LWD instrument air tightness detection device with self-test function

Abstract

The present invention relates to the field of vacuum detection technology, and specifically to an air tightness detection device for a LWD instrument with a self-test function, comprising: a base, including a piston sleeve, and a first interface and a second interface arranged on the wall of the piston sleeve, wherein the piston sleeve has a hollow inner cavity, the first interface and the second interface are connected to the hollow inner cavity of the piston sleeve, and one end of the piston sleeve is further provided with a transfer tube, and the piston sleeve is connected to a vacuum pumping device via the transfer tube; a sealing element, which is detachably and sealedly connected to the first interface; a vacuum pressure gauge, which is sealedly connected to the second interface; a piston switch, which extends into the hollow inner cavity of the piston sleeve, and the piston sleeve is disconnected from the vacuum pumping device through the sealing cooperation between the piston switch and the transfer tube. The present invention has the advantages of convenient self-test, compact structure and easy installation, and effectively improves detection reliability and work efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of vacuum detection, and in particular to an air tightness detection device for a LWD instrument with a self-testing function. Background Art

[0002] Logging while drilling (LWD) is a comprehensive logging application technology developed based on measurement while drilling (MWD) to address formation evaluation and drilling geosteering in horizontal and multi-branch wells. LWD technology is primarily used to distinguish formations, identify water, gas, and water, identify formation changes, and predict high-pressure formations. It can significantly shorten drilling cycles, reduce water and gas immersion time, and mitigate contamination of aquifers. Because LWD instruments are primarily used in underground high-pressure testing environments, they place extremely high demands on airtightness. Failure to meet these requirements can lead to fluid inflow in the wellbore, significantly impacting measurement results and causing irreversible contamination of the instrument.

[0003] To ensure the safety and quality of LWD instruments underground, they must undergo an airtightness test before each downhole run. Existing LWD instrument airtightness test devices have multiple sealing valves. Failure or aging of valve components can cause the test device itself to fail to meet airtightness standards. Furthermore, airtightness testing in existing test devices requires additional testing equipment, preventing a self-test before each use. This can easily lead to inaccurate airtightness test results. Therefore, a reliable and portable LWD instrument airtightness test device with self-testing capabilities is needed to meet the needs of on-site LWD instrument testing. Summary of the Invention

[0004] In response to the above-mentioned problems in the prior art, the present invention aims to provide an air tightness detection device for a LWD instrument with a self-test function. The air tightness detection device for the LWD instrument can perform a self-test before each use. It is compact in size, has reliable sealing and accuracy, and can meet the on-site air tightness detection needs of the LWD instrument.

[0005] In order to solve the above technical problems, the specific technical solutions of the present invention are as follows:

[0006] A LWD instrument air tightness detection device with a self-test function comprises: a base, comprising a piston sleeve, and a first interface and a second interface arranged on the wall of the piston sleeve, the piston sleeve having a hollow inner cavity, the first interface and the second interface being connected to the hollow inner cavity of the piston sleeve, the piston sleeve comprising a first end and a second end being connected, the first end being connected to a vacuum pumping device; a sealing element being detachably and sealedly connected to the first interface; a vacuum pressure gauge being sealedly connected to the second interface; a piston switch extending into the hollow inner cavity of the piston sleeve, the piston switch being able to move away from the first end or sealably cooperate with the first end by reciprocating in the hollow inner cavity of the piston sleeve, and the piston sleeve being disconnected from the vacuum pumping device by the piston switch being sealedly cooperated with the first end.

[0007] Optionally, the sealing element is a sealing end cover or a sealing plug.

[0008] Furthermore, a first sealing ring is provided on the first interface and / or the sealing element, and the sealing element is sealedly connected to the first interface via the sealing member.

[0009] Specifically, the piston switch includes a piston rod, a first piston arranged at the end of the piston rod, and a second piston arranged at the rod end of the piston rod. The first piston extends into the inner cavity of the second end. Driven by the piston rod, the first piston can move away from the first end or seal with the first end, and the second piston seals with the second end.

[0010] Specifically, the inner diameter of the first end is smaller than the inner diameter of the second end, and two openings are provided on the inner side wall of the second end, and the two openings are respectively connected to the first interface and the second interface. After the first piston is matched with the first end, part of the first piston is located in the inner cavity of the second end, and the first piston, the second piston and the inner side wall of the second end form an annular cavity, and the annular cavity is respectively connected to the first interface and the second interface through the two openings.

[0011] Preferably, a second sealing ring is provided on the first piston, and a third sealing ring is provided on the second piston.

[0012] Preferably, the first piston is threadedly connected to the first end, and the second piston is threadedly connected to the second end.

[0013] Preferably, the piston rod has a gripping end away from the first piston, and the gripping end extends out of the second end; the piston rod is also provided with a limit clamp, and the limit clamp is arranged between the gripping end and the second piston; a positioning clip is provided on the inner wall of the piston sleeve, when the first piston is away from the first end, the positioning clip can abut on the second piston, and when the first piston is sealed with the first end, the positioning clip abuts on the limit clamp.

[0014] Preferably, the air tightness detection device further comprises a transfer tube, which is sealed and connected to the end of the first end portion, and the first end portion is connected to the vacuum pumping equipment through the transfer tube.

[0015] Based on the above invention, the method for using the airtightness detection device includes the following steps:

[0016] S1. The sealing element is sealed to the first interface of the base, the vacuum pressure gauge is sealed to the second interface, and the vacuum equipment is sealed to the first end;

[0017] S2. Apply a pulling force on the piston switch to move it away from the first end, turn on the vacuum equipment to exhaust, and record the first self-test value of the vacuum pressure gauge;

[0018] S3. Applying a thrust to the piston switch to seal it against the first end portion, recording a second self-test value of the vacuum pressure gauge after the first set time has expired, and determining the airtightness of the airtightness detection device based on the first and second self-test values. If the airtightness of the airtightness detection device is determined to be acceptable, proceeding to step S4.

[0019] S4. Remove the sealing element on the first interface, seal the LWD instrument to be tested with the first interface, apply tension to the piston switch away from the first end, turn on the vacuum equipment to exhaust, and record the first detection value of the vacuum pressure gauge;

[0020] S5. Apply thrust to the piston switch to seal it with the first end, record the second detection value of the vacuum pressure gauge after the first set time has passed, and determine whether the airtightness of the LWD instrument is qualified based on the first and second detection values.

[0021] By adopting the above technical solution, the air tightness detection device for LWD instrument with self-test function of the present invention has the following beneficial effects:

[0022] 1. By providing a sealing element on the second interface, the present invention enables a self-test of the airtightness before each use of the airtightness detection device without adding additional testing equipment or changing the test conditions, thereby ensuring the accuracy of the airtightness detection results of the LWD instrument.

[0023] 2. Compared with the traditional air tightness detection device, the present invention reduces the number of components such as valve switches, avoids the leakage of negative air at the valve switches, and improves the reliability and accuracy of the sealing detection.

[0024] 3. The present invention has a simple and compact structure, small size, and is easy to install and process, effectively reducing manufacturing costs and improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] To more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0026] Figure 1 A schematic structural diagram of the airtightness detection device of the present invention with the detection channel in an open state;

[0027] Figure 2 A schematic structural diagram of the airtightness detection device of the present invention when the detection channel is in a closed state;

[0028] Figure 3 yes Figure 1 Schematic diagram of the structure after the air tightness detection device is connected to the LWD instrument;

[0029] Figure 4 yes Figure 1 Schematic diagram of the explosion of the air tightness detection device.

[0030] In the figure: 1-base, 2-sealing element, 3-vacuum pressure gauge, 4-piston switch, 5-exhaust pipe, 6-LWD instrument, 11-piston sleeve, 111-first end, 112-second end, 113-opening, 12-first interface, 13-second interface, 14-transfer tube, 15-annular cavity, 21-first sealing ring, 41-piston rod, 42-first piston, 43-second piston, 44-second sealing ring, 45-third sealing ring, 46-holding end, 47-limiting clamp, 48-positioning clamp. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the numbers used in this manner are interchangeable where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product, or device comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or devices.

[0033] refer to Figure 1 、 2 and 4.1. A LWD instrument 6 air tightness detection device with a self-test function, characterized in that it comprises: a base 1, comprising a piston sleeve 11, and a first interface 12 and a second interface 13 arranged on the wall of the piston sleeve 11, the piston sleeve 11 having a hollow inner cavity, the first interface 12 and the second interface 13 being connected to the hollow inner cavity of the piston sleeve 11, the piston sleeve 11 comprising a first end 111 and a second end 112 being connected, the first end 111 being connected to a vacuum pumping device; a sealing element 2 being detachably and sealedly connected to the first interface 12; a vacuum pressure gauge 3 being sealedly connected to the second interface 13; a piston switch 4 extending into the hollow inner cavity of the piston sleeve 11, the piston switch 4 being able to move away from the first end 111 or sealingly cooperate with the first end 111 by reciprocating in the hollow inner cavity of the piston sleeve, and the piston sleeve 11 being disconnected from the vacuum pumping device through the sealing cooperation between the piston switch 4 and the first end 111.

[0034] Preferably, the base 1 is cross-shaped, the piston sleeve 11 is arranged horizontally, and the first interface 12 and the second interface 13 are arranged opposite each other on the outer wall of the piston sleeve 11, and both are perpendicular to the piston sleeve 11. The end of the second interface 13 away from the piston sleeve 11 is connected to the vacuum pressure gauge 3, and the vacuum pressure gauge 3 is connected to the piston sleeve 11 through the second interface 13.

[0035] Optionally, in one embodiment of the present specification, the sealing element 2 is a sealing end cover, and the sealing end cover has an end cover opening, and the first interface 12 can extend into and sealably fit in the end cover opening. Preferably, a first sealing ring 21 is provided on the outside of the first interface 12 and / or the end cover opening of the sealing end cover, and the sealing end cover is sealed and connected to the first interface 12 via the first sealing ring 21. In another embodiment of the present specification, the sealing element 2 is a sealing plug (not shown), and the sealing plug can sealably fit in the inner cavity of the first interface 12. In this way, air leakage is avoided during the self-test of the airtightness detection device, which may cause an erroneous self-test result.

[0036] Specifically, the piston switch 4 includes a piston rod 41, a first piston 42 arranged at the end of the piston rod 41, and a second piston 43 arranged at the rod portion of the piston rod 41. The first piston 42 extends into the inner cavity of the second end 112. Driven by the piston rod 41, the first piston 42 can move away from the first end 111 or seal with the first end 111, and the second piston 43 seals with the second end 112.

[0037] Furthermore, the inner diameter of the first end portion 111 is smaller than the inner diameter of the second end portion 112. Two openings 113 are provided on the inner sidewall of the second end portion 112. The two openings 113 are respectively connected to the first port 12 and the second port 13. After the first piston 42 is engaged with the first end portion 111, a portion of the first piston 42 is located within the inner cavity of the second end portion 112. The first piston 42, the second piston 43, and the inner sidewall of the second end portion 112 form an annular cavity 15. The annular cavity 15 is respectively connected to the first port 12 and the second port 13 through the two openings 113. Preferably, the two openings 113 are provided on the same radial section of the piston sleeve 11.

[0038] The outer diameter of the first piston 42 is smaller than that of the second piston 43. By applying a thrust or pull force to the end of the piston rod 41 distal from the first piston 42, the piston rod 41 drives the second piston 43 and the first piston 42 to reciprocate axially along the piston sleeve 11. The first piston 42 passes through the second end portion 112 and is sealedly connected to the first end portion 111. Both extreme positions of the second piston 43's axial movement along the piston sleeve 11 lie within the inner cavity of the second end portion 112. That is, during movement of the piston rod 41, the second piston 43 remains in a sealed engagement with the inner cavity of the second end portion 112. Furthermore, the second piston 43 remains positioned between the opening 113 and the end surface of the second end portion 112 distal from the first end portion 111. In other words, no matter where the second piston 43 moves within the piston sleeve 11, it will never be located between the opening 113 and the first end portion 111.

[0039] Furthermore, a first sealing ring 21 is provided on the first piston 42 , and a second sealing ring 44 is provided on the second piston 43 .

[0040] Preferably, the first piston 42 is threadedly connected to the first end portion 111, and the second piston 43 is threadedly connected to the second end portion 112. A first external thread is provided on the end of the first piston 42, and a first internal thread is provided on the inner wall of the first end portion 111 to cooperate with the first external thread. The first piston 42 is threadedly connected to the inner cavity of the first end portion 111. A second external thread is provided on the outer wall of the second piston 43, and a second internal thread is provided on the inner wall of the second end portion 112 to cooperate with the second external thread. The second piston 43 is threadedly connected to the inner cavity of the second end portion 112.

[0041] Specifically, the piston rod 41 has a gripping end 46 away from the first piston 42 , and the gripping end 46 is located outside the second end 112 . Preferably, the outer diameter of the gripping end 46 is greater than the inner diameter of the piston sleeve 11 .

[0042] Preferably, the piston rod 41 is further provided with a limiting snap ring 47, which is disposed between the gripping end 46 and the second piston 43. A positioning clamp 48 is provided on the inner wall of the piston sleeve 11. When the first piston 42 is away from the first end 111, the positioning clamp 48 can abut against the second piston 43. When the first piston 42 and the first end 111 are in sealing engagement, the positioning clamp 48 abuts against the limiting snap ring 47. The limiting snap ring 47, the second piston 43, and the piston rod 41 therebetween form an I-shaped structure, with the positioning clamp 48 located within the recessed structure of the I-shape. In this way, the second piston 43 can be positioned at the two extreme positions of movement in the piston sleeve 11, thereby preventing the application of excessive pulling force that could damage the instrument, or the application of insufficient pushing force that could result in an incomplete sealing engagement between the first piston 42 and the first end 111.

[0043] Preferably, the positioning clip 48 is an elastic clip that can extend and retract radially along the piston sleeve 11. In one embodiment, the second piston 43 has a first guiding bevel on the side facing the first end 111, and a second guiding bevel on the side facing the limiting collar 47. The first guiding bevel compresses the elastic clip, allowing the second piston 43 to enter between the elastic clip and the first end 111; the second guiding bevel compresses the elastic clip, allowing the second piston 43 to move and exit the piston sleeve 11. This ensures a removable connection between the piston switch 4 and the piston sleeve 11, allowing for timely replacement of the second and third sealing rings 44, 45.

[0044] Furthermore, the air tightness detection device further includes a transfer tube 14 , which is sealed and connected to the end of the first end portion 111 , and the first end portion is connected to the vacuum pumping device through the transfer tube 14 .

[0045] The adapter tube 14 has a sleeve joint and a vacuum joint, wherein the sleeve joint extends into the inner cavity of the first end portion 111; and the vacuum joint extends out of the first end portion 111. Preferably, the sleeve joint is threadedly connected to the first end portion 111, and the vacuum joint is threadedly connected to the exhaust pipe 5.

[0046] Preferably, a pressure relief port is provided on the air extraction pipe 5 .

[0047] refer to Figure 1-4 Based on the above embodiment, the method for using the airtightness detection device includes the following steps:

[0048] S1. The sealing element 2 is sealed and connected to the first interface 12 of the base 1, the vacuum pressure gauge 3 is sealed and connected to the second interface 13, and the vacuum equipment is sealed and connected to the first end 111;

[0049] S2. Apply a pulling force on the piston switch 4 away from the first end 111, turn on the vacuum equipment to exhaust, and record the first self-test value of the vacuum pressure gauge 3;

[0050] S3. Apply a thrust to the piston switch 4 to seal it against the first end 111. Record the second self-test value of the vacuum pressure gauge 3 after the first set time has expired. Determine the airtightness of the airtightness detection device based on the first and second self-test values. If the airtightness of the airtightness detection device is determined to be acceptable, proceed to step S4.

[0051] The air tightness of the air-tightness detection device itself is judged based on the first self-test value and the second self-test value. Specifically, if the second self-test value is less than or equal to the first self-test value, the air tightness of the air-tightness detection device is qualified; if the second self-test value is greater than the first self-test value, but the difference between the second self-test value and the first self-test value is less than or equal to the self-test error threshold, the air tightness of the air-tightness detection device is qualified; if the second self-test value is greater than the first self-test value, but the difference between the second self-test value and the first self-test value is greater than the self-test error threshold, the air tightness of the air-tightness detection device is unqualified;

[0052] S4. Remove the sealing element 2 on the first interface 12, the LWD instrument to be tested 6 is sealed with the first interface 12, apply tension to the piston switch 4 away from the first end 111, turn on the vacuum equipment to exhaust, record the first detection value of the vacuum pressure gauge 3;

[0053] The LWD instrument 6 is provided with an airtightness detection interface, and the first connector extends into and is sealed in the airtightness detection interface.

[0054] S5. Apply thrust to the piston switch 4 to seal it with the first end 111, record the second detection value of the vacuum pressure gauge 3 after the first set time has passed, and determine whether the airtightness of the LWD instrument 6 is qualified based on the first and second detection values.

[0055] Wherein, whether the air tightness of the LWD instrument is qualified is judged based on the first detection value and the second detection value. Specifically, if the second detection value is less than or equal to the first detection value, the air tightness of the LWD instrument is qualified; if the second detection value is greater than the first detection value, but the difference between the second detection value and the first detection value is less than or equal to a detection error threshold, the air tightness of the LWD instrument is qualified; if the second detection value is greater than the first detection value, but the difference between the second detection value and the first detection value is greater than the detection error threshold, the air tightness of the LWD instrument is unqualified.

[0056] By arranging a sealing element 2 on the second interface 13, the present invention realizes a self-test of the sealing property before each use of the air-tightness detection device without adding additional testing equipment or changing the testing conditions, thereby ensuring the accuracy of the air-tightness detection result of the LWD instrument; and compared with the traditional air-tightness detection device, the present invention reduces components such as valve switches, avoids the leakage of negative air at the valve switches, and improves the reliability and accuracy of the sealing detection; in addition, the present invention has a simple and compact structure, a small size, and is easy to install and process, effectively reducing manufacturing costs and improving work efficiency.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A LWD instrument air tightness detection device with a self-test function, characterized in that: include: A base (1) comprises a piston sleeve (11), and a first interface (12) and a second interface (13) arranged on the wall of the piston sleeve (11); the piston sleeve (11) has a hollow inner cavity; the first interface (12) and the second interface (13) are in communication with the hollow inner cavity of the piston sleeve (11); the piston sleeve (11) comprises a first end (111) and a second end (112) in communication; the first end (111) is in communication with a vacuum pump; a sealing element (2) detachably and sealingly connected to the first interface (12); a vacuum pressure gauge (3) sealingly connected to the second interface (13); A piston switch (4) extends into the hollow inner cavity of the piston sleeve (11); the piston switch (4) can move away from the first end (111) or seal with the first end (111) by reciprocating in the hollow inner cavity of the piston sleeve; the piston sleeve (11) is disconnected from the vacuum device by the sealing cooperation between the piston switch (4) and the first end (111); the piston switch (4) comprises a piston rod (41), a first piston (42) arranged at the end of the piston rod (41), and a second piston (43) arranged at the rod portion of the piston rod (41); the first piston (42) extends into the inner cavity of the second end (112); under the drive of the piston rod (41), the first piston (42) can move away from the first end (111) or seal with the first end (111); the second piston (43) seals with the second end (112); The inner diameter of the first end portion (111) is smaller than the inner diameter of the second end portion (112); two openings (113) are provided on the inner side wall of the second end portion (112); the two openings (113) are respectively connected to the first interface (12) and the second interface (13); after the first piston (42) is matched with the first end portion (111), part of the first piston (42) is located in the inner cavity of the second end portion (112); the first piston (42), the second piston (43) and the inner side wall of the second end portion (112) form an annular cavity (15); the annular cavity (15) is respectively connected to the first interface (12) and the second interface (13) through the two openings (113). The first interface (12) and the second interface (13) are in communication; the second piston (43) is always located between the opening (113) and the end face of the second end portion (112) away from the first end portion (111); the sealing element (2) is a sealing end cover or a sealing plug; a first sealing ring (21) is provided on the first interface (12) and / or the sealing element (2); the sealing element (2) and the first interface (12) are sealed in connection via the sealing element; the sealing end cover and the first interface (12) are sealed in connection via the first sealing ring (21); and the sealing plug can be sealed in the inner cavity of the first interface (12).

2. The airtightness detection device according to claim 1, characterized in that: A second sealing ring (44) is provided on the first piston (42), and a third sealing ring (45) is provided on the second piston (43).

3. The airtightness detection device according to claim 1, characterized in that: The first piston (42) is threadedly connected to the first end portion (111), and the second piston (43) is threadedly connected to the second end portion (112).

4. The airtightness detection device according to claim 1, characterized in that: The piston rod (41) has a gripping end (46) away from the first piston (42), and the gripping end (46) extends out of the second end portion (112); The piston rod (41) is further provided with a limiting snap ring (47), and the limiting snap ring (47) is arranged between the gripping end (46) and the second piston (43); A positioning clamp (48) is provided on the inner wall of the piston sleeve (11). When the first piston (42) is away from the first end (111), the positioning clamp (48) can abut against the second piston (43). When the first piston (42) and the first end (111) are sealed and matched, the positioning clamp (48) abuts against the limiting clamp ring (47).

5. The airtightness detection device according to claim 1, characterized in that: It also includes a transfer tube (14), which is sealed and connected to the end of the first end (111), and the first end is connected to the vacuum equipment through the transfer tube (14).

6. The airtightness detection device according to any one of claims 1 to 5, characterized in that: The method for using the device comprises the steps of: S1. The sealing element (2) is sealed and connected to the first interface (12) of the base (1), the vacuum pressure gauge (3) is sealed and connected to the second interface (13), and the vacuum pumping device is sealed and connected to the first end (111); S2. Apply a pulling force on the piston switch (4) to move it away from the first end (111), start the vacuum pumping device to evacuate air, and record the first self-test value of the vacuum pressure gauge (3); S3. Applying a thrust to the piston switch (4) to seal it with the first end (111), recording a second self-test value of the vacuum pressure gauge (3) after the first set time has passed, and judging the airtightness of the airtightness detection device based on the first self-test value and the second self-test value. If it is determined that the airtightness of the airtightness detection device is qualified, proceeding to step S4; S4. Remove the sealing element (2) on the first interface (12), seal the LWD instrument (6) to be tested with the first interface (12), apply a pulling force to the piston switch (4) to move it away from the first end (111), start the vacuum pumping device to evacuate air, and record the first detection value of the vacuum pressure gauge (3); S5. Apply a thrust to the piston switch (4) to seal it with the first end (111), record the second detection value of the vacuum pressure gauge (3) after the first set time has passed, and determine whether the airtightness of the LWD instrument (6) is qualified based on the first detection value and the second detection value.

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