JPS5820329B2 - 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 to be constructed in an icy area, and more specifically to an artificial island constructed 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 paper concerns an artificial island for oil drilling in ice-cold waters suitable for

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 strong water forces, and (2) it would take a long time and cost a lot of money to construct the artificial island. (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 would have to be transported from land after the construction of the artificial island, which would be 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 solves each of the problems of the above-mentioned prior art, and in fast ice sea areas,
The object of the present invention is to provide an artificial island for oil drilling in an icy area, on which oil drilling can be carried out extremely safely and economically, regardless of whether it is winter or summer.

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

The artificial island for oil drilling of the present invention shown in FIG. 1 and FIG. Waterproof embankments E are formed by sinking the waterproof bodies 1 so that their tops 1b protrude from the sea surface, and at least the outer waterproof bodies 1 have ice-breaking slope walls 1c on their outer surfaces. formed and composed.

In this embodiment, the waterproof body 1 is made of steel, reinforced concrete, or both, and is formed into a hollow triangular prism shape, and has connections on both longitudinal end surfaces thereof that connect the waterproof body 1 in the longitudinal direction. A connecting portion 1d is provided protrudingly provided, and a connecting portion 1f connecting the waterproof body 1 in parallel is provided at an appropriate interval on the lower edge of one side in the longitudinal direction of the waterproof body 1.
are protruding from each other.

Furthermore, in this embodiment, the waterproof body 1 has anti-slip protrusions 1g protruding from its lower surface at intervals, and seawater or the like is injected into the ballast tank 1a of the waterproof body 1 to submerge it. When this occurs, the weight of the anti-slip protrusion 1g is driven into the seabed, and the waterproof embankment E, which is constructed by connecting each waterproof body 1 as described above, is damaged by the pressing force caused by the movement of fast ice and drift ice. Do not move easily.

However, depending on the icy area, there is a large amount of movement of fast ice or drift ice, and if it is predicted that there is a risk that the waterproof embankment E will move with the above-mentioned anti-slip means, as shown in Fig. 3,
By connecting the waterproof bodies 1 both inside and outside by the connecting parts 1f, the space 2 formed by the inner wall of each waterproof body 1 is filled with sand and gravel. Nodotube 3
of each waterproof body, or by directly putting a sand bag 4 filled with sand or gravel into the space 2, or sand, gravel, etc., as shown in FIG.

This increases the weight and prevents the watertight embankment E from moving.

In addition, if the sea floor in the sea area where this waterproof body 1 is planned to be sunk is composed of sand and gravel, as shown in Figure 5,
Waterproofing material made by turning gravel into slurry.

By pressurizing the seawater in the slurry from the injection port 1h and discharging it from the seawater discharge port 11, the waterproof body can be made extremely heavy and the weight of the waterproof body can be increased very easily. If this artificial island for oil drilling is to be removed, the slurry injection port 1h will be removed from the sea.

Buoyancy is easily imparted to the waterproof body 1 by pressurizing water to turn the sand and gravel in the waterproof body 1 into slurry, and by creating a negative pressure in the discharge port 1n provided below the waterproof body 1. be able to.

Furthermore, as mentioned above, most of the waterproof body 1.

The ice-breaking sloped wall 1c is formed on the outer surface of the waterproof body located on the outside of both of the bodies.
30° to 65° to break the ice
The inventor of the present invention has obtained experimental results showing that it is desirable.

Therefore, if the outer surface of the waterproof body located at least immediately outside of the waterproof body 1, that is, the ice-breaking inclined wall 1c, is inclined at 30° to 65° with respect to the bottom surface, as shown in FIG.
Since the drift ice collides with this ice-breaking slope wall 1c, bends, and climbs over the slope, it is possible to avoid a large hydraulic force acting on the waterproof embankment E.

Next, a method of constructing the above-mentioned artificial island for oil drilling will be explained with reference to FIGS. 6 to 11.

The waterproof bodies 1 are towed by a construction support vessel to the construction area of this artificial island for oil drilling, and as shown in FIG. The waterproof bodies 1 are connected by wires 6 through jacks 5, and the jacks 5 are operated to draw them parallel to each other, so that a protrusion is formed on the lower edge of each anti-icing body 1 in the longitudinal direction, as shown in FIG. The two waterproof bodies 1 are connected in parallel to each other by overlapping the connecting portions 1f and connecting them with pins 7.

When constructing a waterproof embankment E (see FIG. 1) that is generally hexagonal in plan view as a whole as in this embodiment, six sets of the above-mentioned two-piece waterproof bodies may be created.

Next, as shown in FIG. 8, each end of each of the two sets of waterproof bodies is connected with a wire 9 via a jack 8.
By activating the jacks 8 to draw each other together, as shown in FIG. , as shown in Fig. 10, each waterproof body is connected in a substantially hexagonal shape in plan view except for the entrance d through which the oil drilling equipment A is brought in, and is fixed to the seabed with anchors 11 at appropriate positions so as not to move due to tides or wind. do.

Here, the oil drilling equipment A is transported from the entrance d by the support ship.
Either the oil drilling equipment A is towed into the sea area a surrounded by the waterproof dike E and is fixed to the seabed with an anchor or the like (not shown), or the rig carrying the oil drilling equipment A is sunk and fixed to the seabed. do.

If the direction in which the drift ice moves is the same every year, if the entrance d is provided on the opposite side of the direction of the drift ice, each waterproof body 1 may be sunk with the entrance d left open, but generally speaking As shown in Fig. 11, after closing the inlet d with a waterproof body, seawater or other water is injected into the ballast tank 1a in each waterproof body 1 and the oil sink is settled to the bottom, thereby constructing the artificial island for oil drilling. This completes the process.

In addition, if there is a risk that the waterproof embankment may move due to hydraulic force such as drift ice, the sand tube 3 or sand should be placed in the space 2 formed between the waterproof bodies 1 connected in parallel as described above. By inserting the bag 4, etc., the weight of each waterproof body is increased and the movement of the waterproof embankment E is prevented.

Since the present invention is configured as described above, it has the following effects.

In other words, the present invention makes it possible to form a waterproof embankment by simply depositing a waterproof body at least twice inside and outside so as to surround the oil drilling equipment, which greatly simplifies the construction of cultivated land for an artificial island. Compared to artificial island construction, 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 makes it easier to remove the artificial island after oil drilling is completed. There is no risk of causing environmental pollution problems.

In addition, since the waterproof embankment is formed by surrounding the oil drilling equipment with at least double inner and outer waterproof bodies, if necessary, it is necessary to add weight to the space formed between the double waterproof bodies. By adding the members, it is possible to increase the weight of each waterproof body and prevent the movement of the waterproof embankment E, thereby eliminating various negative effects on oil drilling equipment caused by movement of drift ice, etc. This can significantly improve the safety of oil drilling operations.

Furthermore, since the water basin surrounded by this waterproof embankment does not move, it can be effectively used as a material base for oil drilling, and unlike conventional artificial islands, there is no need to go to the trouble of reclaiming land for a material base.

Further, in the present invention, an ice-breaking sloped wall is formed on the outer surface of the waterproof body located at least on the outside of the waterproof body, so that the incoming drift ice collides with the water-resistant slope wall and bends around the slope. Since the water can be climbed over, it is possible to avoid large hydraulic forces acting on the waterproof embankment.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view;
Figure 2 is a cross-sectional view taken along arrows - ■ in Figure 1, Figures 3 and 4 are cross-sectional views showing the state in which a heavy member is inserted between the double waterproof bodies, respectively, and Figure 5 is a cross-sectional view of the inside of the waterproof body. Cross-sectional views showing the state in which slurry such as sand and gravel is press-fitted, Figures 6 to 1
FIG. 1 is an explanatory diagram showing a method of constructing an artificial island for oil drilling according to the present invention. 1...Ice protection body, 1a...Ice-breaking slope wall,
E... Ice breakwater.

Claims (1)

[Claims] 1. The sea area where the oil drilling equipment is installed is covered at least twice, inside and out, with a waterproof body containing a built-in ballast tank. A waterproof embankment is formed by enclosing each of these waterproof bodies and sinking them so that their tops protrude above the sea surface, and at least one of the waterproof bodies located on the outside has an ice-breaking sloping wall formed on its outer surface. An artificial island for oil drilling located in an icy area.