Patent Description:
The present invention relates to a machine for applying at least one cable to a pipeline, in particular in a body of water.

In the oil sector, a cable coupled to a pipeline, generally underwater, finds various applications.

Documents <CIT> and <CIT> disclose respective machines for repairing a pipe by means of the application of a tape under tension around the pipe. Documents <CIT> and <CIT> disclose respective systems for mounting a cable to a pipeline.

In underwater oil fields, hydrocarbons are transferred from the field along metal pipes laid on the seabed and rising ("risers") towards a surface plant which has the function of managing production and processing the product so that it can be transferred at greater distances to a refinery, but also of unloading the product onto oil tankers or gas tankers.

In this context, a first application of the cable involves the transfer of monitoring signals from sensors in order to monitor the dynamic behaviour, i.e., the oscillations at various frequencies of the riser, generally induced by the motion of a floating plant (FPSO) to which the riser is connected.

A second application involves the monitoring of the deformation of span pipe sections subject to vibrations induced by the current or by the transported fluid.

A third application involves the installation of heating power cables for heating underwater pipes or sections of underwater pipes.

According to the prior art, the cable is applied to the pipeline during the launching phase (piggy back cable) on board a laying vessel and just before the pipeline is launched. The space available for carrying out these operations on board a laying vessel is generally limited, sometimes the type of launch itself makes it difficult to apply the cable around the pipeline before the laying (the J-lay launching method), and if the operations are carried out by personnel, these operations involve risks. Moreover, when the launching operations comprise joining individual sections of the pipeline, it is also necessary to join the individual sections of the cable, as happens for example in the J-lay launching method.

One object of the present invention is to provide a machine for applying at least one cable to a pipeline, which is free from the drawbacks of the prior art.

According to the present invention, a machine is provided for applying at least one cable to a pipeline, the machine comprising:.

the cable application equipment being configured to wind the cable in a helical manner around the pipeline as the machine advances and the strapping apparatus being configured to apply a succession of straps around the pipeline and the cable wound around the pipeline during a machine stop.

The present invention allows the cable to be applied to the pipeline in the body of water and in a completely automatic way.

In particular, the gripping and moving device comprises a plurality of gripping members, two of which articulated to the frame and movable between an open position to allow the insertion of the pipeline between the gripping members, and a closed position to tighten the pipeline between the gripping members.

This allows the machine to be coupled to the pipeline so that the machine is integral with the pipeline and runs in a determined travel direction with respect to the pipeline.

In particular, each gripping member is motorized to move the machine along the pipeline, in particular each gripping member is a motorized track.

This allows the travel of the machine along the pipeline to be controlled in a simple way.

In particular, the machine comprises a plurality of unwinding devices for the controlled unwinding of respective cables from respective reels, the said unwinding devices being supported by the rotating open ring structure so as to rotate together with the rotating open ring structure.

In particular, the machine comprises at least one thrust module coupled to the frame so as to provide the machine with a given hydrostatic thrust to facilitate the installation of the machine on the pipeline.

In particular, the cable application equipment is mounted at the head of the frame and the strapping apparatus is mounted at the rear of the frame with respect to the direction of travel of the machine.

In this way, from the operational point of view, the cable application equipment winds the cable in a helical manner around the pipeline as the machine advances and the strapping apparatus applies a succession of straps around the pipeline and the cable wound around the pipeline during a machine stop.

In particular, the strapping apparatus comprises:.

In this way, a strap can be guided and applied in the body of water around a selected zone of the pipeline in an inexpensive and reliable manner.

A further object of the present invention is to provide a system for applying at least one cable to a pipeline in a body of water, which allows the drawbacks of the prior art to be overcome or at least mitigated.

According to the present invention, a system is thus provided for applying at least one cable to a pipeline, the system comprising:.

In particular, the system comprises an ROV for installing the machine on the pipeline, closing the said clamps around the pipeline, and optionally attending to the operation of said machine.

In this way, the ROV supports the cable application operations, optionally supplying the machine with electrical and/or hydraulic power, a control unit, and a system for communicating with the surface of the body of water.

A further object of the present invention is to provide a method for applying at least one cable to a pipeline in a body of water, which allows the drawbacks of the prior art to be at least partly mitigated.

According to the present invention, a method is thus provided for applying at least one cable to a pipeline in a body of water, the method comprising:.

This method allows the cable to be applied to the pipeline in a completely automatic way by means of the cable application machine.

A further object of the present invention is to provide a computer program which mitigates the drawbacks of the prior art described herein.

In accordance with the present invention, a computer program is provided, which is configured to control a machine and can be directly loaded into a memory of the computer to carry out the steps of the method as described above, when the program is implemented by the computer.

The program allows the method to be implemented in a simple and economical way.

Furthermore, the present invention relates to a program product comprising a readable medium on which the program is stored.

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:.

With reference to <FIG>, reference numeral <NUM> indicates, as a whole, a system for applying at least one cable <NUM> - two cables <NUM> in the example shown herein - to a pipeline <NUM> in a body of water <NUM>. The system <NUM> comprises a machine <NUM> for applying the cable <NUM>; two clamps <NUM> (only one of which is shown in <FIG>) configured to be clamped around the pipeline <NUM> and provided with respective connectors <NUM> configured to be connected to one end of the cables <NUM>; an ROV <NUM>; and a control station <NUM>, which, in the non-limiting example of the present invention shown herein, is arranged on the surface of the body of water <NUM>.

The machine <NUM> is configured to be coupled to the pipeline <NUM>; move along the pipeline <NUM> using the pipeline <NUM> as a guide; unwind the cables <NUM> from respective reels <NUM> along the pipeline <NUM>; wind each cable <NUM> in a helical manner around the pipeline <NUM>; and attach each cable <NUM> to the pipeline <NUM>.

The machine <NUM> comprises a plurality of thrust modules <NUM> which make the machine <NUM> particularly suitable for underwater use.

The ROV <NUM> is configured to install the machine <NUM> on the pipeline <NUM>, close the clamps <NUM> around the pipeline <NUM>, and optionally attend to the operation of the machine <NUM>.

In accordance with a variant of the present invention, not shown in the accompanying drawings, the ROV <NUM> is configured to transmit electrical and/or hydraulic power to the machine <NUM> and control the machine <NUM>.

With reference to <FIG>, in which the thrust modules <NUM> have been removed, the machine <NUM> comprises a frame <NUM> extending along a longitudinal axis A1; a gripping and moving device <NUM> mounted on the frame <NUM> and configured to couple the machine <NUM> around the pipeline <NUM> and move the machine <NUM> along the pipeline <NUM> (<FIG>) in a travel direction D1 parallel to the longitudinal axis A1; a cable <NUM> application equipment <NUM>; and a strapping apparatus <NUM> for applying straps <NUM> (<FIG>) around the cables <NUM> and the pipeline <NUM> (<FIG>).

The frame <NUM> extends mainly along the longitudinal axis A1 and supports, at its opposite ends along the longitudinal axis A1, the cable application equipment <NUM> and the strapping apparatus <NUM> in succession with reference to the travel direction D1.

The frame <NUM> also supports, between the cable application equipment <NUM> and the strapping apparatus <NUM>, a plurality of gripping members <NUM> configured to be arranged in contact with the pipeline <NUM> (<FIG>).

Two gripping members <NUM> are articulated to the frame <NUM> and selectively movable with respect to the frame <NUM> by means of actuators <NUM> in order to allow the gripping members <NUM> to move between an open position and a closed position. Four gripping members <NUM> are mounted integral with the frame <NUM>. This allows the pipeline <NUM> to be clamped between the gripping members <NUM> and the machine <NUM> to be integral with the pipeline <NUM> (<FIG>).

At least one gripping member <NUM> is motorized to ensure the movement of the machine <NUM> along the pipeline <NUM> (<FIG>). In the example shown herein, all the gripping members <NUM> are motorized so as to prevent the machine <NUM> from being subjected to unbalanced forces. In particular, each gripping member <NUM> comprises a carriage <NUM> and a track <NUM> such that the contact area between the gripping member <NUM> and the pipeline <NUM> can be extended.

The cable application equipment <NUM> comprises a rotating open ring structure <NUM>, which is configured to rotate with respect to the frame <NUM> around the pipeline <NUM> when the machine <NUM> is gripping the pipeline <NUM> (<FIG>); and two unwinding devices <NUM> for the controlled unwinding of the respective cables <NUM> from the respective reels <NUM>.

The frame <NUM> includes an open ring structure <NUM> to house and guide the rotating open ring structure <NUM>.

With reference to <FIG>, the open ring structure <NUM> comprises an open ring crown wheel <NUM> and supports two motors <NUM> and respective pinions <NUM> in mesh with the open ring crown wheel <NUM>. The open ring crown wheel <NUM> has an extension greater than <NUM>° and the pinions <NUM> are arranged such that the open ring crown wheel <NUM> is always in mesh with at least one of the two pinions <NUM>.

With reference to <FIG>, each unwinding device <NUM> is mounted on the rotating open ring structure <NUM> and comprises a support <NUM> for supporting a spool <NUM> on which a reel <NUM> of cable <NUM> is wound; and a pulley <NUM>, which has the function of returning the cable <NUM> in the vicinity of the pipeline <NUM> (<FIG>).

Each spool <NUM> is configured to rotate about a respective axis of rotation A2, so as to unwind the respective cable <NUM> from the respective reel <NUM>. In particular, the rotation of each spool <NUM> about the respective axis of rotation A2 is braked by a respective braking device, not shown in the attached figures, so as to keep the respective cable <NUM> taut during the application of the cables <NUM> around the pipeline <NUM> (<FIG>).

In accordance with a variant of the present invention, each spool <NUM> is motorized so as to control the rotation speed of each spool <NUM> about the respective axis of rotation A2 and keep the respective cable <NUM> taut.

With reference to <FIG>, the strapping apparatus <NUM> comprises: a support element <NUM> fixed to the frame <NUM> (<FIG>); a feeding device <NUM> for feeding a band <NUM> from which the straps <NUM> are cut (<FIG>); two arms <NUM> selectively movable with respect to the frame <NUM> between an open position and a closed position by respective actuators <NUM> and configured to guide the band <NUM> around the pipeline <NUM> and the cables <NUM>; a clamping device <NUM> configured to hold an end portion of the band <NUM>; an advancing device <NUM> configured to advance and tighten the band <NUM> around the pipeline <NUM> and the cables <NUM>; a junction device <NUM> configured to join two overlapping portions of the band <NUM> so as to close the band <NUM> around the pipeline <NUM> and the cables <NUM>; and a cutting device <NUM> configured to separate the band <NUM> from the junction area.

With reference to <FIG>, the system <NUM> comprises a control device <NUM> for controlling the machine <NUM>. The control device <NUM> comprises a control unit <NUM>, which can be arranged on board the machine <NUM> itself or on board the ROV <NUM> or in the control station <NUM> floating on the surface of the body of water <NUM>. The control device further comprises a sensor <NUM> configured to detect the position of the rotating open ring structure <NUM> with respect to the frame <NUM> (<FIG>); at least one sensor <NUM> for detecting the position of the gripping members <NUM>; a sensor <NUM> for detecting whether the arms <NUM> are in the closed position or in the open position; and a sensor <NUM> for detecting whether the band <NUM> has two overlapping portions downstream of the junction device <NUM>.

The control unit <NUM> is configured to control the two motors <NUM> according to the position of the rotating open ring structure <NUM> detected by the sensor <NUM> and to control the gripping members <NUM> and the actuators <NUM> according to the position detected by the sensor <NUM>.

Moreover, the control unit <NUM> is configured to control the feeding device <NUM>, the actuators <NUM> of the two arms <NUM>, the clamping device <NUM>, the advancing device <NUM>, the junction device <NUM> and the cutting device <NUM> according to the signals detected by the sensors <NUM> and <NUM>.

In addition, the control device <NUM> comprises a computer <NUM>, which comprises a memory containing a program for controlling the system <NUM> and is configured to implement said program.

The computer <NUM> can be programmed directly or is configured to read program media through special interfaces.

In use and with reference to <FIG>, the machine <NUM> is coupled around the pipeline <NUM> and clamped to the pipeline <NUM> by the closing of the gripping members <NUM> (<FIG>) around the pipeline <NUM>.

The ROV <NUM> tightens the clamp <NUM> - not shown in the attached figures - to which the starting ends of the cables <NUM> are fastened, around the pipeline <NUM>.

At this point, with reference to <FIG>, the machine <NUM> moves along the pipeline <NUM> by means of the tracks <NUM> of the gripping and moving device <NUM> and using the pipeline <NUM> as a guide.

At the same time, the motors <NUM> (<FIG>) rotate the rotating open ring structure <NUM> around the pipeline <NUM>, and the two unwinding devices <NUM> unwind in a controlled manner the respective cables <NUM> from the respective reels <NUM>, so as to wind the cables <NUM> in a helical manner around the pipeline <NUM> as the machine <NUM> advances.

In greater detail, as each cable <NUM> unwinds from the respective reel <NUM>, the rotation of each spool <NUM> about the respective axis of rotation A2 is braked by a braking device, not shown in the attached figures.

At regular or predetermined intervals, the movement of the machine <NUM> along the pipeline <NUM> is stopped so as to alternate between forward and stop phases, during which the strapping apparatus <NUM> applies a strap <NUM> (<FIG>) around the pipeline <NUM> and the cables <NUM>.

With reference to <FIG>, during this stop phase, the arms <NUM> are moved from the open position to the closed position, and the sensor <NUM> monitors the relative positions of the two arms <NUM> and supplies the relevant signals to the control unit <NUM>.

When the arms <NUM> are in the closed position, the advancing device <NUM> feeds the band <NUM> inside the arms <NUM>.

The sensor <NUM> detects the presence of the band <NUM> inside the arms <NUM> in a given position and provides the relevant signals to the control unit <NUM>.

After receiving the consent from the sensor <NUM>, the control unit <NUM> actuates the clamping device <NUM> so as to hold the band <NUM>.

Next, the advancing device <NUM> tightens the band <NUM> around the pipeline <NUM> and the cables <NUM>, extracting the band <NUM> from the arms <NUM>. Once the band <NUM> is tightened around the pipeline <NUM> and the cables <NUM>, the junction device <NUM> joins the two overlapping portions of the band <NUM>, so as to close the band <NUM> around the pipeline <NUM> and the cables <NUM>. The sensor <NUM> monitors the outcome of the joining operation and supplies relevant signals to the control unit <NUM>.

Subsequently, the cutting device <NUM> separates the band <NUM> upstream of the joined portion.

With reference to a non-limiting embodiment of the present invention, all the steps of the operations for applying the strap <NUM> (<FIG>) around the pipeline <NUM> and the cables <NUM> are controlled by the control unit <NUM>.

With reference to <FIG>, when the operations for applying the cables <NUM> around the pipeline <NUM> are completed, the ROV <NUM> tightens the clamp <NUM>, to which the terminal ends of the cables <NUM> are fastened, around the pipeline <NUM>.

At this point, the gripping members <NUM> are moved from the closed position to the open position so as to uncouple the machine <NUM> from the pipeline <NUM>.

In accordance with one embodiment, during the operations for applying the cables <NUM> around the pipeline <NUM>, the ROV <NUM> assists the machine <NUM> in said operations. In particular, the ROV <NUM> transmits electrical and/or hydraulic power to the machine <NUM> and also controls the machine <NUM> visually by means of a video camera not shown in the attached figures.

Claim 1:
A machine to apply at least one cable to a pipeline, the machine (<NUM>) comprising:
- a frame (<NUM>) extending along a longitudinal axis (A1);
- a gripping and moving device (<NUM>) mounted on the frame (<NUM>) and configured to couple the machine (<NUM>) around the pipeline (<NUM>) and move the machine (<NUM>) along the pipeline (<NUM>) in a travel direction (D1) parallel to the longitudinal axis (A1);
- a cable application equipment (<NUM>) comprising a rotating open ring structure (<NUM>), which is configured to rotate with respect to the frame (<NUM>) and around the pipeline (<NUM>) when the machine (<NUM>) is gripping the pipeline (<NUM>); and an unwinding device (<NUM>) for the controlled unwinding of a reel (<NUM>) of cable (<NUM>); said unwinding device (<NUM>) being mounted on said rotating open ring structure (<NUM>); and
- a strapping apparatus (<NUM>) mounted on the frame (<NUM>) for applying straps (<NUM>) around the cable (<NUM>) and the pipe (<NUM>);
the cable application equipment (<NUM>) being configured to wind the cable (<NUM>) in a helical manner around the pipeline (<NUM>) as the machine (<NUM>) advances and the strapping apparatus (<NUM>) being configured to apply a succession of straps (<NUM>) around the pipeline (<NUM>) and the cable (<NUM>) wound around the pipeline (<NUM>) during a machine stop.