Diverless Bell Mouth Manipulator and Method for Performing Diverless Operations in a Bell Mouth Using the Manipulator

The preset patent of disclosure falls within the technical field of vessels, platforms, rigs, and production facilities, and, more specifically, within the technical field of activities associated with diverless operations carried out in bell mouths.

Up until now, for subsea maintenance and inspection activities, two types of resources are generally used: the diver and the ROV (Remotely Operated Vehicle).

However, performing operations in a bell mouth while shallow diving results in a high-risk operation, as the diver may suffer accidents and traumas such as: barotrauma, decompression sickness, poisoning, asphyxiation, falling cargo, attacks by marine fauna, umbilical cord getting caught in some subsea structure that makes it impossible for the diver to return, among others.

In addition, diving operations are somewhat inefficient, as they have restrictive meteoceanographic conditions and there is a limit to the time in which the diver can remain at the bottom, increasing the time needed to perform the service due to the change of divers.

Due to the risks associated with shallow diving operations, whose activity is considered Man Hour Exposed to Risk (MHER) and which has a history of accidents, including fatal ones, initiatives have been taken to eliminate this type of manual operation by using diverless resources.

In this sense, attempts have begun to replace shallow diving with ROV in operations on platforms that were designed for diving intervention. However, the platforms also present difficult access for the ROV and do not provide stable docking and parking points.

It is further observed that, as the operations are in shallow water depths (WD), especially in the TVZ (Tidal Variation Zone), where hydrodynamic forces are high, the ROV does not operate ideally, as it has difficulty maintaining position and remaining stable enough to be able to perform operations. In addition, the access to the back of the bell mouth is extremely limited or impossible due to the dimensions of the ROV and the high hydrodynamic forces.

Accordingly, operating the ROV in such conditions puts the equipment at risk, since when trying to maintain position in these conditions, the thrusters require a lot of power, which increases the temperature of the ROV oil and puts its integrity at risk.

Furthermore, in cases of attempting to dock with one of the ROV's own robotic arms (manipulator arms) to perform a service with the other arm, the dynamics of the relative movement between the platform and the ROV make this option unfeasible, as there is a risk of the arm breaking, which would limit operations to being carried out only in very restrictive sea conditions.

In view of the disclosure above, for operations in the bell mouth, whether pre-pull in or post-pull in, as well as dog opening operations in the final step of the effective pull out, such as inspection, cleaning, dog softening (bend stiffener helmet locking mechanism), among others, the diving operation becomes complex due to the confined space and associated risks, and the operation with ROV is unfeasible, because in addition to having difficulty maintaining position, there is a risk of collision with the bell mouth, and the ROV does not have access to the dogs at the back of the bell mouth.

Therefore, a solution is needed that makes it possible to replace human diving and also offers a decoupled alternative between the ROV and a platform, so that the solution is solidified with the structure of the unit.

The state of the art includes some means of anchoring in cylindrical structures, some of which are applicable to perform operations in shallow water depths by an ROV.

Document WO20192856 refers to a device for moving along the external surface of pipes of a support jacket of an offshore installation. The document discloses that the device can be used in shallow water depths operations and operates independently of an ROV or diver, and the device can be transported/positioned by the ROV and then remotely controlled by means of an umbilical. The device comprises two attachment units connected to each other by a plurality of longitudinal actuators to move the device along a structure according to the principle of a caterpillar.

Document US20,101,63239 discloses a remotely operated device for inspecting and/or cleaning a subsea flexible pipe joint comprising a support assembly and a tool positioning assembly coupled to the support assembly. The tool positioning assembly includes a rotatable member disposed about a central axis. The tool positioning assembly is rotatable relative to the support assembly about the central axis. Furthermore, the device comprises a cleaning assembly including a cleaning device adapted to clean the flexible pipe joint.

Document US20,212,62186 discloses an apparatus for maintaining a structure comprising a frame for mounting around the structure, the frame having at least a pair of first and second arms pivotally attached at their proximal ends to the frame, and carrying respective rotatable members disposed to contact the structure and actuatable to move the frame along the structure.

Document BR 102021017362 discloses a device capable of enabling remote unlocking and remaining compatible with the possibility of mechanical and manual driving of bell mouths. The device is a hydraulic actuator with hydraulic power supply through lines coming from the platform. The system allows greater agility in pull out operations. In addition, it promotes a reduction in the need for diving and, consequently, lower MHER (Man-hours exposed to risk).

Nevertheless, there are still clearly deficiencies in the state of the art, especially because these documents are not aimed at operations performed on bell mouths in a diverless manner. Accordingly, the features and advantages of the present disclosure will clearly emerge from the detailed description below.

The present patent of disclosure discloses a diverless bell mouth manipulator and a method for performing diverless operations on bell mouths using the manipulator. The disclosure makes it possible to replace human diving in operations carried out in bell mouths and, further, offers an advantageous alternative to the use of an ROV in areas where operations are difficult in shallow water depths. The manipulator comprises a main structure () in a semicircular shape comprising: seats for mounting respective grippers () in the shape of a semicircular rack, a pinion () respectively coupled to the rack of each gripper (), a plurality of magnetic rollers (), and at least one robotic arm ().

The present application discloses a diverless bell mouth manipulator and a method for performing diverless operations on bell mouths using the manipulator.

The disclosure is particularly relevant in diverless operations carried out in bell mouths, such as pre-pull in or post-pull in operations, as well as dog opening operations in the final stage of the effective pull out, such as inspection, cleaning, dog softening (bend stiffener helmet locking mechanism), interconnection and decommissioning of subsea pipelines, among others. Thus, the disclosure makes it possible to replace human diving in operations carried out in bell mouths and, furthermore, offers an advantageous alternative to the use of the ROV in areas with difficult operations in shallow water depths.

The present disclosure is particularly advantageous, in a first aspect, due to the fact that the arms that perform the various services, instead of being integral to the structure of an ROV, are integral to the manipulator of the present disclosure, which is integral/coupled to the bell mouth, thus eliminating the relative movement between the platform and the manipulator.

In this way, by being integral/coupled to the bell mouth, the present disclosure will not be subject to the difficulties of operating in the bell mouth, as it will not need to activate the thrusters of an ROV, for example, to compensate for the resultant of the hydrodynamic forces, thus eliminating the risks to the integrity of the ROV due to the heating of the oil. Furthermore, the fact that the manipulators are attached to the bell mouth eliminates the risk of collision that the ROV would have with the bell mouth.

It is also worth highlighting that the present disclosure advantageously makes it possible to optimize operations in SPUF DL (Stationary Production Unit Front—team that embarks on the platform, launches and operates the ROV directly from the platform instead of a boat), if it is implemented in this type of resource and is launched directly from the SPU (Stationary Production Unit—Platform) instead of an RSV (ROV Support Vessel—ROV Vessel), optimizing its SPUF DL operations, since the main causes of inefficiency, such as meteoceanographic and hydrodynamic conditions existing between the platform the conventional ROV and simultaneous operations are eliminated.

In a first aspect, by being integral to the platform (i.e., coupled to the bell mouth), the present disclosure advantageously would not be subject to meteoceanographic conditions and would not have its operation interrupted due to other operations, since it is attached to the platform as if it were a piece of platform equipment.

Notwithstanding, in addition to the particular and advantageous application to the operations in bell mouths, it will be appreciated that the present disclosure can also assist in carrying out operations in any other cylindrical structures in shallow water depths affected by the tidal variation zone.

To achieve such advantages, the diverless bell mouth manipulator of the present disclosure generally comprises a mechanism that is attached to the bell mouth by means of grippers with wheels that allow a rotation around the entire perimeter of the bell mouth, ensuring that its robotic arms have full access to all the dogs, including those at the back of the bell mouth.

An embodiment of the present disclosure, as illustrated in, describes a diverless bell mouth manipulator, comprising:

Using the features listed above, the diverless bell mouth manipulator comprises the general functions of: facilitated coupling to the bell mouth by the magnetic rollers (); closing of the grippers () for docking in the bell mouth; possibility of controlled rotation along the perimeter of the bell mouth and movement and free use of at least one robotic arm () according to the needs of the operation to be performed.

The main structure () is the base where the other elements of the manipulator are mounted. It is on the main structure () that at least one robotic arm () is mounted. Preferably, the main structure () comprises two manipulators () mounted, respectively, one on each side of the main structure ().

The main structure () has a semicircular shape with seats where the respective grippers () are mounted.

The semicircular main structure () preferably corresponds to an arc of between 90 and 180 degrees, and each of the respective semicircular grippers () preferably corresponds to an arc of between 45 and 95 degrees. More preferably, the semicircular main structure () corresponds to an arc of approximately 180 degrees, and each of the respective semicircular grippers () corresponds to an arc of approximately 95 degrees.

The main structure () further comprises an upper seat and a lower seat, preferably integrated into the main structure, and wherein each of which is designed to accommodate two grippers (). In this way, the lower left, upper left, lower right, and upper right grippers are mounted, in upper and lower pairs, in their respective seats, thus forming a left gripper assembly and a right gripper assembly.

In addition, it will be appreciated that the seats may comprise a slot for a guide tab for the respective grippers (). The guide tab has the function of guiding the sliding movement of the grippers within the seats. Additionally, the guide tab may have the function of acting as a bidirectional limit switch for the grippers ().

The shape of the semicircular rack of the grippers allows them to be driven by a respective pinion () to perform an opening and closing movement, as illustrated in. The pinions () are mounted on a shaft () that couples the movement of the pinion () driving a lower gripper () with that of an upper gripper (), so that, when driven by a driving means (), such as a hydraulic or electric motor, it simultaneously moves the lower grippers and the upper grippers, whether opening or closing.

The main structure () contains magnetic rollers () responsible for the initial docking of the manipulator. These act to hold the main structure () in the bell mouth during the start of docking by using only a magnetic force.

Magnetic rollers () are also mounted on the ends/tips of the respective gripper assemblies (), so that when the grippers () perform a closing movement, as illustrated in, a support point is created opposite the main structure (), which aims at performing a reaction force and prevent the manipulator from falling, if the magnetic force is not sufficient to keep the same docked during the manipulator's movements or during the manipulator's rotation in the structure.

The driving means () for rotating the manipulator is preferably mounted on a rear part of the main structure (), and at least one magnetic roller () of the plurality of magnetic rollers is a magnetic roller driven by the driving means () to rotate the manipulator around a cylindrical structure, such as the perimeter of a bell mouth.

As illustrated in greater detail in, the driven magnetic roller comprises a recess for fitting a belt () that is connected to a pulley () of the driving means () consisting of a hydraulic or electric motor.

The main structure () further comprises a drawer (.). The drawer (.) serves as an extension to facilitate the ROV in positioning the manipulator in the bell mouth. In addition, it also functions as a storage basket for tools, such as at least one camera () for monitoring the operation, as illustrated in, which has a magnet to be attached to the structure of a metal surface (such as the platform, bell mouth or manipulator itself), in order to provide another viewing point for the operation, in addition to a possible camera specific each robotic arm () o tool/gripper of the same.

It will be appreciated that each robotic arm () can be compatible with different types of grippers or tools that are interchangeable, depending on the operations to be performed.

As can be seen, at least in, the drawer (.) has a preferably lowered arrangement in relation to the main structure () and grippers (). Such an arrangement helps with tolerance issues in the docking and turning steps of the manipulator in the bell mouth.

At least one ROV handle () is further mounted on the drawer (.). Preferably, two handles () are mounted on the drawer (.). These handles () make it easier for the ROV to hold the manipulator and position it or remove it from the bell mouth.

The drawer (.) further comprises an umbilical tip (), responsible for transmitting all commands, electrical energy and hydraulic pressure, to the platform or ROV that will control the device. The umbilical () has a bend stiffener () at the point of attachment of the umbilical () to the main structure (), which is responsible for the gradual transition of stiffness to prevent the umbilical cable () from breaking at this attachment point, due to its movement (due to hydrodynamic forces) or due to the ROV's own movement.

The umbilical () allows the manipulator to be connected to the ROV of an RSV or to be connected directly to a SPUF DL on the platform, being operated remotely in both cases. In this sense, the diverless bell mouth manipulator can be controlled by means of the umbilical that connects the same to an ROV of an RSV, as illustrated in, or it can be simply positioned by an ROV and be remotely controlled by the platform by means of the umbilical.

Another preferred embodiment of the present disclosure discloses a method for performing diverless operations in a bell mouth using at least one diverless bell mouth manipulator, comprising at least the steps of:

In an implementation example of the present disclosure, the following steps can be performed using at least one diverless bell mouth manipulator to perform diverless operations in a bell mouth, namely:

The at least one manipulator is positioned in the bell mouth by means of an ROV, wherein the at least one manipulator initially attaches itself to the bell mouth only with the magnetic force of its pulleys, and then the ROV moves away.

A driving means is actuated to rotate a set of pinions, which engage with respective rack-mounted grippers of at least one manipulator and results in the closure of the same, docking the at least one manipulator in the bell mouth.

If the at least one manipulator is operated by an ROV of an RSV, after docking, the ROV moves away and controls the at least one manipulator remotely by means of an umbilical, in order to decouple the movement of the ROV from that of the manipulator and avoid the problems of maintaining position in the ZVM.

Alternatively, if at least one manipulator is operated directly from a platform, after docking by the ROV, the umbilical of at least one manipulator must be managed, organizing and securing the manipulator's umbilical to the hull and/or other structures of the platform (preferably by means of magnetic clamps) that secure the umbilical to these structures.