NO344415B1

NO344415B1 - A cantilever structure for use in well intervention operations

Info

Publication number: NO344415B1
Application number: NO20171404A
Authority: NO
Inventors: Jens Olav Myklebust; Bartlomiej Pieprzowski
Original assignee: Dwellop As
Priority date: 2017-03-30
Filing date: 2017-08-30
Publication date: 2019-12-02
Also published as: NO20171404A1; NO20171677A1

Description

Technical Field

The present invention relates to a cantilever structure for use in well intervention operations, which cantilever structure is arranged on a platform deck of a jackup rig or a liftboat, the cantilever structure being moveable relative to the platform deck, one end of the cantilever structure being adapted to be retractably extended beyond the perimeter of the rig deck, which cantilever structure end carries a hoist adapted to manipulate loads underneath the cantilever structure.

Background Art

The present invention relates to structural supports on jack-up rigs and liftboats when activity like intervention operations, is to take place from such rigs and boats. Such activity is one or more among coiled tubing, wireline and well plugging operations.

EP 2243 922 is an example illustrating a technique that facilitates coiled tubing operations in offshore environments.

WO 2016178576 relates to a cantilever structure with a drilling floor for performing intervention operations. The cantilever is movable relatively a platform deck and carries further a hoist for handling loads.

The hoist arrangement is arranged on the side of the cantilever structure,but could also be arranged around a moonpool at the underside of the cantilever structure.

Summary of invention

This is provided by a cantilever structure of the introductory described nature, which is distinguished in that one or more hoists are arranged on a moveable crane chassis arranged underneath said cantilever structure on a crane beam structure, which crane chassis and crane beam structure are moveable in a substantially horizontal plane by means of rollers driven on rails fixed to said cantilever structure.

In one embodiment, the cantilever structure comprises two hoists arranged on respective ends of the crane beam structure.

In another embodiment, the cantilever structure comprises one hoist arranged on a gantry crane beam structure and beam-mounted crane chassis, which gantry crane beam structure being moveable in a substantially horizontal plane in x and y directions, respectively, by means of rollers driven on rails fixed to the cantilever structure and gantry crane beam structure, respectively.

Preferably, the rails of the gantry crane beam structure extend longitudinally of the gantry crane beam structure and transversally of the cantilever structure.

In one embodiment, the rails of the cantilever structure extend longitudinally on both sides of the lowermost underside of the cantilever structure.

Preferably, each hoist is mounted on a trolley running on a cantilevered crane beam.

In one embodiment, the cantilevered crane beam is arranged as a telescopic beam, which telescopic beam is extendable in its longitudinal direction.

The cantilevered crane beam can be slew ably arranged to the beam-mounted crane chassis.

Each hoist running on a cantilevered beam can enable loads to be delivered externally of the cantilever structure perimeter and drilling rig perimeter.

In one embodiment, the cantilever structure can include a derrick.

The intervention operations are normally one or more among coiled tubing, wireline and well plugging operations.

In one embodiment, the cantilevered crane beam includes an auxiliary hoist arranged on the end of the cantilevered crane beam.

While the various aspects of the present invention have been described in general terms above, a more detailed and non-limiting example of an embodiment will be described in the following with reference to the drawings, in which:

Brief description of drawings

Fig. 1 shows in a perspective view a schematically drawn jack-up rig that includes a cantilever structure moveably arranged on the deck of the jack-up rig,

Fig. 2 shows a detailed view of the encircled view 4 of fig.1, which also more clearly shows a hoist/crane assembly arranged to the cantilever structure according to the present invention, and a lower wellhead template platform,

Fig. 3 shows in a perspective view from above the cantilever structure and derrick assembly separated from the jack-up platform,

Fig. 4 shows in a perspective view from below the cantilever structure and derrick assembly according to fig.3,

Fig. 5 shows in a perspective view from below the hoist/crane assembly separated from the cantilever structure and derrick assembly,

Fig. 6 shows in a perspective view from above the hoist/crane assembly separated from the cantilever structure and derrick separated as shown in fig.5,

Fig. 7 shows in a perspective and elevated view the hoist/crane assembly according to fig.5 and 6,

Fig. 8 shows in a perspective view from above an embodiment of the cantilever structure and hoist/crane assembly without a derrick and separated from the jack-up platform,

Fig. 9 shows in a perspective view from above a different view than fig.8, but the same embodiment of the cantilever structure and hoist/crane assembly as shown in fig.8,

Fig. 10 shows in a perspective view from below the same embodiment of the cantilever structure and hoist/crane assembly as shown in fig.8 and 9,

Fig. 11 shows in a perspective view a second embodiment of the hoist/crane assembly arranged to the cantilever structure of the jack-up rig,

Fig. 12 shows in a perspective view from above the hoist/crane assembly shown in fig.11,

Fig. 13 shows in a perspective view the second embodiment of hoist/crane assembly separated from the cantilever structure and the jack-up rig, and

Fig. 14 shows the hoist/crane assembly shown in fig.13 in a perspective view from above.

Detailed description of the invention

Reference is made to fig.1 showing in a schematically perspective view a jackup rig 3. The jack-up rig 3 includes a rig deck 2. The rig 3 shown has three legs 16 extending into the sea and are supported by the seabed. The deck 2 can be elevated and lowered relative to the sea surface as desired for the particular job or operation to be performed. The jack-up rig 3 also includes a cantilever rig 1, here termed a cantilever structure 1. The cantilever structure 1 is moveably arranged on the deck 2 of the jack-up rig 3. It is to be understood that a jack-up rig 3 is illustrated and described here,but could easily be replaced by a jack-up barge or liftboat well known for the artisans within the oil field industries.

In the fig.1 embodiment, a derrick 15 is shown arranged on top of the cantilever structure 1. The derrick 15 is located on that end 1a of the cantilever structure 1 enabling the derrick 15 to perform intervention operations towards a wellhead template platform 17 located underneath the cantilevered end 1a of the cantilever structure 1. An enlarged view of this is encircled and marked by a number “D4” shown in fig.2 as “DETAIL 4”.

The cantilever structure 1 is designed for use in well intervention operations, and the cantilever structure 1 is arranged on the rig deck 2 to be moveable back and forth on the deck 2. During such movement on the deck 2, one end 1a of the cantilever structure 1 can be extended beyond the perimeter P of the drilling rig 3 deck 2. Subsequent to an intervention operation, the cantilever structure 1 can be retracted back onto the rig deck 2. Then the entire jack-up rig 3 can be removed and transported to a different location.

As more clearly shown in fig.3 and 4, the cantilever structure end 1a carries a crane assembly C supporting a hoist 4. The crane assembly C including the hoist 4 is adapted to manipulate loads L underneath the cantilever structure 1.

The hoist 4 is in turn arranged on a moveable beam-mounted crane chassis 5, as detailed clearly in fig.5, 6 and 7. The crane chassis 5 is arranged underneath, or at the bottom of the cantilever structure 1 on a gantry crane beam structure 6. The beam-mounted crane chassis 5 and gantry crane beam structure 6 are moveable in a substantially horizontal plane in orthogonal x and y directions, respectively. This is enabled through use of rollers R1, R2 driven on rails 7, 8, which are fixed to the cantilever structure 1 and gantry crane beam structure 6, respectively. The hoist 4, the crane chassis 5 and the gantry crane beam structure 6 is in this specification termed a crane assembly C.

In one embodiment, the crane assembly C can be used as indicated in fig.3 and fig.4 just where the reference number 4 is pointing, i.e. without the use of the cantilevered crane beam 10 shown.

As shown in further details in fig.5, 6 and 7, the rails 8 of the gantry crane beam structure 6 extend longitudinally of the gantry crane beam structure 6 and transversally of the cantilever structure 1. In turn, the rails 7 of the cantilever structure 1 extend longitudinally of the cantilever structure 1.

In one embodiment, a second hoist 4’ is mounted on a trolley 9 that is arranged to be running back and forth on the cantilevered crane beam 10. It is to be noted that the main hoist 4 can be used together with a sheave 11 near the end of the cantilevered crane beam 10. The wire from the hoist 4 then extend substantially horizontal along the beam 10, turning into vertical direction after having passed the sheave 11. As clearly shown in fig 5, an auxiliary (smaller) hoist 4’’ can be mounted to the very end of the cantilevered beam 10.

In still another embodiment, the cantilevered crane beam 10’ is arranged as a telescopic beam. This means that telescopic beam is made up by sections nested into each other. The sections are extendable in their longitudinal direction, either hydraulically or by electro mechanic means.

The cantilevered crane beam 10; 10’ will normally be slew ably arranged to the beam-mounted crane chassis 5 as shown in fig.6 by an annular suspension ring 12.

The second hoist 4’ running on the cantilevered crane beam 10; 10’ enables loads L to be delivered externally of the cantilever structure 1 perimeter P’ in addition to the drilling rig perimeter P.

Even if not strictly necessary for all type of operations, the cantilever structure 1 normally includes the derrick 15. However, as illustrated in fig.8, 9 and 10, the cantilever structure 1’ is omit any derrick. All other elements are the same as in fig. 1 to 7 in various versions.

As mentioned, the arrangement with the cantilever structure 1, 1’ is design for performing intervention operations, such as one or more among coiled tubing, wireline and well plugging operations.

With reference to fig.1, the cantilever structure 1, 1’ can be retracted onto the rig deck 2 in its entirety. In such situation, it is necessary to park the hoist assembly 20 away from the underside of the cantilever structure 1,1’. An alternative is to retract the cantilever structure 1,1’ just enough to let the hoist assembly 20 remain suspended and cantilevered just adjacent to the deck perimeter P and let the cantilever structure 1,1’ rest in such position.

As indicated, the crane assembly C will be working underneath the cantilever rig. The cantilever rig is designed to skid outwards of the vessel transom, over existing platforms to do well work on oil wells. The crane assembly C will be utilized for handling equipment on the platform hatch deck, primarily underneath the cantilever where the main rig-crane does not have coverage.

The crane assembly C will also be used for holding the wire line stack during SIMOPS (Simultaneous Operations) on a neighboring well. In addition to holding the stack, it will hold the wire line sheave and handle tool changes with the wire line tool winch.

As with the first embodiment, the cantilever structure 1A shown in fig.11 and 12 is also designed for use in well intervention operations, and the cantilever structure 1A is arranged on the rig deck 2A to be moveable back and forth on the deck 2A. During such motion on the deck 2A, one end 1Aa of the cantilever structure 1A can be extended beyond the perimeter PA of the drilling rig 3A deck 2A. Subsequent to an intervention operation, the cantilever structure 1A can be retracted back onto the rig deck 2A. Then the entire jack-up rig 3A can be removed and transported to a different location.

Adjacent to the cantilever structure end 1Aa, a second embodiment of the crane assembly CA supporting two hoists 4A and 4B, is carried. The hoists 4A and 4B are adapted to manipulate loads L underneath the cantilever structure 1A independently of each other. The suffix “A” is used as an addition to the reference numbers used in the first embodiment to indicate the same or similar element or part on the second embodiment.

The hoists 4A and 4B are arranged on respective crane chassis 5A at respective ends of a moveable crane beam structure 6A, as shown in fig.13 and 14. Each hoist 4A and 4B is moveably carried by respective cantilevered crane beams 10A and will normally be slew ably arranged to the crane chassis 5A as can be understood from studying fig.11 to 14.

The moveable crane beam structure 6A is arranged underneath, or at the underside of the cantilever structure 1A. The crane beam structure 6A is moveable in a substantially horizontal plane in the longitudinal direction of the cantilever structure 1A. This is enabled through use of rollers RA driven on rails 7A, which are fixed to the cantilever structure 1A. The hoists 4A and 4B, the crane chassis 5A, the cantilevered crane beams 10A and the crane beam structure 6A are termed the crane assembly CA.

In one embodiment, the crane assembly CA can be used as indicated in fig.13 and fig.14 for hoist 4A, i.e. without the use of the cantilevered crane beam 10A shown. All the various aspects of the hoist and crane beam 10 of the first embodiment can be adopted to the second embodiment as desired.

Claims

Amended Claims

1. A cantilever structure (1; 1A) for use in well intervention operations, which cantilever structure is arranged on a platform deck (2; 2A) of a jack-up rig/liftboat (3; 3A), said cantilever structure (1; 1A) being moveable relative to said platform deck (2; 2A), one end (1a; 1Aa) of said cantilever structure (1; 1A) being adapted to be retractably extended beyond the perimeter (P; PA) of said rig (3; 3A) deck (2; 2A), which cantilever structure end (1a; 1Aa) carries a hoist adapted to manipulate loads (L) underneath said cantilever structure (1; 1A), characterized in that one or more hoists (4; 4A, 4B) are arranged on a moveable crane chassis (5; 5A) arranged underneath said cantilever structure (1; 1A) on a crane beam structure (6; 6A), which crane chassis (5; 5A) and crane beam structure (6; 6A) are moveable in a substantially horizontal plane by means of rollers (R1, R2; RA) driven on rails (7, 8; 7A) fixed to said cantilever structure (1; 1A).

2. The cantilever structure according to claim 1, characterized in that said cantilever structure (1A) comprises two hoists (4A, 4B) arranged on respective ends of said crane beam structure (6A).

3. The cantilever structure according to claim 1, characterized in that said cantilever structure (1) comprises one hoist (4) arranged on a gantry crane beam structure (6) and beam-mounted crane chassis (5), said gantry crane beam structure (6) being moveable in a substantially horizontal plane in x and y directions, respectively, by means of rollers (R1, R2) driven on rails (7, 8) fixed to said cantilever structure (1) and gantry crane beam structure (6), respectively.

4. The cantilever structure according to claim 3, characterized in that said rails (8) of said gantry crane beam structure (6) extend longitudinally of said gantry crane beam structure (6) and transversally of said cantilever structure (1).

5. The cantilever structure according to any of the claims 1-4,

characterized in that said rails (7; 7A) of said cantilever structure (1; 1A) extend longitudinally on both sides of the underside of said cantilever structure (1; 1A).

6. The cantilever structure according to any of the claims 1-5, characterized in that each hoist (4, 4’; 4A, 4B) is mounted on a trolley (9) running on a cantilevered crane beam (10; 10A), said hoist (4, 4’, 4A, 4B) being coupled to a crane chassis (5, 5a) at respective ends of the moveable crane beam structure (6, 6A).

7. The cantilever structure according to claim 6, characterized in that said cantilevered crane beam (10’; 10A) is arranged as a telescopic beam, which telescopic beam is extendable in its longitudinal direction.

8. The cantilever structure according to any of the claims 1-7, characterized in that said cantilevered crane beam (10, 10A) is slew ably arranged to said beam-mounted crane chassis (5; 5A).

9. The cantilever structure according to any of the claims 6-8, characterized in that each hoist (4, 4’; 4A, 4B) running on a cantilevered crane beam (10, 10’; 10A) enables loads (L) to be delivered externally of said cantilever structure (1, 1A) perimeter (P’, PA) and drilling rig perimeter (P).

10. The cantilever structure according to any of the claims 1-9, characterized in that said cantilever structure (1; 1A) includes a derrick (15).

11. The cantilever structure according to any of the claims 1-10, characterized in that said intervention operations is one or more among coiled tubing, wireline and well plugging operations.

12. The cantilever structure according to any of the claims 6-11, characterized in that said the cantilevered crane beam (10; 10’) includes an auxiliary hoist (4’’) arranged on the end of said cantilevered crane beam (10; 10’).