Multi-stage linkage ring cavity jam releasing mechanism for split type inner pipe assembly

Abstract

The invention discloses a multi-stage linkage annular cavity jam releasing mechanism for a split inner pipe assembly, which belongs to the technical field of wire-line coring drilling and comprises a multi-stage linkage mechanism, a low-friction guide petal type inner pipe mechanism, a chute limiting petal mechanism, a rotary stop block mechanism and a rock core breaking mechanism. Wherein the multi-stage linkage mechanism comprises an inner linkage frame, a first rolling elastic pin, a supporting gasket, a spring, a second rolling elastic pin, an outer linkage frame and a one-way valve, the low-friction guide petal type inner pipe mechanism comprises a coring inner pipe and a steel ball, and the sliding groove limiting petal mechanism comprises a first sliding groove limiting petal set and a second sliding groove limiting petal set. The rotary stop block mechanism comprises a clamping strip and a petal stop block; and the rock core breaking mechanism comprises a clamp spring seat, a clamp spring check ring and a clamp spring. On the basis that all functions of the elastic clamping assembly are reserved, the problem that the inner pipe is difficult to extract due to the fact that rock debris blocks the annular space of the inner pipe and the outer pipe is solved through a step-by-step unloading mechanism, the inner pipe assembly is unclamped under the working condition that a drill is not lifted, and engineering accidents such as necking and hole collapse caused by drill lifting are avoided.

Description

Technical Field

[0001] This invention belongs to the field of wireline coring technology, and more specifically, relates to a multi-stage linkage annular cavity release mechanism for a segmented inner tube assembly. Background Technology

[0002] Wireline coring is a highly efficient geological drilling method, characterized by its ability to retrieve cores without the need for drill string lifting. It employs a separate inner and outer core tube mechanism. The outer tube assembly comprises seven parts: a centralizer, a spring-loaded chuck chamber, a seat ring, the outer core tube, a centralizer ring, a reamer, and the drill bit. The inner tube assembly consists of five parts: a spring-loaded chuck assembly, the inner core tube, a chuck seat, a chuck, and a chuck retainer. The spring-loaded chuck assembly itself includes nine mechanisms: a spear-retrieval mechanism, a positioning mechanism, a suspension mechanism, a positioning signal mechanism, an adjustment mechanism, a full-tube or blockage alarm mechanism, a single-action mechanism, a buffer mechanism, and a one-way valve mechanism. During drilling, the outer tube rotates while the inner tube remains stationary. Once the core fills the core tube, the inner tube assembly is retrieved using a retrieval tool, leaving the drill rod inside the borehole. This significantly reduces the occurrence of engineering accidents such as necking and borehole collapse, improving drilling efficiency and core recovery rate. Currently, wireline coring technology is widely used in coalfield exploration, metal ore exploration, civil engineering geological exploration, and hydrological observation exploration.

[0003] In current wireline coring drilling technology, the difficulty in removing cuttings is a prominent issue due to complex geological conditions and construction techniques. This often leads to cuttings accumulating and clogging in the annular space between the inner and outer tubing assemblies, preventing the inner tubing assembly from being successfully retrieved. In fractured formations, cuttings particles are large; in water-swellable formations, the rock mass expands upon absorbing water; and in clay formations, clay particles are highly viscous. These complex formations all contribute to the difficulty in removing cuttings. Furthermore, when the drilling fluid viscosity is too high and its suspension capacity is strong, cuttings cannot effectively settle during drilling fluid circulation. During the retrieval of the inner tubing assembly, the drilling fluid circulation stops, causing cuttings to deposit in the drill pipe. Simultaneously, when the drilling rig speed is too high, the amount of cuttings generated per unit time exceeds the carrying capacity of the drilling fluid, also preventing complete removal of cuttings. All of these situations can cause cuttings to accumulate and clog in the annular space between the inner and outer tubing assemblies, preventing the inner tubing assembly from being successfully retrieved. The commonly used treatment method requires pulling all drill pipes out of the hole to remove the inner tube assembly. This method not only significantly increases labor intensity and delays the construction period, but also easily induces engineering accidents such as necking and hole collapse, seriously affecting drilling efficiency and project quality.

[0004] In view of this, following the above nine mechanisms, this invention proposes a multi-stage linkage ring cavity unlocking mechanism for a segmented inner tube assembly. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-stage linkage annular cavity unblocking mechanism for a segmented inner tube assembly, which solves the problem of the inner tube assembly being unable to be extracted due to rock cuttings blocking the annular space of the inner and outer tubes, and enables the unblocking and extraction of the inner tube assembly without drilling.

[0006] This invention achieves the above-mentioned objective through the following technical solution: a multi-stage linkage annular cavity unblocking mechanism for a segmented inner tube assembly, comprising a multi-stage linkage mechanism, a low-friction guide-valve inner tube mechanism, a sliding groove limiting valve mechanism, a rotation-stopping block mechanism, and a core-breaking mechanism. The multi-stage linkage mechanism includes an inner linkage frame, a first rolled elastic pin, a support pad, a spring, a second rolled elastic pin, an outer linkage frame, and a one-way valve. The low-friction guide-valve inner tube mechanism includes a core-taking inner tube and steel balls. The rotation-stopping block mechanism includes a locking strip and a valve block. The core-breaking mechanism includes a retaining ring seat, a retaining ring, and a retaining ring. The support pad is threadedly connected to the outer linkage frame, the outer linkage frame is threadedly connected to the core-taking inner tube, and the core-taking inner tube is threadedly connected to the retaining ring seat.

[0007] Furthermore, the upper part of the inner linkage frame is provided with a linkage joint, the lower part of the inner linkage frame is provided with a linkage rod, the linkage joint is hollow inside, the top of the linkage joint is provided with an internal thread, the linkage joint is provided with a baffle plate, the baffle plate is a solid circular piece, the baffle plate is fixedly connected to the linkage joint, the linkage joint is provided with a circular pin hole, the bottom of the linkage joint is symmetrically provided with a petal slide groove, the middle and both sides of the petal slide groove are respectively provided with an arc-shaped slide groove and a guide rib, the bottom end of the linkage joint is provided with a connecting plate, the connecting plate is a solid circular piece, the connecting plate is symmetrically provided with a petal slide groove, the connecting plate is fixedly connected to the linkage joint, a drainage hole is provided between the baffle plate and the connecting plate, the linkage rod is hollow inside, the linkage rod is symmetrically provided with an internal slide groove, the linkage rod is fixedly connected to the connecting plate, and the outer diameter of the linkage joint is larger than the outer diameter of the linkage rod.

[0008] Furthermore: the outer linkage frame is hollow inside; internal threads are provided at the top and bottom of the outer linkage frame; symmetrically arranged petal slide grooves two along the entire length of the outer linkage frame; symmetrically arranged petal slide grooves three along a non-length of the outer linkage frame; symmetrically arranged outer slide grooves three; each petal slide groove includes a guide block and an arc-shaped slide groove; guide ribs are provided on both sides of the guide block; and a baffle plate, which is a solid circular plate, is provided on the outer linkage frame. The barrier plate is symmetrically provided with two petal sliding grooves and three petal sliding grooves. The barrier plate is fixedly connected to the outer linkage frame. The outer linkage frame is provided with a valve cover connecting plate. The valve cover connecting plate is hollow inside. The valve cover connecting plate is symmetrically provided with two petal sliding grooves and three petal sliding grooves. The inner wall of the valve cover connecting plate is provided with internal threads. The valve cover connecting plate is fixedly connected to the outer linkage frame. The upper part of the barrier plate is provided with a second drainage hole, and the middle of the barrier plate and the valve cover connecting plate is provided with a third drainage hole.

[0009] Furthermore, the support pad is hollow inside, the support pad is provided with external threads, the inner diameter of the support pad is larger than the outer diameter of the linkage rod, the spring is sleeved on the linkage rod, the outer diameter of the spring is larger than the inner diameter of the support pad, the outer diameter of the spring is smaller than the inner diameter of the outer linkage frame, the inner diameter of the spring is larger than the outer diameter of the linkage rod, and the two ends of the spring are axially limited by the support pad and the coiled elastic pin, respectively. The one-way valve includes a valve plug and a valve cover, the valve cover is hollow inside, the top of the valve cover is provided with external threads, the valve cover and the valve cover connecting plate are connected by threads, the diameter of the valve plug is smaller than the inner diameter of the top of the valve cover, and the diameter of the valve plug is larger than the inner diameter of the bottom of the valve cover.

[0010] Furthermore, the top and bottom ends of the core-collecting inner tube are provided with external threads, and the core-collecting inner tube is symmetrically provided with four flap sliding grooves. The four flap sliding grooves include two guide blocks and an arc-shaped sliding groove. Two guide ribs are provided on both sides of the two guide blocks. The four flap sliding grooves are normally arranged along the core-collecting inner tube. The core-collecting inner tube is provided with multiple steel ball positioning plates. Multiple steel ball positioning holes are arranged in an array on the steel ball positioning plates. The steel ball positioning plates are fixedly connected to the core-collecting inner tube. The steel balls are placed on the steel ball positioning holes. The core-collecting inner tube is symmetrically provided with locking strip sliding grooves. Two guide rail grooves are provided on both sides of the locking strip sliding grooves. A stop block rotation groove is provided at the bottom of the locking strip sliding grooves. The core-collecting inner tube is provided with a safety pin. The safety pin is fixedly connected to the core-collecting inner tube. An elastic bushing is sleeved on the outside of the safety pin.

[0011] Furthermore, the sliding groove limiting flap mechanism is symmetrically arranged in pairs to form two sets of flaps. The first and second sets of sliding groove limiting flaps are arc-shaped. The two flaps in the first set are of equal length, and a circular pin hole is provided at the top and a variable diameter locking groove is provided at the bottom. Similarly, the two flaps in the second set are of equal length, and a circular pin hole is provided at the top and a semi-circular hole is provided at the bottom. The slide groove limiting petal group one and the slide groove limiting petal group two have different petal lengths. The slide groove limiting petal group one is fixed in the circular pin hole by the rolled elastic pin one. The slide groove limiting petal group two slides by the rolled elastic pin two. The rolled elastic pin two slides in the inner slide groove and the outer slide groove. Guide rail grooves are provided on both sides of the slide groove limiting petal group one and the slide groove limiting petal group two. The slide groove limiting petal group one and the slide groove limiting petal group two are supported on the steel ball.

[0012] Furthermore, the locking strip is arc-shaped, and guide ribs are provided on both sides of the locking strip. The petal block includes a block 1 and a block 2. Guide rail grooves are provided at both ends of the block 1, and guide ribs are provided at both ends of the block 2. The petal block includes a guide block 3 and an arc-shaped sliding groove. The guide block 3 is provided with a locking strip sliding groove, and guide ribs are provided on both sides of the guide block 3. The guide rail groove 3 and the guide rib 3 are interlocked to form a whole.

[0013] Furthermore, the top of the snap ring seat is provided with an internal thread, and the snap ring seat is symmetrically provided with a second flap groove. The second flap groove includes a guide block and an arc-shaped groove. The guide block is provided with guide ribs on both sides. The second flap groove is normally provided along the snap ring seat. The bottom of the snap ring seat is provided with a semi-circular hole. The snap ring seat is provided with a circular groove. The inner surface of the snap ring seat has an inverted conical structure. The snap ring retainer is a circular non-closed structure that can be radially contracted. The snap ring retainer is placed in the circular groove. The snap ring is a circular non-closed structure that can be radially contracted. The outer surface of the snap ring has an inverted conical structure. The inner surface of the snap ring is provided with snap ring teeth. The snap ring is placed in the snap ring seat. The inverted conical structure on the inner surface of the snap ring seat and the inverted conical structure on the outer surface of the snap ring cooperate to guide the snap ring to undergo radial contraction.

[0014] This invention offers the following advantages: Through the coordinated operation of a multi-stage linkage mechanism, a low-friction guide valve-type inner tube mechanism, a chute limiting valve mechanism, a rotating stop block mechanism, and a core clamping mechanism, the chute limiting valve is raised in stages, gradually reducing the contact area between the inner tube assembly and the cuttings. This, in turn, gradually reduces the frictional resistance experienced by the inner tube assembly, ensuring that the inner tube assembly can be unstuck and extracted without the need for drilling. This invention significantly reduces manpower input, shortens operation time, and effectively avoids engineering accidents such as necking and hole collapse caused by drilling, thus strongly guaranteeing construction progress and drilling safety. Furthermore, while fully retaining the original functions of the nine mechanisms—the spear-retrieval mechanism, positioning mechanism, suspension mechanism, arrival signaling mechanism, adjustment mechanism, full tube or blockage alarm mechanism, single-action mechanism, buffer mechanism, and one-way valve mechanism—this invention enables their coordinated operation, successfully solving the technical problem of difficult inner tube extraction due to cuttings blockage, and further optimizing and improving the wireline coring technology system. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] The accompanying drawings of this invention use a Q-series HQ specification inner tube assembly as an example. To facilitate a clearer presentation of the details in the drawings, different scales are used. Figures 1-4 Scale 1:17.5; Figures 5-13 , Figures 32-33 Scale 1:3.2; Figures 14-31 Scale 1:4.5; Figures 34-39 Scale 1:2.5; Figures 40-43 Scale 1:4.7; Figures 40-43 The mid-section detail is magnified 1.3 times.

[0017] Figure 1 This is a schematic diagram of the overall orthographic projection of the inner tube assembly of the present invention in its in-place state.

[0018] Figure 2 This is a schematic side projection of the inner tube assembly of the present invention in its in-place state.

[0019] Figure 3 This is a schematic diagram of the overall orthographic projection of the inner tube assembly of the present invention when it is in the salvage state.

[0020] Figure 4 This is a schematic side projection of the inner tube assembly of the present invention in the salvage state.

[0021] Figure 5 This is a schematic diagram of the structure of the present invention. Figure 1 .

[0022] Figure 6 This is a schematic diagram of the structure of the present invention. Figure 2 .

[0023] Figure 7 This is a schematic diagram of the orthographic projection of the internal linkage frame of the present invention.

[0024] Figure 8 This is a side projection schematic diagram of the internal linkage frame of the present invention.

[0025] Figure 9 This is a schematic diagram of the external linkage frame of the present invention.

[0026] Figure 10 This is a side projection schematic diagram of the external linkage frame of the present invention.

[0027] Figure 11 This is a schematic diagram of the orthographic projection of the support pad of the present invention.

[0028] Figure 12 This is a schematic diagram of the valve plugging of the present invention.

[0029] Figure 13 This is a schematic diagram of the valve gland of the present invention in orthographic projection.

[0030] Figure 14 This is a schematic diagram of the working principle of the multi-level linkage mechanism of the present invention.

[0031] Figure 15 This is a side projection schematic diagram of the working principle of the multi-level linkage mechanism of the present invention.

[0032] Figure 16 This is a schematic diagram of the multi-level linkage mechanism of the present invention in its positioning state.

[0033] Figure 17 This is a cross-sectional view of the present invention, 21-21.

[0034] Figure 18 This is a schematic diagram of the first-level linkage state of the multi-level linkage mechanism of the present invention.

[0035] Figure 19 This is a cross-sectional view of the present invention, shown in sections 27-27.

[0036] Figure 20 This is a schematic diagram of the orthographic projection of the two-stage linkage state of the multi-stage linkage mechanism of the present invention.

[0037] Figure 21 These are cross-sectional views 29-29 of the present invention.

[0038] Figure 22 This is a schematic diagram of the orthographic projection of the multi-level linkage mechanism of the present invention in the salvage state.

[0039] Figure 23 This is a cross-sectional view of the present invention, 32-32.

[0040] Figure 24 This is a side projection diagram of the multi-level linkage mechanism of the present invention in its in-position state.

[0041] Figure 25 This is a cross-sectional view of the present invention at 21'-21'.

[0042] Figure 26 This is a side projection diagram of the first-level linkage state of the multi-level linkage mechanism of the present invention.

[0043] Figure 27 This is a cross-sectional view of the present invention at 27'-27'.

[0044] Figure 28 This is a side projection diagram of the second-level linkage state of the multi-level linkage mechanism of the present invention.

[0045] Figure 29 This is a cross-sectional view of the present invention at 29'-29'.

[0046] Figure 30 This is a side projection diagram of the multi-level linkage mechanism of the present invention in the salvage state.

[0047] Figure 31 This is a cross-sectional view of the present invention at 32'-32'.

[0048] Figure 32 This is a schematic diagram of the orthographic projection of the low-friction guide valve inner tube mechanism of the present invention.

[0049] Figure 33 This is a schematic diagram of the orthographic projection of the sliding groove limiting flap mechanism of the present invention.

[0050] Figure 34 This is a schematic diagram of the card strip of the present invention in orthographic projection.

[0051] Figure 35 This is a schematic diagram of the orthographic projection of the flap block of the present invention.

[0052] Figure 36 This is a schematic diagram of the flap blocking state of the present invention.

[0053] Figure 37 This is a schematic diagram of the blocking state of the petal block in this invention.

[0054] Figure 38 This is a schematic diagram of the orthographic projection of the snap ring holder of the present invention.

[0055] Figure 39 This is a schematic diagram of the card release mechanism of the inner tube assembly of the present invention.

[0056] Figure 40This is a partial orthographic projection schematic diagram of the inner tube assembly of the present invention in the in-place state.

[0057] Figure 41 This is a partial side projection schematic diagram of the inner tube assembly of the present invention in the in-place state.

[0058] Figure 42 This is a partial orthographic projection schematic diagram of the inner tube assembly of the present invention in the salvage state.

[0059] Figure 43 This is a partial side projection schematic diagram of the inner tube assembly of the present invention in the salvage state.

[0060] In the diagram: 1. Multi-stage linkage mechanism; 2. Low-friction guide valve type inner tube mechanism; 3. Slide groove limiting valve mechanism; 4. Rotation stop block mechanism; 5. Core clamping mechanism; 11. Inner linkage frame; 12. Coiled elastic pin one; 13. Support pad; 14. Spring; 15. Coiled elastic pin two; 16. Outer linkage frame; 17. One-way valve; 21. Core-taking inner tube; 22. Steel ball; 31. Slide groove limiting valve. Group 1; 32. Slide limiting flap group 2; 41. Locking strip; 42. Flap stop block; 51. Snap ring seat; 52. Snap ring retaining ring; 53. Snap ring; 61. Core extraction outer tube; 62. Rock cuttings; 110. Linkage joint; 111. Circular pin hole; 112. Flap slide groove 1; 113. Linkage rod; 114. Baffle plate; 115. Drainage hole 1; 116. Connecting plate; 117. Inner slide groove; 1 18. Arc-shaped slide groove; 119. Guide rib one; 160. Petal slide groove two; 161. Drain hole two; 162. Drain hole three; 163. Outer slide groove; 164. Petal slide groove three; 165. Baffle plate; 166. Valve gland connecting plate; 167. Guide block one; 168. Valve plug; 169. Valve gland; 210. Petal slide groove four; 211. Steel ball positioning plate; 212. Steel ball positioning... 213. Hole; 214. Locking bar groove; 215. Stop block rotation groove; 216. Safety pin; 217. Guide block two; 218. Guide rail groove two; 319. Guide rail groove one; 310. Variable diameter locking groove; 321. Semicircular hole; 410. Guide rib two; 420. Guide block three; 421. Guide rail groove three; 422. Guide rib three; 423. Stop block one; 424. Stop block two; 510. Circular groove. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0062] It should be noted that the number of linkage stages in the multi-stage linkage mechanism, the position and number of steel ball positioning plates on the low-friction guide valve type inner tube mechanism, the number of valve groups and lifting length of the sliding groove limiting valve mechanism, and the unloading mechanism shown in the accompanying drawings of this invention are merely illustrative examples intended to facilitate understanding of the invention. Any changes and adjustments made to the above-mentioned number of linkage stages, position and number of steel ball positioning plates, number of valve groups and lifting length, and unloading mechanism based on the concept of this invention should fall within the scope of protection of this invention.

[0063] It should be noted that the inner tube assembly shown in the accompanying drawings of this invention is of the Q series HQ specification, which is merely an illustrative example intended to facilitate understanding of the invention. Any multi-stage linkage annular cavity release mechanism for segmented inner tube assemblies applied to other series and specifications based on the concept of this invention should fall within the scope of protection of this invention.

[0064] like Figures 1-43 As shown, this invention provides a multi-stage linkage annular cavity unblocking mechanism for a segmented inner tube assembly, including a multi-stage linkage mechanism 1, a low-friction guide valve type inner tube mechanism 2, a sliding groove limiting valve mechanism 3, a rotating stop block mechanism 4, and a core jamming mechanism 5. The multi-stage linkage mechanism 1 includes an inner linkage frame 11, a rolled elastic pin 12, a support pad 13, a spring 14, a rolled elastic pin 2 15, an outer linkage frame 16, and a one-way valve 17. The low-friction guide valve type inner tube mechanism 2 includes a core extraction inner tube... The tube 21 and steel ball 22, the sliding groove limiting petal mechanism 3 includes sliding groove limiting petal group one 31 and sliding groove limiting petal group two 32, the rotating stop block mechanism 4 includes a locking strip 41 and a petal block 42, the core cutting mechanism 5 includes a retaining spring seat 51, a retaining spring ring 52, and a retaining spring 53, the support pad 13 is threadedly connected to the outer linkage frame 16, the outer linkage frame 16 is threadedly connected to the core inner tube 21, and the core inner tube 21 is threadedly connected to the retaining spring seat 51.

[0065] The working principle of this invention is as follows: the inner tube assembly is designed as a segmented structure. A multi-stage linkage mechanism 1 drives the sliding groove limiting segment group 31 and the sliding groove limiting segment group 32 to rise step by step, thereby gradually reducing the contact area between the inner tube assembly and the rock cuttings. This achieves gradual unloading of the frictional resistance of the rock cuttings, ultimately allowing the inner tube assembly to be successfully released and extracted. To clarify the unloading mechanism in the multi-stage linkage process of the segmented inner tube assembly, the following uses the location of the safety pin 215 as an example to specifically illustrate the change process of the contact area and frictional resistance between the inner tube assembly and the rock cuttings.

[0066] After the wireline coring rig completes its current drilling cycle, the bottom ends of both the first and second sets of sliding groove limiting flaps 31 and 32 are located at the bottom of the snap ring seat 51. At this point, the contact area between the segmented inner tube assembly and the rock cuttings at the location of the safety pin 215 is 100%, and the segmented inner tube assembly is in its positioned state. The retrieval tool is lowered to retrieve the segmented inner tube assembly. When the retrieval hook grabs the retrieval spearhead and lifts it upward, the inner linkage frame 11 lifts upward, driving the first set of sliding groove limiting flaps 31 to lift upward simultaneously. The guide rail groove 311 and the guide rib 119 cooperate to ensure that the first set of sliding groove limiting flaps 31 does not derail during the lifting process. The inner wall of the first set of sliding groove limiting flaps 31 is supported on the steel balls 22, reducing the frictional resistance between the inner tube and the coring inner tube 21 during the lifting process. Under the combined action of the core's own weight, the force required to break the rock, and the elastic bushing of the safety pin 215 undergoes a slight elastic deformation and slides downward from the neck position of the variable diameter locking groove 312, thereby lifting the sliding groove limiting flap group 1 31 upward. At this time, the sliding groove limiting flap group 2 32 remains stationary. This stage is the first-level linkage stage. During this process, the lifting area of ​​the safety pin 215 and the contact area with the rock cuttings are reduced to 25% of the original area, and the frictional resistance it receives is reduced to 25% of the total frictional resistance. When the bottom end of the inner slide 117 contacts the rolled elastic pin 15, the inner linkage frame 11 continues to lift, driving the slide limit flap assembly 32 to lift upwards synchronously. The guide rail groove 311 and the guide rib 119 cooperate to ensure that the slide limit flap assembly 32 does not derail during the lifting process. The inner wall of the slide limit flap assembly 32 is supported on the steel ball 22, reducing the frictional resistance with the core tube 21 during the lifting process. During the lifting process, the rolled elastic pin 15 compresses the spring 14. The top of the spring 14 is supported by the support pad 13 to keep the top of the spring 14 fixed. At this time, the slide limit flap assembly 31 and the slide limit flap assembly 32 lift synchronously. This stage is the second-level linkage stage. During this process, the lifting area of ​​the safety pin 215 and the contact area with the rock cuttings are reduced to 25% of the original area, and the frictional resistance it receives is reduced to 25% of the total frictional resistance. When the coiled elastic pin 15 is raised to the top of the outer slide groove 163, the inner linkage frame 11 continues to be raised, driving the outer linkage frame 16 to rise synchronously. At this time, the slide groove limiting flap group 1 31 and the slide groove limiting flap group 2 32 stop their relative movement with the core-retrieving inner tube 21, and the three maintain synchronous lifting. This stage is the retrieval state. During this process, the lifting area of ​​the safety pin 215 and the contact area with the rock cuttings are reduced to 50% of the original area, and the frictional resistance it experiences is reduced to 50% of the total frictional resistance. The inner linkage frame 11 continues to be raised until the entire segmented inner tube assembly is removed from the rock cuttings. The segmented inner tube assembly is successfully unblocked and extracted through a 25%, 25%, and 50% unloading mechanism. During the lifting of the segmented inner tube assembly, the valve plug 168 sits in the valve cap 169 under the action of gravity, thereby forming a sealed space inside the core-retrieving inner tube 21, effectively preventing the rock core from falling off during the lifting of the segmented inner tube assembly.

[0067] After the split inner tube assembly is pulled out of the hole, the retaining strip 41 is pushed upward to release the constraint on the flap stop 42. After rotating the flap stop 42 by 45°, the retaining strip 41 is released freely. At this time, the guide block 3 420 blocks the arc-shaped slide groove 118. This operation can prevent the slide groove limiting flap group 1 31 from automatically returning to its position due to the release of the spring retaining assembly and the slide groove limiting flap group 2 32 from automatically returning to its position due to the restoration of the spring 14. At this time, the bottom ends of the slide groove limiting flap group 1 31 and the slide groove limiting flap group 2 32 are both located above the top of the retaining spring seat 51, which facilitates the screwing of the retaining spring seat 51 to realize the core removal operation.

[0068] After the core extraction is completed, the locking bar 41 is moved upwards, rotating the petal stop block 42 by 45°, freeing the locking bar 41 into the locking bar groove 213, thereby constraining the petal stop block 42. At this time, the guide block 3 420 deviates from the arc-shaped groove 118. During the lowering of the spring-lock assembly, the spring 14 gradually recovers its elastic deformation, pushing the coiled elastic pin 2 15 downwards. The coiled elastic pin 1 12 and the coiled elastic pin 2 15 move downwards synchronously, driving the groove limiting petal group 1 31 and the groove limiting petal group 2 32 to move downwards synchronously. When the coiled elastic pin 2 15 moves down to the bottom end of the outer groove 163, the bottom end of the groove limiting petal group 2 32 coincides with the bottom end of the retaining spring seat 51, realizing the reset of the groove limiting petal group 2 32. As the spring-loaded chuck assembly continues to be lowered, the elastic bushing outside the safety pin 215 undergoes slight elastic deformation, sliding upwards from the constricted neck position of the variable-diameter locking groove 312. At this point, the bottom end of the linkage joint 110 contacts the top end of the outer linkage frame 16, and the bottom end of the sliding groove limiting flap group 31 coincides with the bottom end of the snap ring seat 51. The sliding groove limiting flap group 31 resets, and the constricted neck position of the variable-diameter locking groove 312 prevents the safety pin 215 from moving downwards. The split-type inner tube assembly thus enters the positioning state. Continuing to lower the split-type inner tube assembly, the drilling fluid in the core inner tube 21 pushes open the valve plug 168, establishing a drilling fluid discharge channel, and the split-type inner tube assembly is successfully lowered. Once the suspension ring is attached to the seat ring, the spring-loaded chuck springs open to secure the split-type inner tube assembly. At this point, the wireline coring rig begins normal drilling and coring operations.

[0069] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A multi-stage linkage annular cavity unblocking mechanism for a segmented inner tube assembly, characterized in that: The system includes a multi-stage linkage mechanism (1), a low-friction guide valve type inner tube mechanism (2), a sliding groove limiting valve mechanism (3), a rotating stop block mechanism (4), and a core clamping mechanism (5). The multi-stage linkage mechanism (1) includes an inner linkage frame (11), a coiled elastic pin one (12), a support pad (13), a spring (14), a coiled elastic pin two (15), an outer linkage frame (16), and a one-way valve (17). The low-friction guide valve type inner tube mechanism (2) includes a core extraction inner tube (21) and a steel ball (22). The sliding groove limiting valve mechanism (3) includes a multi-stage linkage mechanism (1), a low-friction guide valve type inner tube mechanism (2), a sliding groove limiting valve mechanism (3), a rotating stop block mechanism (4), and a core clamping mechanism (5). The system includes a sliding groove limiting flap group one (31) and a sliding groove limiting flap group two (32). The rotating stop block mechanism (4) includes a locking strip (41) and a flap stop block (42). The core cutting mechanism (5) includes a snap ring seat (51), a snap ring retaining ring (52), and a snap ring (53). The support pad (13) is threadedly connected to the external linkage frame (16). The external linkage frame (16) is threadedly connected to the core extraction inner tube (21). The core extraction inner tube (21) is threadedly connected to the snap ring seat (51).

2. The multi-stage linkage annular cavity unblocking mechanism for the segmented inner tube assembly according to claim 1, characterized in that: The upper part of the inner linkage frame (11) is provided with a linkage joint (110), and the lower part of the inner linkage frame (11) is provided with a linkage rod (113). The linkage joint (110) is hollow inside, and the top of the linkage joint (110) is provided with an internal thread. The linkage joint (110) is provided with a baffle plate (114), which is a solid circular piece. The baffle plate (114) is fixedly connected to the linkage joint (110). The linkage joint (110) is provided with a circular pin hole (111). The bottom of the linkage joint (110) is symmetrically provided with a petal slide groove (112). The petal slide groove (112) is provided with an arc-shaped slide groove (118) in the middle and on both sides. A guide rib (119) is provided at the bottom of the linkage joint (110), and a connecting plate (116) is provided at the bottom of the linkage joint (110). The connecting plate (116) is a solid circular piece. The connecting plate (116) is symmetrically provided with a petal sliding groove (112). The connecting plate (116) is fixedly connected to the linkage joint (110). A drainage hole (115) is provided between the barrier plate (114) and the connecting plate (116). The linkage rod (113) is hollow inside. The linkage rod (113) is symmetrically provided with an inner sliding groove (117). The linkage rod (113) is fixedly connected to the connecting plate (116). The outer diameter of the linkage joint (110) is larger than the outer diameter of the linkage rod (113).

3. The multi-stage linkage annular cavity unblocking mechanism for the segmented inner tube assembly according to claim 1, characterized in that: The outer linkage frame (16) is hollow inside. The top and bottom of the outer linkage frame (16) are provided with internal threads. The outer linkage frame (16) is symmetrically provided with two petal sliding grooves (160), which run the entire length of the outer linkage frame (16). The outer linkage frame (16) is also symmetrically provided with three petal sliding grooves (164), which do not run the entire length of the outer linkage frame (16). The three petal sliding grooves (164) are symmetrically provided with outer sliding grooves (163). The two petal sliding grooves (160) and the three petal sliding grooves (164) include a guide block (167) and an arc-shaped sliding groove (118). Guide ribs (119) are provided on both sides of the guide block (167). The outer linkage frame (16) is provided with a baffle plate (165), which is a solid circular plate. The plate (165) is symmetrically provided with two petal sliding grooves (160), and the barrier plate (165) is symmetrically provided with three petal sliding grooves (164). The barrier plate (165) is fixedly connected to the outer linkage frame (16). The outer linkage frame (16) is provided with a valve cover connecting plate (166). The valve cover connecting plate (166) is hollow inside. The valve cover connecting plate (166) is symmetrically provided with two petal sliding grooves (160), and the valve cover connecting plate (166) is symmetrically provided with three petal sliding grooves (164). The inner wall of the valve cover connecting plate (166) is provided with internal threads. The valve cover connecting plate (166) is fixedly connected to the outer linkage frame (16). The upper part of the barrier plate (165) is provided with two drainage holes (161), and the middle part of the barrier plate (165) and the valve cover connecting plate (166) is provided with three drainage holes (162).

4. The multi-stage linkage annular cavity unblocking mechanism for the segmented inner tube assembly according to claim 1, characterized in that: The support pad (13) is hollow inside and has external threads. The inner diameter of the support pad (13) is larger than the outer diameter of the linkage rod (113). The spring (14) is sleeved on the linkage rod (113). The outer diameter of the spring (14) is larger than the inner diameter of the support pad (13). The outer diameter of the spring (14) is smaller than the inner diameter of the outer linkage frame (16). The inner diameter of the spring (14) is larger than the outer diameter of the linkage rod (113). The two ends of the spring (14) are respectively supported by the support... The gasket (13) and the rolled elastic pin (15) are axially limited. The one-way valve (17) includes a valve plug (168) and a valve cover (169). The valve cover (169) is hollow inside. The top of the valve cover (169) is provided with an external thread. The valve cover (169) is connected to the valve cover connecting plate (166) by a thread. The diameter of the valve plug (168) is smaller than the inner diameter of the top of the valve cover (169). The diameter of the valve plug (168) is larger than the inner diameter of the bottom of the valve cover (169).

5. The multi-stage linkage annular cavity unlocking mechanism for the segmented inner tube assembly according to claim 1, characterized in that: The core-harvesting inner tube (21) is provided with external threads at its top and bottom. The core-harvesting inner tube (21) is symmetrically provided with four flap sliding grooves (210). Each flap sliding groove (210) includes a guide block (216) and an arc-shaped groove (118). Guide ribs (119) are provided on both sides of the guide block (216). The flap sliding grooves (210) are normally arranged along the core-harvesting inner tube (21). The core-harvesting inner tube (21) is provided with multiple steel ball positioning plates (211). Multiple steel ball positioning holes (212) are arrayed on the steel ball positioning plates (211). The ball positioning plate (211) is fixedly connected to the core-taking inner tube (21), the steel ball (22) is placed on the steel ball positioning hole (212), the core-taking inner tube (21) is symmetrically provided with a retaining strip groove (213), the retaining strip groove (213) is provided with guide rail grooves (217) on both sides, the retaining strip groove (213) is provided with a stop block rotation groove (214) at the bottom, the core-taking inner tube (21) is provided with a safety pin (215), the safety pin (215) is fixedly connected to the core-taking inner tube (21), and the safety pin (215) is covered with an elastic bushing.

6. The multi-stage linkage annular cavity unblocking mechanism for the segmented inner tube assembly according to claim 1, characterized in that: The sliding groove limiting flap mechanism (3) is symmetrically arranged in pairs to form two sets of flap pairs. The first sliding groove limiting flap group (31) and the second sliding groove limiting flap group (32) are arc-shaped. The two flaps of the first sliding groove limiting flap group (31) are of equal length. The first sliding groove limiting flap group (31) has a circular pin hole (111) at the top and a variable diameter locking groove (312) at the bottom. The second sliding groove limiting flap group (32) has two flaps of equal length. The second sliding groove limiting flap group (32) has a circular pin hole (111) at the top and a semi-circular hole (322) at the bottom. Group 1 (31) and the second sliding groove limiting petal group (32) have different petal lengths. The first sliding groove limiting petal group (31) is fixed in the circular pin hole (111) by the first rolled elastic pin (12). The second sliding groove limiting petal group (32) slides by the second rolled elastic pin (15). The second rolled elastic pin (15) slides in the inner sliding groove (117) and the outer sliding groove (163). The first sliding groove limiting petal group (31) and the second sliding groove limiting petal group (32) are provided with guide rail grooves (311) on both sides. The first sliding groove limiting petal group (31) and the second sliding groove limiting petal group (32) are supported on the steel ball (22).

7. The multi-stage linkage annular cavity unlocking mechanism for the segmented inner tube assembly according to claim 1, characterized in that: The card strip (41) is arc-shaped, and guide ribs (410) are provided on both sides of the card strip (41). The petal block (42) includes a first block (423) and a second block (424). The first block (423) has guide rail grooves (421) at both ends, and the second block (424) has guide ribs (422) at both ends. The petal block (42) includes a third guide block (420) and an arc-shaped sliding groove (118). The third guide block (420) has a card strip sliding groove (213), and guide ribs (119) are provided on both sides of the third guide block (420). The guide rail grooves (421) and the guide ribs (422) are interlocked to form a whole.

8. The multi-stage linkage annular cavity unblocking mechanism for the segmented inner tube assembly according to claim 1, characterized in that: The top of the snap ring seat (51) is provided with an internal thread. The snap ring seat (51) is symmetrically provided with two flap sliding grooves (160). The two flap sliding grooves (160) include a guide block (167) and an arc-shaped sliding groove (118). The guide block (167) is provided with guide ribs (119) on both sides. The two flap sliding grooves (160) are normally provided along the snap ring seat (51). The bottom of the snap ring seat (51) is provided with a semi-circular hole (322). The snap ring seat (51) is provided with a circular groove (510). The inner surface of the snap ring seat (51) is an inverted cone. The retaining ring (52) is a circular, non-closed structure that can retract radially. The retaining ring (52) is placed in the circular groove (512). The retaining ring (53) is a circular, non-closed structure that can retract radially. The outer surface of the retaining ring (53) is an inverted conical structure. The inner surface of the retaining ring (53) is provided with retaining ring teeth. The retaining ring (53) is placed in the retaining ring seat (51). The inverted conical structure on the inner surface of the retaining ring seat (51) cooperates with the inverted conical structure on the outer surface of the retaining ring (53) to guide the retaining ring (53) to retract radially.

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