KR101395773B1 - A method of contemporaneously constructing more than one semi-submersible rig using transverse skidding - Google Patents

Abstract

A method for drying two (or more) semi-submersible rigs at the shipyard at the same time and for successively assembling these rigs in a shipyard is disclosed. Two upper hulls of the individual league are dried side by side on the ground following the dry dock where the lower body is dried. The first upper body then slides longitudinally into position on the first lower body. The lower body is floated by filling the dry dock with water, and the position of the lower body is adjusted using the ballast tank of the lower body. Once the upper and lower bodies are aligned, they are permanently welded together to complete the first rig assembly in the dry dock. At the same time, the second upper body is then slid transversely to the load-out position and then raised by the jack to the required height. After the truss is pulled back from the mating position of the first rig, it is placed on the skidding truss. The load-out and registration operation is then repeated to assemble the second semi-submerged rig in the dry dock.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of simultaneously drying one or more semi-submerged leiges using lateral skimming,

Cross-reference to related application

The present application is a continuation-in-part of application Serial No. 200306086-0, filed on October 17, 2003, entitled " Method for Drying Semi- submersible Vessels Using Dry Dock Registration " The complete disclosure is hereby incorporated herein by reference and the priority of the above-mentioned first application is hereby incorporated by reference.

Technical field

The present invention relates generally to the drying of offshore structures, and more particularly to a method of drying two (or more) semi-submerged drilling rigs simultaneously in a shipyard using a dry dock matching process.

With rising trends in energy demand, oil prices will remain high in the near future and the emphasis on exploration will increase significantly. It is crucial that deep-sea exploration is vigorously undertaken by maritime activities, which means a high demand for new semi-submersible leagues. From the point of view of shipyards, it is important to shorten the delivery time by increasing productivity.

The international application published under International Publication No. WO 2005/035354 A1 discloses a method of simultaneously drying an upper hull and a lower hull at a shipyard to shorten the overall drying schedule. The upper body is completely erected on the skidding truss and support towers on the ground and the lower body is dried in the dry dock adjacent to the skidding truss. A support truss is installed in the dry dock to support a plurality of skimming beams extending from the upper body drying site to the ground side to a mating position above the lower body in the dry dock. When the upper body and lower body are dry, the upper body is loaded out to the mating position by skidding on the skimming beam using a hydraulic jack system. The matching operation is subsequently performed by floating the lower body in the dry dock up until the lower body meets and supports the upper body. The welding of the joints of the upper and lower bodies is finally carried out. Thus, complete registration is performed in a controllable manner, ensuring quality as well as stability of the job.

However, this method allows only one semi-submerged rig to be dried and assembled at a time. In order to dry the second rig, the upper body must be erected on the skidding truss so that a second load-out and matching operation can be performed only a few months later. The present invention contemplates providing a simultaneous drying method of two or more semi-submersible vessels and eliminating some disadvantages associated with conventional methods.

 It is therefore an object of the present invention to provide a method for drying two (or more) semi-submerged leaks simultaneously in a safe and stable manner at relatively low cost.

Yet another object of the present invention is to provide a method for drying two (or more) semi-submerged leaks at the same time using the dry dock and the ground side of a conventional shipyard.

This and other objects of the present invention are achieved through the provision of a method for causing the upper body and lower body of two leashes to be simultaneously dried in the shipyard, thereby shortening the overall drying schedule. The upper body of the first rig is fully assembled on the skidding truss and the support tower on the ground side near the end of the dry dock and the upper body of the second rig is fully assembled on the ground side to the skid truss holding the first upper body Lt; RTI ID = 0.0 > direction < / RTI > The lower body of the first rig is dried in the dry dock adjacent to the skidding truss and the lower body of the second rig is dried at another location of the shipyard.

A support truss is mounted on the dry dock to support a plurality of skidding beams extending from the upper side body drying site on the ground side to the mating position on the lower body in the dry dock.

When the upper and lower bodies of the two levers are dry, the first upper body is loaded out into the mating position by skidding on the skimming beam using a hydraulic jack system. The mating operation is subsequently performed by floating up in the dry dock until the lower body meets and supports the upper body. The joint welding of the upper and lower bodies is finally performed for the first rig.

During the mating operation of the first rig, the upper body of the second rig moves from the assembled position of the upper body to the load-out position by skewing in the lateral direction on the skidding path. The second upper body is subsequently raised by the jack to a height such that the skidding truss can be returned from the mating position in the dry dock and positioned below the second upper body. The upper body then descends and eventually rests on the skidding truss.

Upon completion of the mating operation of the first lug, the finished rig is pulled out of the dry dock and the lower body of the second rig is pulled to the mating position in the dry dock. The load-out and matching operation of the second league is then performed in exactly the same manner as that of the first league.

By doing so, the complete matching operation for the two leagues is subsequently performed in a controllable state, ensuring safety as well as quality of operation.
A mode of the present invention
In one aspect of the invention, the drying method of two (or more) semi-submerged leigs
Providing means for supporting the first upper body of the first rig and the first upper body on the ground,
Providing a means for supporting the second upper body on the ground at a location adjacent to the second upper body and the first upper body of the second rig,
Providing a first lower body of the first rig and positioning the first lower body with a dry dock adjacent to the first upper body,
Moving the first upper body to a position on the first lower body and balancing to align the first lower body with the first upper body,
Aligning the first upper body with the first lower body to assemble the first rig and then moving the first rig to a certain distance from the dry dock,
Transmitting the second upper body to a means for supporting the first upper body,
Providing a second lower body of the second rig and positioning a second lower body within a dry dock adjacent to the second upper body,
Transferring the second upper body to a position on the second lower body,
Balancing the second lower body to align with the second upper body, and
And aligning the second upper body with the second lower body to assemble the second rig.
In another aspect of the invention, the means for supporting the first upper body includes a skiving truss.
In yet another aspect of the invention, the means for supporting the second upper body includes a stationary support block disposed in a skidding path located transverse to the longitudinal axis of the skidding truss.
In yet another aspect of the invention, the means for supporting the second upper body further comprises means for raising the second upper body.
In another embodiment of the present invention, the drying method of two (or more) semi-submerged leigms further comprises delivering the second upper body to the skidding truss, wherein the first upper body comprises a first lower body Lt; / RTI >
In yet another aspect of the invention, the means for supporting the second upper body further comprises means for raising the second upper body at a relative height above the skidding truss.
In another embodiment of the present invention, the drying method of two (or more) semi-submerged leiges is such that before transferring the second upper body to a position on the second lower body, And transferring the weight of the second upper body to the skidding truss.
How to dry semi-submerged leagues.
In yet another aspect of the invention, the means for raising the second upper body includes a skiving-and-pushing-up shoe capable of raising the second upper body to a predetermined height.
In another aspect of the invention, the drying method of the two (or more) semi-submerged leiges includes the steps of: providing a first upper body and a second upper body, Placing the shoe under the second upper body and delivering the second upper body to the skimming-and-pushing-up shoe.
In another aspect of the invention, after the first upper body is delivered to a position on the first lower body, the second upper body is delivered as a means for supporting the first upper body.
In another aspect of the present invention, a drying method of two (or more than three) semi-submerged leigs includes simultaneously drying the second upper body on the skidding path adjacent to the first upper body, And drying.
In another aspect of the invention, the skidding path supports the second upper body at a level lower than the level that supports the first upper body on the skidding truss to improve the safety of construction.
In another aspect of the present invention, a drying method of two (or more than three) semi-submerged leigs includes drying the first lower body and the second lower body simultaneously with the drying of the second upper body and the first upper body, .
In another aspect of the invention, the drying method of two (or more) semi-submerged leiges comprises simultaneously drying of the first upper body second upper body, the first lower body and the second lower body, And drying the upper body and the three or more lower bodies.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the nature and objects of the present invention, reference is made to the following description, taken in conjunction with the accompanying drawings, in which like parts are designated by like reference numerals.

Figure 1 is a plan view of a load-out, registration and transverse skidding work device,

FIG. 2 is a cross-sectional view of a skirting truss and load-out structure and equipment (including support trusses, longitudinal skimming beams, and shoes, tie bars, barges, jacking systems, Lt; RTI ID = 0.0 > a < / RTI > top)

Figure 3 is a side elevational view showing a second upper body supported on the temporary block,

FIG. 4 is a detail view showing skidding-and-pushing up shoes positioned under the upper body and taking over the weight of the upper body,

Figure 5 shows the steps of a load-out and registration operation of the first league in the dry dock,

Figure 6 shows the step of skidding the second upper body laterally from an erected position to a load-out position,

Figure 7 shows the step of raising the second upper body to the jack at the load-out position,

8 shows the return of the skidding truss from the mating location to the second lower body underload-out location,

Figure 9 shows the operation of pulling the completed first rig to position the second rig lower body within the mating position,

Figure 10 shows the load-out and registration steps of the second league.

1 to 3 show the general arrangement of the shipyard area including the dry dock 4, where the two submerged leagues of the present invention are dried and matched. As can be seen in Figures 2 and 3, the first semi-submersible rig comprises a first upper body 1a and a first lower body 2a. During drying, the first upper body is supported by a skidding truss 3 located on a land adjacent to the dry dock 4. The truss 3 is designed to skew the finished upper body on the longitudinal skimming beam 5 using the longitudinal skimming shoe 6 during the load-out operation.

As can be seen in FIG. 1, the longitudinal skiving beam 5 extends parallel to the longitudinal axis of the skidding truss 3. The detailed construction of the structure required for the load-out and registration operation is described in more detail in the earlier application, entitled " Method of Drying Semi- submersible Vessels Using Dry Dock Registration "(International Publication WO 2005/035354) .

Simultaneously with the first upper body 1a, the second upper body 1b is dried next to the first upper body 1a on a transverse skidding path with a pair of fixed transverse skid beams 9. The second upper body is supported on the skid beam 9 by a temporary support block 7 (Fig. 3). The transverse skid beams 9 each have a longitudinal axis which is oriented transversely with respect to the longitudinal axis of the skidding truss 3. The temporary block 7 is located at a much lower level than the skidding truss 3, which is stationary to support the first upper body 1a.

Upon completion of drying of the second upper body 1b, the transverse skidding and pushing-up shoe 8 is positioned below the second upper body 1b on the transverse skidding path (Fig. 4). The shoe 8 is then pushed up to take over the weight of the second upper body 1b from the temporary support block 7.

Figure 5 shows the load-out and registration steps of the first league. The first upper body 1a is pulled from the load-out position on the dry dock 4 to the mating position. The first lower body is floated by filling the dry dock 4 with water, and the position of the lower body is adjusted by using a ballast tank of the first lower body 2a.

The first lower body 2a is floated upward until the upper portion of the column of the first lower body 2a is in contact with the bottom of the first upper body 1a. A temporary guide piece is then welded at the upper and lower body joints. On the other hand, the first lower body 2a supports the weight of the first upper body 1a and holds the weight of the first lower body 1a until the gap between the first upper body 1a and the first lower body 2a is closed And is continuously floated. The first lower body 2a is permanently attached to the first upper body 1a by sufficient welding at the upper and lower body joints.

The next step in the process involves laterally skiving the second upper body 1b from the assembly position to a load-out position near the end of the dry dock 4 (Fig. 6). The skidding operation is performed by a plurality of skidding-and-pushing-up shoe (8) located on the transverse skidding path beam (9).

When reaching the load-out position, the second upper body 1b has a tolerance (Fig. 7) between which it is slid to a height sufficient to accommodate the skidding truss 3 (to be pulled back in the next step) And-pushing-up shoe (8).

When the second upper body 1b reaches the required height, the skidding truss 3, which was located at the mating position of the first rig, is pulled back to the load-out position of the second upper body 1b. This step is shown in Fig. The first finished rig is then pulled from the mating position as schematically shown at the top of Fig. 9 and the second lower body 2b is positioned at the mated position, as shown in the lower portion of Fig.

Following the positioning of the second lower body 2b in the mated position, the second upper body 1b is pulled along the skidding truss 3 from the load-out position to the mating position on the dry dock 4. The second lower body 2b is ballasted until the upper part of the column of the second lower body 2b contacts the bottom of the second upper body 1b and floated upward. Similar to the drying process of the first league, a temporary guide piece is welded in the upper and lower bodies. During this time, the second lower body 2b supports the weight of the second upper body 1b until the gap between the second upper body 1b and the second lower body 2b is closed, The body is continuously floated. The second upper body 1b and the second lower body 2b are then permanently connected to each other by welding. Figure 10 generally illustrates a load-out and registration operation of a second league that repeats load-out and registration operations for the first league.

The method of the present invention has the advantage of allowing two (or more) drying operations to be applied successively in successive stages of sequential longitudinal load-out and registration operations in the dry dock and on the ground side of the dock end . By doing so, the entire drying period for the two rigs is substantially shortened. In fact, two leagues can be manufactured simultaneously using conventional shipyard equipment.

Two or more leagues can be simultaneously dried in a conventional existing shipyard where one of the upper bodies 1a is assembled on the skidding truss 3 and the remaining upper body 1b is close to the upper body 1a ≪ / RTI > After the first upper body 1a has moved to the mating position with the first lower body 2a the second upper body 1b can be raised above the skidding truss 3 and transferred to the skidding truss 3. When the skidding truss 3 is freed again (following the delivery of the second upper body 1b to the mating position in the dock), the next upper body is continuously delivered to the skidding truss. All final matching operations are performed in the same dry dock.

The efficiency of using the dry dock is significantly increased by reducing the time required for the return of the skidding structure in the dry dock after the first load-out and registration operation and re-installation before the second rig work. A further advantage of the method of the present invention relates to drying the second upper body on the temporary support block 7 at a much lower level than the first upper body, which leads to a safer working environment, Minimize the requirements for.

While the invention has been described with reference to specific embodiments, the description is not intended to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as other embodiments of the invention, will be apparent to those skilled in the art in light of the foregoing detailed description. It is, therefore, to be understood that the appended claims are intended to cover certain modifications or embodiments that fall within the true scope of the invention.

Claims (14)

A method of drying two (or more) semi-submerged leagues, Providing a first upper body of the first rig and means for supporting the first upper body on the ground, Providing a means for supporting the second upper body on the ground at a location adjacent to the second upper body and the first upper body of the second rig, Providing a first lower body of the first rig and positioning the first lower body with a dry dock adjacent to the first upper body, Moving the first upper body to a position on the first lower body and balancing to align the first lower body with the first upper body, Aligning the first upper body with the first lower body to assemble the first rig and then moving the first rig a certain distance from the dry dock, Transmitting the second upper body to the means for supporting the first upper body, Providing a second lower body of the second rig and positioning the second lower body in the dry dock adjacent to the second upper body, Transferring the second upper body to a position on the second lower body, Balancing the second lower body to align with the second upper body, and Aligning the second upper body with the second lower body and assembling the second rig, The means for supporting the first upper body includes a skiving truss, Wherein the means for supporting the second upper body comprises a fixed support block disposed in a skidding path located laterally with respect to a longitudinal axis of the skidding truss. How to dry semi-submerged leagues. delete delete The method according to claim 1, Wherein the means for supporting the second upper body further comprises means for raising the second upper body, How to dry semi-submerged leagues. 5. The method of claim 4, And transferring the second upper body to the skidding truss, wherein the first upper body is aligned with the first lower body, How to dry semi-submerged leagues. The method according to claim 1, Wherein the means for supporting the second upper body further comprises means for raising the second upper body to a relative height above the skidding truss, How to dry semi-submerged leagues. The method according to claim 6, Moving the skidding truss to a position below the raised second upper body and delivering the weight of the second upper body to the skidding truss before delivering the second upper body to a position on the second lower body, Further included, How to dry semi-submerged leagues. The method according to claim 6, Wherein the means for raising the second upper body comprises a skiving-and-pushing-up shoe capable of raising the second upper body to a predetermined height, How to dry semi-submerged leagues. 9. The method of claim 8, Pushing-up shoe below the second upper body and pushing the second upper body into the second upper body and the second upper body, - < / RTI > pushing-up shoe, How to dry semi-submerged leagues. The method according to claim 1, Wherein the first upper body is transmitted to a position on the first lower body and then the second upper body is transmitted to a means for supporting the first upper body, How to dry semi-submerged leagues. The method according to claim 1, Further comprising drying the first upper body over the skidding truss while simultaneously drying the second upper body on a skidding path adjacent the first upper body, How to dry semi-submerged leagues. 12. The method of claim 11, The skidding path supports the second upper body at a level lower than a level that supports the first upper body on the skidding truss to improve the safety of construction. How to dry semi-submerged leagues. 12. The method of claim 11, Further comprising drying the first lower body and the second lower body simultaneously with drying of the second upper body and the first upper body, How to dry semi-submerged leagues. 14. The method of claim 13, Further comprising drying at least three upper bodies and at least three lower bodies simultaneously with drying of the first upper body, the second upper body, the first lower body and the second lower body, How to dry semi-submerged leagues.

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