JPS58207413A - Construction of semisub type platform - Google Patents

Abstract

PURPOSE:To permit the construction of a semibus type platform without the use of large-size cranes by utilizing the buoyancy of the structure in a dry dock. CONSTITUTION:At least a superstructure 3 is built up in a dry dock 1 and floated by charging water 5 into the dock 1, and the floated superstructure 3 is positioned above a supporter 4. Then, a substructure 2 built in the dock 1 or in other place is positioned below the superstructure 3 and then supported on the supporter 4. On the other hand, short columns 6a and 6b extended from the superstructure 3 and the substructure 2 are welded to build up a temporary assembly P1, water 5 is charged into the dock 1, the temporary assembly P1 is floated and supported by a high supporter 4a, and the temporarily welded or assembled columns 6a and 6b are cut off to separate the substructure 2 from the superstructure 3. Then, the substructure 2 is positioned on the bottom of the dock 1, and the columns 6a and 6b are connected with an intermediate column 6c. Thus, the needs to hang down the superstructure 3 by a large-size crane can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a large semi-sub type platform! Concerning improvements in manufacturing methods.

Recently, 811 platforms have been used to develop offshore oil fields. These platforms are large, and in many cases it is possible to introduce everything inside the dock.

Conventionally, when building a semi-sub type platform,
A buoyant body, which is a lower structure, is built in the dock or elsewhere, a platform, which is a lower structure, is built outside the dock, and this platform is suspended by a large crane and placed on the buoyant body to increase the buoyancy. A semi-sub-type platform was completed by joining the column installed on the body and the column installed on the platform.

However, in order to assemble a semi-sub platform using the above method, it is necessary to use a large crane to suspend the upper part of the semi-sub structure and place it on the lower structure. The size of the divided blocks of the semi-sub-type platform was limited by the capacity of the semi-sub-type platform, and therefore it was possible to construct a large platform if the use of a large crane was not possible.

The present invention provides 11 of the conventional semi-sub type platforms.
l on 6! As a result of what has been achieved to solve the problem, a construction method that utilizes the buoyancy of water in a dock without using a large crane is provided.

To achieve the above object, the present invention includes a step of constructing at least a lower structure in a ship dock, injecting water into the ship dock to float the lower structure, and constructing the upper structure in the ship dock or at another location. A step of constructing a third structure, a step of aligning it above the lower structure and supporting it on a support, and a step of temporarily welding or using an appropriate adapter the short columns extending from the upper twin structure and the lower structure. The process of building a temporary assembly with the superstructure supported by the lower IM structure; a step of supporting the assembly, a step of separating the temporarily assembled column and cutting off the lower structure from the upper m1llihiro supported by the support body and positioning the lower structure at the bottom of the dock; and a step of separating the upper structure and the lower structure. A method of constructing a semi-sub-pear platform characterized by comprising a step of connecting the intervals between columns provided in the column by an intermediate body of the columns.

Next, the present invention will be described in detail with reference to the drawings.

(First step) Figure 1 shows the lower tllll structure 2, which is a buoyant body, and the upper part 4113, which is a platform, placed in parallel in the dock 1.
FIG.

A support 4 for supporting the upper structure 3 is arranged in the middle of the lower structure 2. Note that the lower structure 2 and the upper structure 3 are supported on a board 7.

The present invention is characterized in that the upper part t1113 can be assembled above the lower nI structure without using a large crane (4) as in the conventional case. As described above, in the present invention, since the assembly of the lower structure 3 is not suspended using a large crane, there is no limitation on the size.

(Second Step) Figure 2 shows the lower structure 2 and upper structure 3 in the first step.
After constructing the ship, water was poured into the dock 1 and the upper part of the ship was poured. 1111
3 is levitated and this upper part +1113 is moved above the substructure 2 and supported on a support 4 provided in connection with this substructure 2. In addition, since this lower part t1112 has a ballast tank, water is injected into this ballast tank in this second process to prevent this lower structure 2 from floating up.

Of course, the operation of positioning the upper part 13 above the lower structure 2 as described above can be performed by changing the level of the water 5 contained in the dock 1.

(5) In this embodiment, the upper structure 3 has a column 6b.
A part of the column 6a is provided in the lower structure 2, and a part of the column 6a is also provided in the lower structure 2, and the two are aligned so that they face each other.

(Third step) By adjusting the water level in the dock 1 as described above, if the lower structure 3 is positioned on the support 4 as shown in FIG. 6a and 6b are brought close together and temporarily welded together or by a suitable adapter to form a temporary assembly in which the upper structure is supported by the lower structure.

When this temporary assembly work is completed, the semi-saheb type platform temporary assembly P1 is 1! It would have been destroyed.

(Fourth step) Once the short columns 6a and 6b are connected between the upper structure 3 and the lower structure 2 as described above, water is injected 5 into the dock 1 as shown in FIG. The ballast that had been injected into the inside of the platform is drained and the temporary assembly P1 of the platform P is floated (6). Then, the support 4 used in the step of FIG. 3 is added (or replaced with another support) to obtain a support 4a of a predetermined length. In this state, the temporary assembly of the platform P is floating due to the buoyancy of the lower structure 2.

(Fifth step) Once the support 4a has been added to a predetermined length (or may be replaced with another support) as described above, water is gradually drained to form a temporary platform assembly P1. The majority of rLI is supported by the support 4a.

After that, the columns 6a and 6b connecting the lower structure 3 and the lower structure 2 of the temporary assembly P1 are separated, and the lower structure 2 is separated.
float on water 5.

When the water is further drained, the lower structure 2 gradually descends and is finally placed on a board 7 provided at the bottom of the dock 1, as shown in FIG.

Thereafter, a column 60 (7) is inserted into the gap between the ram 6b provided on the upper structure 3 and the column 6a provided on the lower structure 2, and both ends thereof are brought into bath contact.

When the column is welded, the column has a predetermined length, and the platform P has the height of the finished product.

Also, if the length of column 6C is limited by the depth of the dock, platform P will be at the completed height.
And the fifth step will be repeated.

When the morning rise is carried out as described above, oil field drilling equipment and the like are installed on the lower structure to complete the semi-sub-type platform P.

As described in detail above, in the present invention, the lower structure 3 is assembled in the dock 1, and a short column is used to temporarily connect the upper F111 structure 3 and the lower +II structure 2, and this temporary assembly is assembled. The column is supported on the support 4a, the column is separated, the lower structure 2 is lowered, and the column is connected again, thereby laterally drawing the column of a predetermined length to the point where a semi-sub-type platform is completed. I'm lucky.

(8) The present invention achieves the following effects by performing the horizontal drawing as described above.

(A) When assembling the superstructure 3 in the dock and supporting it on the support 4a, the upper part of the lever +1113 is floated by injecting water 5 into the dock, so the lower structure 3 is suspended. Does not require a large crane. tM v A crane with normal capacity was installed 1
A semi-sub-type platform can be constructed in a 1G culvert without using a large crane.

(B) When placing the upper part 3 including tM on the support 4.4a, since this upper side @ 3 itself has buoyancy, the buoyancy can be reduced, and its rise and T Adjacent welding is very easy and safe.

(C) Since the upper structure 3 and lower structure 2 of platform P can be manufactured separately, it is possible to proceed with the manufacturing process at the same time in the same dock, and therefore the construction process of platform P can be significantly reduced. can be shortened to

(9)

[Brief explanation of drawings]

The figures are detailed explanatory diagrams of the present invention, and FIG. 1 is a plan view showing a situation in which an upper structure and a lower structure are being constructed simultaneously in a dock. 2.3.4 and 5 show one of the semi-sub type platforms according to the present invention! It is an explanatory view of a crushing process. 1. Dock, 2. Lower structure, 3. Upper structure, 4.4
a...Support, 5...Water injection, 6a, 6b...Column, 7...Board. Agent Patent attorney Makoto Ogawa − Patent attorney Ken Noguchi Patent attorney Kazuhiko Aoshita (10) Figure 1 Figure 2 Figure 3 Figure 7 4 / Figure 4 1 Figure 5

Claims (1)

[Claims] A step of constructing at least a substructure in a dock;
A process of injecting water into the dock to float the upper transverse to position the lower structure above the support, and aligning the lower structure built in the dock or elsewhere below the lower structure. and a step of supporting the temporary assembly on a support body, a step of welding together the short columns extending from the upper structure and the lower YA structure to create a temporary assembly, and a step of injecting water into the dock to create a temporary assembly. A process of levitating the three-dimensional structure and supporting the temporary assembly with a higher support, and cutting the temporarily welded or temporarily assembled column to separate the lower structure from the upper structure supported by the support to create a dock. A method of constructing a semi-sub-platform (1) home that is characterized by the steps of locating the lower structure at the bottom and connecting the intervals between the columns provided in the upper part and the lower structure by intermediate bodies of the columns. N left.