Design method of blind plate with compression crushing structure

Abstract

The invention relates to the technical field of petroleum machinery, in particular to a design method of a blind plate with a compression and crushing structure, which comprises the following steps: designing a blind plate structure type which is designed into a conical shell; calculating the structural stress level by applying a strength theory, selecting a proper fragile material, and checking and determining the size of the conical shell structure; all structural characteristics of the conical shell blind plate structure are evaluated through a conical shell structure pressure-bearing crushing test, and the structural characteristics comprise the structural size and the material type. According to the principle that the brittle material is large in compression strength, high in stored strain energy and large in structural fracture energy release, the application structure design method which is stable in pressure and sufficient in crushing granularity is achieved, and a new design method is provided for fluid confining pressure temporary plugging.

Description

Technical Field

[0001] The present invention relates to the technical field of petroleum machinery, and is a design method for a blind plate with a compression and crushing structure. Background Art

[0002] The existing common blind plate structures include mechanical type, material type and soluble type. The blind plate belongs to a disposable consumable structure. The reason for the difficulty in lowering the casing of the horizontal well in petroleum is the large frictional resistance. Therefore, temporary plugging buoyancy is commonly used to reduce the self-weight frictional resistance of the casing in the horizontal section. After the casing is lowered, the through-hole needs to be opened by pressure, and the debris is carried away with the fluid circulation. In engineering, it is hoped that the blind plate structure has a certain temporary plugging pressure. After the pressure is increased, the structure is broken, the temporary plugging disappears, and the smaller the particle size of the broken structure is, the better, without affecting subsequent use.

[0003] In the prior art, the Chinese patent with the application number ZL202010566139.1 and the name of "Full-pressure temporary plugging structure and design method for controlling crushing strength" discloses a full-pressure temporary plugging structure and design method for controlling crushing strength, and a hemispherical shell structure is used to form a normal through-hole of the casing. The Chinese patent with the application number CN201120119090.8 and the name of "Drill-free floating collar" discloses a drill-free floating collar, which is composed of a joint body, an annular sleeve and a blind plate. A circular blind plate (made of plastic, glass or synthetic resin) is placed on the annular step in the central hole at the upper end of the joint body. After the casing is lowered, the blind plate is broken by liquid pressure to form a normal through-hole of the casing. The Chinese patent with the application number CN201720830991.5 and the name of "A high-strength self-dissolving collar for floating casing" discloses a high-strength self-dissolving collar, which uses a bearing plate made of self-dissolving high-strength material. When the casing lowering operation is completed, the bearing plate is dissolved by releasing the dissolving liquid through wellhead pressure buildup to form a normal through-hole of the casing. The literature of "Petroleum Machinery" (2016.44) reports the structure and characteristics of a new type of sliding sleeve floating collar. The literature of "West-China Exploration Engineering" (2013.25) discusses the principle and characteristics of the sliding sleeve floating collar. The literature of "Science and Technology Innovation Herald" (2014.11) reports the blind plate type floating collar technology.

[0004] The above-mentioned blind plate structures all have good temporary plugging application effects. However, the temporary plugging structure of the mechanical sliding sleeve type is still prone to blockage when the pipeline is deformed, and there are certain risks; the crushing particle size of the material flat plate type temporary plugging structure is uncontrollable and completely depends on the characteristics of the material itself. Under the same temporary plugging pressure technical conditions, there are many broken debris, and if the particle size is large, it may limit the flow channel; the soluble type temporary plugging structure requires solvents and time periods, and the process is not convenient. Although there is a blind plate temporary plugging structure for controlling the crushing particle size among the blind plate structures retrieved from the above-mentioned literature data, it is different from the conical shell structure of the present application in design. Summary of the Invention

[0005] The present invention provides a blind plate design method with a compression and crushing structure, overcoming the deficiencies of the above-mentioned prior art, and effectively solving the problems of large-sized broken particles, high risk, a large amount of debris, and poor processability in the existing blind plate structure.

[0006] One of the technical solutions of the present invention is achieved through the following measures: A blind plate design method with a compression and crushing structure, comprising the following steps:

[0007] Step 1: Design the blind plate structure type, and the blind plate structure type is designed as a conical shell;

[0008] Step 2: Calculate the dimensions of the conical shell structure: Apply the strength theory to calculate the structural stress level, select an appropriate brittle material, and check and determine the dimensions of the conical shell structure;

[0009] Step 3: Experimental evaluation of the pressure-bearing crushing of the conical shell structure: Through the experimental evaluation of the pressure-bearing crushing of the conical shell structure, finalize all the structural characteristics of the conical shell blind plate structure, where the structural characteristics include structural dimensions and material types.

[0010] The following is a further optimization or / and improvement of one of the above-mentioned technical solutions of the invention:

[0011] The above-mentioned Step 1 may specifically include the following steps:

[0012] Determine the structural characteristics of the conical shell; Under the action of the fluid confining pressure q in the cylindrical coordinate system, the structural characteristics of the conical shell at least include the apex cone angle 2α of the conical shell, the span radius R1 of the conical shell, and the thickness h of the conical shell;

[0013] Determine the range of the apex cone angle of the conical shell; Among them, the range of the apex cone angle 2α of the conical shell is greater than 0 degrees and less than 180 degrees;

[0014] Calculate the span radius R1 of the conical shell; Among them, the span radius R1 of the conical shell is equal to half of the diameter Φ of the flow-through pipeline, plus a step support dimension of more than 2 mm, that is:

[0015] R 1 = Φ / 2 + ~2.00

[0016] The above-mentioned Step 2 may specifically include the following steps:

[0017] Through the engineering algorithm of material mechanics, obtain the principal stress of the dangerous section of the conical shell blind plate structure, as shown in the following formula;

[0018]

[0019] Strength theory calculation, given the Poisson's ratio μ of the brittle material, there are two states of the algorithm state analyzed by applying the second strength criterion, as shown in the following formulas respectively:

[0020] Working state σ of the conical shell blind plate structure 1 -μ(σ 2 +σ 3 ) ≤ [σ]

[0021] Breaking state σ of the conical shell blind plate structure 1 -μ(σ 2 +σ 3 ) ≥ σ bc

[0022] Then the expression of the thickness h of the conical shell blind plate is as follows:

[0023]

[0024] Wherein, σ and σ bc are the allowable strength and the compressive failure strength of the material respectively; q w and q bc are the fluid confining pressures of the conical shell blind plate structure under the working state and the critical crushing condition respectively, and the pressure is defined as a negative value;

[0025] Determine the minimum value of the thickness h of the conical shell blind plate according to the allowable strength and the working pressure of the brittle material;

[0026] Determine the maximum value of the thickness h of the conical shell blind plate according to the compressive strength and the crushing pressure of the brittle material, and then form the structural finalization after size rounding.

[0027] In the above step three, the experimental evaluation of the pressure-bearing crushing particle size of the conical shell blind plate structure can be carried out by a fluid compression test to test the working pressure and the particle size of the pressurized crushing borne by the conical shell blind plate structure; the finalized structural characteristics can be tested by pressure-bearing and crushing tests, and the material type can be continuously adjusted to optimize the structural size; after determining the structural size and the material type, the blind plate with a compressive crushing structure is finalized, and the design method ends.

[0028] The second technical solution of the present invention is achieved by the following measures: A blind plate with a compressive crushing structure, and the structural type is a conical shell;

[0029] Wherein, the structural characteristics of the conical shell include the top cone angle 2α of the conical shell, the span radius R1 of the conical shell, and the thickness h of the conical shell;

[0030] The range of the top cone angle 2α of the conical shell is greater than 0 degree and less than 180 degrees;

[0031] The span radius R1 of the conical shell is equal to half of the diameter Φ of the flow pipeline plus a step support size of more than 2 mm, that is:

[0032] R 1 = Φ / 2 + ~2.00

[0033] The value range of the thickness h of the conical shell blind plate is as follows:

[0034]

[0035] In the formula, σ and σ bc are the allowable strength and compressive failure strength of the material respectively; q w and q bc are the fluid confining pressures of the conical shell blind plate structure under the working condition and the crushing critical condition respectively, and the pressure is defined as a negative value; μ is the Poisson's ratio of the brittle material.

[0036] The third technical solution of the present invention is achieved by the following measures: A terminal device includes a memory and a processor. A program that can run on the processor is stored on the memory. When the processor executes the program, the blind plate design method with a compression and crushing structure described above is implemented.

[0037] The fourth technical solution of the present invention is achieved by the following measures: A storage medium stores one or more programs, and the one or more programs can be executed by one or more processors to implement the blind plate design method with a compression and crushing structure described above.

[0038] The present invention provides a blind plate design method with a compression and crushing structure to supplement the structure type and design method of compression and crushing. Aiming at the problems of large particle size, high risk, many debris and poor processability of the existing blind plate structure, the present invention utilizes the principle that brittle materials have high compressive strength, high stored strain energy and large structural fracture energy release to realize a stable pressure and fully crushed particle size application structure design method, providing a new design method for fluid confining pressure temporary plugging. Description of the Drawings

[0039] Att Figure 1 is a schematic flow chart of the blind plate design method with a compression and crushing structure according to an embodiment of the present invention.

[0040] Att Figure 2 is a schematic diagram of the conical shell structure characteristics of the blind plate with a compression and crushing structure according to an embodiment of the present invention.

[0041] Att Figure 3 is a schematic diagram of the structure of the blind plate with a compression and crushing structure according to an embodiment of the present invention. Detailed Embodiments

[0042] The present invention is not limited by the following embodiments, and the specific implementation manners can be determined according to the technical solutions of the present invention and the actual situation.

[0043] The present invention will be further described below in conjunction with embodiments:

[0044] Embodiment 1: As shown in AttFigure 1 As shown in the figure, an embodiment of the present invention provides a blind plate design method with a compression and crushing structure, including the following steps:

[0045] Step 1: Design the type of blind plate structure. Among them, the blind plate structure type is designed as a conical shell.

[0046] In the embodiment of the present invention, Step 1 specifically includes the following steps:

[0047] Determine the structural characteristics of the conical shell; as Figure 2 shown, under the action of the fluid confining pressure q in the cylindrical coordinate system, the structural characteristics of the conical shell at least include the apex cone angle 2α of the conical shell, the span radius R1 of the conical shell, and the thickness h of the conical shell.

[0048] Determine the range of the apex cone angle of the conical shell; among them, the range of the apex cone angle 2α of the conical shell is greater than 0 degrees and less than 180 degrees, and the recommended value range is:

[0049] 10° < α < 60°

[0050] Calculate the span radius R1 of the conical shell; among them, the span radius R1 of the conical shell is equal to half of the diameter Φ of the flow-through pipeline, plus a step support size of more than 2 millimeters, that is:

[0051] R 1 = Φ / 2 + ~2.00

[0052] In the embodiment of the present invention, the thickness h of the conical shell needs to be determined by the strength calculation in the next step.

[0053] Step 2: Calculate the structural dimensions of the conical shell: Apply the strength theory to calculate the structural stress level, select an appropriate brittle material, check and determine the structural dimensions of the conical shell. Among them, selecting an appropriate brittle material means selecting a material with stable performance, good economy and processability.

[0054] In the embodiment of the present invention, Step 2 specifically includes the following steps:

[0055] First, the structural stress level can be obtained through the engineering algorithm of material mechanics, and the principal stress of the dangerous section of the conical shell blind plate structure can be obtained, as shown in the following formula:

[0056]

[0057] For the strength theory calculation, given the Poisson's ratio μ of the brittle material, there are two states of the algorithm analysis applied by the second strength criterion, which are shown in the following formulas respectively:

[0058] The working state σ of the conical shell blind plate structure 1 - μ(σ 2 + σ 3 ) ≤ [σ]

[0059] The crushing state σ of the conical shell blind plate structure 1 -μ(σ 2 +σ 3 )≥σ bc

[0060] Then the expression of the thickness h of the conical shell blind plate is as follows:

[0061]

[0062] In the formula, σ and σ bc are the allowable strength and compressive failure strength of the material respectively; q w and q bc are the fluid confining pressures of the conical shell blind plate structure under the working state and the crushing critical condition respectively, and the pressure is defined as negative.

[0063] When the mechanical properties of the material are known, the minimum value of the thickness h of the conical shell blind plate can be preliminarily determined according to the allowable strength and working pressure of the brittle material; similarly, the maximum value of the thickness h of the conical shell blind plate can also be determined according to the compressive strength and crushing pressure of the brittle material, and then the structure is finalized after size rounding.

[0064] Step 3: Experimental evaluation of the pressure-bearing crushing of the conical shell structure: Through the experimental evaluation of the pressure-bearing crushing of the conical shell structure, all the structural characteristics of the finalized conical shell blind plate structure are determined, where the structural characteristics include structural dimensions and material types.

[0065] In Step 3, the experimental evaluation of the particle size of the pressure-bearing crushing of the conical shell blind plate structure, that is, through the fluid compression test, the working pressure and the particle size of the pressure-induced crushing borne by the conical shell blind plate structure are tested; the finalized structural characteristics, that is, through the pressure-bearing and crushing tests, the material type is continuously adjusted and the structural dimensions are optimized; after determining the structural dimensions and material types, the blind plate with a compression crushing structure is finalized, as Figure 3 shown, then the design method ends.

[0066] The embodiment of the present invention provides a design method for a blind plate with a compression crushing structure to supplement the structural types and design methods of compression crushing. Aiming at the problems of large crushing particles, high risk, many debris and poor processability of the existing blind plate structure, the embodiment of the present invention utilizes the principle that brittle materials have high compressive strength, high stored strain energy and large structural fracture energy release, and realizes an application structure design method with stable pressure and sufficient crushing particle size, providing a new design method for fluid confining pressure temporary plugging.

[0067] Example 2: This example of the present invention provides a specific application of a blind plate design method with a compression and crushing structure. For a working condition where a blind plate structure is used inside a 5-1 / 2-inch casing according to the API standard, the working condition size parameters are an outer casing diameter of Φ139.7 mm and an inner through diameter of Φ120 mm. Given that the allowable strength of the conical shell blind plate material is 480 MPa, the compression failure strength is 630 MPa, and the Poisson's ratio μ = 0.27. The working pressure of the conical shell blind plate structure with compression and crushing is set at 40 MPa; the crushing pressure is 70 MPa. The specific design method of the conical shell blind plate structure with compression and crushing includes the following steps:

[0068] Step 1: Design the conical shell blind plate structure with compression and crushing.

[0069] Step 1.1: The range of the top cone angle 2α of the conical shell is greater than 0 degrees and less than 180 degrees. In this case, the value range is:

[0070] α = 30°

[0071] Step 1.2: According to the inner through diameter of the casing Φ120 mm, the span radius R1 of the conical shell is designed to be approximately:

[0072] R 1 = Φ / 2 + ~5.00 = 65.00 mm

[0073] Step 2: Calculate the structural dimensions of the conical shell.

[0074] The range of the thickness h of the conical shell calculated by strength is:

[0075]

[0076] Round off the structural dimensions, and the value range is h = 3.00 mm.

[0077] Step 3: Evaluate through the test of the bearing and crushing particle size of the conical shell structure.

[0078] Step 3.1: Structural bearing and crushing test. The mechanical properties of brittle materials have a large dispersion, and the machining deviation of the blind plate structure size is not small. Under the brittle material strength theory, both the structural size obtained by design calculation and the material type selection need to be tested and evaluated through experiments. If the mechanical properties of the material are stable, the structure bears pressure stably, and the crushing particle size is sufficient, then the material type is finalized; if the material is finalized, and the bearing and crushing pressures of the conical shell blind plate structure still cannot be controlled, then first increase the structural size to ensure the safe working load, and take a certain safety amplification coefficient range [1.2, 1.5]. The range of the thickness h of the conical shell blind plate structure is defined as 3.6 mm to 4.5 mm, and here 4.0 mm is taken.

[0079] Step 3.2, Structure shaping. The selected brittle material in the embodiment of the present invention is high borosilicate glass, and its mechanical properties are known as above. Determine the design dimensions of the conical shell blind plate structure: α = 30 degrees, R1 = 65 mm, and h = 4.0 mm. The brittle material and structure of the conical shell blind plate are shaped, and the design is completed.

[0080] In the embodiment of the present invention, by using the principle that brittle materials have high compressive strength, high stored strain energy, and large structural fracture energy release, a structural design method with stable pressure and sufficient crushing particle size is realized, providing a new design method for fluid confining pressure temporary plugging.

[0081] Example 3: The embodiment of the present invention provides a blind plate with a compression and crushing structure, and its structural type is a conical shell;

[0082] Among them, the structural characteristics of the conical shell include the top cone angle 2α of the conical shell, the span radius R1 of the conical shell, and the thickness h of the conical shell;

[0083] In the embodiment of the present invention, the range of the top cone angle 2α of the conical shell is greater than 0 degrees and less than 180 degrees. Preferably, the value range of α is:

[0084] 10° < α < 60°

[0085] In the embodiment of the present invention, the span radius R1 of the conical shell is equal to half of the diameter Φ of the flow-through pipeline, plus a step support size of more than 2 mm, that is:

[0086] R 1 = Φ / 2 + ∼2.00

[0087] In the embodiment of the present invention, the value range of the thickness h of the conical shell blind plate is:

[0088]

[0089] In the formula, σ and σ bc are the allowable strength and compressive failure strength of the material respectively; q w and q bc are the fluid confining pressures of the conical shell blind plate structure under working conditions and under critical crushing conditions respectively, and the pressure is defined as negative; μ is the Poisson's ratio of the brittle material.

[0090] The embodiment of the present invention provides a blind plate with a compression and crushing structure. Aiming at the problems of large broken particles, high risk, many debris, and poor processability of the existing blind plate structure, by using the principle that brittle materials have high compressive strength, high stored strain energy, and large structural fracture energy release, a blind plate structure with stable pressure and sufficient crushing particle size is realized.

[0091] Embodiment 4: The embodiment of the present invention provides a terminal device, which includes a memory, a processor, a communication interface, and a communication bus. A program that can run on the processor is stored in the memory. When the processor executes the program, it implements the blind plate design method with a compression and crushing structure described in the above embodiments.

[0092] The processor can be a central processing unit, and the processor can also be other general-purpose processors, digital signal processors, application-specific integrated circuits, field programmable gate arrays, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. chips, or a combination of the above types of chips.

[0093] As a non-transitory computer-readable storage medium, the memory can be used to store non-transitory software programs, non-transitory computer-executable programs, and units, such as the program units corresponding to the above method embodiments of the present invention. By running the non-transitory software programs, instructions, and modules stored in the memory, the processor executes various functional applications and work data processing of the processor, that is, implements the blind plate design method with a compression and crushing structure described in the above embodiments.

[0094] The memory can include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created by the processor, etc. In addition, the memory can include high-speed random access memory, and can also include non-transitory memory, such as at least one disk storage device, a flash memory device, or other non-transitory solid-state storage devices. The memory optionally includes a memory remotely set relative to the processor, and these remote memories can be connected to the processor through a network. The one or more programs are stored in the memory and, when executed by the processor, implement the blind plate design method with a compression and crushing structure described in the above embodiments.

[0095] Embodiment 5: The embodiment of the present invention provides a storage medium for computer-readable storage. The storage medium stores one or more programs, and the one or more programs can be executed by one or more processors to implement the blind plate design method with a compression and crushing structure provided in the above method embodiments.

[0096] Among them, the storage medium can be an internal storage unit of the terminal device, such as the hard disk or memory of the terminal device. The storage medium can also be an external storage device of the terminal device, such as a plug-in hard disk, a smart memory card, a secure digital card, a flash card, etc. equipped on the terminal device.

[0097] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effects. Non-essential technical features can be added or subtracted according to actual needs to meet the requirements of different situations.

Claims

1. A design method for a blind plate with a compression and crushing structure, characterized in that it includes the following steps: Step 1: Design the type of blind plate structure, and the blind plate structure type is designed as a conical shell; Step 2: Calculate the structural dimensions of the conical shell: Apply strength theory to calculate the structural stress level, select an appropriate brittle material, check and determine the dimensions of the conical shell structure; Step 3: Experimental evaluation of the pressure-bearing and crushing of the conical shell structure: Through the experimental evaluation of the pressure-bearing and crushing of the conical shell structure, finalize all the structural characteristics of the conical shell blind plate structure, where the structural characteristics include structural dimensions and material types.

2. The design method for a blind plate with a compression and crushing structure according to claim 1, characterized in that Step 1 specifically includes the following steps: Determine the structural characteristics of the conical shell; Under the action of the fluid confining pressure q in the cylindrical coordinate system, the structural characteristics of the conical shell at least include the top cone angle 2α of the conical shell, the span radius R1 of the conical shell, and the thickness h of the conical shell; Determine the range of the top cone angle of the conical shell; Among them, the range of the top cone angle 2α of the conical shell is greater than 0 degrees and less than 180 degrees; Calculate the span radius R1 of the conical shell; Among them, the span radius R1 of the conical shell is equal to half of the diameter Φ of the flow-through pipeline, plus a step support dimension of more than 2 mm, that is: R 1 = Φ / 2 + ~2.

00.

3. The design method for a blind plate with a compression and crushing structure according to claim 1 or 2, characterized in that Step 2 specifically includes the following steps: Through the engineering algorithm of material mechanics, obtain the principal stress of the dangerous section of the conical shell blind plate structure, as shown in the following formula: σ 1 = 0 Strength theory calculation, given the Poisson's ratio μ of the brittle material, there are two states of the algorithm analysis applying the second strength criterion, as shown in the following formulas respectively: Working state σ of the conical shell blind plate structure 1 -μ(σ 2 +σ 3 )≤[σ] Breaking state σ of the conical shell blind plate structure 1 -μ(σ 2 +σ 3 )≥σ bc Then the expression of the thickness h of the conical shell blind plate is as follows: where, σ and σ bc are the allowable strength and the compressive failure strength of the material, respectively; q w and q bc are the fluid confining pressures of the conical shell blind plate structure under the working condition and the crushing critical condition, respectively, and the pressure is defined as negative; Determine the minimum value of the thickness h of the conical shell blind plate according to the allowable strength and working pressure of the brittle material; Determine the maximum value of the thickness h of the conical shell blind plate according to the compressive strength and crushing pressure of the brittle material, and then form a structural finalization after dimension rounding.

4. The design method for a blind plate with a compression and crushing structure according to claim 1 or 2, characterized in that In Step 3, the experimental evaluation of the pressure-bearing and crushing particle size of the conical shell blind plate structure, that is, through the fluid compression test, test the working pressure and the particle size of the pressure-induced crushing borne by the conical shell blind plate structure; Finalize the structural characteristics, that is, through the pressure-bearing and crushing tests, continuously adjust the material type and optimize the structural dimensions; After determining the structural dimensions and material types, the blind plate with a compression and crushing structure is finalized, and then the design method ends.

5. The design method for a blind plate with a compression and crushing structure according to claim 3, characterized in that In Step 3, the experimental evaluation of the pressure-bearing and crushing particle size of the conical shell blind plate structure, that is, through the fluid compression test, test the working pressure and the particle size of the pressure-induced crushing borne by the conical shell blind plate structure; Finalize the structural characteristics, that is, through the pressure-bearing and crushing tests, continuously adjust the material type and optimize the structural dimensions; After determining the structural dimensions and material types, the blind plate with a compression and crushing structure is finalized, and then the design method ends.

6. A blind plate with a compression and crushing structure, characterized in that the structural type is a conical shell; Among them, the structural characteristics of the conical shell include the apex cone angle 2α of the conical shell, the span radius R1 of the conical shell, and the thickness h of the conical shell; The range of the apex cone angle 2α of the conical shell is greater than 0 degrees and less than 180 degrees; The span radius R1 of the conical shell is equal to half of the nominal diameter Φ of the flow pipeline, plus the step support dimension of more than 2 mm, that is: R 1 = Φ / 2 + ~2.00 The value range of the thickness h of the conical shell blind plate is: wherein, σ and σ bc are respectively the allowable strength and the compressive failure strength of the material; q w and q bc are respectively the fluid confining pressures of the conical shell blind plate structure under the working condition and the crushing critical condition, and the pressure is defined as a negative value; μ is the Poisson's ratio of the brittle material.

7. A terminal device, comprising a memory and a processor, where a program executable on the processor is stored on the memory, characterized in that when the processor executes the program, it implements the blind plate design method with a compression and crushing structure according to any one of claims 1 to 5.

8. A storage medium, characterized in that the storage medium stores one or more programs, and the one or more programs can be executed by one or more processors to implement the blind plate design method with a compression and crushing structure according to any one of claims 1 to 5.

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