Variable-tooth-width oil casing thread form detection method

Abstract

The invention discloses a tooth-width-variable oil casing thread form detection method, which comprises the following steps: placing a tooth-width-variable oil casing thread to be detected on a detection platform, selecting a full-top thread area as a detection part, pressing uncured plastic sample paste on the thread detection part, ensuring that the plastic sample paste is completely filled into the thread in the detection area, and after the plastic sample paste is completely cured, detecting the tooth-width-variable oil casing thread form. The method comprises the following steps: taking out plastic sample paste from a thread detection area, cutting a detection sheet along the direction of a thread axis on the plastic sample paste by using a blade, placing the detection sheet on a sample holder of a projector, irradiating the detection sheet on a detection display plane through irradiation of a projection lamp, placing a standard thread form pattern above the detection display plane, comparing the difference between the shape projection of the detection sheet and the standard thread form pattern, and judging whether the thread form to be detected meets the technical requirements or not; according to the invention, a sample molding method and an optical method are adopted to detect the thread form of the to-be-detected variable-tooth-width oil casing, the thread form image can be clearly and visually obtained, and the detection accuracy is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil casing quality inspection, and relates to a method for inspecting the thread profile of oil casings with variable tooth widths. Background Art

[0002] Oil casings are key equipment components used in oil drilling and oil production processes. The quality of their thread connections directly affects the oil and gas transportation efficiency and safety. The variable tooth width threads designed according to the needs of oil and gas development have good connection reliability and sealing performance. However, in actual applications, due to processing errors, wear during use, etc., quality problems may occur in the variable tooth width threads of oil casings, such as problems with thread pitch unevenness, tooth width inconsistency, tooth height non-compliance, profile mismatch and other thread profile parameters. These problems may lead to thread connection and sealing failures, and even cause serious safety accidents. Therefore, it is very necessary to inspect the quality of the thread profile of oil casings with variable tooth widths.

[0003] The existing methods for inspecting the quality of oil casing thread profiles mainly include visual inspection method and mechanical measurement method, etc. These methods can detect the quality problems of oil casing thread profiles to a certain extent, but there are still some deficiencies. For example, the visual inspection method relies on the experience of inspectors and has low accuracy, and can only check the appearance quality of the thread profile. The mechanical measurement method requires the use of professional measurement tools and relies on manual operation. The accuracy and inspection efficiency of the detection mainly depend on the proficiency of the operator, and can only detect parameters such as thread tooth height and pitch, and cannot detect parameters such as thread tooth width and thread profile. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for inspecting the thread profile of oil casings with variable tooth widths, which solves the problem that the existing manual visual inspection method and mechanical inspection method cannot completely and accurately detect the quality of the thread profile of oil casings with variable tooth widths.

[0005] The technical solution adopted by the present invention is a method for inspecting the thread profile of oil casings with variable tooth widths, including the following steps:

[0006] Step 1: Place the oil casing thread with variable tooth width to be measured on the inspection platform, and select the full-top thread area as the inspection part;

[0007] Step 2: Press the uncured plastic paste on the thread inspection part, and ensure that the plastic paste completely fills the threads inside the inspection area. After the plastic paste is completely cured, take out the plastic paste from the thread inspection area;

[0008] Step 3: Cut out the inspection thin slice along the direction of the thread axis on the plastic paste with a blade;

[0009] Step 4: Place the inspection thin slice on the specimen holder of the projector, and irradiate it with a projection lamp to project the shape of the inspection thin slice onto the inspection display plane;

[0010] Step 5: Place the standard thread profile pattern above the detection display plane, compare the difference between the shape projection of the detection thin slice and the standard thread profile pattern, and determine whether the thread profile to be measured meets the technical requirements.

[0011] Among them, the plastic paste is in a softened state under the sealed state, can be cured within 5 min - 10 min in the normal temperature open environment, and will not deform after being sliced after curing.

[0012] In Step 3, the thickness of the detection thin slice ≤ 1 mm.

[0013] In Step 4, the specimen holder is located at the middle position of the projector, the projection lamp is arranged at the position below the specimen holder, and the detection display plane is arranged above the specimen holder.

[0014] Both the specimen holder of the projector and the detection display plane are made of transparent materials, and the projection light can penetrate through.

[0015] In Step 5, determining whether the thread profile of the thread to be detected meets the technical requirements includes determining whether the thread pitch, tooth width, tooth height, and tooth profile of the thread to be detected meet the technical requirements.

[0016] In Step 5, when the deviations of the thread pitch, tooth width, tooth height, and tooth profile of the oil casing thread to be measured from the standard thread profile pattern are all within the allowable range, it is considered that the thread profile of the oil casing thread to be measured meets the technical requirements.

[0017] The beneficial effects of the present invention are as follows:

[0018] (1) The present invention uses the plastic sample method and the optical method to detect the thread profile of the variable tooth width oil casing thread to be measured, can clearly and intuitively obtain the image of the thread profile, and improves the detection accuracy;

[0019] (2) The present invention realizes the detection of multiple thread profile parameters such as thread pitch, tooth width, tooth height, and tooth profile by comparing and detecting the thread profile images, which is beneficial to more accurately judge whether the thread profile of the oil casing thread to be measured meets the technical requirements;

[0020] (3) The present invention uses the plastic paste and the projector as the detection tools, reduces the use of mechanical instruments, the detection method is simple to operate, the detection efficiency is high, and it is applicable to the detection of oil casing threads of various sizes. Description of the Drawings

[0021] Figure 1 is the plastic sample schematic diagram of the thread profile of the variable tooth width oil casing thread in the present invention;

[0022] Figure 2 is the detection schematic diagram of the thread profile of the variable tooth width oil casing thread in the present invention.

[0023] In the figure, 1. the variable tooth width oil casing thread to be measured, 2. the plasticine paste, 3. the detection thin slice, 4. the projector, 5. the sample holder, 6. the projection lamp, 7. the standard thread profile pattern, 8. the detection display plane. Detailed implementation manners

[0024] The present invention will be described in detail below in conjunction with the accompanying drawings and the detailed implementation manners.

[0025] The method for detecting the thread profile of the variable tooth width oil casing thread of the present invention refers to Figure 1 and Figure 2 , and includes the following steps:

[0026] Step 1: Place the variable tooth width oil casing thread 1 to be measured on the detection platform, and select the full-top thread area as the detection part;

[0027] Step 2: Press the uncured plasticine paste 2 on the thread detection part, and ensure that the plasticine paste completely fills the thread inside the detection area. After the plasticine paste is completely cured, take out the plasticine paste from the thread detection area;

[0028] The plasticine paste is in a softened state under a sealed state and can be cured within 5 min - 10 min in a normal temperature open environment. After curing, it can be sliced without deformation.

[0029] Step 3: Cut out the detection thin slice 3 along the direction of the thread axis on the plasticine paste, and the thickness of the detection thin slice ≤ 1 mm;

[0030] Step 4: Place the detection thin slice 3 on the sample holder 5 of the projector 4, and irradiate it through the projection lamp 6, and project the shape of the detection thin slice on the detection display plane 8;

[0031] The sample holder 5 is located at the middle position of the projector 4, the projection lamp 6 is arranged at the lower position of the sample holder 5, and the detection display plane is arranged above the sample holder 5;

[0032] Both the sample holder of the projector and the detection display plane are made of colorless transparent materials, and the projection light can penetrate through.

[0033] Step 5: Place the standard thread profile pattern 7 above the detection display plane 8, compare the difference between the projection of the detection thin slice shape and the standard thread profile pattern, and determine whether the thread pitch, tooth width, tooth height and thread profile of the thread to be detected meet the technical requirements. When the deviations of the thread pitch, tooth width, tooth height and thread profile of the oil casing thread to be measured from the standard thread profile pattern are all within the allowable range, it is considered that the thread profile of the oil casing thread to be measured meets the technical requirements.

[0034] Example 1

[0035] A method for detecting the thread profile of a "3 - 1 / 2" variable tooth width oil casing thread includes the following steps:

[0036] Step 1: Place the "3 - 1 / 2" variable tooth width oil casing thread to be tested on the inspection platform, and select the full - top thread area as the inspection part;

[0037] Step 2: Press the uncured plastic paste on the thread inspection part, and ensure that the plastic paste completely fills the threads inside the inspection area. After the plastic paste is completely cured, remove the plastic paste from the thread inspection area;

[0038] This plastic paste is a silicone rubber material of the HEMOULDING brand. It is in a softened state under sealed conditions and can be cured within 5 - 10 minutes in a normal - temperature open environment. After curing, it can be sliced without deformation.

[0039] Step 3: Use a blade to cut out a test thin slice along the direction of the thread axis on the plastic paste. The thickness of the test thin slice is 0.5 mm;

[0040] Step 4: Place the test thin slice on the specimen holder of the projector. Through the illumination of the projection lamp, project the shape of the test thin slice onto the inspection display plane; both the specimen holder of the projector and the inspection display plane are made of colorless transparent materials, and the projection light can penetrate.

[0041] Step 5: Place the standard thread profile pattern above the display plane, compare the difference between the projection of the test thin slice shape and the standard thread profile pattern, and determine whether the thread pitch, tooth width, tooth height, and tooth profile of the thread to be tested meet the technical requirements. After testing, the corresponding deviations of the thread pitch, tooth width, and tooth height of the "3 - 1 / 2" oil casing thread to be tested from the standard thread profile pattern are 0.06 mm, 0.04 mm, and 0.02 mm respectively. The tooth profile of the "3 - 1 / 2" oil casing thread to be tested basically coincides with the standard thread profile pattern, and it is considered that the tooth profile of the oil casing thread to be tested meets the technical requirements.

[0042] Example 2

[0043] A method for detecting the tooth profile of a variable tooth width oil casing thread includes the following steps:

[0044] Step 1: Place the "7" variable tooth width oil casing thread to be tested on the inspection platform, and select the full - top thread area as the inspection part;

[0045] Step 2: Press the uncured plastic paste on the thread inspection part, and ensure that the plastic paste completely fills the threads inside the inspection area. After the plastic paste is completely cured, remove the plastic paste from the thread inspection area;

[0046] This plastic paste is a silicone rubber material of the HEMOULDING brand. The plastic paste is in a softened state under sealed conditions and can be cured within 5 - 10 minutes in a normal - temperature open environment. After curing, it can be sliced without deformation.

[0047] Step 3: Cut out a test thin slice along the direction of the thread axis on the plastic sample paste, and the thickness of the test thin slice is 0.8 mm;

[0048] Step 4: Place the test thin slice on the sample holder of the projector. Through the illumination of the projection lamp, project the shape of the test thin slice onto the test display plane; both the sample holder of the projector and the test display plane are made of colorless transparent materials, and the projection lamp light can penetrate through.

[0049] Step 5: Place the standard thread profile pattern above the display plane, compare the difference between the projection of the test thin slice shape and the standard thread profile pattern, and determine whether the thread pitch, tooth width, tooth height, and thread profile of the thread to be tested meet the technical requirements. After testing, the corresponding deviations of the thread pitch, tooth width, and tooth height of the "7" casing thread to be tested from the standard thread profile pattern are 0.08 mm, 0.06 mm, and 0.04 mm respectively. The thread profile of the "7" casing thread to be tested basically coincides with the standard thread profile pattern, and it is considered that the thread profile of the casing thread to be tested meets the technical requirements.

[0050] Example 3

[0051] A method for detecting the thread profile of a variable tooth width casing thread includes the following steps:

[0052] Step 1: Place the "9-5 / 8" variable tooth width casing thread to be tested on the test platform, and select the full-top thread area as the test part;

[0053] Step 2: Press the uncured plastic sample paste on the thread test part, and ensure that the plastic sample paste completely fills the threads inside the test area. After the plastic sample paste is completely cured, take out the plastic sample paste from the thread test area;

[0054] This plastic sample paste is a silicone rubber material of the HEMOULDING brand. The plastic sample paste is in a softened state under sealed conditions and can be cured within 5 min - 10 min in an open environment at room temperature. After curing, it can be sliced without deformation.

[0055] Step 3: Cut out a test thin slice along the direction of the thread axis on the plastic sample paste, and the thickness of the test thin slice is 0.6 mm;

[0056] Step 4: Place the test thin slice on the sample holder of the projector. Through the illumination of the projection lamp, project the shape of the test thin slice onto the test display plane; both the sample holder of the projector and the test display plane are made of colorless transparent materials, and the projection lamp light can penetrate through.

[0057] Step 5: Place the standard thread profile pattern above the display plane, compare the differences between the projection of the detected thin sheet shape and the standard thread profile pattern, and determine whether the thread pitch, tooth width, tooth height, and thread profile of the thread to be detected meet the technical requirements. After detection, the corresponding deviations of the thread pitch, tooth width, and tooth height of the "9-5 / 8" casing thread to be detected from the standard thread profile pattern are 0.10 mm, 0.08 mm, and 0.06 mm respectively. The thread profile of the "9-5 / 8" casing thread to be detected basically coincides with the standard thread profile pattern, and it is considered that the thread profile of the "9-5 / 8" casing thread to be detected meets the technical requirements.

Claims

1. Detection method for the thread profile of variable tooth-width oil casing, Characterized in that, It includes the following steps: Step 1, Place the variable tooth-width oil casing thread to be measured on the detection platform, and select the full-top thread area as the detection part; Step 2, Press the uncured plastic paste on the thread detection part, and ensure that the plastic paste completely fills the threads inside the detection area. After the plastic paste is completely cured, take out the plastic paste from the thread detection area; Step 3, Use a blade to cut out a detection thin slice along the direction of the thread axis on the plastic paste; Step 4, Place the detection thin slice on the specimen holder of the projector, and through the irradiation of the projection lamp, project the shape of the detection thin slice onto the detection display plane; Step 5, Place the standard thread profile pattern above the detection display plane, compare the difference between the projection of the detection thin slice shape and the standard thread profile pattern, and determine whether the thread profile to be measured meets the technical requirements.

2. The detection method for the thread profile of variable tooth-width oil casing according to claim 1, Characterized in that, The plastic paste is in a softened state under a sealed state, can be cured within 5 min - 10 min in a normal temperature open environment, and does not deform when sliced after curing.

3. The detection method for the thread profile of variable tooth-width oil casing according to claim 1, Characterized in that, In the said step 3, the thickness of the detection thin slice ≤ 1 mm.

4. The detection method for the thread profile of variable tooth-width oil casing according to claim 1, Characterized in that, In the said step 4, the specimen holder is located at the middle position of the projector, the projection lamp is set at the position below the specimen holder, and the detection display plane is set above the specimen holder.

5. The detection method for the thread profile of variable tooth-width oil casing according to claim 4, Characterized in that, Both the specimen holder and the detection display plane of the projector are made of transparent materials, and the projection light can penetrate through.

6. The detection method for the thread profile of variable tooth-width oil casing according to claim 1, Characterized in that, In the said step 5, determining whether the thread profile of the thread to be detected meets the technical requirements includes determining whether the thread pitch, tooth width, tooth height and thread profile of the thread to be detected meet the technical requirements.

7. The detection method for the thread profile of variable tooth-width oil casing according to claim 6, Characterized in that, In the said step 5, when the deviations of the thread pitch, tooth width, tooth height and thread profile of the oil casing thread to be measured from the standard thread profile pattern are all within the allowable range, it is considered that the thread profile of the oil casing thread to be measured meets the technical requirements.

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