JPS6017895B2 - How to build a semi-subrig - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for constructing a semi-subrig, and in particular, it is an object of the present invention to provide a method that can economically and reliably construct a semi-subrig that is wider than a dock.

A semi-sub rig for offshore oil field drilling etc. generally consists of a floating body on both the left and right sides, multiple columns each installed on the top of the floating body, and a working deck installed on the top of the column, but in recent years rigs with this structure have The main dimensions are large for the following reasons.

Since the project will operate offshore, it is necessary to secure sufficient personnel and materials needed during the work period.

Particularly under severe weather conditions, it may be difficult to procure materials, and for this reason, it is necessary to secure sufficient supplies. 'o' With the increasing depth of excavation,
The amount of materials needed for drilling, such as drill pipe, is increasing. However, the larger the size, the lower the response sensitivity to waves, etc., and the drilling operation efficiency improves accordingly.

However, as the size of the rig continues to increase, the width of the rig will eventually exceed the width that can be built using the existing dock, making it impossible to construct the rig using normal construction methods using the existing dock.

Therefore, in such cases, a semi-subrig construction method using existing equipment such as docks is recommended. The following two methods can be considered. The first plan is to apply the catamaran widening construction method using box girders proposed by the applicant and others (see Nippon Kokan Technical Report No. 47) to this semi-saprig. This method, as shown in Figure 1A,
Deck 1 column 2a, 2a. ..., 2b, 2b... and floating bodies 3a, 3b, the deck part 102 to which one column 2b, 2b... and the floating body 3b are fixed to the lower part is replaced with the deck part 101 of the main body. A box garter 14 is spanned over both decks 101 and 102, and this box garter 14 is fixed to the deck 101 of the main body, and the deck 102, columns 2b, 2b... and floating body 3b are connected to the box garter 1.
When building in the dock, the deck 102 and column 2b can be slid along the
, 2b, . . . and the floating body 3b are positioned near the main body, and after launching, these are slid outward as shown by the solid line in the figure to widen the rig to its normal position and fix it. However, when applying this method to a large semi-sub rig, the box garter is placed on deck 101,1.
In order to withstand the bending stress between 02 and 02, the structure must be extremely large-scale, which imposes a heavy burden on equipment. A second option is to construct a semi-subrig using parallel launching platforms 15, 15, each of which has a width greater than the width of the floating body 3, as shown in the opening of Figure 1. However, this method can also be used only in shipbuilding facilities with two rows of wire stands.
■Even if such shipbuilding facilities existed, the slipway construction method is mainly carried out in relatively small-scale shipbuilding facilities that do not have equipment such as large cranes. When building a rig, it is difficult to say that this is a general-purpose method because it often requires investment in new equipment such as a large crane. In this way, the above 2
The proposed method is difficult to put into practical use due to the burden on equipment, etc. Therefore, there was a desire to propose an economical and versatile construction method for large semi-subrigs. The present invention was devised in view of these circumstances, and its features are: D. Of the columns and floating bodies provided on both sides of the lower part of the deck, one column and floating body are integrally fixed to the deck, and the other column and floating body are temporarily fixed at a position closer to the inner side of the lower part of the deck and launched. After the launch, the other column and the floating body are slid and fixed on the water to the proper position in the outward direction along the lower surface of the deck, and then the column and the floating body are fixed to the deck. In particular, a semi-suprig can be constructed economically by using a dock with a construction width smaller than the normal width of the rig. An embodiment of the present invention will be described below based on the drawings. Figure 2 A to 2 show the basic configuration of the construction process of the present invention. It shows.

In the present invention, first, columns 2a, 2a... on one side in the deck width direction in the dock 4 as shown in FIG.
and a floating body 3a is arranged at the bottom of deck 1, and this is placed on deck 1.
be integrally fixed to. Also columns 2b, 2b on the other side
... and the floating body 3b are also disposed below the deck 1, and these columns 2b, 2b, . . . and the floating body 3b can slide with respect to the deck 1 in the width direction thereof. Then, the columns 2b, 2b... and the floating body 3b are connected to the dock 4.
In order to fit within the deck 1, these are positioned closer to the inside than the final mounting position at the bottom of the deck 1, and temporarily fixed at that position. Incidentally, the deck 1 is manufactured to regular dimensions, and at this stage the deck rock is also installed. Once the construction has been completed, the rig is launched as shown in the opening of Figure 2, and the columns 2b, 2b... and floating body 3b are slid along the lower surface of the deck on the water, and the broken lines in the diagram indicate Position it in the correct mounting position as shown. Then, the columns 2b, 2b, . . . and the floating body 3b are fixed to the deck 1 and the rig body, thereby completing the construction of the rig as shown in FIG. 2C. The rig is completed with reinforcing places 5 connected between the columns and the deck, and between the columns, but because the column 2b slides due to the above-mentioned widening work, before the work is done, the reinforcement places 5 are connected between the deck 1 and the column 2b. The extending place 5 is left unconnected to the column 2b. After the width widening work of the column 2b is completed, the place 5 is connected to the column 2b by adding the missing place members. The basic configuration of the method of the present invention has been described above, and the specific configuration of the width widening mechanism for carrying out this process will be explained.

3 to 5 show the sliding mechanism of the column 2b with respect to the deck 1. A sliding garter 6 is attached to the width direction of the lower surface of the deck 1, and the sliding garter 6 is attached to both sides of the upper end of the column 2b. Mounts 7, 7 are provided to engage with the mounts 6, and load receiving sections 8, 8 are formed on the mounts 7, 7. In this embodiment, the receiving parts 8, 8 are made to slide along the sliding garter 6, and for this reason, the receiving parts 8, 8 are made of Teflon or the like to reduce friction during sliding. That's what I do. Note that this slide mechanism can also be constructed of seals and rollers. A driving mechanism 9 for sliding the column 2b is provided between the deck 1 and the column 2b, and its driving force moves the column 20 and the floating body 3b outward as shown by the broken line in the figure along the sliding garter 6. It slides into place. In this embodiment, a worm gear system is adopted as the drive mechanism 9, and the power section 91 is attached to the lower surface of the deck 1, and the forward and backward shaft 92 of the drive mechanism 9 is connected to the column 2b. It should be noted that as the drive mechanism 9, a rack and pinion type, a hydraulic cylinder type, etc. can be adopted as appropriate. Also, generally column 2b
, 2b... Since the columns 2b, 2b... are connected to each other by a place, it is possible to provide the drive mechanism 9 only for some of the plurality of columns 2b. Needless to say, it is preferable to provide one for each column in order to slide smoothly. In addition to the above-mentioned slide mechanism, this embodiment includes a mechanism for widening the floating body 3b (and the column lower part) in synchronization with the column 2b upper part. That is, as shown in FIG. 2A and 2B, a box garter 10 is spanned between the two floating bodies 3a and 3b, and one end of the box garter 10 is fixed to one of the floating bodies 3a (or the lower part of the column). In addition, the other end side of the box garter 10 is connected to the other floating body 3b (
The floating body 3b is inserted into the guide holes of the presser feet 11, 11 which also serve as guides provided at the lower part of the column, and the floating body 3b is guided along this box garter and can slide along this. And this box garter 10
A driving mechanism 12 is provided between the floating body 3b or the column 2b, and this driving force causes the floating body 3b and the lower part of the column 2b to synchronize with the slide of the upper part of the column 2b, and pushes them outward as shown by the broken line in the figure. be. In this embodiment, as described above, a worm gear system is adopted as the drive mechanism 12, and its power section 121 is attached to the box garter 10, and the tip of its advance/retreat shaft 122 is connected to the presser jig 11. . Note that, as described above, suitable drive mechanisms such as a rack and pinion system or a hydraulic cylinder system can be adopted as the drive mechanism. It goes without saying that it is preferable to install the box garter 10' at each position of each column 2b, 2b, etc.;
For example, it can be attached at positions corresponding to the columns before and after in the longitudinal direction. box garter 10
will be removed after the rig is completed. Also, Figures 10 and 11
The figure shows another embodiment of the floating body and column lower ground holding width mechanism, and this embodiment utilizes a horizontal place 5a to be connected between the lower columns.

That is, in order to slide the column 2b as described above, the horizontal place 5a extending from the column 2a is aligned with the column 2b.
However, in this embodiment, the horizontal place 5 whose tip extends to the front of the column 2b is in an unconnected state.
A drive mechanism 13 is provided between a and the column 2b (or a place member attached to the column), and the floating body 3 is driven by this driving force.
b and column 2b outward as shown by broken lines in the figure. This drive mechanism 13 is also of a worm gear type, and power sections 131 are provided at three locations on the lower surface and both side surfaces of the tip of the sailor place 5a, and the tip of each advancing/retracting shaft 132 is connected to the column 2b. The reason why the power unit 131 is provided on the lower surface and both sides of the tip of the horizontal place 53 instead of on the top surface is so that additional place members can be mounted on the top surface of the tip of the horizontal place 5a after the above-mentioned widening work. It's for a reason. It goes without saying that the drive mechanism 13 may also employ a rack and pinion system or a hydraulic sill system. Further, it goes without saying that it is preferable that the drive mechanism 13 is attached to the horizontal place 5a of each column, but it is not necessarily limited to this.

In addition, in the construction method of the present invention as described above, in order to reduce the load on the deck 1 applied to the columns 2b, 2b during the covering work, the deck 1 is lifted up to some extent by a crane ship etc. while the widening work is carried out. This makes it possible to reduce the load on the drive mechanism.

According to the present invention described above, one column and the floating body are integrally fixed to the deck in the dock, and
The other column and floating body are temporarily fixed to the inside of the lower part of the deck and launched, and the other column and floating body are slid outward along the lower surface of the deck on the water, and then the column and floating body are attached to the deck. Since it was made to stick to
Even a semi-subrig having a width larger than the construction width of a dock can be constructed economically and reliably without imposing a large burden on equipment.

BRIEF DESCRIPTION OF THE DRAWINGS Figures 1A and 1B are explanatory diagrams showing a reference example of a method for constructing a large semi-saprig, respectively.

FIGS. 2A to 2C are explanatory diagrams showing the steps of the method of the present invention step by step. 3 to 5 partially show the width widening mechanism at the top of the column used for carrying out the present invention. FIG. 3 is a front view, FIG. 4 is a side view, and FIG. 5 is a side view. FIG. 3 is a cross-sectional view taken along the middle line V-V. Figures 6 to 8 partially show the utility equipment of the lower part of the floating body or column used to implement the present invention, Figure 6 is a front view, Figure 7 is a side view, and Figure 8 is a side view. It is a top view showing a column in a cross-sectional state. 9th
Figures 11 to 11 similarly show other embodiments of the width widening mechanism at the bottom of the floating body or column, and Figure 9 is a front view, and Figure 11 is a front view.
Figure 0 is a side view showing the horizontal place in cross section.
FIG. 1 is a plan view showing the column in cross section. In the figure, 1 is a deck, 2a, 2a..., 2b. 2b... indicates a column, 3a and 3b a floating body, and 4 a dock.

Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11

Claims (1)

[Claims] 1. In a method of constructing a semi-subrig consisting of a deck, columns and floating bodies installed on both sides of the lower part of the deck, one column and floating body are integrally fixed to the deck, and the other column and floating body are integrally fixed to the deck. The floating body is temporarily fixed at a position near the inner side of the lower part of the deck, launched, the other column and the floating body are slid outward along the lower surface of the deck on the water, and then the column and the floating body are fixed to the deck. A distinctive semi-subrig construction method.