FR2921098A1 - Drill rig setting method for e.g. sea bed, involves placing connection unit between barge and rig to permit transfer of energy, people, materials and liquid between barge and rig so as to carry out drilling operations - Google Patents

Abstract

The method involves installing a tanker barge to place an emerged portion (21) of a platform (20) between branches (1a, 1b) of the barge. An interface unit and a drill rig (10) are lowered and installed on the portion of the platform by ballasting the barge. A space is covered between the branches by deployment of a portfolio bridge so as to have a large deck area for drilling operations. A connection unit e.g. footbridge, is placed between the barge and the rig, to permit transfer of energy, people, materials and liquid between the barge and the rig so as to carry out the operations.

Description

The present invention relates to a method of setting up a fully equipped drilling rig on a platform placed or anchored on the seabed or lake and having an emergent part, and preparation for drilling at sea, using a semi-submersible barge tanker. Several methods are known for drilling in shallow waters, typically up to 300 m or beyond. In one of these methods, a tower-like structure is used on the seabed or platform, generally metal and called jacket or well head platform. It has an emergent part at the top of which one finds the heads of well and on which rests a rig composed of a substructure, a derrick and drilling equipment, for example a Blow Out Preventer (BOP ), a winch for handling drill pipes and a cabin to house the measuring devices; such a drilling rig is known as a derrick set or rig and its mass is generally between 600 and 800 tons. The platform is placed on the drilling field before the drilling operation itself, without the drilling rig. The first problem is therefore to install the rig on the platform in the most economical way and without causing deterioration. -2 Moreover, a drilling operation requires many other facilities, in particular to receive personnel, supply energy, and host and store drilling equipment such as drill pipes or drilling mud plants, for example. These installations represent very large areas and volumes consisting for example of technical rooms, living quarters, fluid tanks and a helicopter landing platform. The assembly, which can represent several thousand tons, is located on a different support platform and there is therefore preparatory operations to drilling, such as connecting the platform to the second support so that it can provide all the support necessary for this drilling.

A known solution is to use a platform type self-elevating barge placed on the bottom near the platform and of sufficient size to accommodate the premises and equipment required for drilling. The drilling rig rests on cantilevered beams integral with said barge and is placed in one piece on the platform. It is an expensive and delicate solution on the mechanical level.

Another known solution is to use a barge or a support vessel called a tender that remains docked near the platform during the entire drilling operation. The equipment constituting the drilling rig is delivered by the support barge using its lifting means in packages of about 30 tonnes, placed and mounted on the platform. This is a delicate operation and therefore expensive because it requires perfect weather conditions.

The object of the present invention is to provide an advantageous solution to this problem by means of a method of placing, in one go, a fully equipped drilling rig on a platform, and of preparation for drilling, thanks to the use of a semi-submersible barge. The method is also applicable to a platform anchored to the seabed, for example of the Spar type, the important thing being that said platform is not subjected to movements of wedging created by the swell.

For this purpose, it proposes a method of setting up a drilling rig on a platform anchored or placed on a seabed or lacustrine and comprising an emergent part and preparation for drilling, said drilling rig comprising a substructure , a derrick and drilling equipment integral with said substructure, said method using a semi-submersible barge tanker whose hull comprises two protrusions or branches, substantially parallel and extending one of the barge's bridges, said barge including means of ballasting and deballasting. The method comprises the following steps: 1) docking interface means on the deck of the barge at the branches of said barge,

2) the docking of a drilling rig on said interface means, 3) the transit of the supply barge to the vicinity of the platform with the drilling rig integral with the interface means, 4) When the barge has come close to said platform, the elevation of the interface means and the drilling rig by deballasting of said barge, 5) The maneuvering of the barge supplying vessel so as to place the emergent part of said platform between the two branches of the barge 30 and the feeder under the interface means and the drilling rig, 20 -4 6) The descent and laying on the emergent part of said platform means of interface and the apparatus drilling, by ballasting of the barge, and / or 7) The removal of the barge from the platform and its positioning in the vicinity of said platform, and / or

8) Covering the space between the two branches of the barge by deploying a retractable device so as to have a large deck area for the drilling operations, and / or

9) The provision of means of connection between said barge and the drilling rig in order to allow the transfer of particular energy, people, materials and liquids between the barge and the drilling rig so as to perform the drilling operation.

In the first stage, means are installed on the deck of the barge, at its branches, which will be used as interface between the barge and the drilling rig, the barge being for example docked in a port facility, in using lifting means such as handling cranes of the dock or the barge.

In the second step, the drilling apparatus is disposed on interface means via its substructure, one or more times using lifting means such as dock handling cranes or the barge.

In the fifth step of the method, when the barge arrives in the immediate vicinity of the platform, the drilling apparatus and the interface means are raised by deballasting the barge, so that the interface means are in position. higher than the upper part of the emerged part of the platform which comprises the wellheads.

In the next step, the barge maneuver to move closer to the platform and to place the raised portion of said platform between its branches. In order not to risk damaging the platform, the barge will have previously anchored, either using anchors or by dynamic positioning, or a combination of both. The maneuver is therefore performed by playing on its anchor lines and / or its dynamic positioning.

The drilling rig and the interface means are then lowered and placed on the top of the emergent part of the platform by rapid ballast of the barge.

Once the drilling rig is deposited on the platform and the barge remote from the platform, it is advantageous to cover the space between the branches of the hull of the barge with the aid of a removable or retractable device of the type deck bridge or articulated bilge panel. This considerably increases the available bridge area for drilling equipment, such as drill pipe, and facilitates drilling operations. This device, once deployed, can also contribute to the rigidity of the structure of the barge.

Finally, connecting means are installed between the barge and the platform provided with the drilling system, for example a gangway for the personnel, electrical lines and fluid lines. Large drilling equipment, such as drill pipe, is delivered to the platform via the handling cranes fitted to the barge.30 In some cases, the height at which the barge can raise the rig in playing only on deballasting, in the fourth step of the process, is insufficient. In this case, the barge comprises on its branches lifting means, consisting for example of lifting towers provided with lifting means. In this case, during the first step, the interface means are disposed on said lifting towers and not directly on the deck of the barge. In the third transit stage, the lifting means are generally placed in the low position to gain stability.

In the fourth step, the drilling rig and the interface means are elevated by also acting on the lifting towers on which they rest and more only on deballasting of the barge. They can thus more easily reach a height sufficient to be placed above the emergent part of the platform.

Conversely, in the sixth step, the drilling rig and the interface means are lowered so as to rest on the platform by playing on the lifting towers on which they rest and on a fast ballast.

In some cases, the platform is not strong enough to support the weight of a complete drilling rig and its interface means, for example when it is old and partially corroded. In this case, it is advantageous to ensure that the transfer of the weight of the rig to the platform is partial, that is to say that its weight remains distributed on the barge and on the platform. Servo control is necessary to compensate for the inevitable barge movements, vertical and horizontal, as well as roll, pitch and yaw. In this case, for the drilling operation, said barge remains positioned so that the platform remains between its branches and steps seven and eight do not take place. The interface means may consist of a structure comprising for example two substantially parallel, braced beams arranged in the second step substantially orthogonal to the longitudinal axis of the barge and resting at their ends on the branches of the barge. the barge. In a variant of the method, the drilling apparatus is directly placed on the interface beams during the entire course of the process. In this variant, the interface beams remain on the platform at the end of the process, the drilling apparatus resting entirely on said beams. This has the advantage that the drilling rig can be subsequently removed very quickly with a barge of the same type by unrolling the process in the reverse order of the steps, and for example deposited on another platform. However, said beams have a length at least equal to the inner spacing of the branches of the barge and are therefore considerably longer than the side of the platform and, if they remain in place, may hinder the subsequent maneuvers of the barge. In addition, the beams then constitute a useless mass on the platform.

It may therefore be advantageous to provide that each beam has a removable portion at each end, secured during steps one to six of the method for example by bolting, and then dismounted using the lifting means of the barge.

In another variant of the method, in the second step, the drilling apparatus is carried by the interface beams via its substructure removably; the substructure is made integral by known means such as bolting, keying, splinting or other. It dissociates in the sixth step, when the rig is placed on the platform through its substructure. In this advantageous variant of the method, the interface beams are designed to remain on the barge after removal of the drilling rig, for example by being removable and / or articulated.

In this variant of the method, it is necessary for the beam that is furthest back from the longitudinal axis of the barge to be erased so that the barge can move away from the platform. It is for example made in two pivoting sections which are secured during steps one to six of the process, and which pivot at the end of the sixth step.

The method will be better understood on reading the description which follows and in the light of the appended figures in which:

FIGS. 1A and 1B are two perspective views of a barge used for the implementation of the method,

FIG. 2 is a side view of an equipped drilling rig, placed on interface beams, intended to be installed on a platform,

FIGS. 3A to 3N are side views of the barge schematically showing the steps of the method,

FIG. 4 is a side view of an interface beam,

Figure 5 is a perspective view of an example of a barge used by the method.

The hull of the semi-submersible barge shown in FIG. 1A comprises, at its stern, two branches 1a and 1b, which extend one of the decks of the barge and which delimit a space 2 of sufficient size that the exposed portion of a platform can come to take place, for example of the order of 30 x 40 m. These branches are strong enough to support the weight of a fully equipped drilling rig which will be described in Figure 2. The barge also comprises technical rooms 3a and 3b, a helicopter landing platform 4, living quarters 5, a main crane 6a and an auxiliary crane 6b. It comprises means for ballasting and deballasting, for example hollow bodies within its structure, which can be filled and emptied with seawater or any other fluid using pumps (not shown) to vary the freeboard importantly.

The barge is shown with four lifting towers, 7a and 7b resting on the branch la, 7c and 7d resting on the leg lb. These lifting towers have a height typically of ten to fifteen meters, they include lifting brackets on which can stand the hoist and are equipped for example with powerful hydraulic winches or any other elevation system. They are necessary when the drilling rig needs to be elevated to a height greater than the deballasting of the platform.

In this view, the wallet bridge 8 is folded and the space 2 between the branches 1a and 1b of the shell is thus open. In FIG. 1B, the deck bridge 8 has been deployed and drilling equipment such as drill pipes have been placed therein.

The barge of Figure 1 is shown without means of propulsion, but it is obvious that it can be self-propelled. It comprises dynamic positioning means, for example steerable thrusters, not shown. It has a longitudinal axis A-A '.

Figure 2 shows a rig equipped for installation on a platform. 11 comprises a substructure 11, a derrick 12, and drilling equipment such as a BOP 13 and other equipment 14. FIGS. 3A to 3N illustrate the various steps of the method. In FIGS. 3A to 3E, the drilling apparatus 10 and interface means 15 are installed on the branches of the barge in a port facility in 5 sub-steps; the number of sub-steps may be variable depending, for example, on the capacity of the available lifting means and / or the time at the quay of the barge. In the illustrated example, the drilling apparatus 10 is disposed on the lifting supports in the low position of the lifting towers 7a, 7b, 7c and 7d of the barge.

Figure 3G illustrates the self-propelled transit of the barge carrying the rig to the platform; it can also be towed.

In Figure 3H the barge begins to maneuver to approach the platform 20, coming from the rear so as to place the emerged portion 21 of the platform between the branches and lb lb of the barge. The maneuvers are performed by playing on mooring lines (not shown) and / or its dynamic anchoring means. Anchors may have been arranged in advance or put in place by the barge itself.

In FIG. 31, the barge has approached the platform 20 and raises the drilling apparatus 10 so that the lower part of its substructure 11 or the interface means 15 is higher than the top of the emergent part 21 of the platform 20. This elevation can be done by deballasting the barge or by operating the lifting towers 7 or by a combination of the heavens.

In the next step shown in FIG. 3J, the barge has maneuvered so as to place the exposed portion 21 of the platform between the branches 1a and 1b of the hull. Figure 3K is an elevational view of the barge and rig 10 in the same situation. The drilling apparatus 10 is placed on the beams 15a and 15b (not visible), in the raised position of the lifting means 7a and 7c, and the emergent portion 21 of the platform is located between the branches 1a and 1b. from the barge.

As shown in FIG. 3L, the drilling rig 10 is slowly lowered so as to rest it on the emergent part 21 of the platform 20, either by ballasting or by driving the lifting towers 7 downwards or by a combination both. Shocks (not shown) are disposed between the substructure 11 of the drilling apparatus 10 or the interface means 15 and the upper portion 21 of the platform 20 so as to avoid damage to the platform 20 by a too brutal contact with the drill rig 10 because of heave movements of the barge. Once the contact is established, the barge continues to unpack to clear the rig.

In the last step of the process shown in FIG. 3N, the barge stops in the vicinity of the platform 20 supporting the drilling rig 10, by means of wetting lines (not shown) and / or its dynamic anchoring means. . The deck bridge 8 is unfolded so as to cover the space between the branches 1a and 1b of the barge; drilling equipment is advantageously arranged.

Finally, connecting means 22 such as gangway, electrical conductors and pipes are placed between the barge and the platform 20 so as to allow drilling operations.

FIG. 4 represents one of the interface beams 15b (respectively 15a) resting on the emergent part 21 of the platform, which comprises two demountable portions 15c and 15d (respectively 15e and 15f), held integral with the body of the beam for example by bolting and which are disassembled once the drilling rig placed on the platform, using for example the cranes 6a and 6b of the barge. Figure 5 shows an example of a barge used by the method. Its hull has at its rear two branches la and lb which define a space 2 in which can take place the emerged portion 21 of a platform 20. The 5 pontoons 30a and 30b and the vertical portions 31a and 31b comprise hollow volumes which are used as ballasts. Structure 32 hosts technical premises and living quarters.

Claims (10)

claims A method of placing a drilling rig (10) on a platform (20) anchored or resting on a seabed or lake and having an emergent portion (21) and drilling preparation, said rig ( 10) comprising a substructure (11), a derrick (12) and drilling equipment (13, 14) integral with said substructure (11), said method using a semi-submersible barge with a hull comprising two protrusions or branches (1a, 1b), substantially parallel and extending one of the decks of the barge, said barge comprising means for ballasting and deballasting, characterized in that it comprises the following steps: 1) the loading at the quay of interface means (15) on the deck of the barge at the branches (la, lb) of said barge, 2) docking a drilling apparatus (10) on said interface means (15), 3) The transit of the barge to the vicinity of the platform (20) with the drilling apparatus (10) secured to the interface means (15), 4) When the barge has arrived near said platform (20), raising the interface means (15) and the drilling apparatus (10) by deballasting said barge, 5) The maneuver of the barge refueler so as to place the emergent part (21) of said platform (20) between the two branches (la, lb) of the barge and under the interface means (15) and the drilling rig (10), 6) the descent and the laying on the emergent part (21) of said platform (20) of the interface means (15) and the drilling rig (10), by ballasting of the barge, and / or 7) The distance of the barge from the platform (20) and its positioning near said platform, and / or 2921098 -14- 8) Covering the space (2) between the two legs (1a, 1b) of the barge by deploying a retractable device (8) so as to have a large deck area for the drilling operations , and / or 5 9) The provision of connecting means (22) between said barge and the drilling apparatus (10) to allow the transfer including energy, people, materials and liquids between the barge and the device drilling to perform the drilling operation. 2. Method according to claim 1, characterized in that: • Said method involves a barge refueler in which one of the bridges comprises at each branch (la, lb) at least one lifting means (7a, 7b, 7c, 7d), and in that: • In the first step, the interface means (15) are arranged on the lifting means (7a, 7b, 7c, 7d) associated with each branch (1a, 1b). In the fourth step, the elevation of the interface means and the drilling rig is effected by deballasting the barge and / or by raising the lifting means (7a, 7b, 7c). , 7d), • In the sixth step, the descent and installation of the interface means (15) and the drilling rig (10) on the emergent part (21) of said platform is carried out by ballasting of the barge and / or descent of the lifting means (7a, 7b, 7c, 7d). 3. Method according to one of claims 1 or 2, characterized in that, in the sixth step, the transfer of the weight of the interface means (15) and the drilling rig (10) on the emergent part (21) of said platform (20) is partial so that said weight is distributed on said platform and on said barge so as to limit the forces undergone by said platform (20), in that means Servo control compensates for the barge's movements according to its six degrees of freedom, and that steps 7 and 8 do not take place. 4. Method according to any one of the preceding claims, characterized in that said interface means (15) take the form of a structure comprising at least two beams (15a, 15b) braced, and that: • When in the second step, said beams (15a, 15b) are disposed substantially orthogonal to the longitudinal axis (A-A ') of the barge, a first foremost beam (15a) and a second beam (15b) the most back along said longitudinal axis. 5. Method according to claim 4, characterized in that: • In the second step, the drilling apparatus (10) is placed on said beams (15a, 15b), • In the sixth step, the beams (15a, 15b ) are placed on the emergent portion (21) of said platform, the drilling apparatus (10) resting on said beams. 6. A method according to claim 4, characterized in that each beam (15a, 15b) has a disconnectable portion (15c, 15d, 15e, 15f) at each end, secured to said beams during steps one to six of the method, and in that the method comprises an additional step: • Disconnection of at least one of said removable portions (15c, 15d, 15e, 15f). 7. A method according to claim 4, characterized in that: • In the second step, the drilling apparatus (10) is secured to said beams (15a, 15b) by disconnectable connection means, • In the sixth step, the drilling rig (10) is placed on the emergent part (21) of said platform, then the beams (15a, 15b) are separated from the drilling rig (10) so that they stay on the barge. 8. Method according to claim 7, characterized in that said second beam (15b) comprises two beam sections hinged about a horizontal axis orthogonal to the axis of the beam or a vertical axis, which are made integral. during steps 1 to 6, said beam sections pivoting at the end of the sixth step so as to allow the barge to move away from the platform while said second beam remains on the barge. 9. Method according to any one of the preceding claims, characterized in that damping means are arranged between the emerging part (21) of said platform (20) and the interface means (15) or the substructure (11) of the drilling apparatus (10), so as to, in the sixth step of the method, to allow the non-shocking installation of said drilling apparatus (10). 10. Method according to any one of the preceding claims, characterized in that it implements a barge consisting of two hollow pontoons (30a, 30b) substantially parallel, having a pointed bow, said pontoons being each surmounted by a structure hollow (31a, 3b) substantially vertical and extending from the rear of said pontoons to near the bow of said pontoons, said vertical structures (31a, 3b) being joined at their apex by a structure (32 ) substantially horizontal, 2921098 -17- which extends on the front part of said vertical structures (31a, 3 lb) so as to delimit two branches (la, lb) at the rear of said barge.