Underwater liquid oxygen fracturing pipe base and machining mold and machining method thereof

Abstract

The invention belongs to the field of underwater rock mass fracturing engineering, and particularly relates to an underwater liquid oxygen fracturing pipe base and a machining mold and method thereof, the underwater liquid oxygen fracturing pipe base effectively resists facing buoyancy when a fracturing pipe is installed underwater, it is guaranteed that the fracturing pipe is installed at a designated position, and the fracturing efficiency is improved. And a foundation is firmly built for subsequent underwater liquid oxygen fracturing pipe stable operation. The machining die is simple in structure and low in cost, and batch machining of underwater liquid oxygen fracturing pipe bases can be achieved. According to the machining method, optimization of the key size of the underwater liquid oxygen fracturing pipe base can be accurately achieved, and the safety and reliability of the underwater liquid oxygen fracturing pipe base in the underwater environment are powerfully guaranteed. Meanwhile, the batch machining method has high efficiency, convenience and practicability, complicated and expensive machining equipment does not need to be introduced, and the method has extremely wide application prospects in multiple actual engineering scenes, such as underwater rock breaking engineering and ocean resource development, where underwater liquid oxygen fracturing pipes are frequently used.

Description

Technical Field

[0001] The present application relates to the technical field of underwater rock fracturing engineering, and in particular to an underwater liquid oxygen fracturing pipe base and a processing mold and a processing method thereof. Background Art

[0002] As an emerging rock fracturing technology, liquid oxygen fracturing technology has demonstrated significant advantages in onshore rock breaking operations. Its operation process is relatively simple and clear. Usually, it only needs to place the fracturing tube in the drilled hole, then inject liquid oxygen into it, and then directly ignite it after connecting the wire to achieve the effect of fracturing the rock.

[0003] However, when rock breaking operations are transferred to underwater environments, they face a series of challenges and difficulties. One of them is that during the underwater drilling process, the fracturing pipe will be affected by the buoyancy of the water. This physical property makes it difficult for the fracturing pipe to achieve self-stabilization at the designated underwater position. This problem will cause the rock breaking effect to fail to achieve the expected effect. The existing solution is: one worker uses a gun stick to press the fracturing pipe into the designated position in the water, and then another worker fills the borehole with filler until the weight of the filler and the buoyancy of the fracturing pipe offset each other, so that the fracturing pipe stops at the designated underwater position, and finally the gun stick is taken out. Although such a process is feasible, it is too complicated and will reduce the continuity of construction. Summary of the invention

[0004] In view of the problems mentioned in the above background technology, the embodiments of the present application provide a simple, reliable and effective underwater liquid oxygen fracturing pipe base and a batch processing mold and processing method thereof.

[0005] According to one aspect of the present application, there is provided an underwater liquid oxygen fracturing tube base, comprising a cylinder, a cone cap and a plurality of elastic limiting flaps, wherein the large end of the cone cap is connected to one end of the cylinder, the plurality of limiting flaps are evenly arranged circumferentially at the end of the cylinder away from the cone cap, and the limiting flaps are spread out relative to each other, the cylinder is used to be sleeved on the lower end of the fracturing tube, the cone cap is used to guide the fracturing tube during insertion into a hole, and the limiting flaps are used to elastically abut against the hole wall to overcome the buoyancy of the fracturing tube in water.

[0006] Optionally, the outer diameter of the large end of the cone cap is the same as the outer diameter of the cylinder.

[0007] Optionally, the cylinder, the cone cap and the plurality of limiting flaps are an integrated structure.

[0008] Optionally, the underwater liquid oxygen fracturing pipe base is made of PVC, PET or PE.

[0009] Optionally, the inner wall of the cylinder is provided with an internal thread, and the cylinder is connected to the lower end of the fracturing tube via a thread; or

[0010] The cylinder is provided with a mounting hole, and the cylinder is fixed to the lower end of the fracturing tube by means of screws penetrating through the mounting hole.

[0011] According to another aspect of the present application, a processing mold for an underwater liquid oxygen fracturing tube base is provided, which is used to process the underwater liquid oxygen fracturing tube base as described above, and the processing mold includes an upper mold, a lower mold and a petal angle molding assembly; the upper mold includes a columnar body and a conical pressure head coaxially arranged at one end of the columnar body, and the lower mold is provided with a groove with an inner wall having a conical surface; the petal angle molding assembly includes an upper cone sleeve and a lower cone sleeve, the upper cone sleeve is sleeved on the upper end of the columnar body, the outer diameter of the upper cone sleeve gradually increases from the end close to the conical pressure head to the end away from the conical pressure head, the lower cone sleeve is arranged at the top of the lower mold and is located above the groove, the inner wall of the lower cone sleeve includes a conical surface and a cylindrical surface from top to bottom in sequence, and the conical surface cooperates with the upper cone sleeve to control the deployment angle of the limiting petal.

[0012] Optionally, a flange is provided on one end of the circumferential side of the columnar body away from the conical pressure head, and a groove for embedding the flange is provided on one end of the upper conical sleeve away from the conical pressure head; a circle of limiting protrusions is provided around the groove on the top of the lower mold, and a limiting groove adapted to the limiting protrusion is provided at the lower end of the lower conical sleeve.

[0013] Optionally, the flap angle forming components are provided in a plurality of groups, and the taper of the conical surface of the inner wall of the lower cone sleeve in each group of the flap angle forming components is different.

[0014] According to another aspect of the present application, a method for processing an underwater liquid oxygen fracturing pipe base is provided, which is used to process the underwater liquid oxygen fracturing pipe base as described above, and the processing method comprises the following steps:

[0015] S1. According to the actual drilling diameter of the construction site, determine the appropriate cylinder diameter of the underwater liquid oxygen fracturing pipe base and purchase a certain number of original lower end caps, the original lower end cap is a plastic pipe section with one end closed and one end open;

[0016] S2. Since one end of the limit petal of the underwater liquid oxygen fracturing pipe base is fixed and the other end is free, it can be simplified into a cantilever beam model. According to the material mechanics formula, it can be known that:

[0017]

[0018] Where: f is the magnitude of the sliding friction force on the limiting petal in the borehole; E is the elastic modulus of the limiting petal; μ is the friction coefficient between the limiting petal and the hole wall; y is the difference between the radius of the circle after each limiting petal is unfolded and the radius of the borehole; R is half of the outer diameter of the cylinder; r is half of the inner diameter of the cylinder; L is the length of the limiting petal; n is the number of limiting petals;

[0019] f can be measured on site with a dynamometer. Parameters such as y, L and n can be determined in advance. Eμ is regarded as a whole and recorded as K. The above parameters R, r, f, y, L and n are substituted into the formula to obtain the value of K. Since it is too difficult to adjust the three parameters y, L and n at the same time, the parameters L and n that are difficult to adjust flexibly are determined first. The only unknown parameter on the right side of the above formula is y. The friction force f that the underwater liquid oxygen fracturing pipe base should provide is determined according to the on-site conditions. The value of parameter y is obtained according to the above formula to provide corresponding angle parameters for the processing mold to press the limit petal. The processing mold includes an upper mold, a lower mold and a petal angle A molding component; the upper mold comprises a cylindrical body and a conical pressure head coaxially arranged at one end of the cylindrical body, and the lower mold is provided with a groove whose inner wall is a conical surface; the petal angle molding component comprises an upper cone sleeve and a lower cone sleeve, the upper cone sleeve is sleeved on the upper end of the cylindrical body, the outer diameter of the upper cone sleeve gradually increases from one end close to the conical pressure head to one end away from the conical pressure head, the lower cone sleeve is arranged at the top of the lower mold and is located above the groove, the inner wall of the lower cone sleeve comprises a conical surface and a cylindrical surface from top to bottom, and the conical surface cooperates with the upper cone sleeve to control the deployment angle of the limit petal;

[0020] S3. After determining the specific parameters of the upper die, lower die and petal angle forming components of the processing mold, use the drawing software to draw the schematic diagram of the upper die, lower die and petal angle forming components and indicate the specific values ​​of the parameters. Around the deflection angle of the limiting petal, prepare 2-3 sets of petal angle forming components. The taper of the conical surface of the inner wall of the lower cone sleeve in each set of petal angle forming components is different, so as to flexibly adjust the deflection angle of the limiting petal;

[0021] S4. Submit the schematic diagram to the processing factory, process the processing mold, and split the original lower end cover;

[0022] S5. Put the petal-split lower end cap into a drying oven and place it at about 150°C for 2-3 minutes. During this period, select the petal angle forming components with suitable angles and assemble them. Then take the lower end cap out of the drying oven and put it into the groove of the lower mold. Then press the upper mold and the upper cone sleeve combined with it onto the lower end cap and keep it for 2-3 minutes. After the lower end cap is formed, take it out and the processing is completed.

[0023] S6. When the field test finds that the friction force provided by the underwater liquid oxygen fracturing pipe base is not appropriate, the opening angle of the limit petal can be modified by replacing the petal angle forming assembly, thereby achieving the effect of increasing or decreasing the friction force.

[0024] The underwater liquid oxygen fracturing pipe base provided by the present application and its processing mold and processing method have the following beneficial effects: compared with the prior art, the underwater liquid oxygen fracturing pipe base of the present application includes a cylinder, a cone cap and a plurality of elastic limiting petals, and the overall structure is simple. When in use, it is installed to the lower end of the fracturing pipe. The cone cap has a guiding function and can easily pass through the step between the casing and the borehole, ensuring the normal progress of the lower pipe; a plurality of elastic limiting petals are elastically abutted against the hole wall, effectively resisting the buoyancy faced by the fracturing pipe during underwater installation, ensuring the installation of the fracturing pipe at a designated position, laying a solid foundation for the subsequent stable operation of the underwater liquid oxygen fracturing pipe, and effectively ensuring its safety and reliability in the underwater environment. The processing mold has a simple structure and low cost, and can realize the batch processing of the underwater liquid oxygen fracturing pipe base. The processing method is not only suitable for the production of supporting bases of underwater liquid oxygen fracturing pipes of conventional specifications in engineering practice, but also can be used to make molds according to various sizes and models of underwater liquid oxygen fracturing pipes to meet diverse operation needs. This processing method can accurately optimize the key dimensions of the underwater liquid oxygen fracturing pipe base, lay a solid foundation for the subsequent stable operation of the underwater liquid oxygen fracturing pipe, and effectively guarantee its safety and reliability in the underwater environment. At the same time, this batch processing method is both efficient and convenient and practical, without the need to introduce complicated and expensive processing equipment. It has extremely broad application prospects in many actual engineering scenarios such as underwater rock breaking engineering and marine resource development where underwater liquid oxygen fracturing pipes are frequently used. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] in:

[0027] Figure 1 This is a front view of an underwater liquid oxygen fracturing tube base of an underwater liquid oxygen fracturing tube shown in one embodiment of the present application;

[0028] Figure 2 yes Figure 1 A top view of the underwater liquid oxygen fracturing tube base is shown;

[0029] Figure 3 It is a structural schematic diagram of a processing mold shown in an embodiment of the present application;

[0030] Figure 4 It is a schematic diagram of the cross-sectional structure of a processing mold shown in one embodiment of the present application.

[0031] Description of reference numerals:

[0032] 10. Underwater liquid oxygen fracturing pipe base; 11. Cylinder; 12. Cone cap; 13. Limiting petal;

[0033] 20. Original lower end cover;

[0034] 100, upper die; 110, columnar body; 111, flange; 120, conical pressure head; 130, handle;

[0035] 200, lower die; 210, limiting protrusion;

[0036] 300, petal angle forming assembly; 310, upper cone sleeve; 311, embedded groove; 320, lower cone sleeve; 3201, limiting groove. DETAILED DESCRIPTION

[0037] In order to facilitate the understanding of the present application, the present application will be described more comprehensively with reference to the relevant drawings below. The preferred embodiments of the present application are provided in the drawings. However, the present application can be implemented in many other different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0038] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0039] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0041] It should also be noted that, in the embodiments of the present application, the same figure mark is used to represent the same component or the same part. For the same parts in the embodiments of the present application, the figure may only mark one of the parts or components as an example. It should be understood that the figure mark also applies to other identical parts or components.

[0042] According to one aspect of the present application, an embodiment of the present application provides an underwater liquid oxygen fracturing pipe base for an underwater liquid oxygen fracturing pipe, such as Figure 1-Figure 2 As shown, the underwater liquid oxygen fracturing tube base 10 includes a cylinder 11, a cone cap 12 and a plurality of elastic limiting flaps 13. The large end of the cone cap 12 is connected to one end of the cylinder 11. The plurality of limiting flaps 13 are evenly arranged along the circumferential direction at the end of the cylinder 11 away from the cone cap 12, and the limiting flaps 13 are spread out from each other. The cylinder 11 is used to be sleeved on the lower end of the fracturing tube, the cone cap 12 is used to guide the fracturing tube during insertion into the hole, and the limiting flaps 13 are used to elastically abut against the hole wall to overcome the buoyancy of the fracturing tube in water.

[0043] It can be understood that the outer diameter of the large end of the cone cap 12 and the outer diameter of the cylinder 11 are both smaller than the on-site drilling diameter, and the size of the plurality of limiting petals 13 after being unfolded is larger than the on-site drilling diameter.

[0044] In the embodiment of the present application, the underwater liquid oxygen fracturing tube base 10 is composed of a cylinder 11, a cone cap 12 and a plurality of elastic limiting flaps 13. The overall structure is simple. When in use, it is installed to the lower end of the fracturing tube. The cone cap 12 has a guiding function and can easily pass through the step between the casing and the borehole, which is convenient for sinking the tube and ensures the normal sinking of the tube. The plurality of elastic limiting flaps 13 elastically abut against the hole wall, effectively resisting the buoyancy faced by the fracturing tube during underwater installation, so that the tube body can self-stabilize and hover at the optimal position of the blasthole, which is convenient for optimizing the blasting parameters.

[0045] In one embodiment, if Figure 1 As shown, the outer diameter of the large end of the cone cap 12 is the same as the outer diameter of the cylinder 11, which is convenient for processing and manufacturing.

[0046] In one embodiment, if Figure 1 As shown, the cylinder 11, the cone cap 12 and the plurality of limiting flaps 13 are an integrated structure, which makes the connection between the various components of the structure tighter, reduces the seams and complex nodes, and thus improves the overall strength and stability of the underwater liquid oxygen fracturing pipe base 10.

[0047] Specifically, the underwater liquid oxygen fracturing pipe base 10 can be formed by using an end cap made of PVC, PET or PE material, which is split into petals and then heat-processed and then processed by a processing mold in the following embodiment.

[0048] In one embodiment, the inner wall of the cylinder 11 is provided with an internal thread (not shown), and the cylinder 11 is connected to the lower end of the fracturing tube by a thread; or

[0049] The cylinder 11 is provided with a mounting hole (not shown), and the cylinder 11 is fixed to the lower end of the fracturing tube by means of screws passing through the mounting hole.

[0050] By adopting the above connection mode, a reliable connection between the cylinder 11 of the underwater liquid oxygen fracturing pipe base 10 and the lower end of the fracturing pipe can be achieved. Of course, it is conceivable that the cylinder 11 of the underwater liquid oxygen fracturing pipe base 10 and the lower end of the fracturing pipe can also be connected by hot melt connection or glue.

[0051] According to another aspect of the present application, the embodiment of the present application also provides a processing mold for an underwater liquid oxygen fracturing tube base, which is used to process the underwater liquid oxygen fracturing tube base in the above embodiment, such as Figure 3-Figure 4 As shown, the processing mold includes an upper mold 100, a lower mold 200 and a petal angle forming component 300; the upper mold 100 includes a columnar body 110 and a conical pressure head 120 coaxially arranged at one end of the columnar body 110, and the lower mold 200 is provided with a groove with an inner wall having a conical surface; the petal angle forming component 300 includes an upper cone sleeve 310 and a lower cone sleeve 320, the upper cone sleeve 310 is sleeved on the upper end of the columnar body 110, and the outer diameter of the upper cone sleeve 310 gradually increases from the end close to the conical pressure head 120 to the end away from the conical pressure head 120, the lower cone sleeve 320 is arranged at the top of the lower mold 200 and is located above the groove, and the inner wall of the lower cone sleeve 320 includes a conical surface and a cylindrical surface from top to bottom, and the conical surface cooperates with the upper cone sleeve 310 to control the expansion angle of the limit petal 13.

[0052] The upper die 100 and the lower die 200 can be made of cast iron, and the two cooperate with each other to jointly complete the pressing and forming of the cone cap 12 and the cylinder 11 of the underwater liquid oxygen fracturing pipe base. The petal angle forming assembly 300 can also be made of cast iron. The upper cone sleeve 310 and the lower cone sleeve 320 in the petal angle forming assembly 300 limit the opening angle (expansion degree) between each limiting petal 13 during the process of the upper die 100 and the lower die 200 being pressed together.

[0053] The processing mold can produce a suitable underwater liquid oxygen fracturing pipe base according to the actual working conditions of on-site drilling. The processing method is simple to operate, the material is easy to obtain, and it has the advantages of low cost and high efficiency.

[0054] Furthermore, a handle 130 is provided at one end of the columnar body 110 of the upper mold 100 away from the conical pressing head 120 , and the handle 130 is convenient for taking out the upper mold 100 after the processing is completed.

[0055] In one embodiment, if Figure 4As shown, a flange 111 is provided at one end of the circumferential side of the columnar body 110 away from the conical pressure head 120, and an embedding groove 311 is provided at one end of the upper cone sleeve 310 away from the conical pressure head 120 for the flange 111 to be embedded. Through the cooperation between the flange 111 and the embedding groove 311, the upper cone sleeve 310 can be prevented from relative movement with respect to the columnar body 110 during the process of pressing the base of the underwater liquid oxygen fracturing pipe, thereby improving the stability during the pressing process.

[0056] A circle of limiting protrusions 210 are arranged around the groove at the top of the lower die 200, and a limiting groove 3201 is arranged at the lower end of the lower cone sleeve 320 to match the limiting protrusions 210. The cooperation between the limiting protrusions 210 and the limiting grooves 3201 plays a role in positioning the lower cone sleeve 320 and the lower die 200, and also improves the stability during the pressing process.

[0057] In one embodiment, multiple groups of flap angle forming assemblies 300 are provided, and the taper of the conical surface of the inner wall of the lower cone sleeve 320 in each group of flap angle forming assemblies 300 is different. According to this arrangement, the opening angle of the limiting flap 13 in the underwater liquid oxygen fracturing pipe base 10 can be adjusted by replacing the flap angle forming assemblies 300, thereby achieving the effect of increasing or reducing the friction between the limiting flap 13 and the hole wall.

[0058] Combination Figure 1-Figure 4 As shown, the present application also provides a method for processing an underwater liquid oxygen fracturing pipe base, comprising the following steps:

[0059] S1. According to the actual drilling diameter at the construction site, determine the appropriate diameter of the cylinder 11 of the underwater liquid oxygen fracturing pipe base 10 and purchase a certain number of original lower end covers 20, which are plastic pipe sections with one end closed and the other end open.

[0060] S2. Since the limit flap 13 of the underwater liquid oxygen fracturing pipe base 10 is fixed at one end and free at the other end, and the deformation after being subjected to pressure is very small, it can be simplified into a cantilever beam model. According to the material mechanics formula, it can be known that:

[0061]

[0062] Wherein: f is the magnitude of the sliding friction force on the limiting petal 13 in the borehole; E is the elastic modulus of the limiting petal 13; μ is the friction coefficient between the limiting petal 13 and the hole wall; y is the difference between the radius of each limiting petal 13 after expansion and the radius of the borehole; R is half of the outer diameter of the cylinder 11; r is half of the inner diameter of the cylinder 11; L is the length of the limiting petal 13; and n is the number of the limiting petals 13.

[0063] Due to the complex working conditions on site, the two parameters E and μ are difficult to obtain, but f can be measured on site with a dynamometer, R and r are known inherent parameters of the cylinder 11 in the underwater liquid oxygen fracturing pipe base 10, and the parameters y, L and n can be determined in advance, so Eμ can be regarded as a whole and recorded as K, and the value of K can be obtained by substituting the above-mentioned easily obtained parameters (R, r, f, y, L and n) into the formula. Therefore, 3-4 underwater liquid oxygen fracturing pipe bases 10 are first processed in the processing plant, and the attribute parameters of these underwater liquid oxygen fracturing pipe bases 10 are all set in advance, and then these underwater liquid oxygen fracturing pipe bases 10 are brought to the site, and the magnitude of the sliding friction force f they are subjected to in the borehole is measured with a dynamometer, and the value of K can be obtained according to the above formula after taking the average value.

[0064] Since it is too difficult to adjust the three parameters y, L and n at the same time, the parameters L and n that are difficult to adjust flexibly can be determined first. In this way, the only unknown parameter on the right side of the above equation is y. As long as the friction force f that the underwater liquid oxygen fracturing pipe base 10 should provide is determined according to the on-site conditions, the value of the parameter y can be obtained according to the above formula, thereby providing the corresponding angle parameters for the processing mold to press the limit petal.

[0065] It should be noted here that, because the drilling radius is known, after y is calculated, the value of the outermost radius of the underwater liquid oxygen fracturing tube base 10 (the radius of the circle after each limit flap 13 is unfolded) can be obtained, and then the outermost radius minus half of the outer diameter of the cylinder 11 can be obtained to obtain the corresponding length of the limit flap 13 in the radial direction of the cylinder 11, and then the actual length of the limit flap 13 is also determined in advance, so that according to the Pythagorean theorem, the corresponding length of the limit flap 13 in the axial direction of the cylinder 11 can be obtained, which is equivalent to knowing the three sides of a right triangle. Then, according to the sine and cosine, the angle at which the limit flap 13 is to be deflected relative to the axis of the cylinder 11 can be calculated, and then the processing plant can prepare the flap angle forming component 300 in the processing mold according to this degree.

[0066] S3. After determining the specific parameters of the upper mold 100, the lower mold 200 and the petal angle molding assembly 300, use professional drawing software to draw a schematic diagram of the upper mold 100, the lower mold 200 and the petal angle molding assembly 300 and indicate the specific values ​​of the parameters. Around the deflection angle of the limiting petal 13, 2-3 sets of petal angle molding assemblies 300 are made. The taper of the conical surface of the inner wall of the lower cone sleeve 320 in each set of petal angle molding assemblies 300 is different, so as to flexibly adjust the deflection angle of the limiting petal 13.

[0067] S4. Submit the schematic diagram to the processing plant, process the mold and the plurality of flap angle forming components 300, and perform flap processing on the original lower end cover 20, that is, cut multiple incisions evenly along the circumferential direction at the open end of the original lower end cover 20.

[0068] S5. Put the petal-split lower end cap into a drying oven and place it at about 150°C for 2-3 minutes. During this period, select the petal angle forming assembly 300 corresponding to the upper mold 100 and the lower mold 200 with suitable angles and assemble them. Then take the lower end cap out of the drying oven and quickly put it into the groove of the lower mold 200. Then immediately press the upper mold 100 and the upper cone sleeve 310 combined with it onto the lower end cap and keep it for 2-3 minutes. After the lower end cap is formed, take it out and the processing is completed.

[0069] S6. When the field test finds that the friction force provided by the underwater liquid oxygen fracturing pipe base 10 is not appropriate, the angle of the limiting flap 13 can be modified by replacing the flap angle forming assembly 300, thereby achieving the effect of increasing or decreasing the friction force.

[0070] In this embodiment, the processing method of the underwater liquid oxygen fracturing tube base is not only suitable for the production of supporting bases of underwater liquid oxygen fracturing tubes of conventional specifications in engineering practice, but also can be used to make processing molds according to various sizes and models of underwater liquid oxygen fracturing tubes to meet diverse operational needs. This method can accurately optimize the key dimensions of the underwater liquid oxygen fracturing tube base 10, lay a solid foundation for the subsequent stable operation of the underwater liquid oxygen fracturing tube, and effectively guarantee its safety and reliability in the underwater environment. At the same time, this batch processing method is both efficient and convenient and practical, without the need to introduce complicated and expensive processing equipment, and has extremely broad application prospects in many actual engineering scenarios such as underwater blasting engineering and marine resource development where underwater liquid oxygen fracturing tubes are frequently used.

[0071] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An underwater liquid oxygen fracturing pipe base, characterized in that: It includes a cylinder, a cone cap and a plurality of elastic limiting petals, the large end of the cone cap is connected to one end of the cylinder, the plurality of limiting petals are evenly arranged along the circumferential direction at the end of the cylinder away from the cone cap, and the limiting petals are spread out from each other, the cylinder is used to be sleeved on the lower end of the fracturing tube, the cone cap is used to guide the fracturing tube during the process of inserting it into the hole, and the limiting petals are used to elastically abut against the hole wall to overcome the buoyancy of the fracturing tube in water.

2. The underwater liquid oxygen fracturing pipe base according to claim 1, characterized in that: The outer diameter of the large end of the cone cap is the same as the outer diameter of the cylinder.

3. The underwater liquid oxygen fracturing pipe base according to claim 1, characterized in that: The cylinder, the cone cap and the plurality of limiting flaps are an integrated structure.

4. The underwater liquid oxygen fracturing pipe base according to claim 1, characterized in that: The underwater liquid oxygen fracturing pipe base is made of PVC, PET or PE material.

5. The underwater liquid oxygen fracturing pipe base according to claim 1, characterized in that: The inner wall of the cylinder is provided with internal threads, and the cylinder is connected to the lower end of the fracturing tube through threads; or The cylinder is provided with a mounting hole, and the cylinder is fixed to the lower end of the fracturing tube by means of screws penetrating through the mounting hole.

6. A processing mold for an underwater liquid oxygen fracturing pipe base, used for processing the underwater liquid oxygen fracturing pipe base as claimed in any one of claims 1 to 5, characterized in that: The processing mold includes an upper mold, a lower mold and a petal angle forming component; the upper mold includes a cylindrical body and a conical pressure head coaxially arranged at one end of the cylindrical body, and the lower mold is provided with a groove with an inner wall having a conical surface; the petal angle forming component includes an upper cone sleeve and a lower cone sleeve, the upper cone sleeve is sleeved on the upper end of the cylindrical body, the outer diameter of the upper cone sleeve gradually increases from the end close to the conical pressure head to the end away from the conical pressure head, the lower cone sleeve is arranged at the top of the lower mold and is located above the groove, the inner wall of the lower cone sleeve includes a conical surface and a cylindrical surface from top to bottom, and the conical surface cooperates with the upper cone sleeve to control the expansion angle of the limit petal.

7. The processing mold according to claim 6, characterized in that: A flange is provided on one end of the circumferential side of the columnar body away from the conical pressure head, and a groove for embedding the flange is provided on one end of the upper conical sleeve away from the conical pressure head; a circle of limiting protrusions is provided around the groove on the top of the lower mold, and a limiting groove adapted to the limiting protrusion is provided at the lower end of the lower conical sleeve.

8. The processing mold according to claim 6, characterized in that: The petal angle forming components are provided in a plurality of groups, and the taper of the conical surface of the inner wall of the lower cone sleeve in each group of the petal angle forming components is different.

9. A method for processing an underwater liquid oxygen fracturing pipe base, used for processing the underwater liquid oxygen fracturing pipe base as claimed in any one of claims 1 to 5, characterized in that: The processing method comprises the following steps: S1. According to the actual drilling diameter of the construction site, determine the appropriate cylinder diameter of the underwater liquid oxygen fracturing pipe base and purchase a certain number of original lower end caps, the original lower end cap is a plastic pipe section with one end closed and one end open; S2. Since one end of the limit petal of the underwater liquid oxygen fracturing pipe base is fixed and the other end is free, it can be simplified into a cantilever beam model. According to the material mechanics formula, it can be known that: Where: f is the magnitude of the sliding friction force on the limiting petal in the borehole; E is the elastic modulus of the limiting petal; μ is the friction coefficient between the limiting petal and the hole wall; y is the difference between the radius of the circle after each limiting petal is unfolded and the radius of the borehole; R is half of the outer diameter of the cylinder; r is half of the inner diameter of the cylinder; L is the length of the limiting petal; n is the number of limiting petals; f can be measured on site with a dynamometer. Parameters such as y, L and n can be determined in advance. Eμ is regarded as a whole and recorded as K. The above parameters R, r, f, y, L and n are substituted into the formula to obtain the value of K. Since it is too difficult to adjust the three parameters y, L and n at the same time, the parameters L and n that are difficult to adjust flexibly are determined first. The only unknown parameter on the right side of the above formula is y. The friction force f that the underwater liquid oxygen fracturing pipe base should provide is determined according to the on-site conditions. The value of parameter y is obtained according to the above formula to provide corresponding angle parameters for the processing mold to press the limit petal. The processing mold includes an upper mold, a lower mold and a petal angle A molding component; the upper mold comprises a cylindrical body and a conical pressure head coaxially arranged at one end of the cylindrical body, and the lower mold is provided with a groove whose inner wall is a conical surface; the petal angle molding component comprises an upper cone sleeve and a lower cone sleeve, the upper cone sleeve is sleeved on the upper end of the cylindrical body, the outer diameter of the upper cone sleeve gradually increases from one end close to the conical pressure head to one end away from the conical pressure head, the lower cone sleeve is arranged at the top of the lower mold and is located above the groove, the inner wall of the lower cone sleeve comprises a conical surface and a cylindrical surface from top to bottom, and the conical surface cooperates with the upper cone sleeve to control the deployment angle of the limit petal; S3. After determining the specific parameters of the upper die, lower die and petal angle forming components of the processing mold, use the drawing software to draw the schematic diagram of the upper die, lower die and petal angle forming components and indicate the specific values ​​of the parameters. Around the deflection angle of the limiting petal, prepare 2-3 sets of petal angle forming components. The taper of the conical surface of the inner wall of the lower cone sleeve in each set of petal angle forming components is different, so as to flexibly adjust the deflection angle of the limiting petal; S4. Submit the schematic diagram to the processing factory, process the processing mold, and split the original lower end cover; S5. Put the petal-split lower end cap into a drying oven and place it at about 150°C for 2-3 minutes. During this period, select the petal angle forming components with suitable angles and assemble them. Then take the lower end cap out of the drying oven and put it into the groove of the lower mold. Then press the upper mold and the upper cone sleeve combined with it onto the lower end cap and keep it for 2-3 minutes. After the lower end cap is formed, take it out and the processing is completed. S6. When the field test finds that the friction force provided by the underwater liquid oxygen fracturing pipe base is not appropriate, the opening angle of the limit petal can be modified by replacing the petal angle forming assembly, thereby achieving the effect of increasing or decreasing the friction force.

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