JPS5820331B2 - Artificial island for oil drilling in frozen waters - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an artificial island for oil drilling constructed in an icy area, and more specifically, an artificial island suitable for construction in an icy area where the water depth is approximately 20 m or less and the movement of fast ice or drift ice is small. This concerns an artificial island for oil drilling in the ocean.

For example, in fast-ice sea areas such as the Arctic Ocean, the amount of fast-ice movement is small, and is said to be about 20 m at most during winter.

In such fast ice areas, and in shallow water areas (20m
Conventionally, when drilling for oil in the following areas, an artificial island is constructed using sand, gravel, or a basin of water, and oil drilling equipment is installed on this artificial island.

However, in this case, (1) it would be necessary to construct an artificial island over a larger area than necessary in order to withstand drifting ice and powerful water forces; (2) therefore, the construction of an artificial island would take a long time and require a lot of effort. (3) If the artificial island is constructed with sand or gravel, it is difficult to remove the artificial island after excavation is completed, and there is a problem of environmental pollution.

(4) Furthermore, all of the oil drilling equipment and materials must be transported from land after the construction of the artificial island, which is difficult and costly.

(5) Furthermore, if an artificial island is constructed using a water basin, not only will the period during which excavation is possible be limited to one to two months during the mid-winter season, but there is also the risk that drilling drills etc. will be damaged due to movement of the water basin. .

Currently, there are many problems that need to be resolved.

Therefore, the present invention was made in view of the above-mentioned current situation, and it solves each of the problems of the above-mentioned prior art and allows oil drilling to be carried out extremely safely and economically in areas with ugly fast ice, regardless of whether it is winter or summer. The purpose of this project is to provide an artificial island for oil drilling in icy waters.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An artificial island for oil drilling in an icy area according to the present invention will be described below by way of example with reference to the drawings.

First, a first embodiment of the present invention shown in FIGS. 1 and 2 will be described.

In the illustrated artificial island El for oil drilling of the first embodiment, a waterproof embankment B is constructed by stacking sand tubes 1 from the seabed so that their tops 1a protrude from the sea surface so as to surround the area where oil drilling equipment A is installed. The installation part G of the oil drilling equipment A is formed by charging a fabric weight member 2 such as sand or gravel into the waterproof embankment B.

The sand tube 1 is formed by press-fitting sand or gravel in the form of a slurry into a cylindrical bag body 1b having flexibility and water permeability using a one-way dredge or the like. As shown in the figure, the top parts 1a are stacked one after another upward from the seabed to the required height above the sea surface, that is, to a height where the oil drilling equipment is not affected by wind waves and drift ice, and as described above. , the waterproof embankment B is formed by stacking them in the longitudinal direction so as to surround the area where the oil drilling equipment A is installed.

Furthermore, when the sand tubes 1 are stacked as described above to form the waterproof embankment B, it is desirable to stack the sand tubes so that the cross-sectional shape thereof is approximately triangular as shown in FIG.

This is because the internal slope of the waterproof embankment B is pressed downward by the cloth heavy material 2 such as sand and gravel thrown into the waterproof embankment B, and the waterproof embankment B has sufficient resistance to the strong ice force and wave force. This is because it can impart resistance.

Furthermore, the present study has shown that the angle of inclination of the outer inclined surface 1c of the waterproof embankment B with respect to the bottom surface is preferably 30° to 65° in order to allow the rushing ice to ride on the outer inclined surface 1c and break the ice. The inventor of the invention has earned it.

Therefore, the outer inclined surface 1c of the waterproof embankment B is 3
If the ice is tilted at an angle of 0° to 65°, the drift ice will collide with this outer slope 1c, bend, break, and go over the slope, thereby avoiding the application of a strong hydraulic force to the waterproof embankment B. I can do it.

Therefore, as shown in FIG. 2, if an ice-breaking inclined plate 3 made of steel or reinforced concrete blocks is attached to the outer peripheral surface of the waterproof embankment B, the ice-breaking effect can be further promoted. be.

Next, a second embodiment of the present invention shown in FIGS. 3 and 4 will be described.

The illustrated artificial island for oil drilling E2 of the second embodiment has a sand tube 4 at its top 4a so as to surround the aforementioned artificial island for oil drilling E1 at a required interval a.
It is constructed by stacking up from the seabed so that they protrude above the sea surface to form an outer waterproof embankment C.

The sand tube 4 is constructed in the same manner as the sand tube 1 of the first embodiment, and the process of stacking the sand tubes from the seabed to form the outer waterproof embankment C and its cross-sectional shape are also similar to the waterproof embankment B of the first embodiment. Since they are equivalent, detailed explanation will be omitted here.

However, in this second embodiment, as shown in FIG. 6, in addition to installing the ice-breaking inclined plate 3 on the outer circumferential surface as in the first embodiment, the outer waterproof embankment C has anti-slip means 5 at its base.
It is desirable that the outer waterproof embankment C is not easily moved by the pressing force caused by moving fixed water or drift ice.

In this embodiment, as shown in FIG. 4, the anti-slip means 5 is constructed by protruding anti-slip protrusions 5b at intervals from the lower surface of a steel mounting plate 5a. Due to the weight of the outer waterproof levee C placed on the mounting plate 5a, the anti-slip protrusion 5b is pushed into the seabed so that the outer waterproof levee C can be given resistance against the hydraulic force of the drift ice, etc. It has become.

Further, in this second embodiment, the area of the installation part G of the oil drilling equipment A can be made as small as possible compared to that of the first embodiment.

This is because in the case of this second embodiment, the water basin stretched within the distance a between the artificial island El for oil drilling and the outer waterproof levee C surrounding it is not moved by the outer waterproof levee C, so this water basin is used for oil drilling. This is because it can be effectively used as a base for various necessary materials.

Next, a third embodiment of the present invention shown in FIGS. 5 and 6 will be described.

The illustrated artificial island for oil drilling E3 of the third embodiment is a partial modification of the artificial island for oil drilling E2 of the second embodiment described above.

That is, as described above, the artificial island E2 of the second embodiment has the fabric weight member 2 in the inner waterproof embankment a, as in the first embodiment.
In this third embodiment, the cloth weight member 2 is inserted between the inner waterproof embankment B and the outer waterproof embankment C to form the installation part G of the oil drilling equipment A. It has a structure in which it is inserted within the interval a.

Therefore, in the third embodiment, the diameter of the inner waterproof levee B is made larger than that of the second embodiment, and the distance a between the inner waterproof levee B and the outer waterproof levee C is
It is narrower than that of the second embodiment.

Therefore, since the oil drilling equipment A will be installed in the sea area d surrounded by the inner waterproof levee B, if a part of the waterproof levee is opened in advance when constructing each waterproof levee, The rig equipped with the oil drilling equipment A can be towed into the waterproof embankment by a support ship and then installed by being sunk as it is.

Note that the opening through which the oil drilling equipment A is carried in may be left open depending on the direction of movement of the drift ice, but if there is a risk that drift ice may flow into the waterproof embankment from this opening, the opening may be left open. occlude.

In this third embodiment, as described above, the oil drilling equipment is surrounded at least twice, inside and outside.
The various negative effects on oil drilling equipment caused by the movement of settled water or drift ice can be completely eliminated, significantly improving the safety of oil drilling operations. Since the ice floes do not move, they can be effectively used as a material base for excavation.

Since the present invention is configured as described above, the following effects are achieved.

In other words, the present invention makes it possible to form a waterproof embankment simply by stacking sand tubes around oil drilling equipment, making the on-site construction work of an artificial island extremely simple.
Therefore, compared to the conventional artificial island construction mentioned above, it is possible to construct an artificial island in a shorter period of time, which not only significantly reduces the cost of constructing an artificial island, but also reduces the work required to remove the artificial island after oil drilling is completed. It is easy and there is no risk of causing environmental pollution problems.

[Brief explanation of the drawing]

1 and 2 show a first embodiment of the present invention, in which FIG. 1 is a plan view, FIG. 2 is a cross-sectional view taken along arrows -■ in FIG.
3 and 4 show a second embodiment of the present invention, FIG. 3 is a plan view, FIG. 5 shows a third embodiment of the present invention, FIG. 5 is a plan view, and FIG. 6 is a sectional view taken along the line VI-Vl in FIG. 1... Sand tube, 1a... Top, 2... Cloth weight member, A... Oil drilling equipment, B... Anti-icing Embankment, G... Installation part of oil drilling equipment.

Claims (1)

[Claims] 1. An artificial island for oil drilling in icy waters that is made by stacking sand tubes from the seabed so that their tops protrude above the sea surface to form a waterproof embankment surrounding the area where oil drilling equipment is to be installed.