises feeding a pressurized fluid into the cylinder for pushing the piston in the first direction. In practice, sea water is pumped into the cylinder, which operates like a real single-acting hydraulic cylinder.

In particular, the method comprises pulling the piston in a second direction opposite to the first direction. In this case, the movement of the piston in the second direction is obtained by means of mechanical devices.

In particular, the launching method comprises guiding the aligning structure along an end section of the pipeline; and clamping the aligning structure around the end section of the pipeline. The guiding step allows the cylinder to be aligned with the pipeline, whereas the clamping step prevents relative movements between the cylinder and the pipeline during the step of transferring the vehicle.

In particular, the method comprises supporting the cylinder and the aligning structure at least partly by means of a floating device, which in particular is tubular in shape and arranged about the cylinder, to allow a greater manoeuvrability of the assembly comprising the cylinder, the aligning structure, the piston and the vehicle .

In accordance with one embodiment, the method comprises arranging the piston partly in the cylinder and partly in the pipeline, and sealing the space between the piston and the pipeline and between the piston and the cylinder .

In other words, the piston is capable of tightly connecting the cylinder to the pipeline.

In accordance with this embodiment, the method comprises opening a conduit, which extends through the piston for fluidically connecting the space upstream of the piston to the space downstream of the piston, and advancing the vehicle into the pipeline, while the piston remains stationary to ensure the seal between the cylinder and the pipeline.

BRIEF DESCRIPTION OF THE FIGURES

Further features and advantages of the present invention will be apparent from the following description of a non-limiting embodiment thereof, with reference to the figures of the accompanying drawings, wherein:

- Figure 1 is a perspective view, with parts removed for clarity, of a launching system coupled to a pipeline and constructed in accordance with the present invention;

- Figure 2 is a perspective view, with parts removed for clarity and in enlarged scale, of a detail of the launching system in Figure 1;

- Figures 3 and 4 are sectional views, with parts removed for clarity, of the launching system of Figure 1 in different steps of the method object of the present invention; and

- Figures 5 to 6 are sectional views, with parts removed for clarity and in enlarged scale, of the launching system of Figures 3 and 4 in further operating steps of a different embodiment of the present invention.

PREFERRED EMBODIMENT OF THE INVENTION

Figure 1 depicts a launching system, as a whole, which is constructed in accordance with the present invention and coupled to a pipeline 2.

The launching system 1 comprises a cylinder 3, which extends along an axis Al and has an open end 4 (Fig.3) , and a closed end 5; an aligning structure 6, which is connected to the cylinder 3 and is configured to be clamped to an end section of the pipeline 2 which extends along an axis A2.

The aligning structure 6, when clamped to the end section of the pipeline 2, allows the cylinder 3 to be aligned with the pipeline 2, i.e. the axis Al to be substantially aligned with the axis A2.

The launching system 1 comprises a pumping station 7; and a conduit 8 to connect the pumping station 7 to the cylinder 3 at the closed end 5; and a restoring device 9 which, in the example shown, comprises a winch 10 and a cable 11 guided inside the cylinder 3 (Figure 3) .

With reference to Figure 3, the launching device 1 has the function of inserting a vehicle 12 in the pipeline 2. This vehicle 12 is initially housed in the cylinder 3 and must be transferred to the pipeline 2 through the open end 4 of the cylinder 3 and an open end 13 of the pipeline 2 facing the open end 4 of the cylinder 3. For this purpose, the launching system 1 comprises a piston 14, which is housed in the cylinder 3, is connected in a selectively releasable manner to the vehicle 12, and has the function of pushing the vehicle 12 along the cylinder 3 until the vehicle 12 is transferred into the pipeline 2.

In the example shown, the vehicle 12 comprises a central module 15; two end modules 16; and two spacers 17, each of which keeps an end module 16 at a suitable distance from the central module 15 and is hinged to the central module 15 and to the end module 16 to allow curved sections of the pipeline 2 to be travelled. In the example shown, the central module 15 includes rollers 18 configured to roll along the inner surface of the pipeline 2, whereas the end modules 16 are equipped with scrapers 19 for the cleaning of the inner surface of the pipeline 2.

The cylinder 3 comprises a pipe 20; a blind flange 21; and at least one connector 22, through which a pressurized fluid can be fed into the cylinder 3.

The aligning structure 6 comprises a frame 24, which is mounted on the cylinder 3 and defines a housing space for housing the pipeline 2; at least three guiding devices 25; and a plurality of clamping devices 26.

The launching system 1 comprises a floating device 27 which, as a whole, has a tubular shape, is arranged around the cylinder 3, and comprises a plurality of containers 28, for example buoy blocks housed in compartments formed in the aligning structure 6.

With reference to Figure 3, the piston 14 comprises a module 29 having the shape of an elongated body; three annular gaskets 30, 31 and 32 mounted along the module 29 and spaced from one another; a spacer 33 for pushing the vehicle 12; and a connecting element 34 for connecting the piston 14 to the restoring device 9.

In use, inserting the vehicle 12 in the pipeline 2 comprises performing the following operations. The cylinder 3 and the aligning structure 6 are arranged in the body of water, and the aligning structure 6 is fitted on the pipeline 2 section, until reaching the configuration shown in Figure 1. The positioning of the cylinder 3 and of the aligning structure 6 is remotely controlled by means of ROVs (not shown in the accompanying figures) and the weight of the cylinder 3 and of the aligning structure 6 is lessened by the floating device 27. The aligning structure 6 is fitted on the outside of the pipeline 2 without the need to remove the coating of the pipeline 2 and to carry out machining operations along the outer surface of the pipeline 2. The coupling to the pipeline 2 allows the axes Al and A2 to be aligned, and the tightening of the clamping devices 26 allows the cylinder 3 to be made integral with the pipeline 2.

With reference to Figure 3, the cylinder 3 is coupled to the pipeline 2 by means of the aligning structure 6, which is clamped to the pipeline 2. In the configuration shown, the open end 4 of the cylinder 3 faces the open end 13 of the pipeline 2 and is slightly spaced from the open end 13. Since it is not necessary to provide a tight coupling, the diameter of the cylinder 3 can also be different from the diameter of the pipeline 2, as is actually illustrated in the attached figures.

Subsequently, the pumping station 7 (Figure 1) feeds pressurized fluid into the cylinder 3 between the piston 14 and the blind flange 21, and the piston 14 starts to move in direction Dl and to push the vehicle 12 in the same direction Dl until the entire vehicle 12 is arranged in the pipeline 2, as shown in Figure 4. At this point, the operation of inserting the vehicle 12 is completed and the piston 14 can be returned to the initial position by means of the restoring device 9, which, in this case, comprises the winch 10 and the cable 11 for pulling the piston 14 in direction D2 opposite to direction Dl.

In accordance with the embodiment illustrated in Figures 5 and 6, the piston 14 comprises a conduit 35, which extends within the module 29 and is configured for fluidically connecting the space upstream of the piston 14 to the space downstream of the piston 14; and a remotely controlled valve 36 for selectively opening and closing the conduit 35.

In accordance with this embodiment, the valve 36 is kept closed until the vehicle 12 is fully inserted in the pipeline 2 and the annular gasket 32 is arranged inside the pipeline 2, as shown in Figure 5, whereas the annular gaskets 30 and 31 are arranged in the area of the cylinder 3 so as to define two sealed chambers downstream and upstream of the piston 14. At this point, the valve 36 is opened and the pressurized fluid flows through the conduit 35 into the chamber located between the piston 14 and the vehicle 12 and pushes the vehicle 12, which advances inside the pipeline 2 and separates from the piston 14.

It is understood that the present invention includes variants that are not explicitly described, without however departing from the scope of protection of the following claims .