Chip breaking method for thread machining of petroleum perforating gun

Abstract

The invention discloses a chip breaking method for thread machining of a petroleum perforating gun, and relates to the technical field of thread chip breaking machining. Comprising the following steps that a, thread chip breaking machining parameters are set according to machining requirements, wherein the thread chip breaking machining parameters include the thread small diameter D1, the single-tool thread engagement ap, the thread pitch p, the thread height h, the effective thread length L, the radial feeding and retracting amount f, the axial feeding amount m, the axial retracting amount r and the thread starting point position L1; b, according to the parameters given in the step a, the tool starting position, the thread tooth number and the thread cutting cycle index of initial thread cutting are calculated; and c, according to the parameters given in the step a and the parameters calculated in the step b, a thread cutter is set at the thread cutting starting position, then an oblique-feeding type segmented thread cutting mode is carried out, scrap iron formed through machining in the method is in a short strip shape, the scrap iron is prevented from winding the cutter, automatic chip breaking of the threads for the petroleum perforating gun is achieved, and the cutting efficiency is improved. And the thread precision is greatly improved, the service life of the cutter is greatly prolonged, and the field application effect is good.

Description

Technical Field

[0001] The invention relates to the technical field of thread chip breaking processing, and in particular to a chip breaking method for thread processing of a petroleum perforating gun. Background Art

[0002] The oil perforating gun is a tool used for oil and gas extraction. It can form holes in underground wells so that oil and gas can flow out smoothly. The perforating gun is a tubular structure with sealing surfaces and threads inside. These design elements can ensure the stability and reliability of the perforating gun under high pressure and impact force, prevent oil and gas leakage, and facilitate assembly and disassembly. Therefore, the processing quality of the sealing surface and threads of the perforating gun plays a vital role in the performance of the perforating gun.

[0003] At present, the most efficient and effective method for processing the sealing surface and threads of the perforating gun is to use CNC lathes for turning. However, during the thread processing of the perforating gun, the iron chips cannot be cut off in time and effectively, resulting in long iron chips often entangled on the tool, which not only affects the service life of the tool and the processing quality of the perforating gun, but also restricts the further development of the automation of perforating gun processing. Summary of the invention

[0004] The purpose of the present invention is to provide a chip breaking method for oil perforating gun thread processing, so that the iron chips formed by processing are in short strips, and the iron chips are prevented from being entangled with the tool. While realizing automatic chip breaking of the thread, the thread accuracy and the service life of the tool are also greatly improved, and the on-site application effect is good.

[0005] The present invention is achieved through the following technical solutions:

[0006] A chip breaking method for oil perforating gun thread machining comprises the following steps:

[0007] a. Set the thread chip breaking processing parameters according to the processing requirements: thread minor diameter D1, single-knife thread cutting amount ap, thread pitch p, thread tooth height h, effective thread length L, radial feed and retract amount f, axial feed amount m, axial retract amount r, thread starting point position L1;

[0008] b. Calculate the starting position of the initial thread cutting, the number of thread teeth, and the number of thread cutting cycles based on the parameters given in step a;

[0009] c. According to the parameters given in step a and the parameters calculated in step b, the thread cutter is set at the starting position of thread cutting, and then the oblique segmented thread cutting method is performed to realize automatic chip breaking of oil perforating gun thread processing.

[0010] Furthermore, in step b, the starting position of the initial thread cutting is obtained as follows:

[0011] The starting position of thread cutting is recorded as (X1, Z1), where X1 is the radial starting point of the thread, and Z1 is the axial starting point of the thread. X1 and Z1 satisfy the following formulas (I) and (II):

[0012] X1=D1+ap-f (Ⅰ);

[0013] Z1=-(L1-P)(Ⅱ).

[0014] Furthermore, in step b, the number of thread teeth N is calculated by the following formula (III):

[0015] N=L / p(Ⅲ).

[0016] Furthermore, in step b, the value of N is an integer. When the value of N is not an integer, it is rounded down. The last pitch axial feed amount m1=L-L1-Np.

[0017] Furthermore, in step b, the number of thread cutting cycles n is calculated by the following formula (IV):

[0018] n=2h / ap(Ⅳ).

[0019] Furthermore, in step b, the value of n is an integer. When the value of n is not an integer, it is rounded up by 1. Then the back cutting depth ap1 of the last thread cutting cycle is 2h-ap(n-1).

[0020] Furthermore, in step c, the thread cutting method is:

[0021] a1. Radial feed increases the thread back cutting amount, that is, radial feed ap;

[0022] b1. Oblique thread feed, i.e. radial feed f and axial feed m at the same time;

[0023] c1. Turn the first thread in the first cycle, i.e., axial feed m;

[0024] d1. Oblique thread withdrawal, i.e. radial withdrawal f and axial advance m at the same time;

[0025] e1. Return to the next pitch starting point, i.e. axial retraction r;

[0026] f1. Repeat steps b1 to e1 to complete the first cycle of thread cutting;

[0027] g1. Repeat steps a1 to f1 until all thread cutting is completed.

[0028] Furthermore, when the value of n calculated by formula (IV) in step b is not an integer, the rounding method is adopted, and the back cutting amount ap1 of the last thread cutting cycle is 2h-ap(n-1); in the thread cutting method, steps a1 to f1 are repeated until the penultimate thread cutting cycle is completed.

[0029] h1. Radial feed increases the thread back cutting amount, that is, radial feed ap1, ap1 = 2h-ap(n-1);

[0030] i1. Oblique thread feed, i.e. radial feed f and axial feed m at the same time;

[0031] j1. Turn the last thread of the first cycle, i.e. axial feed m;

[0032] k1. Oblique thread withdrawal, i.e. radial withdrawal f and axial advance m at the same time;

[0033] l1. Return to the starting point of the next pitch, i.e. axial retraction r;

[0034] m1. Repeat steps i1 to l1 until all thread cutting is completed.

[0035] Further, when the N value calculated by formula (III) in step b is not an integer, it is rounded down, and the last pitch axial feed amount m1=L-L1-Np; in the thread cutting method, steps a1 to f1 are repeated until the penultimate cycle of thread cutting is completed.

[0036] h1. Radial feed increases the thread back cutting amount, that is, radial feed ap;

[0037] i1. Oblique thread feed, i.e. radial feed f and axial feed m at the same time;

[0038] j1. Turn the last thread in the first cycle, i.e., axial feed m1, m1 = L-L1-Np;

[0039] k1. Oblique thread withdrawal, i.e. radial withdrawal f and axial advance m at the same time;

[0040] l1. Return to the starting point of the next pitch, i.e. axial retraction r;

[0041] m1. Repeat steps i1 to l1 until all thread cutting is completed.

[0042] Furthermore, in step c, the entire thread is divided into several segments for segmented cutting by oblique segmented cutting, that is, one pitch is one segment. The thread iron chips obtained by the oblique segmented cutting method are in the shape of short strips, and automatic chip breaking of the thread can be achieved.

[0043] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0044] 1. In the present invention, the thread machining of the perforating gun is automatic chip breaking, which solves the problem that long iron chips are entangled on the tool during the turning process of the internal thread of the perforating gun, which easily scratches the sealing surface of the barrel and the tool, and the thread machining quality and the service life of the tool are greatly improved.

[0045] Second, in the present invention, the thread processing of the perforating gun automatically breaks chips, which solves the problem of scratching the barrel sealing surface and the tool when manually using tools to clean the iron chips wrapped around the perforating gun or the tool, and also reduces the safety risks of manual operation.

[0046] 3. In the present invention, the automatic chip breaking technology for thread processing of the perforating gun adopts a segmented cutting method, the tool processing resistance is small, the chip heat dissipation is fast, and the thread processing quality is more stable.

[0047] Fourth, in the present invention, the thread processing of the perforating gun is automatically chip-breaking, which realizes the automation and unmanned processing of the perforating gun, and can greatly save the labor cost of the perforating gun processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Processing drawings for perforating guns.

[0049] Figure 2 Program tool path for perforating gun thread chip breaking.

[0050] Figure 3 A comparison of the iron chips generated by thread turning of the perforating gun. DETAILED DESCRIPTION

[0051] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0052] Example 1

[0053] To facilitate the public to understand this solution, this embodiment takes the thread processing and chip breaking of Tr78×4 type perforating gun as an example, and the perforating gun processing drawings are referenced. Figure 1 The above and other purposes and features of the present invention will become more apparent through the following description in conjunction with the accompanying drawings. The following embodiments are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0054] A chip breaking method for thread machining of a petroleum perforating gun, which relates to the technical field of thread chip breaking machining, comprises the following steps:

[0055] first step:

[0056] The thread chip breaking processing parameters are set according to the processing requirements: thread minor diameter D1=74.2mm, single-knife thread cutting amount ap=0.3mm, thread pitch p=4mm, thread tooth height h=2.25mm, effective thread length L=60mm, radial feed and retract amount f=5mm (greater than 2h), axial feed amount m=4mm (preferably an integer multiple of the pitch), axial retract amount r=8mm (preferably an integer multiple of the pitch), thread starting point position L1=25mm.

[0057] Step 2:

[0058] According to the parameters given in the first step, the starting position of the initial thread cutting, the number of thread teeth and the number of thread cutting cycles are calculated;

[0059] In this step, the starting position of the initial thread cutting is obtained as follows:

[0060] The starting position of thread cutting is recorded as (X1, Z1), where X1 is the radial starting point of the thread, and Z1 is the axial starting point of the thread. X1 and Z1 satisfy the following formulas (I) and (II):

[0061] X1=D1+ap-f (Ⅰ);

[0062] Z1=-(L1-P) (Ⅱ),

[0063] Calculation shows that X1=D1+ap-f=74.2+0.3-5=69.5, Z1=-(L1-P)=-(25-4)=-21, that is, the starting position of thread cutting is recorded as (69.5, -21).

[0064] The number of thread teeth N is calculated by the following formula (III):

[0065] N=(L-L1) / p=(60-25) / 4=8.75(Ⅲ).

[0066] In this step, the value of N is an integer. When the value of N is not an integer, it is rounded down, that is, N=8, and the last pitch axial feed amount m1=L-L1-Np=60-25-8*4=3mm.

[0067] The number of thread cutting cycles n is calculated by the following formula (IV):

[0068] n=2h / ap=2*2.25 / 0.3=15 (IV).

[0069] Step 3:

[0070] According to the parameters given in the first step and the parameters calculated in the second step, a thread breaking program is compiled, the thread cutter is set at the starting position of thread cutting, and then the oblique segmented thread cutting method is performed to realize automatic chip breaking of oil perforating gun thread processing.

[0071] The thread cutting method is:

[0072] a1. Radial feed increases the thread back cutting amount ap, that is, radial feed is 0.3mm;

[0073] b1. Oblique thread feed, i.e. radial feed f is 5 mm and axial feed m is 4 mm;

[0074] c1. Turn the first thread in the first cycle, i.e. the axial feed m is 4 mm;

[0075] d1. Oblique thread withdrawal, that is, the radial withdrawal f is 5mm and the axial feed m is 4mm;

[0076] e1. Return to the next pitch starting point, that is, the axial retraction r is 8mm;

[0077] f1. Repeat steps b1 to e1 until the first cycle of thread cutting is completed;

[0078] g1. Repeat steps a1 to f1 until the penultimate thread cutting cycle is completed;

[0079] h1. Radial feed increases the thread back cutting amount ap, that is, radial feed is 0.3mm;

[0080] i1. Oblique thread feed, i.e. radial feed f is 5 mm and axial feed m is 4 mm;

[0081] j1. Turn the last thread in the first cycle, that is, the axial feed m1 is 3mm;

[0082] k1. Oblique thread retraction, that is, the radial retraction f is 5mm and the axial feed m is 4mm;

[0083] l1. Return to the next pitch starting point, that is, the axial retraction r is 8mm;

[0084] m1. Repeat steps i1 to l1 until all thread cutting is completed.

[0085] In this embodiment, the cutting path of the perforating gun thread chip breaking program is referenced Figure 2 .

[0086] In this step, the entire thread is divided into several segments by oblique segment cutting, that is, one pitch is one segment, so that the thread iron chips are short strips. Figure 3 , realizing automatic chip breaking of thread.

[0087] This method uses an oblique segmented cutting method to cut the perforating gun thread, realizes automatic chip breaking during thread processing, and effectively avoids tool tip wear caused by thread wrapping around the cutter during processing. The perforating gun thread processing quality and stability are greatly improved, and the service life of the thread blade is also greatly improved.

[0088] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A chip breaking method for oil perforating gun thread machining, characterized in that: The steps include: a. Set the thread chip breaking processing parameters according to the processing requirements: thread minor diameter D1, single-knife thread cutting amount ap, thread pitch p, thread tooth height h, effective thread length L, radial feed and retract amount f, axial feed amount m, axial retract amount r, thread starting point position L1; b. Calculate the starting position of the initial thread cutting, the number of thread teeth, and the number of thread cutting cycles based on the parameters given in step a; c. According to the parameters given in step a and the parameters calculated in step b, the thread cutter is set at the starting position of thread cutting, and then the oblique segmented thread cutting method is performed to realize automatic chip breaking of oil perforating gun thread processing.

2. A chip breaking method for oil perforating gun thread machining according to claim 1, characterized in that: In step b, the starting position of the initial thread cutting is obtained as follows: The starting position of thread cutting is recorded as (X1, Z1), where X1 is the radial starting point of the thread, and Z1 is the axial starting point of the thread. X1 and Z1 satisfy the following formulas (I) and (II): X1=D1+ap-f (Ⅰ); Z1=-(L1-P)(Ⅱ).

3. The chip breaking method for thread machining of a petroleum perforating gun according to claim 1, characterized in that: In step b, the number of thread teeth N is calculated by the following formula (III): N=L / p(Ⅲ).

4. A chip breaking method for oil perforating gun thread machining according to claim 3, characterized in that: In step b, the value of N is an integer. When the value of N is not an integer, it is rounded down. The last pitch axial feed amount m1=L-L1-Np.

5. The chip breaking method for thread machining of petroleum perforating gun according to claim 1, characterized in that: In step b, the number of thread cutting cycles n is calculated by the following formula (IV): n=2h / ap(Ⅳ).

6. A chip breaking method for oil perforating gun thread machining according to claim 5, characterized in that: In step b, the value of n is an integer. When the value of n is not an integer, it is rounded up by 1. Then the back cutting depth ap1 of the last thread cutting cycle is 2h-ap(n-1).

7. A chip breaking method for oil perforating gun thread machining according to claim 6, characterized in that: In step c, the thread cutting method is: a1. Radial feed increases the thread back cutting amount, that is, radial feed ap; b1. Oblique thread feed, i.e. radial feed f and axial feed m at the same time; c1. Turn the first thread in the first cycle, i.e., axial feed m; d1. Oblique thread withdrawal, i.e. radial withdrawal f and axial advance m at the same time; e1. Return to the next pitch starting point, i.e. axial retraction r; f1. Repeat steps b1 to e1 to complete the first cycle of thread cutting; g1. Repeat steps a1 to f1 until all thread cutting is completed.

8. A chip breaking method for oil perforating gun thread machining according to claim 7, characterized in that: When the value of n calculated by formula (IV) in step b is not an integer, the rounding method is adopted, and the back cutting amount ap1 of the last thread cutting cycle is 2h-ap(n-1); in the thread cutting method, steps a1 to f1 are repeated until the penultimate thread cutting cycle is completed. h1. Radial feed increases the thread back cutting amount, that is, radial feed ap1, ap1 = 2h-ap(n-1); i1. Oblique thread feed, i.e. radial feed f and axial feed m at the same time; j1. Turn the last thread of the first cycle, i.e. axial feed m; k1. Oblique thread withdrawal, i.e. radial withdrawal f and axial advance m at the same time; l1. Return to the starting point of the next pitch, i.e. axial retraction r; m1. Repeat steps i1 to l1 until all thread cutting is completed.

9. A chip breaking method for oil perforating gun thread machining according to claim 7, characterized in that: When the value of N calculated by formula (III) in step b is not an integer, it is rounded down to the nearest integer, and the last pitch axial feed amount m1=L-L1-Np; in the thread cutting method, steps a1 to f1 are repeated until the penultimate thread cutting cycle is completed. h1. Radial feed increases the thread back cutting amount, that is, radial feed ap; i1. Oblique thread feed, i.e. radial feed f and axial feed m at the same time; j1. Turn the last thread in the first cycle, i.e., axial feed m1, m1 = L-L1-Np; k1. Oblique thread withdrawal, i.e. radial withdrawal f and axial advance m at the same time; l1. Return to the starting point of the next pitch, i.e. axial retraction r; m1. Repeat steps i1 to l1 until all thread cutting is completed.

10. A chip breaking method for oil perforating gun thread machining according to claim 9, characterized in that: In step c, the entire thread is divided into several segments for segmented cutting by oblique segmented cutting, that is, one pitch is one segment. The thread iron chips obtained by the oblique segmented cutting method are in the shape of short strips, and automatic chip breaking of the thread can be achieved.

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