CN109881670B - Submarine self-disposable recyclable pile shoe of jack-up drilling platform and drilling platform - Google Patents

Abstract

The invention discloses a submarine self-recoverable jack-up drilling platform pile shoe and a drilling platform, wherein the submarine self-recoverable jack-up drilling platform pile shoe comprises a pile shoe body (1) and a pile shoe (2), the pile shoe body (1) and the pile shoe (2) are arranged up and down, the pile shoe (2) consists of a plurality of pile shoe small blocks (211) arranged along the circumferential direction, and the pile shoe body (1) can move upwards and be separated from the pile shoe (2). This seabed is from recoverable jack-up drilling platform pile shoe under the difficult circumstances of operation when platform pile pulling is evacuated, can carry out the tripping operation under water at any time, make things convenient for platform pile pulling operation to the pile shoe after the tripping, follow-up can carry out independent recovery operation, the pile shoe can decompose into a plurality of independent small blocks, very big reduction the degree of difficulty of recovery operation, avoided the pile shoe of tripping to cause adverse effect to follow-up pile inserting operation, make the seafloor soil resume the original appearance in the maximum.

Description

A seabed self-abandonment and recyclable self-elevating drilling platform spud shoe and drilling platform

Technical field

The invention relates to the field of offshore oil and gas field development equipment, specifically a self-abandonment and recyclable self-elevating drilling platform spud shoe on the seabed, and a drilling platform.

Background technique

As the country puts forward instructions to increase the exploration and development of oil and gas resources, major oil companies have gradually increased the exploration and development of my country's onshore and offshore oil and gas blocks to ensure national energy security. Oil and gas exploration and development in shallow ocean areas are inseparable from the operational support of offshore jack-up drilling platforms. The pile insertion and pile extraction operations of jack-up drilling platforms are two extremely critical links in their offshore operations. The safety of the platform during pile insertion operations is closely related to the load-bearing capacity of the lower soil, and the load-bearing capacity of the upper platform is directly related to the properties of the soil and the size of the platform spud boots. A larger spud shoe size can Ensure a large stress-bearing area, so that the soil can provide a strong bearing capacity to ensure the safety of the platform's operations. At the same time, the depth of the pile legs entering the mud is relatively smaller; during pile pulling operations, the difficulty of the platform's operation depends on the parameters of the underlying soil. There is a close relationship between the self-weight of the pile legs and the depth of the pile legs entering the mud. The smaller self-weight of the pile legs and the smaller depth of the pile legs entering the mud can ensure relatively smaller resistance to pulling out piles, making it easier for the platform to perform pile pulling operations. However, in the actual operation process, safe pile insertion and smooth pile extraction on the platform are two goals that are difficult to achieve at the same time. Due to soil quality, in most cases the pile legs need to be penetrated deeper into the mud to ensure a strong bearing capacity, and the deeper depth into the mud causes greater resistance to pulling out the piles, making it difficult to pull out the piles.

Chinese patent CN 206986884U, published on February 9, 2018, discloses "A detachable spud shoe suitable for truss-type pile legs", which increases the maximum cross-sectional area of the original spud shoe through bolted ring blocks. The load-bearing capacity of the spud shoe is increased, and the rapid mud entry effect of the spud shoe is enhanced by increasing the height of the pile tip. However, the bolts between the ring block and the main body of the detachable spud shoe bear shear strength, and the overall stability is relatively poor. .

Contents of the invention

In order to solve the problem of poor stability of the existing detachable spud shoes, the present invention provides a seabed self-abandoning and recyclable self-elevating drilling platform spud shoe and a drilling platform. The seabed self-abandoning and recyclable self-elevating drilling platform spud shoe When it is difficult to pull out piles on the platform and evacuate them, underwater relief can be carried out at any time to facilitate the platform pile pulling operation. After the pile boots are freed, subsequent separate recovery operations can be carried out. The pile shoes can be decomposed into multiple independent small pieces. The whole body greatly reduces the difficulty of recovery operations, avoids the adverse effects of freed pile shoes on subsequent pile insertion operations, and restores the seabed soil to its original appearance to the greatest extent. At the same time, after the combination of this pile shoe and the original pile shoe, the height of the pile tip of the pile shoe is increased, making the pile shoe less difficult to drive into the harder seabed soil layer, and the operation efficiency is higher, and because the pile The overall size of the tip is relatively larger, and it is more indestructible and more stable.

The technical solution adopted by the present invention to solve the technical problem is: a seabed self-abandonment and recyclable self-elevating drilling platform spud shoe, which includes a spud shoe body and a spud shoe. The center line of the spud shoe body and the center line of the spud shoe are both In the upright state, the spud boot body and the spud shoe are arranged up and down, and the spud boot body can move upward and separate from the spud shoe; the spud boot body has a block structure, and the longitudinal section of the spud boot body is octagonal. The top surface, upper slope, outer peripheral surface, lower slope and bottom surface are connected in sequence; the pile shoe is composed of a plurality of small pieces of pile shoes arranged along the circumferential direction. The lower surface of the pile shoe is a cone-shaped structure with the top facing downward. There is a plug-in groove in the upper end of the shoe. Along the diameter direction of the pile shoe, the longitudinal section of the pile shoe contains an inner core section and an outer ring section. The inner side of the upper end of the outer ring section is the plug groove. The inner peripheral surface; the lower part of the pile shoe body is matched and inserted into the insertion groove.

The top surface is parallel to the bottom surface. The lower surface of the spud shoe is an enlargement of the lower slope and bottom surface of the spud shoe body. The center line of the spud shoe body is perpendicular to the top surface. The diameter of the upper end of the outer peripheral surface is the same as the diameter of the lower end of the outer peripheral surface. The inner core section The longitudinal section is octagonal, and the longitudinal section of the outer ring section is trapezoidal.

The spud shoe body and the spud shoe are detachably connected through a plurality of pins. The plurality of pins are evenly spaced along the circumference of the spud shoe. The outer circumferential surface of the spud shoe body is provided with pin insertion holes, and the upper end of the outer ring section is provided with pins. Install through holes.

When the depth of the pile legs entering the mud is predicted to be small and the pile shoes do not need to be released for pile pulling operations;

The formula for calculating the number of pins is:

When it is predicted that the depth of the pile legs entering the mud is relatively deep and the pile shoes need to be released during pile pulling operations;

The formula for calculating the number of pins is:

L is the number of pins, the unit is units, rounded to an integer;

W is the gravity of the pile shoe, the unit is N;

F is the adsorption force of the soil on the pile shoes, the unit is N;

F _s is the soil shear force exerted by the pile shoe, the unit is N;

F _r is the soil friction force on the pile shoe, the unit is N;

N is the shear strength of the pin, in N/m ² ;

D is the diameter of the pin, in m;

n is the safety factor, unitless, and its value is greater than or equal to 1.5.

The upper end surface of the small block of the pile shoe is provided with a recovery cable that can pull the small block of the pile shoe. Along the circumferential direction of the pile shoe, one side of the small block of the pile shoe is provided with a groove, and the other side of the small block of the pile shoe is provided with a groove. Protrusions are provided, and two adjacent pile shoe small blocks are plugged and fixed through the protrusions and grooves.

The self-abandonment and recyclable self-elevating drilling platform spud shoes on the seabed also include a plurality of traction ropes, the number of traction ropes is the same as the number of pins, and the lower ends of the traction ropes are connected and fixed in one-to-one correspondence with the outer ends of the pins.

The seabed self-abandonment and recyclable self-elevating drilling platform spud shoe also includes a straight pipe and a plurality of inclined pipes. The number of inclined pipes is the same as the number of pins. The upper end of the inclined pipe is connected to the lower end of the straight pipe. The lower end of the inclined pipe is connected to the lower end of the straight pipe. Corresponding to the outer ends of the pins, the traction rope is set in the straight tube and the inclined tube.

The lower end of the inclined tube is located above the outer end of the pin. There is an end fixed pulley outside the lower end of the inclined tube. The traction rope is connected to the end fixed pulley. Along the diameter direction of the spud shoe body, the distance from the end fixed pulley to the outer end of the pin is greater than the pin. length.

The self-abandonment and recyclable self-elevating drilling platform spud boots on the seabed also include an upright truss, a straight pipe is set in the truss, a plurality of fixed pulleys in the pipe are provided in the inclined pipe, the upper end of the truss is provided with a top fixed pulley, and the traction rope is connected to the truss. The fixed pulley inside the pipe is connected to the fixed pulley at the top, the inclined pipe is connected and fixed to the spud shoe body through a support rod, and the straight pipe is connected and fixed to the truss through a support rod.

A drilling platform, the bottom of which is provided with the above-mentioned seabed self-abandonment and recyclable jack-up drilling platform spud shoe.

The beneficial effects of the present invention are: the seabed self-abandonment and recyclable self-elevating drilling platform spud boots can be detached underwater at any time when it is difficult to pull out piles and evacuate the platform, which facilitates the platform piling operations, and also provides good protection for the piles after detachment. The boots can be recycled separately in the future. The pile shoes can be decomposed into multiple independent small pieces, which greatly reduces the difficulty of the recycling operation and avoids the adverse effects of the freed pile shoes on the subsequent pile insertion operations, causing the seabed soil to be damaged. Restore the original appearance to the greatest extent possible. At the same time, after the combination of this pile shoe and the original pile shoe, the height of the pile tip of the pile shoe is increased, making the pile shoe less difficult to drive into the harder seabed soil layer, and the operation efficiency is higher, and because the pile The overall size of the tip is relatively larger, and it is more indestructible and more stable.

Description of the drawings

The description and drawings that constitute a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

Figure 1 is a schematic diagram of the spud shoe of the self-abandonment and recyclable self-elevating drilling platform on the seabed according to the present invention.

Figure 2 is a schematic diagram of the diameter relationship between the spud shoe body and the spud shoe.

Figure 3 is a schematic longitudinal section of the spud shoe body.

Figure 4 is a schematic longitudinal section of the pile shoe.

Figure 5 is a schematic three-dimensional view of the small block of the pile shoe.

Figure 6 is a schematic diagram of the connection and cooperation of the small pieces of the pile shoe in the pile shoe.

Figure 7 is a schematic diagram of the lower end of the inclined tube.

1. Pile shoe body; 2. Pile shoe; 3. Pin; 4. Self-abandonment module; 5. Truss;

11. Top surface; 12. Upper slope; 13. Peripheral surface; 14. Lower slope; 15. Bottom surface;

21. Inner core section; 22. Outer ring section; 23. Inner side; 24. Insertion groove; 25. Lower surface; 26. Outer side;

41. Inclined tube; 42. Fixed pulley inside the tube; 43. Traction rope; 44. Support rod; 45. Straight tube; 46. Top fixed pulley; 47. End fixed pulley;

211. Small piece of pile shoe; 212. Groove; 213. Recovery cable; 214. Bump;

221. The first small piece of pile shoe; 222. The small piece of the second pile shoe; 223. The small piece of the third pile shoe; 224. The small piece of the fourth pile shoe; 225. The fifth pile Small piece of shoe; 226. The sixth small piece of pile shoe.

Detailed ways

It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

A self-abandonment and recyclable self-elevating drilling platform spud shoe on the seabed, including a spud shoe body 1 and a spud shoe 2. The center lines of the spud shoe body 1 and the spud shoe 2 are both in an upright state. The spud shoe body 1 and the pile shoe are Shoes 2 are stacked up and down, and the spud boot body 1 can move upward and separate from the spud shoe 2; the spud boot body 1 has a block structure, and the longitudinal section of the spud boot body 1 is an octagon. The top surface 11, the upper slope 12, the outer peripheral surface 13, the lower slope 14 and the bottom surface 15 are connected in sequence; the pile shoe 2 is a flat structure, and the pile shoe 2 is composed of a plurality of pile shoe small pieces 211 arranged along the circumferential direction. The lower surface 25 of the pile shoe 2 is a conical structure with the top facing downward. The upper end of the pile shoe 2 is provided with a plug-in groove 24. Along the diameter direction of the pile shoe 2, the longitudinal section of the pile shoe 2 contains an inner core section. 21 and the outer ring section 22, the inner side 23 of the upper end of the outer ring section 22 is the inner peripheral surface of the insertion groove 24; the lower part of the spud shoe body 1 is matched and inserted into the insertion groove 24 (i.e. the spud shoe The surface of the insertion part of the body 1 completely fits the inner surface of the insertion groove 24), as shown in Figures 1 to 7.

In this embodiment, the center line of the pile shoe body 1 coincides with the center line of the pile shoe 2. The longitudinal section of the pile shoe body 1 is octagonal. The top view of the pile shoe body 1 is circular or square. The pile shoe body 1 is The metal block body 1 has the largest diameter at the outer peripheral surface 13 . The pile shoe 2 is circular or square in plan view, and has a flat block structure. The pile shoe 2 can be a hollow structure or a solid structure. When the pile shoe 2 is a hollow structure, the pile shoe 2 can be made of steel; when the pile shoe 2 is a solid structure, the pile shoe 2 can be made of concrete.

In this embodiment, the top surface 11 and the bottom surface 15 are parallel to each other, and the bottom surface 15 is parallel to the horizontal plane. The center line of the spud shoe body 1 is perpendicular to the top surface 11 . The diameter of the upper end of the outer peripheral surface 13 is the same as the diameter of the lower end of the outer peripheral surface 13 . The diameter of the surface 13 is the same as the diameter of the inner side 23 of the outer ring section 22 (i.e. the inner peripheral surface of the insertion groove 24), both are d1, the diameter of the outer side 26 of the outer ring section 22 is d2, and the pile shoe 2 is on the outer side. The diameter at 26 is the largest, and d2 is larger than d1. The inner core section 21 has an octagonal longitudinal section, and the outer ring section 22 has a trapezoidal longitudinal section. The upper slope 12 and the upper surface of the outer ring section 22 are located in the same conical plane.

In this embodiment, the lower surface 25 of the spud shoe 2 is an enlargement of the lower slope 14 and the bottom surface 15 of the spud shoe body 1. In this way, the height of the pile tip of the spud shoe as a whole increases from the original h1 to the current h2, thereby making the platform The pile boots are easier to penetrate into the mud, making the descent process smoother and faster, as shown in Figure 1.

In this embodiment, the spud shoe body 1 and the spud shoe 2 are detachably connected through a plurality of pins 3. The plurality of pins 3 are evenly spaced along the circumferential direction of the spud shoe 2. Pins are provided in the outer peripheral surface 13 of the spud shoe body 1. As for the insertion hole, the upper end of the outer ring section 22 is provided with a pin mounting through hole, and the pin insertion hole corresponds to the position of the pin mounting through hole one by one. The pin 3 passes through the pin installation through hole, the inner end of the pin 3 is located in the pin insertion hole of the pile shoe body 1, and the outer end of the pin 3 is located outside the pile shoe 2. The pin 3 is transitionally matched with the pin insertion hole on the pile shoe body 1, and the pin 3 is clearance matched with the pin installation through hole on the outer ring section 22.

In this embodiment, the number of pins 3 is calculated using the following calculation formula:

When it is predicted that the depth of the pile legs entering the mud is small (it can be understood as the current depth of the platform entering the mud, when the pile pulling is completed and the platform is evacuated in the later stage, the platform can smoothly carry out the pile pulling operation, that is, there will be no difficulty in pulling out the piles on the platform), And the pile pulling operation does not require the pile shoe to be released for 2 hours;

The formula for calculating the number of pins 3 is:

When it is predicted that the depth of the pile legs entering the mud is relatively deep (it can be understood that the depth of the current platform entering the mud is relatively large, causing the platform to pull out the piles later, due to the limited pile pulling ability of the platform, the platform cannot smoothly pull out the piles and evacuate. The platform's pile pulling ability is different from the The draft capacity of the platform is related to the properties of the seabed soil, platform parameters, pile driving capacity of the pile shoes, the weight of the platform itself, etc.), and the pile shoes need to be released for 2 hours during pile pulling operations;

The formula for calculating the number of pins 3 is:

L is the number of pins 3, the unit is units, rounded to an integer;

W is the gravity of pile shoe 2, the unit is N;

F is the adsorption force of the soil on the pile shoe 2, the unit is N;

F _s is the soil shear force exerted by pile shoe 2, the unit is N;

F _r is the soil friction force on the pile shoe 2, the unit is N;

N is the shear strength of pin 3, the unit is N/m ² ;

D is the diameter of pin 3, the unit is m;

n is the safety factor, unitless, and its value is greater than or equal to 1.5.

Among them, the specific calculation methods of F, F _s and F _r can refer to API specifications and existing calculation methods, such as the monograph "Control Technology of Piling Operation of Jack-up Drilling Platform - Jiang Wei, Wang Shunwen, Yang Jin, Liu Shujie" The calculation part of the pile pullout resistance in the journal "Numerical calculation method for predicting the pile pullout resistance of jack-up drilling platform - Duan Menglan, Zhang Aixia, Wang Jianjun, Song Linsong" calculates the pile pullout resistance.

A plurality of evenly spaced pins 3 are inserted into the pin holes reserved on the pile shoe body 1 and the pile shoes 2, and play a longitudinal limiting role for the pile shoe body 1 and the pile shoes 2: during the process of lowering the platform pile legs. , the multiple pins are mainly used to bear the gravity of the pile shoe 2; when the platform is evacuated and the pile is pulled out and the pile shoe 2 does not need to be released, the multiple pins 3 are mainly used to bear the gravity of the pile shoe 2, the soil adsorption force on the pile shoe, and the pile The soil shear force on the pile shoe, the soil friction force on the pile shoe and other forces; because the pile shoe 2 is circumscribed on the outside of the pile shoe body 1, it limits the horizontal direction of the pile shoe body 1. The role of bits.

In this embodiment, the pile shoe 2 is composed of a plurality of pile shoe small blocks 211 arranged along the circumferential direction of the pile shoe 2. Each pile shoe small block 211 contains at least one of the above-mentioned pin mounting through holes. The upper end surface of the small block 211 is provided with a recovery cable 213 that can pull the small block 211 of the pile shoe. Along the circumferential direction of the pile shoe 2, a groove 212 is provided on one side of the small block 211 of the pile shoe. The lower end of the groove 212 It is connected with the lower surface of the pile shoe small block 211, that is, the lower end of the groove 212 forms a gap. The other side of the pile shoe small block 211 is provided with a convex block 214, and the two adjacent pile shoe small blocks 211 pass through the convex block 214. The block 214 is plugged and fixed into the groove 212, as shown in Figure 5 .

The pile shoe small blocks 211 are generally in a fan-shaped structure, and the size and shape of each pile shoe small block 211 are basically the same. Figure 6 shows the combination of the small pile shoe blocks 211 of the pile shoe 2. In order to facilitate the recovery of each pile shoe small block 211, the pile shoe 2 is composed of a total of six pile shoe small blocks 211 that cooperate with each other. combination, the six pile shoe small blocks 211 are respectively the first pile shoe small block 221, the second pile shoe small block 222, the third pile shoe small block 223, and the fourth pile shoe small block 211 along the circumferential direction. The shoe small block 224, the fifth pile shoe small block 225, and the sixth pile shoe small block 226 are shown in Figure 6. In Figure 6, "+" represents the convex block 214, and "-" represents the concave block. slot 212.

Along the circumferential direction of the pile shoe 2, the first pile shoe small block 221, the second pile shoe small block 222, the third pile shoe small block 223 and the fourth pile shoe small block 224 are all one. A convex block 214 is provided on one side and a groove 212 is provided on the other side, and grooves 212 are provided on both sides of the fifth pile shoe small block 225, and convex blocks 214 are provided on both sides of the sixth pile shoe small block 226. When the fifth pile shoe small block 225 is lifted up through the recovery cable at the upper end surface of the fifth pile shoe small block 225, it will connect with the sixth pile shoe small block 224 along the fourth pile shoe small block 225. The bumps on the side of the block 226 move upward and are separated from other pile shoe blocks, and then the fourth pile shoe block 224, the third pile shoe block 223, and the second pile are lifted up in sequence. Shoe small block 222, the first pile shoe small block 221, and the sixth pile shoe small block 226, so that each pile shoe small block can be lifted up in sequence for recycling.

In this embodiment, the seabed self-abandonment and recyclable jack-up drilling platform spud shoe also includes a plurality of traction ropes 43. The number of traction ropes 43 is the same as the number of pins 3. The lower end of the traction ropes 43 is connected to the outer surface of the pins 3. The ends are connected and fixed in one-to-one correspondence. Through the pulling effect of the traction rope 43, the plurality of pins 3 used to fix the spud shoe body 1 and the spud shoe 2 can be pulled out.

Specifically, the lower end of the inclined tube 41 is located above the outer end of the pin 3 (the lower end of the inclined tube 41 can be slightly higher than the outer end of the pin 3). The lower end of the inclined tube 41 is provided with an end fixed pulley 47, and the traction rope 43 is connected to the end Along the diameter direction of the spud shoe body 1, the distance between the end fixed pulley 47 and the outer end of the pin 3 is greater than the length of the pin 3. When the traction rope 43 is pulled in this way, the plurality of pins 3 in the spud shoe body 1 and the skirt spud shoe block 2 can be pulled out, further realizing the separation between the spud shoe body 1 and the skirt spud shoe block 2, as shown in As shown in Figure 6. In addition, the distance between the end fixed pulley 47 and the center line of the skirt spud shoe block 2 is preferably smaller than the radius of the outer surface 26 of the skirt spud shoe block 2, so as to reduce the skirt's self-abandonment resistance, puncture resistance, and self-lifting. During the running process of the spud shoe of the type drilling platform, the inclined pipe 41, the end fixed pulley 47 and the traction rope 43 are subjected to the resistance of seawater and seabed soil.

In this embodiment, the seabed self-abandonment and retrievable jack-up drilling platform spud shoe also includes a straight pipe 45 and a plurality of inclined pipes 41. The number of the inclined pipes 41 is the same as the number of pins 3. The inclined pipes 41 extend along the spud shoe. The upper inclined surface 12 of the body 1 is inclined, the upper end of the inclined tube 41 is connected to the lower end of the straight tube 45, the straight tube 45 is in an upright state, the lower end of the inclined tube 41 corresponds to the outer end of the pin 3, and the traction rope 43 is set on In the straight tube 45 and the inclined tube 41 , that is, each traction rope 43 includes a section located in the inclined tube 41 and a section located in the straight tube 45 .

In this embodiment, the seabed self-abandonment and recyclable jack-up drilling platform spud shoe also includes an upright truss 5. The straight pipe 45 is sleeved in the truss 5, and the two ends of the inclined pipe 41 and between the two ends are provided. There are a plurality of fixed pulleys 42 arranged in the tube at intervals. The upper end of the truss 5 is provided with a top fixed pulley 46. The traction rope 43 is connected to the fixed pulley 42 in the tube and the top fixed pulley 46. The inclined tube 41 is connected to the spud shoe body 1 through a support rod 44. Fixed, the straight pipe 45 is connected and fixed with the truss 5 through the support rod 44.

In the present invention, the inclined tube 41, the fixed pulley 42 inside the tube, the traction rope 43, the support rod 44, the straight tube 45 and the top fixed pulley 46 can be called the self-abandonment module 4, that is, the self-abandonment module 4 contains the inclined tube 41, the fixed pulley 42 inside the tube. 42. Traction rope 43, support rod 44, straight pipe 45 and top fixed pulley 46. The truss 5 is located at the upper end of the pile shoe body 1 and is fixedly connected to its upper end surface. The outer wall of the straight pipe 45 and the truss 5 are welded and fixed by a plurality of support rods 44 to limit the position of the straight pipe 45 .

In this embodiment, the fixed pulleys 42 in the pipe are evenly spaced and symmetrically arranged on the inner wall of the inclined pipe 41 and the uppermost port of the straight pipe 45. The top fixed pulley 46 is fixed on the top of the truss 5, and the straight pipe 45 is located in the center of the truss 5; the traction rope One section of 43 is located inside the inclined tube 41 and cooperates with the fixed pulley 42 in the tube to change the direction of the force. Its bottom is fixedly connected to the end of each pin 3. Its number is consistent with the number of pins 3. Its top ends are gathered together and connected to another section of traction rope. , this section of the traction rope is located in the straight pipe 45, and cooperates with the top outlet of the straight pipe 45 and the top fixed pulley 46 at the upper end of the truss.

By pulling the traction rope 43 on the platform, the plurality of pins 3 located in the pin holes of the pile shoe body 1 and the pile shoe 2 are pulled out, so that the pile shoes 2 and the pile shoe body 1 are released. When the pile legs are lifted up, the pile The shoe body 1 is separated from the pile shoe 2, and the pile shoe 2 is temporarily left in the pile shoe footprints on the seabed, thereby reducing the pile pulling resistance of the platform and making the pile pulling operation easier. The number of the inclined tubes 41 is consistent with the number of the pins 3 , and the inclined tubes 41 are evenly spaced along the side of the spud shoe body and fixed by a plurality of support rods 44 .

A drilling platform is introduced below. The bottom of the drilling platform is provided with the above-mentioned seabed self-abandonment and recyclable jack-up drilling platform spud shoes.

The following introduces the working process of the shoe type self-abandonable self-elevating drilling platform spud shoe, including the following steps:

Step 1. Place the pile shoe body 1 in the pile shoe 2, and align the pin holes of the pile shoe body 1 and the pile shoe 2;

Step 2. Insert multiple pins 3 into the pin holes of the spud shoe body 1 and the spud shoe 2;

Step 3. Fixedly connect the lower ends of multiple sections of traction ropes 43 located inside the inclined tube 41 to the outer ends of each pin 3 respectively;

Step 4: Lower the pile legs for ballast operation, and comprehensively analyze whether the platform needs to release the pile shoes 2 during the evacuation operation based on the platform's pile pulling capacity, the depth of the pile legs entering the mud, and the seabed soil parameters.

Step 5. If the analysis shows that the resistance to pulling out the pile is large and may make it difficult to pull out the pile, pull out the multiple pins 3 located in the pin holes of the pile shoe body 1 and the pile shoe 2 by pulling the traction rope 43 on the platform, so that the pile shoe 2 is detached from the pile shoe body 1. When the pile leg is lifted up, the pile shoe body 1 is separated from the pile shoe 2, and the pile shoe 2 is temporarily left in the pile shoe footprints on the seabed, thereby reducing the resistance to pulling out the pile and allowing the pile to be pulled out. Pile work is easier;

Step 6: Lift the pile shoe small block 211 through the recovery cable 213 at the upper end surface of the pile shoe small block 211 (the fifth pile shoe small block 225 in Figure 6), which will move along the fourth pile. The shoe block 224 and the convex block on the side of the sixth pile shoe block 226 travel up and separate from other pile shoe blocks;

Step 7: Lift up the fourth stake shoe block 224, the third stake shoe block 223, the second stake shoe block 222, the first stake shoe block 221, and the sixth stake shoe block 221 in sequence. The small pieces of the pile shoe 226 can be lifted up in sequence for recycling.

By using the skirt-type self-abandonment self-elevating drilling platform spud shoes and drilling platform of the present invention, the soil bearing capacity of the platform at the same well position can be greater and the depth of the pile legs entering the mud can be shallower. When the depth of mud makes the pile pulling operation difficult, the pile shoes can be released through the action of the traction rope to reduce the dead weight of the pile legs, making the pile pulling operation less resistant and the pile pulling operation smoother. At the same time, since the pile shoe is composed of multiple small blocks, when the platform completes the pile pulling operation and the pile shoe block is left on the seabed, each small block can be recycled separately, which greatly reduces the difficulty of recycling the pile shoe and makes the seabed The original appearance is restored to the greatest extent without adversely affecting subsequent pile insertion and re-installation operations.

The above are only specific embodiments of the present invention and cannot be used to limit the scope of the invention. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the patent protection scope of the present invention, should still be covered by this patent. category. In addition, technical features and technical features, technical features and technical solutions, and technical solutions and technical solutions in the present invention can be freely combined and used.

Claims (2)

1. The pile shoe for the self-elevating drilling platform is characterized by comprising a pile shoe body (1) and a pile shoe (2), wherein the center line of the pile shoe body (1) and the center line of the pile shoe (2) are in an upright state, the pile shoe body (1) and the pile shoe (2) are arranged up and down, and the pile shoe body (1) can move upwards and be separated from the pile shoe (2);

the pile shoe body (1) is of a block structure, the longitudinal section of the pile shoe body (1) is octagonal, and the pile shoe body (1) comprises a top surface (11), an upper inclined surface (12), an outer peripheral surface (13), a lower inclined surface (14) and a bottom surface (15) which are sequentially connected from top to bottom;

the pile shoe (2) consists of a plurality of pile shoe small blocks (211) arranged along the circumferential direction, the lower surface (25) of the pile shoe (2) is of a conical structure with the top end facing downwards, an inserting groove (24) is formed in the upper end of the pile shoe (2), the longitudinal section of the pile shoe (2) comprises an inner core section (21) and an outer ring section (22) which are sleeved outside along the diameter direction of the pile shoe (2), and the inner side surface (23) of the upper end of the outer ring section (22) is the inner circumferential surface of the inserting groove (24); the lower part of the pile shoe body (1) is inserted into the insertion groove (24) in a matching way;

the top surface (11) is parallel to the bottom surface (15), the lower surface (25) of the pile shoe (2) is the enlargement of the lower inclined surface (14) and the bottom surface (15) of the pile shoe body (1), the central line of the pile shoe body (1) is vertical to the top surface (11), the diameter of the upper end of the outer peripheral surface (13) is the same as the diameter of the lower end of the outer peripheral surface (13), the longitudinal section of the inner core section (21) is octagonal, and the longitudinal section of the outer ring section (22) is trapezoidal;

the pile shoe comprises a pile shoe body (1) and pile shoes (2), wherein the pile shoe body and the pile shoes (2) are detachably connected through a plurality of pins (3), the pins (3) are uniformly arranged at intervals along the circumferential direction of the pile shoes (2), pin inserting holes are formed in the peripheral surface (13) of the pile shoe body (1), and pin mounting through holes are formed in the upper end of an outer ring section (22);

when the depth of the predicted pile leg into mud is smaller and pile pulling operation does not need to release the pile shoe (2);

the number calculation formula of the pins (3) is as follows:

when the depth of the predicted pile leg into mud is deeper and pile shoe (2) needs to be released during pile pulling operation;

the number calculation formula of the pins (3) is as follows:

l is the number of pins (3), in units of one, rounded to a reserved integer;

w is the gravity of the shoe pile (2) and the unit is N;

f is the soil adsorption force born by the pile shoe (2), and the unit is N;

F _s the shear force of soil body is applied to the pile shoe (2) and the unit is N;

F _r the unit of the friction force of the soil body born by the pile shoe (2) is N;

n is the shear strength of the pin (3) and is given in N/m ² ；

D is the diameter of the pin (3) and the unit is m;

n is a safety coefficient, no unit exists, and the value is more than or equal to 1.5;

the upper end face of the pile shoe small block body (211) is provided with a recovery rope (213) capable of pulling the pile shoe small block body (211), a groove (212) is formed in one side of the pile shoe small block body (211) along the circumferential direction of the pile shoe (2), a bump (214) is formed in the other side of the pile shoe small block body (211), and two adjacent pile shoe small block bodies (211) are fixedly spliced with the groove (212) through the bump (214);

the pile shoe of the submarine self-elevating drilling platform comprises a plurality of traction ropes (43), wherein the number of the traction ropes (43) is the same as that of the pins (3), and the lower ends of the traction ropes (43) are connected and fixed with the outer ends of the pins (3) in a one-to-one correspondence manner;

the pile shoe of the submarine self-elevating drilling platform comprises a straight pipe (45) and a plurality of inclined pipes (41), the number of the inclined pipes (41) is the same as that of the pins (3), the upper ends of the inclined pipes (41) are correspondingly connected with the lower ends of the straight pipe (45), the lower ends of the inclined pipes (41) are in one-to-one correspondence with the outer ends of the pins (3), and the traction ropes (43) are sleeved in the straight pipe (45) and the inclined pipes (41);

the lower end of the inclined tube (41) is positioned above the outer end of the pin (3), an end fixed pulley (47) is arranged outside the lower end of the inclined tube (41), the traction rope (43) is connected with the end fixed pulley (47), and the distance from the end fixed pulley (47) to the outer end of the pin (3) is larger than the length of the pin (3) along the diameter direction of the pile shoe body (1);

the pile shoe of the submarine self-elevating drilling platform comprises a pile shoe body (1), a vertical truss (5) is further arranged on the pile shoe body, a straight pipe (45) is sleeved in the truss (5), a plurality of inner-pipe locating pulleys (42) are arranged in an inclined pipe (41), a top locating pulley (46) is arranged at the upper end of the truss (5), a traction rope (43) is connected with the inner-pipe locating pulleys (42) and the top locating pulley (46), the inclined pipe (41) is fixedly connected with the pile shoe body (1) through a supporting rod (44), and the straight pipe (45) is fixedly connected with the truss (5) through the supporting rod (44).

2. A drilling platform, characterized in that the bottom of the drilling platform is provided with the self-elevating drilling platform pile shoe which is self-disposable and recyclable on the seabed and is as claimed in claim 1.