KR101559409B1 - Method for calculating equipment number of semi-submersible drilling rig and method for deciding size of anchoring device using the equipment number - Google Patents

Abstract

The present invention relates to a method for calculating the number of semi-submersible rigs and a method for determining the size of a mooring device using the calculated number of designs. According to an embodiment of the present invention, there is provided a method of calculating the number of designs of semi-submersible drilling rigs, the method comprising the steps of: obtaining a projection cross-sectional area of a side of the submersible drilling rig below the waterline; Obtaining a projection cross-sectional area of the front surface of the semi-submersible drilling line below the waterline; Obtaining a projection cross-sectional area of the main deck of the semi-submersible drilling rig and the side surface of the main deck upper structure; Determining a projected cross-sectional area of the main deck of the semi-submersible drill rig and the main deck upper structure; And the projected cross-sectional area of the lower side of the waterline, the projected cross-sectional area of the front surface of the lower portion of the waterline, the projected cross-sectional area of the main deck and the side surface of the main deck upper structure, And calculating a number of designs, wherein the main deck superstructure is provided with a method of calculating a number of designs, excluding a truss structure.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of calculating the number of semi-submersible drill rigs and a method of determining the size of a mooring device using the number of semi-submersible drill rigs. }

More particularly, the present invention relates to a method for calculating the number of semi-submersible rigs and a method for determining the size of the mooring apparatus using the calculated number of designs.

It is called mooring that a ship puts an anchor into the sea to anchor the ship. In order to moor the ship, a mooring device such as an anchor and anchor chain is necessary. However, when determining the size, quantity, etc. of such a mooring device, it is determined by using Equipment Number.

The number of designs is determined by the weight and quantity of anchors used as a means to maintain a certain position of the ship from the influence of the wind acting on the upper part of the ship and the currents acting on the lower part of the ship, the length and diameter of the anchors, The numbers used to determine the cutting loads, lengths and yields of ropes and towboats are defined as numerical values as a function of the displacement area and the pressure of the fluid acting on the lower part of the water surface, acting on the shape of the vessel exposed at the upper part of the water surface. Korean Register of Shipping has completely revised the number formula for the general ship in 1998 and added the method of calculation of the detailed number of the hall in 2002 and unified with international standards.

Semi-submersible drilling rig is a half-seawater ship with drilling function. 1 is a view showing a semi-submersible drilling line. As shown in FIG. 1, the semi-submersible drill ship is composed of two pontoons 110 and four or six columns 120 as the substructure.

Pontoon is the structure of semi-submersible drilling rig, which makes buoyancy to float semi-submersible drilling rigs in the sea. When the semi-submersible drilling rig moves, the upper part of the pontoon is slightly exposed, but during drilling, the pontoon is completely submerged in seawater to minimize resistance. The interior of the pontoon consists of several tanks, most of which are used as tanks for ballast. Outside the pontoon, there is a thruster for automatic positioning (Dynamic Positioning) and a device (ICCP) to prevent corrosion of the hull shell by seawater.

 The column, which serves as a connection between the pontoon and the main deck, is divided into a plurality of columns to minimize the impact on the water by reducing the area of the water. Semi-submersible drilling rigs typically have four or six columns, and may have more columns.

The lower part of the inside of the column is used as a ballast tank as well as the pontoon, and the upper part is used as a tank for storing oil and the like required for drilling. There is also a brace that connects the pontoon to the pontoon, between the columns and columns, the pontoons and main decks to make semi-submersible rigs more robust.

As shown in FIG. 1, semi-submersible drill rigs are different from general submarines in that the submersible drill rigs can not be used for semi-submersible drill rigs.

Currently, DNV, Det Norske Veritas, and the American Bureau of Shipping (ABS) are required to obtain the number of seats by an approved method from a separate classification for offshore plants including semi-submersible drilling rigs. And the number of times that the number of people in the world can be counted.

The number of fittings stipulated by DNV is shown in Equation (1).

Where A is the amount of mold drainage for the load line and A is the projected area of all surfaces exposed to the wind above the light waterline when projected onto a mathematical plane with respect to the wind direction.

In this case, Δ ^2/3 means the area under pressure from seawater. FIG. 2 is a view showing a part where semi-submersible drilling rig receives pressure from seawater. In Fig. 2, the shaded portion represents the part where semi-submersible drilling rig receives pressure from seawater.

According to DNV, there is a problem that the semi-submersible drill ship is calculated to be larger than the area under pressure from seawater and wind, based on the load line and the light-water area based on the light water line when calculating the drainage amount. In addition, the formula for calculating the number of fittings prescribed by DNV is that the density and velocity of seawater and air are different, and this problem is not reflected.

Therefore, there is a need for a method to calculate the new design number reflecting the characteristics of semi-submersible drilling rigs.

It is an object of the present invention to provide a method of calculating the number of semi-submersible drill rigs reflecting semi-submersible drill ship characteristics and a method of determining the size of a mooring device using the calculated number of drill rigs.

According to an aspect of the present invention, there is provided a method of calculating a number of semi-submersible drill rigs, the method comprising: obtaining a projection cross-sectional area of a side of the semi-submersible drill ship below the waterline; Obtaining a projection cross-sectional area of the front surface of the semi-submersible drilling line below the waterline; Obtaining a projection cross-sectional area of the main deck of the semi-submersible drilling rig and the side surface of the main deck upper structure; Determining a projected cross-sectional area of the main deck of the semi-submersible drill rig and the main deck upper structure; And the projected cross-sectional area of the lower side of the waterline, the projected cross-sectional area of the front surface of the lower portion of the waterline, the projected cross-sectional area of the main deck and the side surface of the main deck upper structure, And calculating a number of designs, wherein the main deck superstructure is provided with a method of calculating a number of designs, excluding a truss structure.

Particularly, in the step of calculating the number of designs, a step of obtaining a first value by multiplying a maximum value of a projected cross-sectional area of a side surface below the waterline and a projection cross-sectional area of a front surface of the waterline by a first weight; A second value is obtained by multiplying a value obtained by multiplying the square of the projected cross-sectional area of the main deck and the main deck upper structure and the square of the projected cross-sectional area of the main deck and the main deck upper structure, step; And calculating the number of designs by summing the first value and the second value.

The first weight may be 1.5 or more and 2 or less.

The second weight may be 0.05 or more and 0.15 or less.

Calculating the number of pieces of equipment by multiplying the maximum cross-sectional area of the lower side of the waterline and the projected cross-sectional area of the lower side of the waterline by a first weight to obtain a first value; A second value is obtained by multiplying a value obtained by multiplying the square of the projected cross-sectional area of the main deck and the main deck upper structure and the square of the projected cross-sectional area of the main deck and the main deck upper structure, step; Multiplying the second value by a premium for the height to obtain a third value; And calculating the number of designs by summing the first value and the third value.

Further, the premium coefficient of the height may be 1.1 or more and 1.5 or less.

In addition, the waterline may be a light waterline.

In addition, the waterline may be a load line.

According to another aspect of the present invention, there is provided a method of calculating a number of semi-submersible drill rigs, the method comprising: obtaining a projection cross-sectional area of a side of the semi-submersible drill ship below the waterline; Obtaining a projection cross-sectional area of the front surface of the semi-submersible drilling line below the waterline; Obtaining a projection cross-sectional area of the main deck of the semi-submersible drilling rig and the side surface of the main deck upper structure; Determining a projected cross-sectional area of the main deck of the semi-submersible drill rig and the main deck upper structure; Obtaining a projected cross-sectional area of the side of the column above the water line of the semi-submersible drill ship; Obtaining a projected cross-sectional area of the front surface of the column above the water line of the semi-submersible drilling rig; Sectional area of the main deck and the main deck upper structure, a projection cross-sectional area of the main deck and the main deck upper structure, a projected cross-sectional area of the main deck and the main deck upper structure, Calculating the number of designs using the projection cross-sectional area of the side of the column of the main deck and the projection cross-sectional area of the front side of the column above the waterline, wherein the main deck upper structure is a method of calculating the number of designs / RTI >

Particularly, in the step of calculating the number of designs, a step of obtaining a first value by multiplying a maximum value of a projected cross-sectional area of a side surface below the waterline and a projection cross-sectional area of a front surface of the waterline by a first weight; A second value is obtained by multiplying a value obtained by multiplying the square of the projected cross-sectional area of the main deck and the main deck upper structure and the square of the projected cross-sectional area of the main deck and the main deck upper structure, step; The number of columns including the semi-submergible drill ship and the third weight, which is the sum of the square of the projected cross-sectional area of the side of the column above the waterline and the square of the projected cross-sectional area of the front side of the column above the waterline, To obtain a third value; And calculating the number of designs by summing the first value, the second value, and the third value.

The third weight may be 0.05 or more and 0.15 or less.

According to another aspect of the present invention, there is provided a method of determining a size of a semi-submersible drilling rig, comprising the steps of: obtaining a projected cross-sectional area of a side of a submergible drill ship below a waterline; Obtaining a projection cross-sectional area of the front surface of the semi-submersible drilling line below the waterline; Obtaining a projection cross-sectional area of the main deck of the semi-submersible drilling rig and the side surface of the main deck upper structure; Determining a projected cross-sectional area of the main deck of the semi-submersible drill rig and the main deck upper structure; The projected cross-sectional area of the lower side of the waterline, the projected cross-sectional area of the main deck and the main deck upper structure, and the projected cross-sectional area of the main deck and the main deck upper structure, Calculating a number; And determining the size of the mooring device using the number of pieces of equipment, wherein the main deck upper structure is excluded from the truss structure, and a method for determining the size of the mooring device is provided.

Particularly, in the step of calculating the number of designs, a step of obtaining a first value by multiplying a maximum value of a projected cross-sectional area of a side surface below the waterline and a projection cross-sectional area of a front surface of the waterline by a first weight; A second value is obtained by multiplying a value obtained by multiplying the square of the projected cross-sectional area of the main deck and the main deck upper structure and the square of the projected cross-sectional area of the main deck and the main deck upper structure, step; And calculating the number of designs by summing the first value and the second value.

The first weight may be 1.5 or more and 2 or less.

The second weight may be 0.05 or more and 0.15 or less.

Calculating the number of pieces of equipment by multiplying the maximum cross-sectional area of the lower side of the waterline and the projected cross-sectional area of the lower side of the waterline by a first weight to obtain a first value; A second value is obtained by multiplying a value obtained by multiplying the square of the projected cross-sectional area of the main deck and the main deck upper structure and the square of the projected cross-sectional area of the main deck and the main deck upper structure, step; Multiplying the second value by a premium for the height to obtain a third value; And calculating the number of designs by summing the first value and the third value.

In addition, the waterline may be a light waterline.

The mooring device may be an anchor and a chain cable.

According to another aspect of the present invention, there is provided a method of determining a size of a semi-submersible drilling rig, comprising the steps of: obtaining a projected cross-sectional area of a side of a submergible drill ship below a waterline; Obtaining a projection cross-sectional area of the front surface of the semi-submersible drilling line below the waterline; Obtaining a projection cross-sectional area of the main deck of the semi-submersible drilling rig and the side surface of the main deck upper structure; Determining a projected cross-sectional area of the main deck of the semi-submersible drill rig and the main deck upper structure; Obtaining a projected cross-sectional area of the side of the column above the water line of the semi-submersible drill ship; Obtaining a projected cross-sectional area of the front surface of the column above the water line of the semi-submersible drilling rig; A projection cross-sectional area of the main deck and the main deck upper structure, a projection cross-sectional area of the main deck and the main deck upper structure, a projected cross-sectional area of the main deck and the main deck upper structure, Calculating the number of designs using the projected cross-sectional area of the side of the column and the projected cross-sectional area of the front side of the column above the waterline; And determining the size of the mooring device using the number of pieces of equipment, wherein the main deck upper structure is excluded from the truss structure, and a method for determining the size of the mooring device is provided.

Particularly, in the step of calculating the number of designs, a step of obtaining a first value by multiplying a maximum value of a projected cross-sectional area of a side surface below the waterline and a projection cross-sectional area of a front surface of the waterline by a first weight; A second value is obtained by multiplying a value obtained by multiplying the square of the projected cross-sectional area of the main deck and the main deck upper structure and the square of the projected cross-sectional area of the main deck and the main deck upper structure, step; The number of columns including the semi-submergible drill ship and the third weight, which is the sum of the square of the projected cross-sectional area of the side of the column above the waterline and the square of the projected cross-sectional area of the front side of the column above the waterline, To obtain a third value; And calculating the number of designs by summing the first value, the second value, and the third value.

In particular, the third weight may be 0.05 or more and 0.15 or less.

The mooring device may be an anchor and a chain cable.

According to the embodiment of the present invention, the projection cross-sectional area of the lower side of the water line of semi-submersible drill rig, the projection cross-sectional area of the front lower side of the waterline, the projected cross sectional area of the main deck and the side surface of the main deck upper structure, The number of designs that can accurately reflect the pressure from the seawater and the wind can be obtained by calculating the number of designs using the projected cross-sectional area of the front side of the semi-submersible drilling rig.

By multiplying the area of the main deck and the main deck structure by the wind pressure, the height of the main deck and the main deck structure are multiplied by the premium of the height, the characteristics of the semi-submersible drill ship can be reflected in the number of designs.

1 is a view showing a semi-submersible drilling line.
FIG. 2 is a view showing a part where semi-submersible drilling rig receives pressure from seawater.
FIG. 3 is a flowchart illustrating a method of calculating the number of designs of semi-submersible drill rigs according to an embodiment of the present invention and a method of determining a size of a mooring device using the calculated number of designs.
4 is a diagram showing the projection sectional area of the side surface below the waterline of semi-submersible drilling rig.
5 is a diagram showing the projection sectional area of the front surface of the lower part of the water line of semi-submersible drilling rig.
6 is a view showing the projection cross-sectional area of the main deck and the side surface of the main deck upper structure.
7 is a view showing the projection sectional area of the main deck and the front surface of the main deck upper structure.
8 is a diagram showing the projection sectional area of the side of the columns above the water line of semi-submersible drilling rig.
9 is a view showing the projection sectional area of the front surface of the columns above the water line of semi-submersible drill ship.
10 is a view showing a projection sectional area of a side surface of the main deck upper truss structure.
11 is a view showing the projection sectional area of the front surface of the main deck upper truss structure.
12 is a bottom view of a semi-submersible drilling rig.
13 is a perspective view schematically showing the main deck.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In the embodiment of the present invention, a method of calculating the number of semi-submersible drill rigs reflecting the characteristics of semi-submersible drill rigs is proposed.

The Equipment Number is the means to maintain a constant position of the semi-submersible drilling rig from the effect of the seawater acting on the bottom of the semi-submersible drill ship and the wind acting on the semi-submersible drill ship when the semi-submersible drill ship is at anchor Is the number used to determine the weight and quantity of the anchors used and the length and diameter of the chains for the anchors and should be a value that reflects the area of the wind pressure acting on the shape of the semi- do.

Therefore, in the present invention, the number of designs is calculated by using the projection cross-sectional area of the side surface and the front surface of semi-submersible drilling rig. The projected cross-sectional area is the area when the three-dimensional shape is projected on the background plane as it is, and is actually the area of the connected figure of the outermost line. In recent years, semi-submersible drilling rigs are computer aided design (CAD), so accurate projected cross-sectional area can be obtained.

Now, a method for calculating the number of designs according to the embodiment of the present invention and a method for determining the size of the mooring device using the calculated number of designs will be described with reference to Figs. 3 to 10. Fig.

FIG. 3 is a flowchart illustrating a method of calculating the number of designs of semi-submersible drill rigs according to an embodiment of the present invention and a method of determining a size of a mooring device using the calculated number of designs.

First, the projected cross-sectional area of the side surface below the water line of semi-submersible drilling rig is obtained (S301). In this case, the lower side of the semi-submersible drill ship's side of the waterline means the side of the lower part of the semi-submersible drill ship's waterline, and the waterline may be the load line or the light waterline.

The line where the water surface meets the hull is called the load line, and the water line has the load line and the light water line.

The light waterline is a light line, ie a waterline in which the ship is not carrying items other than equipment and statutory equipment such as hull and machinery. The load line is the maximum limit that the ship can safely navigate with passengers and cargoes loaded with sufficient reserve buoyancy for the safety of navigation and the maximum permitted draft is called the full load draft (Full Draft, Load Draft) In no event shall the cargo be loaded in excess of this.

In the merchant ships requiring mooring with full cargo, the density of seawater is higher than the density of air. Therefore, the number of seats is determined on the basis of the load water line reporting that the pressure due to seawater affects the ship more than the pressure caused by wind. However, in the case of semi-submersible drilling rigs, it is not the purpose of loading cargoes, so the number of designs may be determined on the basis of the load line or light waterline.

Semi-submersible drilling rigs can be found on the basis of the light water line, because the most load-bearing condition is considered to be the lightest condition because the ballast tank is filled with wind when the wind is blowing and the ballast tank is emptied.

Alternatively, the number of designs may be determined on the basis of the light waterline, the number of designs may be determined on the basis of the load waterline, and a larger value may be determined as the number of designs.

4 is a diagram showing the projection sectional area of the side surface below the waterline of semi-submersible drilling rig. In FIG. 4, the hatched portion is the projected cross-sectional area of the side surface below the waterline of semi-submersible drilling rig. As shown in FIG. 4, in step S301, the projected cross-sectional area of the side of the lower part of the waterline of the semi-submersible drilling rig is obtained. That is, the area of the lower part of the waterline in the area when the side of the ship is projected in the background plane is obtained. This is because the projected cross-sectional area of the lower side of the water line of semi-submersible drill ship is an area subject to seawater pressure.

Next, the projected cross-sectional area of the front surface of the semi-submersible drilling line below the water line is obtained (S302). In this case, the front of the lower part of the water line of semi-submersible drill ship means the front part of the lower part of the water line of semi-submersible drill ship.

5 is a diagram showing the projection sectional area of the front surface of the lower part of the water line of semi-submersible drilling rig. In Fig. 5, the hatched portion is the projected cross-sectional area of the front surface below the waterline of semi-submersible drilling rig. As shown in FIG. 5, in step S302, the projected cross-sectional area of the front part of the lower part of the waterline of the semi-submersible drilling rig is obtained. That is, the area of the lower part of the waterline in the area when the front surface of the ship is directly projected on the background plane is obtained. This is because the projected cross-sectional area of the lower part of the water line of the semi-submersible drill ship is the area subject to the pressure of seawater.

Subsequently, the projection sectional area of the main deck 610 of the semi-submersible drilling rig and the side surfaces of the main deck upper structure 620 are obtained (S303), and the main deck 610 and the main deck upper structure 620 of the semi- Is obtained (S304).

The main deck 610 is a wide, flat floor located on top of the column 120 and is generally box shaped and equipped with various equipment required for drilling. The main deck upper structure 620 refers to a structure other than the truss structure 630 among the structures installed on the main deck 610. That is, it means a structure including a wall or a column among the structures installed above the main deck 610. The truss structure 630 refers to a structure in which a member such as a derrick, a crane, a helideck, or a main deck structure is connected to a member such as steel or wood. Because the truss structure receives wind pressure because the wind passes through it, it is excluded.

6 is a view showing the projection cross-sectional area of the main deck and the side surface of the main deck upper structure. In Fig. 6, hatched portions represent the projected sectional areas of the main deck and the side surfaces of the main deck upper structure. As shown in FIG. 6, in step S303, the area of the main deck of semi-submersible drilling rig and the side surface of the main deck upper structure are directly projected on the background plane.

7 is a view showing the projection sectional area of the main deck and the front surface of the main deck upper structure. In Fig. 7, hatched portions represent the projection cross-sectional area of the main deck and the front surface of the main deck upper structure. 7, in step S304, the area of the main deck of semi-submersible drill ship and the front surface of the main deck upper structure are directly projected on the background plane.

Next, the projection cross-sectional area of the side of the column above the water line of semi-submersible drilling rig is obtained (S305), and the projected cross-sectional area of the front side of the column above the water line of semi-submersible drilling rig is obtained (S306). In this case, the side of the column above the water line of the semi-submersible drill ship means the side of the column above the water line of semi-submersible drill ship, and the front of the column above the water line of semi-submersible drill ship means the column above the water line of semi-submersible drill ship. .

8 is a diagram showing the projection sectional area of the side of the columns above the water line of semi-submersible drilling rig. 8 shows the projected cross-sectional area of the side of the columns above the water line of semi-submersible drilling rig.

9 is a view showing the projection sectional area of the front surface of the columns above the water line of semi-submersible drill ship. 9 shows the projected cross-sectional area of the front surface of the columns above the water line of semi-submersible drilling rig.

In the embodiment of the present invention, assuming that the shapes of the columns are the same, the projection cross-sectional area of the upper side of the waterline and the projection cross-sectional area of the front side of the water line are obtained for one column. And multiplies the number of columns. However, when the shapes of the columns are different, the projection cross-sectional area of the upper side of the waterline and the projected cross-sectional area of the front face of the upper portion of the waterline are obtained for each of the plurality of columns, and the area where each of the plurality of columns receives the wind pressure is obtained It is possible.

Next, the projection cross-sectional area of the side of the main deck upper truss structure of semi-submersible drilling rig is obtained (S307), and the projected sectional area of the front side of the main deck upper truss structure of semi-submersible drilling rig is obtained (S308). At this time, the main deck upper truss structure 630 refers to the truss structure 630 among the structures installed on the main deck 610. The truss structure 630 refers to a structure in which a member such as a derrick, a crane, a helideck, or a main deck structure is connected to a member such as steel or wood. Since the truss structure receives a smaller wind pressure than a structure including a wall or a column because the wind passes through it, the projection sectional area is obtained separately from the main deck upper structure 620 to multiply the projection sectional area by a weight less than 1.

10 is a view showing a projection sectional area of a side surface of the main deck upper truss structure. In Fig. 10, the shaded portions represent the projection cross-sectional area of the side surface of the main deck upper truss structure. As shown in FIG. 10, in step S307, the area of the largest contour line of the main deck upper truss structure of semi-submersible drilling rig is projected on the background plane.

11 is a view showing the projection sectional area of the front surface of the main deck upper truss structure. In Fig. 11, the hatched portion represents the projection sectional area of the front surface of the main deck upper truss structure. As shown in FIG. 11, in step S308, the area of the largest contour line of the main deck upper truss structure of semi-submersible drilling rig is directly projected on the background plane.

Next, the area of the bottom of semi-submersible drilling rig is obtained (S309). 12 is a bottom view of a semi-submersible drilling rig. In Fig. 12, the hatched portion represents the area of the bottom surface of semi-submersible drilling ship. Semi-submersible drill rigs are flat on the bottom, so friction is generated as the current flows through the bottom. Therefore, the area of the bottom surface can be taken into account in calculating the number of designs to reflect the friction between the bottom of semi-submersible drilling rig and the ocean current.

The projected cross-sectional area of the lower side of the waterline, the projected cross-sectional area of the main deck and the main deck upper structure, the projected cross-sectional area of the main deck and the main deck upper structure, The projected sectional area of the main deck upper truss structure, the projected sectional area of the main deck upper truss structure, the projected sectional area of the front side of the main deck upper truss structure, and the bottom area, (S309).

In the embodiment of the present invention, four methods for calculating the number of designs are proposed.

The first method uses the projected cross-sectional area of the lower side of the waterline, the projected cross-sectional area of the main deck and the upper deck of the main deck structure, the projected cross-sectional area of the main deck and the main deck upper structure, . Equation (2) represents the number of designs according to the first method proposed in the embodiment of the present invention.

Here, Max (x, y) represents the maximum value of x and y. S _{l and profile} represent the projected cross-sectional area of the lower side of the waterline, S _{l and section} represent the projected cross-sectional area of the lower front of the waterline, S _{m and profile} represent the projected cross-sectional area of the sides of the main deck and main deck structure S _{m , section} represents the projected cross-sectional area of the main deck and the main deck superstructure.

W ₁ is the weight of the projected cross-sectional area of the lower side of the waterline and the projected cross-sectional area of the lower portion of the waterline, and W ₂ is the weight of the main deck and the main deck structure.

In Equation (2), the projected cross-sectional area of the lower side of the water line of the semi-submersible drill ship and the projected cross-sectional area of the lower portion of the water line of the semi-submersible drill ship are to be reflected in the design number, The projected cross-sectional area of the lower side of the waterline or the projected cross-sectional area of the lower front of the waterline of the semi-submersible drill ship may be the area under pressure from the seawater. To reflect on the number of designs.

13 is a perspective view schematically showing the main deck. Semi-submersible drilling rigs are anchored at each of the multiple columns during mooring, so they are fixed without turning unlike marine vessels. Thus, as shown in FIG. 13, when the wind blows perpendicularly to the diagonal plane of the main deck, semi-submersible drill ships receive the wind pressure the most, and the area subjected to wind pressure is the main deck for the diagonal of the main deck, The projected cross-sectional area of the structure. The projected cross-sectional area of the main deck and main deck superstructure for the diagonal of the main deck is (S _{m , profile} ² ₊ S _{m , section} ² ) ^1/2 according to Pythagorean theorem.

In the equation (2), W ₁ may be a value in a range of 1.5 or more and 2 or less, and W ₂ may be a value in a range of 0.05 or more and 0.15 or less. This is because the pressure due to seawater and the pressure due to wind are multiplied by the weights because they are different in size.

Then, the premium of the height can be multiplied by W ₂ (S _{m , profile} ² ₊ S _{m , section} ² ) ^1/2 . The wind gets faster as it goes up from the sea level, and the wind pressure is also deteriorated accordingly. However, since the height of the normal merchant vessel is not high, it is not necessary to consider the premium coefficient of height. However, the semi-submersible vessel has higher height than the normal merchant vessel, so the main deck and main deck superstructure have higher wind pressure. Therefore, the coefficient of the high premium to ₂ W (S _m, S _{m +} ² _{profile, section} ^{2) 1/2} to reflect that the wind pressure is semi-submersible drill ships receiving sensor according to the half-height of the submersible rig High You can multiply it. The premium coefficient of height may be a value in the range of 1.1 to 1.5.

In the second method, the projected cross-sectional area of the lower side of the waterline, the projected cross-sectional area of the front of the main deck and the main deck upper structure, the projected cross-sectional area of the main deck and the main deck upper structure, And the projected sectional area of the front surface of the column above the waterline is used to calculate the number of designs. Equation (3) represents the number of designs according to the second method proposed in the embodiment of the present invention.

Here, Max (x, y) represents the maximum value of x and y. S _{l and profile} represent the projected cross-sectional area of the lower side of the waterline, S _{l and section} represent the projected cross-sectional area of the lower front of the waterline, S _{m and profile} represent the projected cross-sectional area of the sides of the main deck and main deck structure represents, S _{m, section} represents the projection cross-sectional area of the front surface of the main deck and the main deck superstructure, S _{c, profile} represents the projection cross-sectional area of the water line top column side, S _{c, section} is a front view of the water line upper column And N represents the number of columns.

W ₁ represents the weight of the maximum value of the projection cross-sectional area of the projection cross-sectional area and the water line of the lower front side of the water line lower side, W ₂ denotes the weight of the area of the main deck and the main deck superstructure receiving wind pressure, W ₃ Represents the weight of the area above the waterline where the columns are subjected to wind pressure.

In principle, as described for the main deck and main deck superstructure in equation (2), when the wind blows perpendicularly to the diagonal of the main deck, that is, when the wind blows perpendicularly to the diagonal of the column, The area that receives the most pressure, at this time, becomes the projected cross-sectional area of the column relative to the diagonal of the column. Projecting the cross-sectional area of the column to the diagonal of the column is in accordance with ^{_{(S c, profile 2 + S}} c, section 2) 1/2 the Pythagorean theorem, the area of the N columns of the wind pressure is received N (S _{c, profile} ² ₊ S _{c , section} ² ) ^1/2 .

In the formula (3), W ₁ may be a value in the range of 1.5 or more and 2 or less, W ₂ may be a value in the range of 0.05 or more and 0.15 or less, and W ₃ may be a value in the range of 0.05 or more and 0.15 or less.

Then, the premium of the height can be multiplied by W ₂ (S _{m , profile} ² ₊ S _{m , section} ² ) ^1/2 . The premium coefficient of height may be a value in the range of 1.1 to 1.5.

The third method is to calculate the cross sectional area of the lower side of the waterline, the projected cross sectional area of the front side of the lower part of the water line, the projected cross sectional area of the main deck and the main deck upper structure, The projected sectional area of the side surface of the structure and the projected sectional area of the front surface of the main deck upper truss structure. Equation (4) represents the number of designs according to the third method proposed in the embodiment of the present invention.

Here, Max (x, y) represents the maximum value of x and y. S _{l and profile} represent the projected cross-sectional area of the lower side of the waterline, S _{l and section} represent the projected cross-sectional area of the lower front of the waterline, S _{m and profile} represent the projected cross-sectional area of the sides of the main deck and main deck structure represents, S _{m, section} is the main deck and the main deck represents the projection cross-sectional area of the front of the superstructure, S _{t, profile} includes a main deck represents the projection cross-sectional area of the side of the upper truss structure, S _{t, section} is the main deck, the upper truss structure Sectional area of the front surface.

W ₁ represents the weight of the maximum value of the projection cross-sectional area of the projection cross-sectional area and the water line of the lower front side of the water line lower side, W ₂ denotes the weight of the area of the main deck and the main deck superstructure receiving wind pressure, W ₄ Represents the weight of the area where the main deck upper truss structure receives wind pressure.

In principle, as described for the main deck and the main deck superstructure in equation (2), when the wind blows perpendicularly to the diagonal of the main deck, the main deck upper truss structure receives the most wind pressure, This is the projected cross-sectional area of the main deck upper truss structure with respect to the diagonal of the main deck. The projected cross-sectional area of the main deck upper truss structure with respect to the diagonal of the main deck is (S _{t, profile} ² ₊ S _{t , section} ² ) ^1/2 according to Pythagorean theorem.

In Equation (4), W ₁ may be a value in a range of 1.5 or more and 2 or less, and W ₂ may be a value in a range of 0.05 or more and 0.15 or less. And W ₄ can be aW ₂ when a is a value in the range of more than 0 and less than 1. Since the truss structure receives wind pressure less than the wall or column structure due to the passage of wind, the weight of the main deck upper truss structure subjected to the wind pressure is larger than the weight of the main deck and main deck upper structure So as to have a smaller value than the weighting value.

Then, the premium of the height can be multiplied by W ₂ (S _{m , profile} ² ₊ S _{m , section} ² ) ^1/2 . The premium coefficient of height may be a value in the range of 1.1 to 1.5.

The fourth method is a method in which the projected cross-sectional area of the lower side of the waterline, the projected cross-sectional area of the main deck and the main deck upper structure, the projected cross-sectional area of the main deck and the main deck upper structure, This is a method of calculating the number of designs using the projected cross-sectional area of the front surface of the structure. Equation (5) represents the number of designs according to the fourth method proposed in the embodiment of the present invention.

Here, Max (x, y) represents the maximum value of x and y. S _{l and profile} represent the projected cross-sectional area of the lower side of the waterline, S _{l and section} represent the projected cross-sectional area of the lower front of the waterline, S _{m and profile} represent the projected cross-sectional area of the sides of the main deck and main deck structure S _{m , section} is the projected cross-sectional area of the main deck and the main deck superstructure, and S _base is the area of the bottom surface.

W ₁ represents the weight of the maximum value of the projection cross-sectional area of the projection cross-sectional area and the water line of the lower front side of the water line lower side, W ₂ denotes the weight of the area of the main deck and the main deck superstructure receiving wind pressure, W ₅ Represents the weight for the area of the bottom surface.

In Equation (5), W ₁ may be a value in a range of 1.5 or more and 2 or less, and W ₂ may be a value in a range of 0.05 or more and 0.15 or less. Since the friction force is smaller than the resistance due to seawater, W ₅ can have a relatively small value. For example, W ₅ may be a value ranging from 0.05 to 0.15.

Then, the premium of the height can be multiplied by W ₂ (S _{m , profile} ² ₊ S _{m , section} ² ) ^1/2 . The premium coefficient of height may be a value in the range of 1.1 to 1.5.

Referring again to FIG. 3, the size of the mooring device is determined using the calculated number of fittings (S311).

The mooring device may be a chain for anchors and anchors. The number and mass of the anchors, the length and diameter of the chains for the anchors, etc., may be predetermined for a specific number of designs. Then, after calculating the number of designs, the size of the mooring device is determined by the number and mass of anchors previously determined for the number of pieces of equipment calculated, the length and diameter of anchor chains, and the like.

Alternatively, the mooring device may be a wire for an anchor and an anchor. That is, an anchor wire may be used instead of the anchor chain.

Table 1 shows the part of the table showing the number and mass of bow anchors and the length and diameter of chain cables according to the number of fittings defined by DNV.

Number of Chairmen Design symbol Player anchor Chain cable Over Below Number Mass per anchor (kg) Total length
(m) diameter KV R3 or K3 KV R3S KV R4 KV R4S KV R5 720
780
840 780
840
910 S
T
U 2
2
2 2280
2460
2640 467.5
467.5
467.5 36
38
40 910
980
1060 980
1060
1140 V
W
X 2
2
2 2850
3060
3300 495
495
495 42
44
46

For example, if the number of fittings is 730, two 2280 kg athletes are used for the player anchor, and the length of the chain cable is 467.5 m.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (22)

CLAIMS 1. A method for calculating a number of semi-submersible rigs by a computer system,
Obtaining a projected cross-sectional area of a side of the semi-submersible drilling rig below the waterline;
Obtaining a projection cross-sectional area of the front surface of the semi-submersible drilling line below the waterline;
Obtaining a projection cross-sectional area of the main deck of the semi-submersible drilling rig and the side surface of the main deck upper structure;
Determining a projected cross-sectional area of the main deck of the semi-submersible drill rig and the main deck upper structure; And
The projected cross-sectional area of the lower side of the waterline, the projected cross-sectional area of the main deck and the main deck upper structure, and the projected cross-sectional area of the main deck and the main deck upper structure, Calculating a number,
The main deck upper structure, except for the truss structure,
The step of calculating the number of designs
Calculating a first value by multiplying a maximum of a projected cross-sectional area of a lower side of the waterline and a projected cross-sectional area of a front surface of the lower portion of the waterline by a first weight;
A second value is obtained by multiplying a value obtained by multiplying the square of the projected cross-sectional area of the main deck and the main deck upper structure and the square of the projected cross-sectional area of the main deck and the main deck upper structure, step;
Multiplying the second value by a premium for the height to obtain a third value; And
And summing the first value and the third value to calculate a number of designs. delete The method according to claim 1,
Wherein the first weight is 1.5 or more and 2 or less. The method according to claim 1,
Wherein the second weight is greater than or equal to 0.05 and less than or equal to 0.15. delete The method according to claim 1,
Wherein the premium coefficient of the height is not less than 1.1 and not more than 1.5. The method according to any one of claims 1, 3, 4, and 6,
Wherein said waterline is a light waterline. The method according to any one of claims 1, 3, 4, and 6,
Wherein said waterline is a load line. delete delete delete A method for determining the size of a mooring device of semi-submersible drilling rig by a computer system,
Obtaining a projected cross-sectional area of a side of the semi-submersible drilling rig below the waterline;
Obtaining a projection cross-sectional area of the front surface of the semi-submersible drilling line below the waterline;
Obtaining a projection cross-sectional area of the main deck of the semi-submersible drilling rig and the side surface of the main deck upper structure;
Determining a projected cross-sectional area of the main deck of the semi-submersible drill rig and the main deck upper structure;
The projected cross-sectional area of the lower side of the waterline, the projected cross-sectional area of the main deck and the main deck upper structure, and the projected cross-sectional area of the main deck and the main deck upper structure, Calculating a number; And
And determining the size of the mooring device using the number of pieces of equipment,
The main deck upper structure, except for the truss structure,
The step of calculating the number of designs
Calculating a first value by multiplying a maximum of a projected cross-sectional area of a lower side of the waterline and a projected cross-sectional area of a front surface of the lower portion of the waterline by a first weight;
A second value is obtained by multiplying a value obtained by multiplying the square of the projected cross-sectional area of the main deck and the main deck upper structure and the square of the projected cross-sectional area of the main deck and the main deck upper structure, step;
Multiplying the second value by a premium for the height to obtain a third value; And
And summing the first value and the third value to calculate a number of designs. delete The method of claim 12,
Wherein the first weight is greater than or equal to 1.5 and less than or equal to 2. The method of claim 12,
Wherein the second weight is greater than or equal to 0.05 and less than or equal to 0.15. delete The method according to any one of claims 12, 14 and 15,
Wherein said waterline is a light waterline. The method according to any one of claims 12, 14 and 15,
Wherein the mooring device is an anchor and a chain cable. A method for determining the size of a mooring device of semi-submersible drilling rig by a computer system,
Obtaining a projected cross-sectional area of a side of the semi-submersible drilling rig below the waterline;
Obtaining a projection cross-sectional area of the front surface of the semi-submersible drilling line below the waterline;
Obtaining a projection cross-sectional area of the main deck of the semi-submersible drilling rig and the side surface of the main deck upper structure;
Determining a projected cross-sectional area of the main deck of the semi-submersible drill rig and the main deck upper structure;
Obtaining a projected cross-sectional area of the side of the column above the water line of the semi-submersible drill ship;
Obtaining a projected cross-sectional area of the front surface of the column above the water line of the semi-submersible drilling rig;
A projection cross-sectional area of the main deck and the main deck upper structure, a projection cross-sectional area of the main deck and the main deck upper structure, a projected cross-sectional area of the main deck and the main deck upper structure, Calculating the number of designs using the projected cross-sectional area of the side of the column and the projected cross-sectional area of the front side of the column above the waterline; And
And determining the size of the mooring device using the number of pieces of equipment,
The main deck upper structure, except for the truss structure,
The step of calculating the number of designs
Calculating a first value by multiplying a maximum of a projected cross-sectional area of a lower side of the waterline and a projected cross-sectional area of a front surface of the lower portion of the waterline by a first weight;
A second value is obtained by multiplying a value obtained by multiplying the square of the projected cross-sectional area of the main deck and the main deck upper structure and the square of the projected cross-sectional area of the main deck and the main deck upper structure, step;
The number of columns including the semi-submergible drill ship and the third weight, which is the sum of the square of the projected cross-sectional area of the side of the column above the waterline and the square of the projected cross-sectional area of the front side of the column above the waterline, To obtain a third value; And
And summing the first value, the second value and the third value to calculate a number of designs. delete The method of claim 19,
Wherein the third weight is 0.05 to 0.15. The method according to claim 19 or 21,
Wherein the mooring device is an anchor and a chain cable.

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