Catheter shoe and directional piling method

Abstract

The present invention relates to the field of directional piling technology, and more particularly to a conduit shoe comprising a connecting section and an orienting section, the connecting section being configured as a circular tube structure; the orienting section being connected to the connecting section, the end of the orienting section remote from the connecting section being configured as a first orienting surface, and a half of the tube wall of the orienting section corresponding to the bottom end of the first orienting surface gradually extending outward from the end proximal to the connecting section toward the end remote from the connecting section to form a second orienting surface. The first orienting surface and the second orienting surface act together to provide the conduit shoe with excellent directional deflection performance. A directional piling method utilizing the conduit shoe can deflect the conduit toward a predetermined orientation, thereby avoiding collision with adjacent conduits and improving operational safety.

Description

Technical Field

[0001] The present invention relates to the technical field of directional piling, in particular to a guide shoe and a directional piling method. Background Art

[0002] Offshore oil and gas resources are typically developed and produced using jacket platforms. Wellheads are established by driving piles through the jacket slots and running jackets down. Depending on the scale of the oil and gas field and the size of the jacket platform, a jacket platform is typically equipped with 20-30 slots, with one wellhead established in each slot.

[0003] Generally, the end surface of the casing shoe is set to be flat. Theoretically, the casing is lowered vertically after being piled into the mud. However, during the actual lowering process, due to the influence of the casing pile and the formation, the casing will experience a certain degree of uncontrolled tilt after entering the mud. This will cause the subsequent casings of adjacent wells to easily collide with it during the piling process. Not only will the subsequent casings be unable to be lowered to the designed depth, but in severe cases, it may even cause the casings to collide and rupture, resulting in the risk of oil and gas leakage, posing a great threat to the production safety of the oil and gas field and causing economic losses. Especially in the later stage of oil and gas field development, new slots will be densely arranged in the gaps between the original slots to increase the number of wells and achieve the purpose of more oil and gas production. At this time, the problem of preventing the casing from being collided during piling is very serious.

[0004] To this end, the patent application with application number CN202110488280.5 proposes a directional piling method and Figure 1 The casing shown in the figure has an end face of 45-75° inclined relative to the axis when piling. Under the action of the inclined surface, the casing will carry the casing group in a deflected direction to be lowered in the set direction, thus solving the problem of collision between the casing and the adjacent well casing.

[0005] However, this solution still has several drawbacks: directional capability is insufficient in soft formations, and directional deviation of the casing is achieved solely by penetration of the bottom slope. During piling in soft formations, the bottom and top slopes of the casing face similar resistance, making both prone to penetration, thus failing to fully utilize the sharp penetration capability of the bottom slope, resulting in insufficient directional deviation capability. Furthermore, even in hard formations, the aforementioned solution, with only a single directional surface at the bottom slope, can result in the casing deviation angle and distance not meeting engineering design requirements. Summary of the Invention

[0006] The object of the present invention is to provide a conduit shoe, which can realize the directional deviation of the conduit during the process of entering the mud during piling construction in various strata, and avoid collision with adjacent conduits.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] The catheter shoe includes a connecting section and an orienting section, wherein the connecting section is configured as a circular tube structure; the orienting section is configured as a tubular structure, the orienting section is connected to the connecting section, and the end face of the orienting section away from the connecting section is inclined to form a first orienting surface, and the half tube wall of the orienting section corresponding to the bottom end of the first orienting surface gradually extends outward from the end close to the connecting section to the end away from the connecting section to form a second orienting surface.

[0009] Optionally, the inclined tube wall of the directional section has an inclination angle α relative to the connecting section, and α is less than 45°.

[0010] Optionally, the inclination angle of the first orientation surface relative to the axis of the connecting section is β, and β is between 45° and 90°.

[0011] Optionally, the lowest point of the first orientation surface is set as point A, and the highest point of the first orientation surface is set as point B, then AB·sinβ<inner diameter of the catheter rack notch.

[0012] Optionally, tube shoe teeth are further provided on the first orientation surface, and the tube shoe teeth are evenly distributed on the first orientation surface.

[0013] Optionally, reinforcing ribs are further included, and the reinforcing ribs are arranged on the connecting section and the directional section, and the extending direction of the reinforcing ribs is consistent with the axial direction of the connecting section.

[0014] Optionally, the number of the reinforcing ribs is 20-30.

[0015] Optionally, the catheter shoe is made by casting.

[0016] Another object of the present invention is to provide a directional piling method, which can achieve directional piling by connecting the above-mentioned catheter shoe to the catheter for piling.

[0017] Optionally, before the conduit connected to the conduit shoe is piled and lowered, the direction in which the inclined pipe wall of the conduit shoe is to face is marked on the turntable surface of the wellhead.

[0018] The beneficial effects of the present invention are as follows: the catheter shoe in the present invention includes a connecting section and a directional section, and a section of the directional section away from the connecting section is set as a first directional surface. The first directional surface can reduce the resistance when penetrating into the soil layer and has a certain guiding effect. At the same time, the half pipe wall of the directional section corresponding to the bottom end of the first directional surface is extended outward to form a second directional surface. The second directional surface has a pre-inclined effect and cooperates with the first directional surface for a better directional effect, especially when facing soft formations. It can make up for the shortcomings of insufficient directional ability of the first directional surface. The directional piling method using the above-mentioned catheter shoe can make the catheter deviate to a preset direction, thereby improving operation safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of a catheter shoe in the prior art;

[0020] Figure 2 This is a schematic structural diagram of a catheter shoe according to an embodiment of the present invention from one angle;

[0021] In the figure: 1, connecting section; 2, directional section; 3, first directional surface; 4, second directional surface; 5, tube shoe teeth; 6, reinforcing ribs. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0023] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0024] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0025] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., referring to positions or locations, are based on the positions or locations shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0026] When driving a conduit into the mud, a pile hammer hammers the conduit, along with the conduit shoe, into the seabed to a set depth. The conduit shoe guides the conduit. To ensure the conduit is inserted into the formation along a predetermined direction, this embodiment proposes a conduit shoe with an inclined surface at one end, further enhancing its directional capability. This allows the conduit to be oriented and deflected in various formations, thereby avoiding collisions with adjacent wellbore conduits and improving operational safety.

[0027] refer to Figure 2 As shown, the catheter shoe in this embodiment includes a connecting section 1 and a directional section 2, and both the connecting section 1 and the directional section 2 are tubular structures, wherein the connecting section 1 is set to a circular tube structure, which can be connected to the lowermost end of the catheter, specifically by welding or screwing, and the directional section 2 is set to a tubular structure. The directional section 2 is connected to the connecting section 1, and the inner and outer diameters of the end connected to the connecting section 1 are the same as the inner and outer diameters of the connecting section 1, so as to avoid a sudden change in resistance when the catheter shoe is lowered into the soil. The end face away from the connecting section 1 is inclined to form a first directional surface 3, and the half-side pipe wall of the directional section 2 corresponding to the bottom end of the first directional surface 3 gradually extends outward from the end close to the connecting section 1 to the end away from the connecting section 2 to form a second directional surface 4.

[0028] Based on the principle that objects always move in the direction of least resistance, during the process of piling, the catheter shoe penetrates the ground under the directional action of the above-mentioned catheter shoe, and its offset direction can be kept consistent with the preset direction. First, the first directional surface 3 of the directional section 2 penetrates the ground. During the piling process, the bottom end of the first directional surface 3 contacts the ground first compared to the top end of the first directional surface 3 to achieve groundbreaking penetration. The second directional surface 4 has a certain pre-inclined effect, which makes up for the shortcoming of the first directional surface 1 having weak directional ability when facing a soft bottom layer. Under the joint action of the first directional surface 3 and the second directional surface 4, the bottom end of the first directional surface 3 can be offset in the direction of the inclination of the second directional surface 4 during the groundbreaking penetration process, thereby achieving the purpose of directional piling. The setting of the first directional surface 3 can also reduce the resistance of the catheter to entering the mud and increase the speed of the catheter piling.

[0029] The directional deflection capability of the catheter shoe is related to the inclination angle of the second directional surface 4 and the inclination angle of the first directional surface 3. When the inclination angle of the first directional surface 3 is constant, the deflection angle of the catheter shoe is positively correlated with the inclination angle of the second directional surface 4. Figure 2As shown, assuming that the inclination angle of the second orientation surface 4 relative to the axis of the connecting section 1 is α, and the inclination angle of the first orientation surface 3 relative to the axis of the connecting section 1 is β, the sharp angle formed by the intersection of the second orientation surface 4 and the bottom end of the first orientation surface 3 is β-α. The smaller the sharp angle, the stronger the directional deviation capability of the guide shoe. In other words, when the angle β is constant, the larger α is, the stronger the directional deviation capability of the entire guide shoe. In order to prevent the guide shoe from being damaged by the squeezing of the formation soil during the guide piling construction, it is necessary to limit α and β. Generally speaking, α is less than 45°, and β is kept between 45° and 90° (which can both avoid damage to the guide shoe and ensure that the guide shoe quickly penetrates the formation when encountering hard formations), for example 67.5°. The specific angle needs to be calculated and determined according to the guide shoe directional deviation requirements of the drilling project design.

[0030] At the same time, in order to ensure that the catheter shoe can smoothly pass through the notch on the catheter rack, assuming that the lowest point of the first orientation plane 3 is set to point A and the highest point of the first orientation plane 3 is set to point B, then AB·sinβ<the inner diameter of the catheter rack notch.

[0031] In order to enable the catheter to be smoothly inserted into the formation, especially the hard formation, the first orientation surface 3 is further provided with tube shoe teeth 5. The tube shoe teeth 5 are evenly distributed on the first orientation surface and the tooth tips of the tube shoe teeth 5 face downward, which can enable the catheter to have better passability in the hard formation.

[0032] Furthermore, reinforcing ribs 6 are circumferentially provided on the connecting section 1 and the orienting section 2. These ribs extend in the same direction as the axial direction of the connecting section 1 and extend from the end of the connecting section 1 for connecting to the conduit to the end of the orienting section 2 where the first orienting surface 3 is provided, thereby enhancing structural strength. Exemplarily, the number of reinforcing ribs 6 is 20-30.

[0033] Currently, conduit shoes with inclined surfaces are typically mechanically cut from conduit. This cutting process can easily damage the strength of the conduit shoe. Under the high compressive pressure of the stratum, the conduit shoe can easily be damaged, leading to piling failure. In this embodiment, the conduit shoe is cast based on a model. During the casting process, the inclination angle β of the first orientation surface 3 and the inclination angle α of the second orientation surface 4 are first calculated based on the desired conduit offset angle and the inner diameter of the notch. A model is then designed and cast using the model to produce the conduit shoe. Specifically, the conduit shoe is cast from steel.

[0034] The conduit shoe obtained by the above processing method is an integrated structure, and the reinforcing ribs 6 and the conduit shoe teeth 5 can be produced at one time by a casting process, thereby improving the structural strength to better meet the construction requirements of hard formations and improve construction efficiency.

[0035] This embodiment also provides a directional piling method, which utilizes the above-mentioned catheter shoe to connect with the catheter, and then performs directional offset drilling. During the catheter lowering process, the connecting section 1 is lowered vertically, and the second directional surface 4 is oriented in the same direction as the preset offset orientation to play a directional deflection role. For example, if the entire catheter needs to be offset to the southeast, the second directional surface 4 should face the southeast. During specific construction, the direction of the second directional surface 4 is determined according to the design requirements of the catheter piling of the drilling project and the offset direction of the adjacent catheter to be avoided, and then marked on the turntable surface of the wellhead.

[0036] It can be understood that the conduit shoe in this embodiment can not only be used in connection with a conduit during offshore oil exploration and development, but can also be used as a pile shoe in directional piling construction of building pile foundations.

[0037] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Catheter shoe, characterized in that, include: A connecting section (1), wherein the connecting section (1) is configured as a circular tube structure; The orientation section (2) is configured as a tubular structure, the orientation section (2) being connected to the connecting section (1), the end face of the orientation section (2) being away from the connecting section (1) being inclined to form a first orientation face (3), and the half tube wall of the orientation section (2) corresponding to the bottom end of the first orientation face (3) gradually extending outwards from the end close to the connecting section (1) to the end away from the connecting section (1) to form a second orientation face (4).

2. The catheter shoe according to claim 1, characterized in that The inclination angle α of the second orientation surface (4) relative to the axis of the connecting section (1) is less than 45°.

3. The catheter shoe according to claim 2, characterized in that: The inclination angle β of the first orientation surface (3) relative to the axis of the connecting section (1) is between 45° and 90°.

4. The catheter shoe according to claim 3, characterized in that: The lowest point of the first orientation surface (3) is set as point A, and the highest point of the first orientation surface (3) is set as point B, then AB·sinβ<inner diameter of the catheter rack notch.

5. The catheter shoe according to claim 1, characterized in that: Tube shoe teeth (5) are also provided on the first orientation surface (3), and the tube shoe teeth (5) are evenly distributed on the first orientation surface (3).

6. The catheter shoe according to claim 1, characterized in that: It also includes reinforcing ribs (6), which are arranged on the connecting section (1) and the directional section (2), and the extending direction of the reinforcing ribs (6) is consistent with the axial direction of the connecting section (1).

7. The catheter shoe according to claim 6, characterized in that: The number of the reinforcing ribs (6) is 20-30.

8. The catheter shoe according to claim 1 or 5, characterized in that: The catheter shoe is made by casting.

9. Directional piling method, characterized in that: The catheter shoe according to any one of claims 1 to 8 is connected to the catheter, and then the piling operation is carried out.

10. The directional piling method according to claim 9, characterized in that before the guide tube connected to the guide tube shoe is lowered for piling, the direction to which the second directional surface (4) is to face is marked on the turntable surface of the wellhead.

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