Downhole while-drilling gas logging testing device

Abstract

The underground while-drilling gas logging testing device comprises a collecting and discharging mechanism, a drill rod, a water guide pipe and a drill bit, the drill rod, the water guide pipe and the drill bit are connected in sequence, a testing cylinder arranged outside the water guide pipe in a sleeving mode is installed on the drill rod, a testing and collecting module ring is installed outside the water guide pipe, and a testing cavity with an opening facing the drill bit is formed by the testing cylinder and the water guide pipe; a first inlet hole is formed in the end, close to the drill bit, of the testing barrel, a first outlet hole is formed in the end, away from the drill bit, of the testing barrel, a blocking mechanism is further installed outside the testing barrel and comprises a sleeve shell rotationally arranged outside the testing barrel in a sleeving mode, and a second inlet hole corresponding to the first inlet hole and a second outlet hole corresponding to the first outlet hole are formed in the sleeve shell. A sealing mechanism used for sealing a drilled well is further installed on the portion, between the second inlet hole and the second outlet hole, of the sleeve shell. The plugging mechanism further comprises a control mechanism used for controlling the sleeve shell to rotate.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas exploration and development, and in particular to an underground gas logging while drilling test device. Background Art

[0002] In the field of oil and gas exploration and development, traditional gas logging technology relies on analyzing the gas components carried by the drilling fluid returning from the well to the surface to indirectly evaluate the formation characteristics. This technology infers the oil and gas reservoir conditions in the formation by detecting gas mixtures such as methane, carbon dioxide, and hydrogen sulfide in the drilling fluid.

[0003] At present, drilling fluid needs to pass through thousands of meters of annular pipelines to return to the ground, resulting in a significant time lag in information transmission and unable to immediately reflect the actual situation of the drill bit's location. Secondly, during the ascent of the drilling fluid, its temperature, pressure and other environmental conditions will change, which may cause the dissolved gas in the drilling fluid to be converted into a free state. Some of the gas is released in the degasser, while the other part may escape directly into the atmosphere after the drilling fluid reaches the ground. These processes not only increase the complexity of gas composition analysis, but also reduce the accuracy of the detection data.

[0004] Therefore, it is necessary to provide a downhole gas logging while drilling test device to solve the problems raised in the above background technology. Summary of the invention

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a downhole gas logging and drilling test device, comprising a collection and discharge mechanism and a drill pipe, a water pipe and a drill bit connected in sequence, the drill pipe is equipped with a test cylinder sleeved on the outside of the water pipe, the water pipe is equipped with a test collection module ring, the test cylinder and the water pipe form a test cavity with an opening facing the drill bit, an end of the test cylinder close to the drill bit is provided with an inlet hole 1, and an end of the test cylinder away from the drill bit is provided with an outlet hole 1, the collection and discharge mechanism comprises a push-pull ring and a sealing ring, the push-pull ring is sleeved on the outside of the test collection module The push-pull ring is driven and controlled by a telescopic rod installed on the drill pipe, the sealing ring is connected to one end of the drill bit close to the test cavity through a spring, the sealing ring is sleeved with a sealing sleeve that matches the opening of the test cavity, and a blocking mechanism is also installed on the outside of the test cylinder, the blocking mechanism includes a sleeve rotatably sleeved on the outside of the test cylinder, the sleeve is respectively provided with an inlet hole 2 corresponding to the inlet hole 1 and an outlet hole 2 corresponding to the outlet hole 1, a sealing mechanism for sealing drilling is also installed on the sleeve located between the inlet hole 2 and the outlet hole 2, and the blocking mechanism also includes a control mechanism for controlling the rotation of the sleeve.

[0006] As a preferred technical solution of the present invention, a filter plug one is installed on the second inlet hole and the second outlet hole respectively.

[0007] As a preferred technical solution of the present invention, the control mechanism includes a protective shell and a carrier ring, the protective shell is installed on the sleeve shell, a gear ring is installed on the shell wall of the protective shell, the carrier ring is installed on the drill rod, a motor is installed on the carrier ring, and a gear meshing with the gear ring is installed at the output end of the motor.

[0008] As a preferred technical solution of the present invention, the sealing mechanism includes a sealing bag installed on the outer wall of the casing, a pump body connected to the sealing bag is also installed on the casing, a filter plug is also provided at the delivery end of the pump body, and the interior of the sealing bag is also provided with reinforcing elastic rods circumferentially distributed on the outer wall of the casing.

[0009] As a preferred technical solution of the present invention, the reinforcing elastic rod includes a hole tube connected to the outer wall of the shell, and the end of the hole tube away from the outer wall of the shell is slidably connected with a sliding rod. The sliding rod and the hole tube are connected by a spring, and the end of the sliding rod away from the hole tube is installed with a support plate for supporting the inner wall of the sealing bag.

[0010] As a preferred technical solution of the present invention, the outer wall of the sealing ring is provided with an outer ring groove, and the end of the sealing ring close to the test cavity is provided with a scraper groove arranged circumferentially, and the sealing sleeve includes a swivel ring rotatably installed at the bottom of the outer ring groove and a ring frame sleeved on the outer ring groove, the ring frame and the swivel are connected by spring 2, a support rod corresponding to the scraper groove is installed on the ring frame, and a scraper matching the scraper groove is installed on the support rod, and a plurality of the scrapers are connected to a sealing ring, and the sealing ring is sleeved on the outer ring groove, and one end of the scraper close to the test cavity is flush with the end of the sealing ring close to the test cavity.

[0011] As a preferred technical solution of the present invention, the drill bit is also provided with a limit ring for limiting the displacement of the sealing ring, and the inner wall of the sealing ring is provided with a limit cavity cooperating with the limit ring, and the displacement of the sealing ring limited by the limit ring is the same as the height of the scraper.

[0012] As a preferred technical solution of the present invention, the sealing ring is further provided with a positioning magnet corresponding to the scraper groove, and the support rod is provided with a conductor that cooperates with the positioning magnet for magnetic attraction.

[0013] As a preferred technical solution of the present invention, a buffer shell covering the outside of the test cavity opening is installed at one end of the casing close to the drill bit, and a water-permeable hole is provided on the shell wall of the buffer shell.

[0014] Compared with the prior art, the present invention provides a downhole gas logging and drilling testing device, which has the following beneficial effects:

[0015] 1. In the present invention, the return gas and liquid in the area near the drill bit are controlled to flow unidirectionally through the test chamber through the control mechanism and the sealing mechanism for collection and testing, so as to judge whether the gas and liquid flow rate through the test chamber is uniform, collect the uniformly flowing gas and liquid for testing, and then obtain more accurate test data, thereby improving the collection and testing efficiency and the collection and testing accuracy.

[0016] 2. The reinforcing support function of the reinforcing elastic rod in the present invention is helpful to improve the impact resistance of the sealing bag to the reflux gas and liquid in the drilling, improve the sealing effect between the sealing bag and the drilling wall, improve the sufficiency of the one-way flow of gas and liquid through the test cavity, and thus improve the accuracy of gas and liquid collection while drilling.

[0017] 3. In the present invention, when it is necessary to discharge the gas and liquid in the test cavity, the push-pull ring is driven by the telescopic rod to squeeze the gas and liquid in the test cavity. The push-pull ring can scrape and clean the side cavity wall of the test cavity and the outer surface of the test collection module ring. The squeezed gas and liquid push the scraper to rotate, so that the upper end surface of the sealing ring and the lower end surface of the push-pull ring can be continuously rotated and scraped to clean. After the gas and liquid in the test cavity are discharged, the push-pull ring is driven back by the telescopic rod. At this time, the sealing ring enters the opening area of ​​the test cavity again under the action of spring 1, and the sealing ring and the test cavity are separated. The side wall of the test chamber produces a friction effect, and the friction force generated causes the sealing ring to drive the scraper to reset to the scraper groove. Therefore, each time the test chamber completes a collection test program, the inner wall of the test chamber and the surface of the test collection module ring are cleaned, which is beneficial to make the gas and liquid entering the test chamber each time relatively consistent with the actual collected gas and liquid, thereby improving the accuracy of the test data. At the same time, the cleanliness of the surface of the test collection module ring is maintained, thereby improving the efficiency of the test and the accuracy of the test data, and making the downhole gas logging test while drilling more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a downhole gas logging and drilling testing device of the present invention;

[0019] Figure 2 It is a schematic diagram of the partial structure of the blocking mechanism of the present invention;

[0020] Figure 3 It is a schematic diagram of the partial structure of the control mechanism of the present invention;

[0021] Figure 4 It is a schematic diagram of the local structure of the test tube of the present invention;

[0022] Figure 5 for Figure 3 Schematic diagram of partial enlarged structure;

[0023] Figure 6 It is a schematic diagram of the positioning magnet structure of the present invention;

[0024] Figure 7 It is a schematic diagram of the local structure of the sealing sleeve of the present invention;

[0025] Figure 8 It is a schematic diagram of the local structure of the sealing ring of the present invention;

[0026] In the figure: 1, drill rod; 2, test tube; 3, collection and discharge mechanism; 4, buffer shell; 5, plugging mechanism; 6, reinforcement elastic rod; 11, water guide pipe; 12, drill bit; 21, inlet hole 1; 22, outlet hole 1; 23, test cavity; 24, test collection module ring; 31, telescopic rod; 32, push-pull ring; 33, sealing ring; 34, spring 1; 35, sealing sleeve; 331, outer ring groove; 332, scraper groove; 333, limit cavity; 334, limit ring; 351, swivel; 352, ring frame; 353, spring 2 ; 354, support rod; 355, sealing ring; 356, scraper; 357, positioning magnet; 3541, conductor; 41, water permeable port; 51, casing; 52, control mechanism; 53, sealing mechanism; 54, filter plug one; 511, inlet hole two; 512, outlet hole two; 521, protective shell; 522, gear ring; 523, carrier ring; 524, motor; 525, gear; 531, sealing capsule; 532, pump body; 533, filter plug two; 61, hole cylinder; 62, slide rod; 63, spring three; 64, support plate. DETAILED DESCRIPTION

[0027] Reference Figure 1-Figure 8 The present invention provides a technical solution: a downhole gas logging and drilling test device, comprising a collection and discharge mechanism 3 and a drill pipe 1, a water pipe 11 and a drill bit 12 connected in sequence, the drill pipe 1 is equipped with a test tube 2 sleeved on the outside of the water pipe 11, the water pipe 11 is equipped with a test collection module ring 24, the test tube 2 and the water pipe 11 form a test cavity 23 with an opening toward the drill bit 12, the end of the test tube 2 close to the drill bit 12 is provided with an inlet hole 21, the end of the test tube 2 away from the drill bit 12 is provided with an outlet hole 22, the collection and discharge mechanism 3 comprises a push-pull ring 32 and a sealing ring 33, the push-pull ring 32 is sleeved on the outside of the test collection module 24, and the push-pull ring 32 is passed through The telescopic rod 31 installed on the drill pipe 1 is driven and controlled, the sealing ring 33 is connected to the end of the drill bit 12 close to the test cavity 23 through a spring 34, the sealing ring 33 is sleeved with a sealing sleeve 35 that matches the opening of the test cavity 23, and a blocking mechanism 5 is also installed on the outside of the test cylinder 2. The blocking mechanism 5 includes a sleeve 51 that is rotatably sleeved on the outside of the test cylinder 2, and the sleeve 51 is respectively provided with an inlet hole 21 corresponding to the inlet hole 21 and an outlet hole 2 512 corresponding to the outlet hole 22. A sealing mechanism 53 for sealing drilling is also installed on the sleeve 51 located between the inlet hole 511 and the outlet hole 512, and the blocking mechanism 5 also includes a control mechanism 52 for controlling the rotation of the sleeve 51.

[0028] In this embodiment, a filter plug 54 is installed on the second inlet hole 511 and the second outlet hole 512 respectively.

[0029] In this embodiment, the control mechanism 52 includes a protective shell 511 and a carrier ring 523, the protective shell 511 is installed on the sleeve shell 51, a gear ring 522 is installed on the shell wall of the protective shell 51, the carrier ring 23 is installed on the drill rod 1, a motor 524 is installed on the carrier ring 23, and a gear 525 meshing with the gear ring 522 is installed at the output end of the motor 524; specifically, the motor 524 drives the control gear 525 to drive the gear ring 522 to rotate, and the gear ring 522 drives the protective shell 511 and the sleeve shell 51 to rotate, so as to control the alignment or stagger of the inlet hole 1 21 and the inlet hole 2 511 and the alignment or stagger of the outlet hole 1 22 and the outlet hole 2 512.

[0030] In this embodiment, the sealing mechanism 53 includes a sealing bag 531 installed on the outer wall of the casing 51, a pump body 532 connected to the sealing bag 531 is also installed on the casing 51, a filter plug 533 is also provided at the delivery end of the pump body 522, and a reinforcing elastic rod 6 is also provided inside the sealing bag 531 which is circumferentially distributed on the outer wall of the casing 51; specifically, the pump body 532 controls the suction of gas and liquid outside the casing 51 to fill the sealing bag 531, so that the sealing bag 531 can be sealed against the inner wall of the well, thereby changing the reflux trajectory of the drilling fluid refluxed from the well, and the drilling fluid in the area of ​​the drill bit 12 can be effectively controlled. The gas and liquid are collected and introduced into the test chamber 23. When the collection is completed, the gas and liquid in the suction sealing bag 531 are discharged through the pump body 532, so that the sealing bag 531 can be separated from the inner wall of the wellbore, so as to collect and test while drilling, thereby improving the collection and test efficiency and collection and test accuracy. Among them, by changing the trajectory of the drilling fluid backflow, it is convenient to make the returned gas and liquid flow through the test chamber 23 in one direction. At the same time, it is helpful to judge whether the gas and liquid flow rate flowing through the test chamber 23 is uniform, so as to collect uniformly flowing gas and liquid for testing, and then obtain more accurate test data.

[0031] In this embodiment, the reinforced elastic rod 6 includes a hole tube 61 connected to the outer wall of the casing 51, and the end of the hole tube 61 away from the outer wall of the casing 51 is slidably connected with a slide rod 62, the slide rod 62 is connected to the hole tube 61 by a spring three 63, and the end of the slide rod 62 away from the hole tube 61 is installed with a support sheet 64 for supporting the inner wall of the sealing bag 531; that is, through the reinforcing support effect of the reinforced elastic rod 6, it is beneficial to improve the impact strength of the sealing bag 531 against the reflux gas and liquid in the drilling, improve the sealing effect between the sealing bag 531 and the drilling wall, improve the sufficiency of the gas-liquid unidirectional flow test cavity 23, and thus improve the accuracy of the gas and liquid collection while drilling.

[0032] In this embodiment, the outer wall of the sealing ring 33 is provided with an outer ring groove 331, and the end of the sealing ring 33 close to the test cavity 23 is provided with a scraper groove 332 arranged circumferentially. The sealing sleeve 35 includes a swivel 351 rotatably mounted at the bottom of the outer ring groove 331 and a ring frame 352 sleeved on the outer ring groove 331. The ring frame 352 is connected to the swivel 351 through a spring 2 353. A support rod 354 corresponding to the scraper groove 332 is installed on the ring frame 352. A scraper 356 matching the scraper groove 332 is installed on the support rod 354. A plurality of the scrapers 356 are connected to a sealing ring 355. The sealing ring 355 is sleeved on the outer ring groove 331. The end of the scraper 356 close to the test cavity 23 and the sealing ring 35 5 is flush with one end close to the test chamber 23; specifically, when the gas and liquid flow through the test chamber 23 and the gas and liquid in the test chamber 23 are tested, the upper ends of the sealing ring 33 and the sealing sleeve 35 are in real time at the opening of the test chamber 23, and the test chamber 23 is blocked in real time. That is to say, when the gas and liquid in the test chamber 23 need to be discharged, at this time, the push-pull ring 32 is driven by the telescopic rod 31 to move close to the sealing ring 33, and the push-pull ring 32 squeezes the gas and liquid in the test chamber 23. At the same time, the push-pull ring 32 can scrape and clean the side wall of the test chamber 23 and the outer surface of the test collection module ring 24, and the squeezed gas and liquid push the sealing ring 33 and the sealing sleeve 35 to separate The test chamber 23 is opened, and the gas and liquid in the test chamber 23 are discharged outwardly. When the sealing ring 33 and the sealing sleeve 35 are separated from the test chamber 23, the squeezed gas and liquid are continuously discharged. At this time, the scraper 356 is driven to separate from the scraper groove 332 under the action of the spring 2 353, and the squeezed gas and liquid push the scraper 356 to rotate. The end of the scraper 356 close to the sealing ring 33 can continuously rotate and scrape the upper end surface of the sealing ring 33 to clean it. When the push-pull ring 32 is close to the contact scraper 356, the end of the scraper 356 close to the push-pull ring 32 can continuously rotate and scrape the lower end surface of the push-pull ring 32 to clean it. After the gas and liquid in the test chamber 23 are discharged, the push-pull ring 32 is driven to pull back by the telescopic rod 31. At this time, the sealing ring 33 enters the opening area of ​​the test chamber 23 again under the action of the spring 1 34, and the sealing ring 355 produces a friction effect with the side wall of the test chamber 23. The generated friction force causes the sealing ring 355 to drive the scraper 356 to return to the scraper groove 332. Therefore, each time the test chamber 23 completes a collection test program, the inner wall of the test chamber 23 and the surface of the test collection module ring 24 are cleaned, which is beneficial to make the gas and liquid entering the test chamber 23 each time relatively consistent with the actual collected gas and liquid, thereby improving the accuracy of the test data. At the same time, the cleanliness of the surface of the test collection module ring 24 is maintained, thereby improving the efficiency of the test and the accuracy of the test data.

[0033] In this embodiment, a limit ring 334 for limiting the displacement of the sealing ring 33 is further provided on the drill bit 12, and a limit cavity 333 cooperating with the limit ring 334 is provided on the inner wall of the sealing ring 33. The limit ring 334 limits the displacement of the sealing ring 33 to be the same as the height of the scraper 356, so that the scraper 356 can perform rotational scraping and cleaning of the sealing ring 33 and the push-pull ring 32.

[0034] In this embodiment, the sealing ring 33 is also provided with a positioning magnet 357 corresponding to the scraper groove 332, and the support rod 354 is provided with a conductor 3541 that cooperates with the positioning magnet 357 for magnetic attraction; so that when the support rod 354 is in the process of rotating, when it gradually stops rotating, the magnetic force of the conductor 3541 adsorbed by the positioning magnet 357 is used to actively position the stop position of the support rod 354, so that the scraper 356 is aligned with the scraper groove 332.

[0035] In this embodiment, a buffer shell 4 covering the outside of the opening of the test cavity 23 is installed at one end of the casing 51 close to the drill bit 12, and a water-permeable hole 41 is provided on the shell wall of the buffer shell 4 so as to reduce the impact of the gas-liquid flow in the opening area of ​​the test cavity 23, so as to discharge the gas and liquid in the test cavity 23.

[0036] In specific implementation, when the drill pipe 1 is drilling, if it is necessary to collect and test the area drilled by the drill bit 12, at this time, the control mechanism 52 controls the casing 51 to rotate, so that the inlet hole 21 is aligned with the inlet hole 2 511 and the outlet hole 22 is aligned with the outlet hole 2 512, and then the pump body 532 controls the suction of the gas and liquid outside the casing 51 to fill the sealing bag 531, so that the sealing bag 531 is sealed with the inner wall of the well, the drilling fluid reflux trajectory of the well is changed, the gas and liquid in the area of ​​the drill bit 12 are collected, and introduced into the test chamber 23. When the gas and liquid flowing through the test chamber 23 flows evenly, the gas and liquid are collected and introduced into the test chamber 23. The pump body 532 controls the gas and liquid in the suction sealing bag 531 to be discharged, so that the sealing bag 531 can be separated from the inner wall of the well. At the same time, the control mechanism 52 controls the housing 51 to rotate, so that the inlet hole 21 and the inlet hole 2 511 are staggered, and the outlet hole 22 and the outlet hole 2 512 are staggered. Then, the gas and liquid in the test cavity 23 are tested and data collected through the test collection module ring 24. After the data test collection is completed, the gas and liquid in the test cavity 23 are discharged. At this time, the push-pull ring 32 is driven by the telescopic rod 31 to move close to the sealing ring 33, and the push-pull ring 32 squeezes the gas and liquid in the test cavity 23. At the same time, the push-pull ring 32 can scrape and clean the side cavity wall of the test cavity 23 and the outer surface of the test collection module ring 24. The squeezed gas and liquid push the sealing ring 33 and the sealing sleeve 35 to separate from the opening of the test cavity 23, and the gas and liquid in the test cavity 23 are discharged outward. When the sealing ring 33 and the sealing sleeve 35 separate from the test cavity 23, as the squeezed gas and liquid continue to be discharged, at this time, under the action of the spring 2 353, the scraper 356 is driven to separate from the scraper groove 332, and the squeezed gas and liquid push the scraper 356 to rotate, and the end of the scraper 356 close to the sealing ring 33 can be used to clean the upper end surface of the sealing ring 33. Continuously rotate and scrape to clean. When the push-pull ring 32 is close to the contact scraper 356, the end of the scraper 356 close to the push-pull ring 32 can continuously rotate and scrape to clean the lower end surface of the push-pull ring 32. When the gas and liquid in the test chamber 23 are discharged, the push-pull ring 32 is driven to pull back by the telescopic rod 31. At this time, the sealing ring 33 enters the opening area of ​​the test chamber 23 again under the action of the spring 1 34. The sealing ring 355 and the side wall of the test chamber 23 produce a friction effect. The friction force generated makes the sealing ring 355 drive the scraper 356 to reset to the scraper groove 332, and then the gas logging while drilling test is carried out underground.

[0037] The above description is only a preferred specific implementation manner of the invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the invention, which should be covered by the protection scope of the present invention.

Claims

1. A downhole gas logging and testing device while drilling, comprising a collection and discharge mechanism (3) and a drill pipe (1), a water pipe (11) and a drill bit (12) connected in sequence, characterized in that: The drill rod (1) is provided with a test tube (2) sleeved on the outside of the water pipe (11); the water pipe (11) is provided with a test collection module ring (24); the test tube (2) and the water pipe (11) form a test cavity (23) with an opening facing the drill bit (12); an end of the test tube (2) close to the drill bit (12) is provided with an inlet hole (21); an end of the test tube (2) away from the drill bit (12) is provided with an outlet hole (22); the collection and discharge mechanism (3) comprises a push-pull ring (32) and a sealing ring (33); the push-pull ring (32) is sleeved on the outside of the test collection module (24); the push-pull ring (32) is driven and controlled by a telescopic rod (31) installed on the drill rod (1); the sealing ring (33) is connected to the drill bit (24) and the test tube (23) is connected to the drill bit (24); 12) is connected to one end of the test chamber (23) by a spring 1 (34); the sealing ring (33) is covered with a sealing sleeve (35) matching the opening of the test chamber (23); a blocking mechanism (5) is also installed on the outside of the test chamber (2); the blocking mechanism (5) comprises a sleeve (51) rotatably sleeved on the outside of the test chamber (2); an inlet hole 2 (511) corresponding to the inlet hole 1 (21) and an outlet hole 2 (512) corresponding to the outlet hole 1 (22) are respectively arranged on the sleeve (51); a sealing mechanism (53) for sealing the drilling is also installed on the sleeve (51) between the inlet hole 2 (511) and the outlet hole 2 (512); the blocking mechanism (5) also comprises a control mechanism (52) for controlling the rotation of the sleeve (51).

2. A downhole gas logging while drilling test device according to claim 1, characterized in that: The second inlet hole (511) and the second outlet hole (512) are respectively installed with a filter plug one (54).

3. A downhole gas logging while drilling test device according to claim 1, characterized in that: The control mechanism (52) comprises a protective shell (511) and a carrier ring (523); the protective shell (5111) is mounted on the casing (51); a gear ring (522) is mounted on the shell wall of the protective shell (51); the carrier ring (23) is mounted on the drill rod (1); a motor (524) is mounted on the carrier ring (23); and a gear (525) meshing with the gear ring (522) is mounted on the output end of the motor (524).

4. A downhole gas logging while drilling test device according to claim 1, characterized in that: The sealing mechanism (53) comprises a sealing capsule (531) mounted on the outer wall of the casing (51); a pump body (532) connected to the sealing capsule (531) is also mounted on the casing (51); a second filter plug (533) is also provided at the delivery end of the pump body (522); and reinforcing elastic rods (6) circumferentially distributed on the outer wall of the casing (51) are also provided inside the sealing capsule (531).

5. A downhole gas logging while drilling test device according to claim 4, characterized in that: The reinforcing elastic rod (6) comprises a hole tube (61) connected to the outer wall of the casing (51); one end of the hole tube (61) away from the outer wall of the casing (51) is slidably connected to a slide rod (62); the slide rod (62) and the hole tube (61) are connected via a spring three (63); and one end of the slide rod (62) away from the hole tube (61) is provided with a support sheet (64) for supporting the inner wall of the sealing bag (531).

6. A downhole gas logging while drilling test device according to claim 1, characterized in that: The outer wall of the sealing ring (33) is provided with an outer ring groove (331), and one end of the sealing ring (33) close to the test chamber (23) is provided with a scraper groove (332) arranged circumferentially. The sealing sleeve (35) comprises a rotating ring (351) rotatably mounted on the bottom of the outer ring groove (331) and a ring frame (352) sleeved on the outer ring groove (331). The ring frame (352) is connected to the rotating ring (351) through a spring 2 (353). The ring frame (352) ) is mounted on a support rod (354) corresponding to the scraper groove (332); a scraper (356) matching the scraper groove (332) is mounted on the support rod (354); a plurality of scrapers (356) are connected to a sealing ring (355); the sealing ring (355) is sleeved on the outer ring groove (331); one end of the scraper (356) close to the test cavity (23) is flush with one end of the sealing ring (355) close to the test cavity (23).

7. A downhole gas logging while drilling test device according to claim 6, characterized in that: The drill bit (12) is also provided with a limit ring (334) for limiting the displacement of the sealing ring (33); the inner wall of the sealing ring (33) is provided with a limit cavity (333) cooperating with the limit ring (334); the limit ring (334) limits the displacement of the sealing ring (33) to be the same as the height of the scraper (356).

8. A downhole gas logging while drilling test device according to claim 6, characterized in that: The sealing ring (33) is also provided with a positioning magnet (357) corresponding to the scraper groove (332), and the support rod (354) is provided with a conductor (3541) that cooperates with the positioning magnet (357) for magnetic attraction.

9. The downhole gas logging while drilling test device according to claim 1, characterized in that: A buffer shell (4) covering the outside of the opening of the test cavity (23) is installed on one end of the sleeve shell (51) close to the drill bit (12), and a water-permeable hole (41) is provided on the shell wall of the buffer shell (4).

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