FR2997692A1 - SYSTEM AND METHOD FOR FLUID TRANSFER - Google Patents

Abstract

A fluid product transfer system (1) having a balanced fluid transfer arm (10) having a transfer compass (13, 14) having a transfer line having a line end attached to a carrier and a movable line end (23) provided with a connection / disconnection member (12) for connecting the line to a target tubular (24), characterized in that it further comprises a telescopic arm (25) adapted to be secured by one of its longitudinal ends to the moving line end (23) to move it to a connection position of the connection / disconnection member (12) to the target tubing (24) and mounted by its opposite longitudinal end on a parallel robot (25) controlled in dependence of the motion detection that the target tubing (24) undergoes to compensate at the connection / disconnection member movements of the target tubing.

Description

The invention relates to a fluid transfer system, such as a petroleum product, and an associated transfer method. It is more particularly a liquefied natural gas transfer system where the transfer is operated between two ships at open sea (offshore transfer). The first of the two vessels may be a production vessel known as LNGP (LNGP) or LNG-FPSO (for Liquefied Natural Gas Floating Production Storage and Offloading). , ie "floating system for producing, storing and discharging liquefied natural gas"), or FLNG (for Floating Liquid Natural Gas Unit, or Floating Liquid Natural Gas Unit), a reliquance vessel (FSRU for "Floating Storage and Regasification Unit"), a GBS (for "Gravity Base Structure" ie "a platform with weighted base" ) or finally a platform. The second of the two vessels may be a vessel intended to receive gas for transportation such as a tanker or LNG-C (for "Liquefied Natural Gas Carrier", for example a LNG carrier). In particular, rigid and articulated loading systems are known which have a fluid transfer line end attached to a base or a support and connected to a fluid reservoir to be transferred, and an opposite mobile line end provided with a connection / disconnection member for connection to a target tubing, itself connected to a fluid reservoir. Generally, in such a system (see FR 2813872 and FR 2854156), the loading arm comprises an articulated pipe, mounted on a base, connected to a fluid reservoir, and on which is mounted a first pipe said internal pipe via a portion of the tube bent at 90 ° for one of its ends a rotation along a vertical axis, and at the other end along a horizontal axis. At the opposite end of the inner tube, is rotatably mounted along a horizontal axis, a second pipe, said external pipe. At the end of the outer pipe is mounted the connection / disconnection member, for example a hydraulic coupler.

The coupler thus has at least three degrees of freedom relative to the base carrying the fixed end of the tubing, and the movements following each of these degrees of freedom are controlled by actuators, such as cylinders or hydraulic motors. The operator has for this purpose a control interface.

The transfer of fluid at open sea has always proved difficult because of the relative movements of the two vessels and more particularly those of the second, the first of the two defined above being generally in the form of a more or less fixed platform. To allow the connection of the loading arms in difficult weather conditions (very rough sea), it is therefore implemented on the aforementioned arms a cable system subjected to a constant voltage, cooperating with the mobile line end to synchronize the movements of the arm on those of the receiving ship. This type of system is entirely satisfactory, but it would nevertheless be desirable to have a loading system that does not request, or as little as possible, this mobile line end during the connection process. The present invention proposes, for this purpose, a system for transferring a fluid product, comprising a balanced transfer arm of the fluid product, having a transfer compass comprising a transfer line having a line end attached to a support and a mobile line end provided with a connection / disconnection member for connecting the line to a target pipe, the system being characterized in that it further comprises a telescopic arm adapted to be secured by one of its longitudinal ends at the moving line end to move it to a connection position of the connection / disconnection member to the target tubing and mounted by its opposite longitudinal end on a parallel robot controlled in dependence of the detection of movements that undergoes the target tubing to compensate at the connection / disconnection member movements of the target tubing. Thanks to these arrangements, it is possible to perform a complete connection / disconnection process with little or no stress on the mobile line end and further leading to other advantages, as will be seen in more detail. in detail infra. According to other provisions of the present invention, which can be implemented independently or in combination, in particular because of their ease of manufacture or use: the parallel robot comprises a support on which the telescopic arm is mounted and actuators for moving the support in at least three degrees of freedom. the parallel robot is in the form of a Stewart platform. the actuators of the parallel robot are hydraulic, pneumatic or electric cylinders. the system comprises a control system adapted to control the actuators of the parallel robot as a function of signals received from means for detecting movements of the target tubing with respect to a surrounding element. the detection means comprise a global positioning system, in particular of the GPS type, an optical system, such as a camera or a laser or infrared system, an acceleration measuring system, an inertial stabilization system for measuring angles, an autonomous initial coordinate tracking system, or a combination of two or more such systems. the control system is adapted to process the signals received from the detection means by means of preprogrammed algorithms. The telescopic arm is pivotally mounted on the support so that it can be raised or lowered. the telescopic arm is rigidly connected to the mobile line end. - The system comprises a carriage mounted to move in translation on an outer segment of the telescopic arm and adapted to be fixed to the end of the moving line. the transfer arm comprises at least three actuators for controlling each movement of the transfer arm according to a degree of freedom according to a first mode of operation, and is adapted to be freewheeled according to a second mode of operation. - The movable line end of the transfer arm comprises means for guiding and aligning the connection / disconnection member on the target tubing when it comes in close proximity thereto. - The transfer arm is equipped with sensors adapted to act on the movement controls thereof to limit the loads on a vessel carrying the target tubing. The invention also relates to a transfer assembly of a fluid product, comprising a transfer system as defined above and a target tubing provided with a support member for the end of the telescopic arm located on the end of the moving line.

Finally, the invention relates to a method for transferring fluid by means of a system as defined above, comprising the steps of: - bringing the telescopic arm to the target tubing, to a position at a distance from the latter; - connect the telescopic arm to the moving line end of the transfer arm; put the transfer arm in freewheel mode; and - bringing the connection / disconnection member to a position of connection to the target pipe by means of the telescopic arm. In such a case, the connection / disconnection member can be moved, on a final race portion, by sliding a carriage on the telescopic arm.

The presentation of the present invention will now be continued by the detailed description of two embodiments, given below by way of illustration and not limitation, with reference to the accompanying drawings. On these: - Figure 1 is a very schematic side elevational view of a transfer system according to a first embodiment of the invention; and FIG. 2 is a very schematic side elevational view of a transfer system according to a second embodiment of the invention. These figures represent a transfer system, here double counterweight transfer of a fluid product according to the invention, and have two embodiments of the actuating means and motion compensation means. In these embodiments chosen solely by way of example to illustrate the application of the invention, the transfer system 1 comprises a transfer arm 10 generally comprising a deformable tubular portion 11 adapted to be connected. at one end to a fixed pipe leading to a tank (not shown) and terminated at its other end by a coupler 12, here hydraulic motor, or any other connection / disconnection (coupling) of a known type and intended for be connected to a second pipe or target pipe carried by the ship 2. This hydraulic coupler 12 is connected by a set of elbows and rotary joints, here cryogenic and Chiksan® rotary joint type, at the free end of the deformable tubular portion 11. The elbows and rotary joints assembly is, in practice, a style 80 equipped with an emergency release system (ERS). System) and a quick connect-disconnect system (QCDC). This quick connect / disconnect system is in operation during normal operation. It will be recalled here that we know in the field the terms "style 40" and "style 50" which define one, a coupling or rotating joint whose two ends are each welded on one elbow, and the other , joining a first rotating connection, then an elbow, then a second rotating connection making a 90 ° angle with said first connection, then a bend. A style 80 corresponds to a style 50 supplemented by a third connection parallel to the first connection and connected to the second by an elbow. The rotating joints of these styles are all cryogenic, here of the rotating joint type Chiksan 0. The deformable tubular portion 11 mainly comprises two tubes 13, 14, or transfer elements connected by a rotary joint 15 of horizontal axis (style 40). , thus forming a variable opening compass. One of these tubes, called internal tube 13, is intended to be connected via a style 50 to a pipe intended to fluidly connect the transfer arm to the tank (elements not shown in the figures) while the other tube, called the outer tube 14, is connected, as indicated above, to the coupler 12. To the deformable tubular portion 11 are associated counterbalanced balancing systems adapted to allow that, empty, the arm can remain stable in any configuration. This is necessary for the smooth running of the coupling and uncoupling of the arm to the mobile pipe. There is thus no significant effort to provide to keep the arm in position. The main balancing, that is to say movable elements of the arm that are the inner tubes 13 and outer 14 hinged together and the coupling assembly formed by the hydraulic coupler 12 and the connection means of this to the outer tube 14 is provided by means of at least one primary counterweight 16. A balancing system of the outer tube section 14 and the aforementioned coupling assembly is here also provided. It is in the form of a pantograph system 17 which comprises at least a secondary counterweight 18. Cylinders are, moreover, actuators or actuators of these inner tubes 13 and outer 14. This is here hydraulic cylinders controlled by an operator by means of a control interface. These cylinders are here three in number, that is to say a jack for controlling the movement of the arm according to each degree of freedom. That of actuating the arm 10 in rotation about a vertical axis is not visible in the figures while those for actuating the inner and outer tubes 13 and 14 respectively bear the numerical markers 14 and 20. Furthermore, the The mobile line end is equipped with the hydraulic coupler which is of the QCDC type as well as an emergency disconnection system (ERS). The transfer arm as just described is well known to those skilled in the art and will not be described in more detail here. This is in fact an arm similar to those described in the aforementioned applications (FR 2813872 and FR 2854156). The remainder of the description relates more specifically to the two embodiments of the actuation and motion compensation means according to the invention. In the case of the first embodiment, the transfer system 15 1 of a fluid product comprises, as indicated, a double counterbalanced balanced transfer arm 10, installed here on an offshore platform 21, with its deformable tubular portion 11 or a transfer compass forming a transfer line with a line end attached to a mat 22 and a moving line end 23 provided with the hydraulic coupler 12 for connecting this transfer line 20 to a target tubing 24 installed here on a LNG-C. In practice, the transfer arm 10 comprises, in the case of this embodiment and as also indicated, three hydraulic cylinders (not shown in the figure) to each control the movement of the arm according to a degree of freedom in a first embodiment. operating (by actuating the inner tube 17, the outer tube 14 and rotating about a vertical axis). This arm 10 is further adapted to be freewheeled in a second mode of operation. According to the present invention, the transfer system further comprises a telescopic arm 25, here hydraulic and two segments 26, 27, adapted to be secured by one of its longitudinal ends to the end of moving line 23, for move it to a position of connection of the hydraulic coupler 12 to the target pipe 24.

This telescopic arm is, moreover, mounted by its opposite longitudinal end on a parallel robot 28 controlled in dependence of the detection of the movements that the target tubing 24 undergoes, to compensate at the level of the hydraulic coupler 12 for movements of the target tubing 24.

More specifically, the parallel robot 28 is, in the case of this embodiment, a Stewart platform with hydraulic cylinders, also known as a hexapod positioner. It is a parallel robot comprising six actuators (hydraulic cylinders) and thus having six degrees of freedom: the three translation coordinates as well as pitch, roll and yaw angles (Euler angles) or alternatively, their nautical equivalent. Examples of such platforms are described in particular in patent applications WO99 / 28095 and US2010 / 0191500. Only two of these hydraulic cylinders of the Stewart platform are shown here in Figure 1 and bear the numeral 29.

To enslave the movements of this Stewart platform, there is provided a control system (not shown) adapted to control the hydraulic cylinders of the platform based on signals received from movement detection means of the ship LNG-C and hence the target tubing 24, with respect to a surrounding element, such as the hydraulic coupler 12, or another element in the surrounding world. These detection means comprise, in the case of this embodiment, a laser system (30a, 30b), of the kind emitting a laser or infrared beam towards the target tubing 24 or a fixed target with respect to this tubing, and adapted to detecting the reflected ray and measuring the travel time of the beam to derive relative positioning information of the target tubular 24 relative to the coupler 12. This system is advantageously coupled to other motion sensors, such as accelerometers, for this servo need. The control system is, for its part, adapted to process the signals received from these detection means by means of preprogrammed algorithms. It may be, for example, a computer system equipped with a processor and a memory in which these algorithms are stored.

These can of course also be stored on an external medium, thus forming a computer program product. This control system can, moreover, manage the hydraulic cylinders of the transfer arm. A user control interface may advantageously complement this control system. It will be observed that the telescopic arm is pivotally mounted on the Stewart platform, so as to raise or lower it, for example by means of a hydraulic cylinder (not shown in Figure 1). This is in practice a pivoting about an axis 31 extending parallel to the upper plate 32 of the Stewart platform and transversely to the axis of the mast 22 supporting the transfer compass. At its other end, the telescopic arm 25 comprises, in the case of this first embodiment, a carriage 33 mounted to move in translation on the outer segment 27 of the telescopic arm 25, in two opposite directions shown schematically by the arrows A and B In order to be able to move the hydraulic coupler 12 in translation, this carriage is fixed to the end of the moving line 23. In the case of this embodiment, there is also provided on the LNG-C, a manifold 34, or more simply a flange, at the end of target pipe 24, intended to be connected to the hydraulic coupler, and which is in the form of an insert on a standard pipe section 35 equipping the LNG-C. A bracket 36, in the form of a bracket, is fixed to and under this manifold to be able to receive, in support, the free end of the telescopic arm 25. The connection process is performed, according to this first embodiment, as follows - The telescopic arm 25 and the transfer arm 10 (with its own cylinders) are first deployed to be positioned between a storage position or withdrawal and a connection position to the target tubing. - The transfer arm 10 is then connected (in practice connected for example by screwing) to the movable carriage 33 of the telescopic arm 25. - The transfer arm 10 is not yet in freewheel mode but the carriage is able to make a recoil movement (direction of the arrow B) in translation to compensate for the movement in the opposite direction of the outer segment 27 of the telescopic arm 25.

Then, the telescopic arm 25 is brought into the support position on the support 36 at right angles connected to the manifold 34, by translation of the outer segment 27 of the arm. This leads to the positioning visible in FIG. 1. In this position, the hydraulic coupler 12 is still set back with respect to the free end of the telescopic arm 25, that is to say the free end of the outer segment. of this arm. In other words, the movements of this end are synchronized with those of the LNG-C and this end is found in a fixed position relative to the LNG-C. The same applies to the hydraulic coupler 12, with the exception of its translational displacement movement intended to bring it closer to the manifold 34. While performing this movement compensation, the carriage 33, with the transfer arm 10 connected to it is then moved in translation until the hydraulic coupler 12 is in the position of connection to the manifold 34. During this translational movement, the transfer arm is set in freewheel mode. The final coupling between the hydraulic coupler 12 and the manifold 34 is, in the case of this first embodiment, carried out manually thanks to the degrees of freedom possessed, in practice and in a manner known per se, the end of the moving line. 23 alternatively to the rest of the outer tubing 14. Alternatively, as will be seen below, the final alignment can also be provided by guiding and alignment means. We will now describe the second embodiment in support of Figure 2. The elements of this Figure 2 identical to those of Figure 1, bear the same numerical references. According to this second embodiment shown in FIG. 2, the transfer arm 10, via its moving line end 23, is rigidly connected directly to the outer segment 27 of the telescopic arm 25. In other words, there is no mobile cart in translation. This is, in practice, a tab 37 fixed, on the one hand, to the outer segment of the telescopic arm and, on the other hand, to the mobile end 23 of the transfer line, between the last rotation of this and the hydraulic coupler 12. The attachment can be made for example by screwing. It will also be observed that the last rotation can be blocked during the translational movement of the hydraulic coupler 12 described below. It will be further observed that the transfer system 1 according to this second embodiment comprises means for guiding and aligning the hydraulic coupler 12 on the manifold 34 when it comes in close proximity to it. This is, here, two complementary frustoconical guide elements (a male frustoconical element and a female frustoconical element adapted to fit one into the other). It will be observed that this embodiment does not require, on the other hand, a telescopic arm support 25 on the manifold 34. The connection process according to this second embodiment is as follows: the telescopic arm 25 is, all of first, extended to a position remote from the manifold 34 (without motion compensation by means of the parallel robot). The transfer arm 10 is then deployed by means of its actuators until the hydraulic coupler 12 is located in the vicinity of the free end of the outer segment 27 of the telescopic arm 25. The transfer arm 10 is then rigidly connected. at this end of the telescopic arm 25 and set freewheel mode. Then the telescopic arm 25 is moved to a connection position of the hydraulic coupler 12 to the manifold 34, the parallel robot 28 being simultaneously operated to compensate for the movements of the manifold 34. The guiding and aligning means then provide guidance and final alignment of the hydraulic coupler 12 on the manifold 34.

In practice, it is of course possible to consider, for example, to compensate a movement of the LNG-C towards the platform by a lack of advance movement of the hydraulic coupler 12, instead of back and forward. This takes advantage of the reconciliation of the LNG-C to bring the hydraulic coupler 12 manifold 34. The disconnection procedure can be done in a manner similar to the connection procedure, but in the opposite direction. It should however be noted that in case of emergency disconnection, the guidance system formed by the telescopic arm is not used. Indeed, the telescopic arm is removed after the connection of the arm to the manifold of the ship, and therefore during the emergency disconnection there is only the arm and it. The emergency disconnect sequence is identical to that traditionally done on the transfer arms. With the present invention, the procedure of connecting a transfer arm to a target tubing can be performed without exerting particular stress on the moving end of the transfer line and without the need to install on it additional means used during the connection procedure, which would impose at that end additional weight transferred to the manifold after connection. In addition, the connection can be made smoothly and with an almost conventional transfer arm. The present invention is not limited to the preferred embodiments described above by way of non-limiting examples and illustrated in the drawings. It relates to all embodiments within the scope of the skilled person. In particular, it may be envisaged, for example, to move the support or platform of the parallel robot, on which the telescopic arm is mounted, only in three degrees of freedom (pitch, roll and yaw), while translation movements could be supported by a movement of the telescopic arm equipped with adequate actuators. Movement compensation may also be considered for relative movements of the first and second vessels, if the platform is not substantially stationary.

In this case, it is possible to determine the relative positioning of the connection / disconnection member with respect to the target pipe, instead of, for example, detecting only the movements of the second vessel relative to a reference point or a fixed element.

In addition, the guiding and alignment means may be in a form other than the male and female frustoconical elements, such as for example in the form of rods having a shape for guiding and aligning the hydraulic coupler in order to bring it to its final position of connection to the manifold.

Furthermore, it may be envisaged to use the telescopic arm mounted on the parallel robot to ensure the compensation of movements of two transfer arms arranged side by side. The transfer arm can, meanwhile, be a balanced arm on a single counterweight.

It will also be noted that the autonomous system for locating initial coordinates (position, orientation, etc.) mentioned above and of the type described in application EP 0 029 768. The sensors that can equip the transfer arm (preferably its end outer tube outer) to act on its controls to limit the loads exerted on the second ship may be for example of the type of force or acceleration sensors.

Claims (16)

REVENDICATIONS1. A fluid product transfer system (1) having a balanced fluid transfer arm (10) having a transfer compass (13, 14) having a transfer line having a line end attached to a carrier and a movable line end (23) provided with a connection / disconnection member (12) for connecting the line to a target tubular (24), characterized in that it further comprises a telescopic arm (25) adapted to be secured by one of its longitudinal ends to the moving line end (23) to move it to a connection position of the connection / disconnection member (12) to the target tubing (24) and mounted by its opposite longitudinal end on a parallel robot (25) controlled in dependence on the detection of movements that the target tubing (24) undergoes to compensate at the connection / disconnection member movements of the target tubing. 2. System according to claim 1, characterized in that the parallel robot comprises a support on which is mounted the telescopic arm and actuators for moving the support in at least three degrees of freedom. 3. System according to claim 2, characterized in that the parallel robot is in the form of a Stewart platform. 4. System according to claim 2 or 3, characterized in that the actuators of the parallel robot are hydraulic cylinders, pneumatic or electric. 5. System according to any one of the preceding claims, characterized in that it comprises a control system adapted to control the actuators of the parallel robot as a function of signals received from movement detection means of the target tubing with respect to a surrounding element. 6. System according to claim 5, characterized in that the detection means comprise a global positioning system, in particular of the GPS type, an optical system, such as a camera or a laser or infrared system, a measurement system of acceleration, an inertial stabilization system for measuring angles, an autonomous system for locating initial coordinates, or a combination of two or more such systems. 7. System according to claim 5 or 6, characterized in that the control system is adapted to process the signals received from the detection means by means of preprogrammed algorithms. 8. System according to any one of claims 2 to 7, characterized in that the telescopic arm is pivotally mounted on the support so as to raise or lower it. 10 9. System according to any one of claims 1 to 8, characterized in that the telescopic arm is rigidly connected to the mobile line end. 10. System according to any one of claims 1 to 9, characterized in that it comprises a carriage mounted movable in translation on an outer segment of the telescopic arm and adapted to be fixed to the end of the moving line. 11. System according to any one of claims 1 to 10, characterized in that the transfer arm comprises at least three actuators to each control the movement of the transfer arm to a degree of freedom according to a first mode of operation, and is adapted to be freewheeled according to a second mode of operation. 12. System according to any one of claims 1 to 11, characterized in that the movable line end of the transfer arm comprises means for guiding and aligning the connection / disconnection member on the target tubing when comes in close proximity to it. 13. System according to any one of claims 1 to 12, characterized in that the transfer arm is equipped with sensors adapted to act on the movement controls thereof to limit the loads on a vessel carrying the target tubing. 30 14. A fluid product transfer assembly, comprising a transfer system according to any one of claims 1 to 13 and a tubulurecible provided with a support member for the end of the telescopic arm located on the moving line end side. 15. A method of transferring fluid by means of a system according to any one of claims 1 to 13, comprising the steps of: - bringing the telescopic arm to the target tubing, to a position at a distance from the latter ; connect the telescopic arm to the moving line end of the transfer arm; - put the transfer arm in freewheel mode; and bringing the connection / disconnection member to a position of connection to the target tubing by means of the telescopic arm. 16. The method of claim 15, wherein the connection / disconnection member is moved on a final race portion, by sliding a carriage on the telescopic arm.