WO2009090321A2 - Method for installing a drilling apparatus on a rig and for preparing drilling operations - Google Patents

Abstract

The invention relates to a method for preparing drilling operations that comprises the single-operation installation, in a repositionable manner, of a fully equipped drilling apparatus (10) on a rig (20) in which the emerged portion (21) includes at least one upper deck (16). The method comprises using a semi-submersible supply barge in which the hull includes two protrusions (1a, 1b) supporting lift means (7a, 7c). The drilling apparatus (10) is first installed on the two legs of the barge (1a, 1b) via interface means (15b), and the barge moves into the vicinity of the rig (20). It moves so as to place the emerged portion (21) of the rig between the protrusions thereof, lifts the drilling apparatus (10) at a height higher than that of the upper deck of the rig using said lift means while releasing ballast, places in a single operation the drilling apparatus on the upper deck (16) of the rig (20) and moves away therefrom.

Description

 METHOD FOR OPERATING A PLATFORMFORFOREING ANDPREPARATIONFORFORFOR

The present invention relates to a method of preparation for drilling operations comprising the placing in one go of a fully equipped drilling rig on a platform placed or anchored on the seabed or lake and having an emerging part, at help from a semi-submersible barge.

There are several methods for drilling in shallow waters, typically up to 300 m. In one of these processes, drilling is divorced from production, and a wellhead platform is used. This platform consists of a tower-shaped structure placed on the seabed or lacustrine, usually metal and called "jacket", unmanned and un-equipped, on which is installed a drilling rig. This unit is installed only for drilling or well maintenance operations ("Work over"). It consists of a substructure, a derrick and drilling equipment, such as a "Blow Out Preventer" (BOP), a winch for handling drill pipes and a cabin for measuring equipment. ; such a drilling rig is known as a "derrick set" or "rig" and its mass is generally between 600 and 800 tons. The platform (the "jacket") is placed on the drilling field before the actual drilling operation, equipped with its bridges but without the drilling rig.

The problem is then to install a drilling rig on the upper deck of such a platform, so at a relatively high height above the water level, for example 20 m, the most economical way so the faster than possible. The reverse operation must also be able to be executed economically once the drilling or maintenance operation is completed, for example to reposition the drilling rig on another platform.

Moreover, a drilling operation requires many other installations (technical and residential premises, fluid tanks, helicopter landing platform ...), so as to receive staff, provide energy, accommodate and store drilling equipment such as drill pipe or drilling mud facilities for example. These installations represent very large volumes and masses (several thousand tons).

A known solution (UK 2199791, FR 2474992) is to deposit on the platform a complete superstructure called "top side", in one piece, including all the drilling and production facilities, This installation is usually carried out either with one or more large capacity floating cranes, using ballastable barges according to a method called

"Float over". However ballasting does not allow to raise the superstructure beyond a few meters. Moreover, this operation is irreversible for the lifespan and operation of the platform.

Another known solution is to use a self-raising barge platform or "Jackup" 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 of said barge and is translated in one piece above the platform, possibly at a high height. However, it is an expensive and mechanically delicate solution. In addition, the self-elevating barge, which is massive, leaves deep footprints on the seabed or lake that make it difficult to reposition later another barge of the same type.

Another solution is to use a barge or a support vessel called a "tender" which drops the rig on the platform in packages of about 30 to 100 tonnes using its lifting equipment, the drilling rig. being assembled as and when. It is a long operation, delicate and risky in terms of security so expensive because it requires excellent weather for several days.

The object of the present invention is to provide an advantageous solution to this problem by means of a method of placing, in a single and repositionable manner, a complete drilling rig on a platform already equipped with bridges designed to support the wellheads and the rig. The device that must install the drilling rig at a great height provides for 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 heave movements created by the swell. In the reverse order of the steps, the method is also applicable to the removal in one operation of a complete drilling rig.

For this purpose, it proposes a method of preparation for drilling operations comprising the one-time and repositionable installation of a drilling rig on a platform anchored or placed on a seabed or lake, the part of which hatch includes at least one upper deck for receiving at least one wellhead and one rig, said method using a semi-submersible barge having a longitudinal axis whose hull comprises two substantially parallel protuberances defining a space, said barge comprising lifting means supported by the protrusions as well as ballasting and deballasting means, characterized in that it comprises the following steps:

1) The loading of interface means on the lifting means of the barge,

2) loading a drilling rig on said interface means,

3) The transit of the barge supplying up to the vicinity of the platform with the drilling device secured to the interface means,

4) When the barge has come close to said platform, the elevation of the interface means and the drilling apparatus by deballasting said barge and by actuating the lifting means, so as to place said interface means at a height above the water greater than that of the upper deck of said platform,

5) The maneuver of the barge refueler so as to place the emergent part of said platform between the two protrusions of the barge,

6) Lowering and laying on the upper deck of said platform interface means and the drilling rig, by ballasting the barge and supplying the lifting means.

In the first step, the means for lifting the barge, at the level of its protuberances, are installed with means which will be used as interface between the barge and the drilling rig, then between the platform and the rig, the barge being for example docked in a port facility, using lifting means such as handling cranes dock or barge.

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

During the transit which is the subject of the third step, the assembly consisting of the interface means and the drilling rig is made integral with the lifting means and these lifting means are preferably placed in the lower position to improve the stability of the barge.

In the fourth step of the method, when the barge arrives in the immediate vicinity of the platform, the drilling rig and the interface means are elevated by deballasting the barge and playing on the lifting means, successively or simultaneously . By the combination of the two, it is possible to raise the whole to a high height.

In the next step, the barge maneuver so as to approach the platform and to place the raised portion of said platform between its growths. 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 apparatus and the interface means are then lowered and placed on the upper deck of the platform, for example by rapid ballasting of the barge and / or rapid descent of the lifting means.

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 as it goes through the handling cranes on the barge. The size of the barge allows it to accommodate all the equipment (technical and housing, energy production, mud factory, helicopter platform ...) to provide logistical support for a drilling operation.

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 protuberances 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.

In some cases, the platform is not strong enough to support the weight of a complete drilling rig, including the drill pipe, 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 on the platform during the sixth step is partial, that is to say that its weight is distributed over the lifting brackets from the barge and on the platform. Force sensors (strain gauges for example) arranged for example between the interface means and the bridge on which they rest, and a servocontrol are necessary to compensate for the inevitable movements of the barge and therefore lifting means. In this case, for the drilling operation, the barge remains positioned so that the platform remains between its growths and steps seven and eight do not take place.

The interface means may consist of a structure comprising for example two substantially parallel beams disposed in the first step substantially orthogonal to the longitudinal axis of the barge and resting at their ends on the lifting means of the barge. The drilling rig rests on the interface beams during the entire course of the process. The interface beams remain on the platform during all the drilling operations, the drilling rig 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 steps, and for example deposited on another platform. In known manner, the interface beams are also used to move the drilling rig on the upper deck in both directions of the plane, so as to access each of the drilling heads provided on the platform.

However, said beams have a length at least equal to the inner spacing of the barge growths and are therefore longer than the side of the bridge on which they rest and, if they remain in place, may hinder the subsequent maneuvers of the barge. In addition, the beams then constitute a mutilated mass on the platform. It may therefore be advantageous to provide that each beam comprises a removable portion at each end, secured during the steps one to six of the method for example by bolting, and then dismounted using the lifting means of the barge.

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 1 shown in FIG. 1A comprises at its stern two protuberances 1a and 1b, which for example 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 protuberances are strong enough to support the weight of a fully equipped drill rig. The barge also includes technical rooms 3a and 3b, a helicopter landing platform 4, living quarters 5, a main crane

6a and an auxiliary crane 6b which allow it to provide all the support necessary for a drilling operation. 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. It has a longitudinal axis A-A '.

The barge 1 has four lifting towers, 7a and 7b resting on the protrusion 1a, 7c and 7d resting on the protrusion Ib. These lifting towers have a height typically of ten to fifteen meters, they include lifting brackets on which can rest the drilling rig via its interface means, and are equipped for example with powerful hydraulic winches or any other elevation system allowing them to lift each up to 2501. In this view, the wallet bridge 8 is folded and the space 2 between the protuberances 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.

FIG. 2 represents an equipped drilling rig installed on a platform 20. It comprises a substructure 11, a derrick 12, and drilling equipment such as a "BOP" 13 and other equipment 14. It is based on interface beams 15a and 15b. The platform 20 comprises an emergent part 21, comprising two bridges, including an upper bridge 16 on which the interface means 15a and 15b rest. The upper deck 16 is typically at a height of 18 to 20 meters above sea level O.

Figures 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 lifting towers supported by the protuberances of the barge 1a, 1b, for example in a harbor installation 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 available for 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. During the transit, for example maritime, the barge is ballasted to ensure better stability.

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 protuberances Ia and Ib 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 interface means 15 is higher than the upper deck 16 of the platform 20. This elevation by unballasting the barge and operating the hoisting towers 7.

In the next step shown in FIG. 3J, the barge has maneuvered so as to place the emergent part 21 of the platform between the protuberances Ia and Ib of the hull. Figure 3K is an elevational view of the barge, the rig 10 and the platform 20 in the same situation. The drilling apparatus 10 is placed on the beams 15a (not visible) and 15b, in the raised position of the lifting means 7a, 7b, 7c and 7d, and the emergent part 21 of the platform is located between the protuberances 1a and 1b. from the barge.

As shown in FIG. 3L, the drilling apparatus 10 is slowly lowered so as to rest it on the upper deck 16 of the platform 20 via the interface means 15a and 15b, either by ballasting or by actuating at lower the lifting towers 7a, 7b, 7c and 7d, either by a combination of both. Shocks (not shown) are arranged between the interface means 15a and 15b and the upper deck 16 of the platform 20 so as to avoid damaging the platform 20 by too abrupt contact with the drilling apparatus 10, by example because of the movements of heave 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, thanks to the wetting lines (not shown) and / or its dynamic anchoring means. The deck bridge 8 is unfolded so as to cover the space 2 between the protuberances 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 upper deck 16 of the platform 20, 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 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 protuberances 1a and 1b delimiting a space 2 in which can take place the emerged portion 21 of a platform 20. The protuberances 1a and 1b support four lifting towers 7a, 7b, 7c and 7d. The pontoons 30a and 30b and the vertical portions 31a and 31b have hollow volumes which are used as ballasts. Structure 32 hosts technical premises and living quarters. FIGS. 1A and 1B illustrate an example of a barge comprising a retractable means 8, for example of the type deck-bridge or hatch-board articulated, to cover the space 2 when the drilling rig 10 has been deposited on the platform 20.

Claims

claims A method of preparing for drilling operations comprising the one-time and repositionable placement of a drilling rig (10) on a platform (20) anchored or resting on a seabed or lacustrine, whose an emergent portion (21) has at least one upper deck (16) for receiving at least one wellhead and one rig, said method using a semi-submersible barge (1) having a longitudinal axis (A-A ' ) whose hull comprises two substantially parallel protuberances (la, Ib) delimiting a space (2), said barge (1) comprising lifting means (7a, 7b, 7c, 7d) supported by the protuberances (la, Ib) and that means ballasting and deballasting, characterized in that it comprises the following steps: 7) loading interface means (15a, 15b) on the lifting means (7a, 7b, 7c, 7d) of said barge (1), 8) loading a drilling apparatus (10) on said interface means (15a, 15b), 9) The transit of the supply barge to near the platform (20) with the drilling apparatus (10) secured to the interface means (15a, 15b), 10) When the barge has come close to said platform (20), the elevation of the interface means (15a, 15b) and the drilling rig (10) by deballasting said barge and by actuating means of lifting (7a, 7b, 7c, 7d), so as to place said interface means (15a, 15b) at a height above the water greater than that of the upper deck (16) of said platform (20) , H) The maneuvering of the barge to place the emergent part (21) of said platform (20) between the two protuberances (la, Ib) of the barge, 12) The descent and installation on the upper deck (16) of said platform (20) interface means (15a, 15b) and the drilling apparatus (10), by ballasting the barge and supplying the lifting means (7a, 7b, 7c, 7d). 2. Method according to claim 1, characterized in that it further comprises the following steps: 13) the removal of the barge from the platform (20) and its positioning in the vicinity of said platform, and 14) the provision of connecting means (22) between said barge and the drilling rig (10) in view of allow the transfer of energy, persons, materials and liquids between the barge and the drilling rig so as to carry out the drilling operations. 3. Method according to claim 1, characterized in that it further comprises the following step: 15) Covering the space (2) between the two protuberances (la, Ib) of the barge by deploying a retractable device (8) so as to have a large deck area for drilling operations . 4. Method according to claim 1, characterized in that, in the sixth step, the transfer of the weight of the interface means (15a, 15b) and the drilling rig (10) onto the upper deck (16) of said platform (20) is partial, so that said weight is distributed on said platform (20) and on said barge (1) so as to limit the forces experienced by said platform (20). 5. Method according to any one of the preceding claims, characterized in that said interface means take the form of a structure comprising at least two beams (15a, 15b), and in that: • In the first step, said beams (15a, 15b) are disposed on said lifting means (7a, 7b, 7c, 7d) substantially orthogonal to the longitudinal axis (A-A ') of the barge, a first beam (15a) foremost and a second beam (15b) furthest back along said longitudinal axis, In the second step, the drilling apparatus (10) is disposed on said beams (15a, 15b), • In the sixth step, the beams (15a, 15b) are placed on the upper deck (16) of said platform, the drilling apparatus (10) resting on said beams. 6. Method according to claim 5, characterized in that each beam (15a, 15b) comprises a disconnectable portion (15c, 15d, 15e, 15f) at each end, secured to said beams during steps one to six of the method, and the process includes an additional step: • Disconnection of at least one of said disconnectable portions (15c, 15d, 15e, 15f). 7. Method according to any one of claims 1, 4, 5 or 6, characterized in that damping means are arranged between the upper bridge (16) of said platform (20) and the interface means (15a , 15b), so as to allow the shock-free installation of said drilling apparatus (10) during the sixth step of the method. 8. Semi-submersible barge specially adapted to the implementation of the method according to any one of the preceding claims, characterized in that it comprises two hollow pontoons (30a, 30b) substantially parallel, having a pointed bow (33a, 33b). ), said pontoons being each surmounted by a substantially vertical hollow structure (3Ia ₅ 31b) and extending from behind said pontoons to the vicinity of the bow said pontoons, said vertical structures (31a, 31b) being joined at their apex by a substantially horizontal structure (32), which extends over the front portion of said vertical structures (31a, 31b) so as to form two protuberances (1a, Ib) delimiting a space (2) at the rear of said barge, said protuberances supporting lifting means (7a, 7b, 7c, 7d). 9. Barge according to claim 8, characterized in that it further comprises a retractable means (8) which covers the space (2) between said protuberances (la, Ib) when it is deployed.