A wire-line coring drill and coring method based on flow control core breaking

Abstract

A kind of rope coring drill based on flow control core breaking and coring method, it is related to the field of core taking.Rope coring drill based on flow control core breaking includes the outer tube assembly of pop-on head, pop-on chamber, outer tube and drill bit and the inner tube assembly of pop-on mechanism, flow adapter, torsion driver, core inner tube and core breaker;Core breaker includes the inner shaft sleeve pipe connected with core inner tube, outer shaft sleeve pipe and a plurality of rotatable cutting blades;Flow adapter can selectively deliver mud to the mud channel between outer tube assembly and inner tube assembly or deliver mud to torsion driver after being pressurized;Torsion driver is used to drive outer shaft sleeve pipe to rotate relative to inner shaft sleeve pipe when delivering pressurized mud, to push cutting blades to rotate synchronously and break core.Rope coring drill based on flow control core breaking and coring method can control the size of mud flow into coring drill on the ground to actively control the action of core breaking downhole.

Description

Technical Field

[0001] This application relates to the field of core extraction, and more specifically, to a wireline coring drill and coring method based on flow control core fragmentation. Background Technology

[0002] Wireline coring is a drilling method that involves obtaining core samples with minimal or no drilling operations. It is widely used due to its high drilling efficiency, low cost, and low failure rate. Currently, wireline coring tools have become standardized and serialized. However, existing wireline coring tools primarily use the spring clip method for core extraction. While this method is effective for medium-hard and harder intact rock formations, it is significantly unsuitable for loose, plastic, or fractured complex formations, especially soft sandy soils and loose, fractured formations. The technical problems include: 1. When using the spring clip to extract core samples from soft formations, slippage, peeling, and failure to hold the core are frequent, making effective core extraction impossible; 2. When coring from fractured formations, a wedge effect easily occurs at the spring clip, preventing the core from smoothly entering the core tube. During drilling, the fractured core is easily dislodged, making it difficult to meet core quality requirements. Summary of the Invention

[0003] The purpose of this application is to provide a wireline coring tool and coring method based on flow control core extraction, which can actively control the downhole core extraction action by controlling the mud pressure introduced into the coring tool at the surface.

[0004] This application is implemented as follows:

[0005] This application provides a wireline coring tool based on flow control core extraction, which includes an outer tube assembly and an inner tube assembly disposed within the outer tube assembly. A mud channel is formed between the outer tube assembly and the inner tube assembly. The outer tube assembly includes a spring clip stop, a spring clip chamber, an outer tube, and a drill bit connected in sequence. The inner tube assembly includes a spring clip mechanism, a flow adapter, a torsion drive, an inner core tube, and a core extractor connected in sequence.

[0006] The core extractor includes an inner sleeve connected to the inner core tube, an outer sleeve rotatably fitted onto the inner sleeve, and multiple cutting mechanisms. The inner and outer sleeves are respectively provided with a first receiving hole and a second receiving hole corresponding to each cutting mechanism. Each cutting mechanism includes a cutting blade rotatably connected to the first and second receiving holes. When the outer sleeve rotates relative to the inner sleeve, it pushes each cutting blade to rotate synchronously and extend into the inner sleeve to cut and support the core or retract into the first and second receiving holes.

[0007] When the flow rate of the slurry through the flow adapter is less than or greater than or equal to a preset value, the flow adapter delivers the slurry to the slurry channel or pressurizes it and delivers it to the torsion drive. The torsion drive is used to drive the outer shaft sleeve to rotate relative to the inner shaft sleeve when receiving the pressurized slurry delivered by the flow adapter.

[0008] In some optional implementations, a single-action mechanism is connected between the card ejector mechanism and the flow adapter. The single-action mechanism includes an upper cylinder and a lower cylinder connected to the card ejector mechanism, a rotating shaft with both ends rotatably passing through the upper cylinder and the lower cylinder respectively, and an annular bearing seat. The inner walls of adjacent ends of the upper cylinder and the lower cylinder are respectively connected to the outer walls of both ends of the bearing seat by threads. The inner walls of both ends of the bearing seat are respectively connected to bearings sleeved on both ends of the rotating shaft. The rotating shaft has shaft holes passing through both ends of it. The rotating shaft is connected to the flow adapter.

[0009] In some optional embodiments, a suspension sealing short joint connects the spring clip mechanism and the single-action mechanism. The suspension sealing short joint includes a suspension short joint connected to the spring clip mechanism, a suspension ring disposed on the outer wall of the suspension short joint, and a positioning signal device. The inner wall of the outer tube is provided with a suspension seat ring for suspending the suspension ring. The suspension short joint is provided with a mud short joint channel that connects the mud flow channel and the shaft hole. The positioning signal device includes a sealing ring disposed on the inner wall of the mud short joint channel and a steel ball that seals and presses against the sealing ring. When the pressure in the mud short joint channel exceeds the threshold, it pushes the steel ball to squeeze through the sealing ring and fall into the single-action mechanism.

[0010] In some optional embodiments, the flow adapter includes a distribution valve body with a valve cavity, a distribution valve seat fixedly disposed within the valve cavity, a valve core assembly movably disposed within the distribution valve body along the axial direction, and a distribution spring sleeved on the valve core assembly. The two ends of the distribution spring respectively press against the valve core assembly and the distribution valve body. The valve cavity and the shaft hole are connected. The outer wall of the distribution valve body has multiple diversion holes communicating with the mud channel and the valve cavity. When the valve core assembly moves axially, it closes or opens the diversion holes. The distribution valve seat has valve seat holes communicating with its two ends. One end of the valve core assembly is slidably disposed in the valve seat hole and seals the valve seat hole. The valve core assembly and the distribution valve seat enclose a distribution cavity. The valve core assembly is provided with a distribution channel connecting the valve cavity and the distribution cavity. The outer wall of the end of the valve core assembly that is slidably disposed in the valve seat hole is provided with multiple connecting holes that connect to the torsion actuator. When the mud flow rate through the flow adapter is above the preset value, the mud enters the distribution cavity through the valve cavity, pushes the valve core assembly to move axially and compresses the distribution spring, so that the valve core assembly moves to close the diversion hole and connects the connecting hole to the distribution cavity.

[0011] In some optional embodiments, the torsion actuator includes an actuator cylinder connected to a distribution valve body, a stator fixedly disposed within the actuator cylinder, a rotor rotatably disposed within the actuator cylinder, and a retaining shaft coaxially connected to the rotor. The stator has multiple sector teeth, and the rotor has sector blades corresponding one-to-one with the sector teeth. The sector teeth and sector blades are arranged alternately along the circumference of the actuator cylinder. The actuator cylinder, stator, sector teeth, rotor, and sector blades enclose and form multiple high-pressure chambers and multiple low-pressure chambers arranged alternately along the circumference of the actuator cylinder. The actuator cylinder has at least one high-pressure damping hole connecting the high-pressure chamber and the mud channel, and at least one low-pressure damping hole connecting the low-pressure chamber and the mud channel. The rotor has a mud hole that connects to the connecting hole and each high-pressure chamber. The actuator cylinder is connected to the outer shaft sleeve through a middle layer tube, and the retaining shaft is connected to the inner shaft sleeve through a core inner tube.

[0012] In some alternative implementations, the drive cylinder has multiple fan-shaped grooves arranged circumferentially, and the retaining shaft is threadedly connected to a limiting screw corresponding to each fan-shaped groove. One end of the limiting screw extends into the corresponding fan-shaped groove. When the rotor rotates relative to the stator, the fan-shaped groove blocks the corresponding limiting screw to limit the rotation angle of the rotor.

[0013] In some alternative embodiments, the inner core tube includes a core receiving tube and a core tube end cap connected to one end of the core receiving tube. The retaining shaft has a retaining hole extending through both ends thereto. The core tube end cap is engaged with the retaining hole. The core tube end cap has an end cap channel connecting the core receiving tube and the mud hole. The core tube end cap has a one-way overflow valve inside for limiting the one-way flow of mud from the core receiving tube into the end cap channel.

[0014] In some alternative implementations, when the core tube end cap is snapped into the snap-fit ​​hole, the limiting screw moves axially to press against or stop pressing against the outer wall of the core tube end cap.

[0015] In some alternative implementations, each cutting mechanism includes a first pin and a second pin, with one end of the cutting blade sleeved on the corresponding first pin and the second pin through a pin hole and an arc-shaped hole, respectively. The two ends of the first pin and the two ends of the second pin are respectively connected to the two sides of the corresponding first receiving hole and the two sides of the corresponding second receiving hole.

[0016] This application also provides a wireline coring method based on flow-controlled core fragmentation, which includes the following steps:

[0017] The outer tube assembly of the wireline coring tool based on flow control core extraction is placed into the borehole.

[0018] The inner tube assembly of the wireline coring tool based on flow control core extraction is lowered into the outer tube assembly;

[0019] Control the mud flow rate through the flow adapter to be less than the preset value, and continue normal core drilling until the drilling depth of the cycle is reached. Stop drilling after the target core passes through the inner shaft casing and enters the core inner tube.

[0020] Controlling the mud flow rate through the flow adapter to a preset value causes the torsion drive to rotate the outer shaft sleeve relative to the inner shaft sleeve, pushing each cutting blade to rotate synchronously and extend into the inner shaft sleeve to cut and support the core.

[0021] After the inner tube assembly was salvaged, the core was removed.

[0022] The beneficial effects of this application are as follows: The wireline coring tool based on flow control core extraction provided by this application includes an outer tube assembly and an inner tube assembly disposed within the outer tube assembly. A mud channel is formed between the outer tube assembly and the inner tube assembly. The outer tube assembly includes a spring-loaded stop, a spring-loaded chamber, an outer tube, and a drill bit connected in sequence. The inner tube assembly includes a spring-loaded mechanism, a flow adapter, a torsion actuator, an inner core tube, and a core extractor connected in sequence. The core extractor includes an inner shaft sleeve connected to the inner core tube, an outer shaft sleeve rotatably fitted on the inner shaft sleeve, and multiple cutting mechanisms. The inner shaft sleeve and the outer shaft sleeve are respectively provided with openings for the cutting mechanisms. The system comprises a first receiving hole and a second receiving hole with a one-to-one correspondence; each cutting mechanism includes a cutting blade rotatably connected to the first receiving hole and the second receiving hole; when the outer shaft sleeve rotates relative to the inner shaft sleeve, it drives each cutting blade to rotate synchronously and extend into the inner shaft sleeve to cut and support the core or retract into the first receiving hole and the second receiving hole; the flow adapter delivers mud to the mud channel or pressurizes it and delivers it to the torsion drive when the mud flow rate through it is less than or greater than or equal to a preset value; the torsion drive drives the outer shaft sleeve to rotate relative to the inner shaft sleeve when receiving the pressurized mud delivered by the flow adapter. The wireline coring drill string and coring method based on flow control core cutting provided in this application can actively control the downhole core cutting action by controlling the mud flow rate entering the coring drill string at the surface, making core cutting more reliable and coring action more controllable, with the effects of simple operation, high reliability, high core recovery rate, and good sample fidelity. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, 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 this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is an exploded structural diagram of a wireline coring drill based on flow control core extraction, provided in an embodiment of this application.

[0025] Figure 2 A partial cross-sectional view of the wireline coring tool based on flow control core extraction provided in this application embodiment;

[0026] Figure 3 A partial cross-sectional view of the connection between the spring clip mechanism, the suspension sealing short circuit and the single-action mechanism in the wireline coring tool based on flow control core extraction provided in this application embodiment;

[0027] Figure 4 A partial cross-sectional view of the connection between the single-action mechanism, flow adapter, torsion actuator, and core inner tube in a wireline coring tool based on flow control core extraction provided in this application embodiment;

[0028] Figure 5 For along Figure 4 Sectional view of section line AA in the middle;

[0029] Figure 6 For along Figure 4 Sectional view of the BB section line;

[0030] Figure 7 An exploded structural diagram of the core extractor in a wireline coring tool based on flow control core extraction, provided in an embodiment of this application.

[0031] Figure 8 This is a cross-sectional view of the core extractor in a wireline coring tool based on flow control core extraction, as provided in an embodiment of this application.

[0032] Figure 9 For along Figure 8 A schematic diagram of the cross-sectional structure of the core extractor in the first use state of the CC profile.

[0033] Figure 10 For along Figure 8 A schematic diagram of the cross-sectional structure of the core extractor in the second operational state at the CC profile.

[0034] In the diagram: 100, Outer tube assembly; 110, Spring-loaded stop; 120, Spring-loaded chamber; 130, Outer tube; 140, Drill bit; 150, Suspension seat ring; 160, Mud channel; 170, Reamer; 200, Inner tube assembly; 210, Spring-loaded mechanism; 211, Retrieval spearhead; 212, Spring-loaded bracket; 213, Spring-loaded clip; 214, Recovery tube; 215, Mud flow channel; 220, Suspension seal short connector; 221, Suspension short connector; 222, Suspension ring; 223, Seal; 224, Mud short connector channel; 225, Sealing ring; 226, Steel ball; 230, Middle tube; 3 00. Single-acting mechanism; 310. Upper cylinder; 320. Lower cylinder; 330. Rotating shaft; 331. Shaft hole; 332. Ball seat; 333. Bypass hole; 340. Bearing seat; 350. Bearing; 360. Locking nut; 370. Sealing ring; 380. Lubrication chamber; 390. Oil nozzle; 400. Flow adapter; 410. Distribution valve body; 411. Upper distribution valve body; 412. Lower distribution valve body; 413. Diverter hole; 420. Flow limiting ring; 430. Flow limiting valve head; 431. Valve head hole; 432. Filter screen; 440. Piston spindle; 441. Spindle hole; 442. Plug; 450, Flow control valve stem; 451, Valve stem hole; 452, Flow control hole; 453, Connecting hole; 460, Flow control valve seat; 461, Valve seat hole; 470, Flow control spring; 480, Valve chamber; 490, Flow control cavity; 500, Torsional actuator; 510, Actuator cylinder; 511, High-pressure damping hole; 512, Low-pressure damping hole; 513, Sector-shaped groove; 520, Stator; 521, Sector-shaped tooth; 522, Connecting screw; 530, Rotor; 531, Sector-shaped blade; 532, Mud hole; 533, Mud connection port; 540, Shaft retainer; 541, Limiting screw; 542. Snap-fit ​​hole; 550. High-pressure chamber; 560. Low-pressure chamber; 600. Core inner tube; 610. Core receiving tube; 620. Core tube end cap; 630. End cap channel; 640. One-way overflow valve; 700. Core cutter; 710. Inner shaft sleeve; 711. First receiving hole; 720. Outer shaft sleeve; 721. Second receiving hole; 730. Cutting mechanism; 731. Cutting blade; 732. First pin; 733. Second pin; 740. End sampling tube; 750. Pin hole; 760. Arc-shaped hole; 770. First pin hole; 780. Second pin hole. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0037] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0038] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0040] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0041] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0042] The following describes in further detail the features and performance of the wireline coring tool and coring method based on flow control core extraction of this application, with reference to embodiments.

[0043] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10 As shown in the figure, this application provides a wireline coring tool based on flow control core extraction, which includes an outer tube assembly 100 and an inner tube assembly 200 disposed within the outer tube assembly 100. A mud channel 160 is formed between the outer tube assembly 100 and the inner tube assembly 200. The outer tube assembly 100 includes a spring-loaded stop 110, a spring-loaded chamber 120, an outer tube 130, a reamer 170, a drill bit 140, and a suspension seat ring 150 connected to the inner wall of the outer tube 130 in sequence. The inner tube assembly 200 includes a spring-loaded mechanism 210, a suspension sealing short-circuit 220, a single-action mechanism 300, a flow adapter 400, a torsion actuator 500, a middle tube 230, a core inner tube 600, and a core extractor 700.

[0044] The structure of the spring clip mechanism 210 is consistent with that of the spring clip mechanism in existing wireline coring tools, and is not the focus of this application. The structure is only briefly described. The spring clip mechanism 210 includes a retrieval spearhead 211, a spring clip frame 212, a spring clip 213, and a recovery pipe 214 that are matched with the spring clip stop head 110. The retrieval spearhead 211 is connected to the spring clip frame 212. The spring clip 213 is movably connected to the spring clip frame 212 through a pin. The spring clip frame 212 is provided with a mud flow channel 215. The recovery pipe 214 is sleeved on the outside of the spring clip frame 212. The lower end of the spring clip frame 212 is connected to the suspension sealing short circuit 220.

[0045] The suspension sealing short joint 220 includes a suspension short joint 221, a suspension ring 222 disposed on the outer wall of the suspension short joint 221, a sealing element 223 disposed on the outer wall of the suspension short joint 221, and a positioning signal device. One end of the suspension short joint 221 is threadedly connected to the spring clip 212, and the other end is connected to the single-action mechanism 300. The suspension ring 222 is used to position and suspend the entire inner tube assembly 200 on the suspension seat ring 150 on the inner wall of the outer tube 130. The suspension short joint 221 is provided with a mud short joint channel 224 that connects to the mud flow channel 215. The sealing element 223 is located at the overlapping part of the suspension short joint 221 and the suspension seat ring 150 to seal the annular flow passage between the suspension short joint 221 and the outer pipe 130. The arrival signal device includes a sealing ring 225 located on the inner wall of the mud short joint channel 224 and a steel ball 226 that seals and presses against the top of the sealing ring 225. The outer diameter of the steel ball 226 is larger than the inner diameter of the sealing ring 225. The sealing ring 225 has a plastic shape. When the steel ball 226 is subjected to a pressure greater than the preset pressure, it is squeezed and passes through the sealing ring 225 and falls to the single-action mechanism 300. When the inner tube assembly 200 is lowered, the steel ball 226 presses against the sealing ring 225 to block the mud short-connection channel 224. After the inner tube assembly 200 is lowered to the point where the suspension ring 222 and the suspension seat ring 150 are in close contact and sealed, the pump pressure in the mud short-connection channel 224 increases. When the pump pressure in the mud short-connection channel 224 increases to the threshold, it pushes the steel ball 226 to squeeze through the sealing ring 225 and fall into the single-action mechanism 300, so that the mud short-connection channel 224 is reopened to achieve normal drilling state, realizing reliable positioning of the drill string and the positioning signal device.

[0046] The single-action mechanism 300 includes an upper cylinder 310, a lower cylinder 320, a rotating shaft 330 rotatably passing through the upper cylinder 310 and the lower cylinder 320 at both ends, and an annular bearing seat 340. One end of the upper cylinder 310 is connected to a suspension short connector 221 via a thread. The inner walls of adjacent ends of the upper cylinder 310 and the lower cylinder 320 are respectively connected to the outer walls of both ends of the bearing seat 340 via threads. Bearings 350 sleeved on both ends of the rotating shaft 330 are respectively connected to the inner walls of both ends of the bearing seat 340. A locking nut 360 for limiting its axial position is sleeved on the rotating shaft 330. Sealing rings 370 that seal against the inner walls of the upper cylinder 310 and the lower cylinder 320 are respectively sleeved on the outer walls of both ends of the rotating shaft 330. The inner walls of the upper cylinder 310, the lower cylinder 320, and the rotating shaft 330 are sealed together. A lubrication cavity 380 is formed between the outer wall of the shaft 330 and the inner wall of the bearing housing 340. The bearing housing 340 is provided with an oil injection nozzle 390 for injecting lubricating oil into the lubrication cavity 380. The end of the rotating shaft 330 near the suspension seal short-circuit 220 is provided with a ball seat 332 for receiving and supporting the steel ball 226. The bottom wall of the ball seat 332 is provided with a shaft hole 331 that passes through both ends of the rotating shaft 330. When the steel ball 226 falls into the ball seat 332, it closes one end of the shaft hole 331. The end of the rotating shaft 330 near the suspension seal short-circuit 222 is provided with eight bypass holes 333 that connect to the shaft hole 331. When the steel ball 226 falls into the ball seat 332 and closes one end of the shaft hole 331, the bypass holes 333 are used to transport mud to the shaft hole 331 through the mud short-circuit channel 224.

[0047] When the mud flow rate through the flow adapter 400 is lower than the preset value, the flow adapter 400 delivers the mud from the shaft hole 331 to the mud channel 160. When the mud flow rate through the flow adapter 400 is higher than the preset value, the flow adapter 400 pressurizes the mud from the shaft hole 331 and delivers it to the torsion drive 500 to generate torque. The preset value is a characteristic parameter of the flow adapter 400, and its value can be dynamically adjusted and set according to actual needs.

[0048] The flow adapter 400 includes a flow distribution valve body 410, a flow limiting ring 420, a flow limiting valve head 430, a piston-type spindle 440, a flow distribution valve rod 450, a flow distribution valve seat 460, and a flow distribution spring 470. The flow distribution valve body 410 includes an upper flow distribution valve body 411 and a lower flow distribution valve body 412 connected by threads. The upper flow distribution valve body 411 and the lower flow distribution valve body 412 are respectively connected to the rotating shaft 330 and the torsion actuator 500 by threads. The flow distribution valve body 410 is provided with a valve cavity 480 that penetrates the upper flow distribution valve body 411 and the lower flow distribution valve body 412. The flow limiting ring 420 is provided on the inner wall of the upper flow distribution valve body 411. The outer wall of the upper flow distribution valve body 411 is provided with four diversion holes 413 that connect the mud channel 160 and the valve cavity 480. The flow limiting valve head 430 is axially movable. When the flow-limiting ring 420 cooperates with the flow-limiting ring 420 to close or open the flow-dividing orifice 413, the flow-limiting valve head 430, the piston-type spindle 440, and the flow-distributing valve stem 450 are connected coaxially in sequence by threads to form a valve core assembly. The flow-distributing valve seat 460 is fixed to the inner wall of the lower flow-distributing valve body 412 by threads. The flow-distributing valve seat 460 is provided with a valve seat hole 461 connecting its two ends. One end of the flow-distributing valve stem 450 is slidably disposed in the valve seat hole 461 and seals the valve seat hole 461. The flow-distributing spring 470 is sleeved on the piston-type spindle 440 and its two ends respectively abut against the lower flow-distributing valve body 412 and the piston-type spindle 440. The flow-limiting valve head 430, the piston-type spindle 440, and the flow-distributing valve stem 451 are respectively provided with a valve head hole 431, a spindle hole 441, and a valve stem hole 451 connected in sequence. The valve head hole 431 is connected to the flow-limiting valve head 430. The valve chamber 480 is connected to the piston-type spindle 440, and the end of the spindle 440 connected to the flow distribution valve stem 450 expands outward to form a piston head 442. The piston head 442, the flow distribution valve stem 450, and the flow distribution valve seat 460 enclose a flow distribution cavity 490. The cross-sectional area of ​​the flow distribution cavity 490 is larger than that of the flow limiting valve head 430. The end of the flow distribution valve stem 450 extending out of the valve seat hole 461 has four flow distribution holes 452 that connect the valve stem hole 451 and the flow distribution cavity 490. The valve head hole 431, the spindle hole 441, the valve stem hole 451, and the flow distribution holes 452 cooperate to form a flow distribution channel connecting the valve chamber 480 and the flow distribution cavity 490. The flow distribution valve stem 450 is slidably disposed in the valve seat hole 461, and the outer wall of one end has six connecting holes 453 that connect the torsional actuator 500. The assembly is slidably mounted axially within the lower distribution valve body 412. When the mud flow rate through the flow adapter 400 exceeds a preset value, the mud enters the distribution chamber 490 through the valve cavity 480, valve head hole 431, main shaft hole 441, valve stem hole 451, and distribution hole 452, pushing the valve core assembly to move and compressing the distribution spring 470. This causes the flow-limiting valve head 430 to move axially to close the flow-limiting ring 420, which in turn closes the diversion hole 413 and connects the connection hole 453 to the distribution chamber 490. The valve head hole 431 is connected to a filter screen 432. The inner diameter of the flow-limiting ring 420 is slightly larger than the outer diameter of the flow-limiting valve head 430, so that the flow-limiting valve head 430 and the flow-limiting ring 420 do not completely close the diversion hole 413 when they cooperate to close it, thus avoiding pump blockage and protecting the mud pump from damage.

[0049] The torsion actuator 500 includes an actuator cylinder 510 with one end threadedly connected to the lower distribution valve body 412, a stator 520 fixedly connected to the actuator cylinder 510 by connecting screws 522, a rotor 530 rotatably disposed within the actuator cylinder 510, and a retaining shaft 540 coaxially connected to the rotor 530 by threads. The stator 520 has two sector teeth 521, and the rotor 530 has two sector blades 531 corresponding one-to-one with the sector teeth 521. The two sector teeth 521 and the two sector blades 531 are arranged alternately around the circumference of the actuator cylinder 510. The actuator cylinder 510, stator 520, sector teeth 521, rotor 530, and sector blades 531 enclose and form two high-pressure chambers 550 and two [other components] arranged alternately around the circumference of the actuator cylinder 510. The low-pressure chamber 560 and the actuator cylinder 510 are provided with a high-pressure damping hole 511 connecting the high-pressure chamber 550 and the mud channel 160, and a low-pressure damping hole 512 connecting the low-pressure chamber 560 and the mud channel 160. The rotor 530 is provided with a mud hole 532 connecting the connecting hole 453. The mud hole 532 passes through both ends of the rotor 530, and the inner wall of the mud hole 532 is connected to each high-pressure chamber 550 through a mud connecting port 533. The actuator cylinder 510 has three fan-shaped waist grooves 513 arranged circumferentially. The retaining shaft 540 is threadedly connected to three limiting screws 541, one end of which extends into the fan-shaped waist grooves 513. When the rotor 530 rotates relative to the stator 520, the fan-shaped waist grooves 513 block the rotation of the limiting screws 541 to limit the rotation angle of the rotor 530. The end of the actuator cylinder 510 away from the lower distribution valve body 412 is threadedly connected to the middle layer tube 230.

[0050] like Figure 3 and Figure 6 As shown, the core inner tube 600 includes a core receiving tube 610 and a core tube end cap 620 connected to one end of the core receiving tube 610 by a thread. The retaining shaft 540 is provided with retaining holes 542 passing through both ends of it. The core tube end cap 620 is retained in the retaining holes 542. The core tube end cap 620 is provided with an end cap channel 630 connecting the core receiving tube 610 and the mud hole 532. The core tube end cap 620 is provided with a one-way overflow valve 640 for limiting the one-way flow of mud from the core receiving tube 610 into the end cap channel 630. When the core tube end cap 620 is retained in the retaining holes 542, the limiting screw 541 moves axially to press or stop pressing against the outer wall of the core tube end cap 620 to limit or stop limiting the position of the core tube end cap 620.

[0051] like Figure 7 , Figure 8 , Figure 9 and Figure 10As shown, the core extractor 700 includes an inner shaft sleeve 710, an outer shaft sleeve 720 rotatably sleeved on the outside of the inner shaft sleeve 710, four cutting mechanisms 730, and an end sampling cylinder 740 sleeved on the end of the inner shaft sleeve 710; the other end of the core receiving tube 610 is connected to the inner shaft sleeve 710, and the end of the middle tube away from the driver cylinder 510 is threadedly connected to the outer shaft sleeve 720; wherein, the outer wall of the inner shaft sleeve 710 has four first receiving holes 711 penetrating its inner wall, each first receiving hole 711 extending along the circumference of the inner shaft sleeve 710, and the four first receiving holes 711 along the inner shaft sleeve 710. The inner sleeve 710 is arranged circumferentially; the outer sleeve 720 has four second receiving holes 721 penetrating its inner wall on its outer wall, each second receiving hole 721 extending circumferentially along the outer sleeve 720, and the four second receiving holes 721 are arranged circumferentially along the outer sleeve 720. The first receiving hole 711 and the second receiving hole 721 correspond one-to-one, and each first receiving hole 711 and the corresponding second receiving hole 721 are arranged sequentially radially along the inner sleeve 710; each cutting mechanism 730 includes an arc-shaped cutting blade 731, a first pin 732 and a second pin 733, for cutting... One end of the cutting blade 731 is respectively fitted onto the corresponding first pin 732 and second pin 733 through pin holes 750 and arc-shaped holes 760. The two ends of the first pin 732 and the two ends of the second pin 733 are respectively connected to the two sides of a first receiving hole 711 and the two sides of a corresponding second receiving hole 721. The outer wall of one end of the inner shaft sleeve 710 has first pin holes 770 that pass through the two sides of the four first receiving holes 711. The first pins 732 of the four cutting mechanisms 730 pass through the four first pin holes 770 and the arc-shaped holes 760 on the four cutting blades 731 respectively. The outer shaft sleeve 72 One end of the outer wall of the 0 has a second pin hole 780 that passes through both sides of the four second receiving holes 721. The second pins 733 of the four cutting mechanisms 730 pass through the four second pin holes 780 and the pin holes 750 on the four cutting blades 731 respectively. The end sampling tube 740 is sleeved on the outer wall of the end of the inner shaft sleeve 710 that has a first pin hole 770 and the end of the tube abuts against the end of the outer shaft sleeve 720 that has a second pin hole 780. When the outer shaft sleeve 720 rotates relative to the inner shaft sleeve 710, it pushes the four cutting blades 731 to rotate synchronously and extend into the inner shaft sleeve 710 to cut and support the rock core.

[0052] The wireline coring tool based on flow control provided in this application can actively control the downhole core extraction action by controlling the flow rate of mud entering the core extraction tool at the surface. This allows for control of the mud pressure according to the actual core shearing force requirements of the formation, ensuring that the core is sheared, sealed, and lifted. This makes core extraction more reliable and the core extraction action more controllable. It features simple operation, high reliability, high core recovery rate, and good sample fidelity.

[0053] The core extraction method using a wireline coring drill based on flow control core extraction provided in this application includes the following steps:

[0054] Insert the outer tube assembly 100 into the borehole;

[0055] The inner tube assembly 200 is lowered into the outer tube assembly 100, so that the suspension ring 222 on the outer wall of the suspension short-connection 221 in the inner tube assembly 200 is suspended on the suspension seat ring 150 on the inner wall of the outer tube 130 in the outer tube assembly 100. The mud pump is pumped sequentially through the mud flow channel 215 to the mud short-connection channel 224. When the pump pressure in the mud short-connection channel 224 rises to the threshold, it pushes the steel ball 226 to squeeze through the sealing ring 225 and fall into the ball seat 332 of the single-action mechanism 300. The mud in the mud short-connection channel 224 sequentially passes through the bypass hole 333, shaft hole 331, valve cavity 480, and diversion hole 413 before entering the mud channel 160 to reach the normal drilling state. The change of pump pressure first increases and then decreases ensures that the inner tube assembly 200 is installed in place.

[0056] Normal coring drilling continues until the drilling depth is reached, allowing the target core to pass through the inner shaft sleeve 710 and enter the core receiving tube 610 of the core inner tube 600. Drilling stops after obtaining the target core. During normal coring drilling, mud is pumped at a flow rate lower than the preset value through the mud flow channel 215, mud short-circuit channel 224, bypass hole 333, and shaft hole 331 into the valve chamber 480. The mud in the valve chamber 480 enters the mud channel 160 through the diversion hole 413 and flows into the distribution chamber 490 through the distribution channel composed of valve head hole 431, main shaft hole 441, valve stem hole 451, and distribution hole 452. At this time, the mud pressure flowing into the distribution chamber 490 is insufficient to compress the distribution spring 470 and push the valve core assembly to move.

[0057] The core is cut off and supported in the core receiving tube 610. Mud is pumped at a flow rate exceeding a preset value through the mud flow channel 215, mud short-circuit channel 224, bypass hole 333, shaft hole 331, and valve chamber 480, then enters the mud channel 160 through the diversion hole 413 and flows into the distribution chamber 490 through the valve head hole 431, main shaft hole 441, valve stem hole 451, and distribution hole 452. At this time, the mud pressure flowing into the distribution chamber 490 is greater than the elastic force of the distribution spring 470, pushing the distribution spring 470 to compress and move the valve core assembly. This causes the flow-limiting valve head 430 to move axially, cooperating with the flow-limiting ring 420 to isolate the diversion hole 413 from the valve chamber 480, and connecting the connection hole 453. In the distribution chamber 490, the mud channel 160 and the valve chamber 480 are isolated. The mud can only enter the torsion actuator 500 through the valve head hole 431, the main shaft hole 441, the valve stem hole 451, the distribution hole 452, the distribution chamber 490 and the connecting hole 453, and drive the rotor 530 of the torsion actuator 500 to rotate relative to the stator 520. Thus, through the clamping shaft 540 connected to the rotor 530, the core receiving tube 610 and the inner shaft sleeve 710 of the core inner tube 600 are driven to rotate relative to the middle tube 230 and the outer shaft sleeve 720 connected to the actuator cylinder 510, generating torsion. This drives the cutting mechanism 730 in the core cutter 700 to cut and support the core in the core receiving tube 610.

[0058] After retrieving the inner tube assembly 200, the core inner tube 600 was removed and the core was extracted, completing the core extraction operation.

[0059] When the mud enters the torsion actuator 500 through the valve head hole 431, main shaft hole 441, valve stem hole 451, distribution cavity 490, and connecting hole 453, the pressure increases due to the reduced flow cross-section. The increased pressure mud flows through the connecting hole 453, through the mud hole 532 and mud communication port 533 on the rotor 530 of the torsion actuator 500, into each high-pressure chamber 550, and then flows into the mud channel 160 through the high-pressure damping hole 511. At this time, the pressure connecting each low-pressure chamber 560 and the mud channel 160 of the torsion actuator 500 is less than the pressure inside each high-pressure chamber 550. When the pressure in the high-pressure chamber 550 is greater than the pressure in the low-pressure chamber 560, the rotor 530 rotates relative to the stator 520. This, through the clamping shaft 540 connected to the rotor 530, sequentially drives the core receiving tube 610 and the inner shaft sleeve 710 of the core inner tube 600 to rotate relative to the middle layer tube 230 and the outer shaft sleeve 720 connected to the actuator cylinder 510. When the outer sleeve 720 rotates relative to the inner sleeve 710, one end of each of the four second receiving holes 721 on the outer sleeve 720 pushes one end of each of the four cutting blades 731 fitted onto the first pin 732 and the second pin 733 to rotate, causing the four cutting blades 731 to rotate clockwise around the first pin 732 until they extend into the inner sleeve 710 to cut and support the core. When the core extractor 700 is pulled out of the ground along with the inner tube assembly 200, and the outer sleeve 720 is rotated counterclockwise relative to the inner sleeve 710 to reset, one end of each of the four second receiving holes 721 on the outer sleeve 720 moves in the opposite direction, pushing one end of each of the four cutting blades 731 fitted onto the first pin 732 and the second pin 733 to rotate, causing the four cutting blades 731 to rotate in the opposite direction around the first pin 732 until they retract into the first receiving hole 711 and the second receiving hole 721 to stop supporting the core and expose the core for easy removal to complete the core extraction operation.

[0060] The flow-limiting valve head 430 is equipped with a filter screen 432 for filtering the mud passing through the valve head hole 431, which can prevent particles in the mud from clogging the valve head hole 431 and affecting the mud entering the torsion drive 500 to drive the rotor 530 to rotate.

[0061] The single-action mechanism 300 is supported by a bearing 350 connected to the inner walls of the upper cylinder 310, lower cylinder 320, and bearing seat 340. A rotating shaft 330 rotatably passes through the upper cylinder 310 and lower cylinder 320. A shaft hole 331 is provided on the rotating shaft 330, which can be connected to the mud short-circuit channel 224 for stable mud delivery to the flow adapter 400. The outer walls of the two ends of the rotating shaft 330 are respectively fitted with sealing rings 370 that seal with the inner walls of the upper cylinder 310 and lower cylinder 320. The inner walls of the upper cylinder 310, lower cylinder 320, rotating shaft 330, and bearing seat 340 form a lubrication cavity 380. The bearing seat 340 is provided with an oil injection nozzle 390 for injecting lubricating oil into the lubrication cavity 380, which can keep the bearing 350 in the sealed lubrication cavity 380, which is beneficial to lubrication of the bearing 350 and improves the service life of the bearing 350.

[0062] The driver cylinder 510 has three fan-shaped grooves 513 arranged circumferentially. The retaining shaft 540 is threadedly connected to three limiting screws 541, one end of which extends into the fan-shaped grooves 513. When the rotor 530 rotates relative to the stator 520, the fan-shaped grooves 513 block the rotation of the limiting screws 541 to limit the rotation angle of the rotor 530. Thus, the fan-shaped grooves 513 of the driver cylinder 510 limit the rotation angle of the limiting screws 541 of the retaining shaft 540 connected to the rotor 530, thereby limiting the rotation angle of the rotor 530 relative to the stator 520 to drive the outer shaft sleeve 720 to rotate relative to the inner shaft sleeve 710 by a preset angle. This ensures that the cutting blade 731 rotates by a preset angle to extend into the inner shaft sleeve 710 to cut the rock core or retract into the first receiving hole 711 and the second receiving hole 721.

[0063] The inner core tube 600 includes a core receiving tube 610 and a core tube end cap 620 that is threaded to one end of the core receiving tube 610. The retaining shaft 540 is provided with retaining holes 542 that pass through both ends of it. The core tube end cap 620 is engaged in the retaining holes 542. The inner core tube 600 transmits torque through the retaining holes 542 of the retaining shaft 540 and the core tube end cap 620. This enables the rotor 530 to drive the retaining shaft 540 to rotate, which in turn drives the core tube end cap 620 and the core receiving tube 610 to rotate, thereby driving the inner shaft sleeve 710 to rotate.

[0064] The core tube end cap 620 is provided with an end cap channel 630 connecting the core receiving tube 610 and the mud hole 532. The core tube end cap 620 is provided with a one-way overflow valve 640 to limit the unidirectional flow of mud from the core receiving tube 610 into the end cap channel 630. This allows the mud carried by the core to be discharged through the one-way overflow valve 640 into the end cap channel 630 when the core enters the core receiving tube 610, and further allows the mud to pass through the end cap channel 630 and the snap-fit ​​hole 54. 2. After entering the mud hole 532, the mud is discharged into the mud channel 160; when the core tube end cap 620 is engaged in the engagement hole 542, the limiting screw 541 moves axially to press or stop pressing the outer wall of the core tube end cap 620 to limit or stop the position of the core tube end cap 620. The limiting screw 541 connected to the retaining shaft 540 can be used to radially press the outer wall of the core tube end cap 620, thereby ensuring a stable connection between the core tube end cap 620 and the retaining shaft 540.

[0065] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A wireline coring drill bit based on flow control core extraction, comprising an outer tube assembly and an inner tube assembly disposed within the outer tube assembly, wherein a mud channel is formed between the outer tube assembly and the inner tube assembly, and the outer tube assembly comprises a spring-loaded stop, a spring-loaded chamber, an outer tube, and a drill bit connected in sequence, characterized in that, The inner tube assembly includes a spring clip mechanism, a flow adapter, a torsion actuator, a core inner tube, and a core extractor connected in sequence. The core extractor includes an inner sleeve connected to the inner core tube, an outer sleeve rotatably fitted onto the inner sleeve, and multiple cutting mechanisms. The inner sleeve and the outer sleeve are respectively provided with a first receiving hole and a second receiving hole corresponding to each of the cutting mechanisms. Each cutting mechanism includes a cutting blade rotatably connected to the first receiving hole and the second receiving hole. When the outer sleeve rotates relative to the inner sleeve, it pushes each of the cutting blades to rotate synchronously and extend into the inner sleeve to cut and support the core or retract into the first receiving hole and the second receiving hole. When the flow rate of the mud through the flow adapter is less than or greater than a preset value, the flow adapter delivers the mud to the mud channel or pressurizes it and delivers it to the torsion drive. The torsion drive is used to drive the outer shaft sleeve to rotate relative to the inner shaft sleeve when receiving the pressurized mud delivered by the flow adapter, so as to drive each of the cutting blades to rotate synchronously and extend into the inner shaft sleeve to cut and support the rock core.

2. The wireline coring drill bit based on flow control core extraction according to claim 1, characterized in that, A single-action mechanism is connected between the card ejector mechanism and the flow adapter. The single-action mechanism includes an upper cylinder and a lower cylinder connected to the card ejector mechanism, a rotating shaft with both ends rotatably passing through the upper cylinder and the lower cylinder respectively, and an annular bearing seat. The inner walls of adjacent ends of the upper cylinder and the lower cylinder are respectively connected to the outer walls of both ends of the bearing seat by threads. The inner walls of both ends of the bearing seat are respectively connected to bearings sleeved on both ends of the rotating shaft. The rotating shaft has shaft holes passing through both ends of it. The rotating shaft is connected to the flow adapter.

3. The wireline coring tool based on flow control core extraction according to claim 2, characterized in that, A suspension sealing short-connector connects the spring-loaded mechanism and the single-action mechanism. The spring-loaded mechanism includes a retrieval spearhead, a spring-loaded frame, a spring-loaded clip, and a recovery pipe that cooperate with the spring-loaded clip stop. The spring-loaded frame is provided with a mud flow channel. The suspension sealing short-connector includes a suspension short-connector connected to the spring-loaded mechanism, a suspension ring disposed on the outer wall of the suspension short-connector, and a positioning signal device. The inner wall of the outer pipe is provided with a suspension seat ring for suspending the suspension ring. The suspension short-connector is provided with a mud short-connector channel that connects the mud flow channel and the shaft hole. The positioning signal device includes a sealing ring disposed on the inner wall of the mud short-connector channel and a steel ball that seals and presses against the sealing ring. When the pressure in the mud short-connector channel exceeds a threshold, it pushes the steel ball to squeeze through the sealing ring and fall into the single-action mechanism.

4. The wireline coring drill bit based on flow control core extraction according to claim 3, characterized in that, The flow adapter includes a distribution valve body with a valve cavity, a distribution valve seat fixedly disposed within the valve cavity, a valve core assembly movably disposed within the distribution valve body along the axial direction, and a distribution spring sleeved on the valve core assembly. The two ends of the distribution spring respectively press against the valve core assembly and the distribution valve body. The valve cavity and the shaft hole are connected. The outer wall of the distribution valve body has multiple diversion holes connecting the mud channel and the valve cavity. When the valve core assembly moves axially, it closes or opens the diversion holes. The distribution valve seat has valve seat holes connecting its two ends. One end of the valve core assembly is slidably disposed... The valve core assembly and the distribution valve seat form a distribution cavity by sealing the valve seat hole. The valve core assembly is provided with a distribution channel connecting the valve cavity and the distribution cavity. The outer wall of the end of the valve core assembly that is slidably disposed in the valve seat hole is provided with multiple connecting holes that connect to the torsion actuator. When the mud flow rate through the flow adapter is above a preset value, the mud enters the distribution cavity through the valve cavity, pushing the valve core assembly to move axially and compressing the distribution spring, causing the valve core assembly to move and close the diversion hole and connect the connecting hole to the distribution cavity.

5. The wireline coring drill bit based on flow control core extraction according to claim 4, characterized in that, The torsional actuator includes an actuator cylinder connected to the distribution valve body, a stator fixedly disposed within the actuator cylinder, a rotor rotatably disposed within the actuator cylinder, and a retaining shaft coaxially connected to the rotor. The stator has multiple sector teeth, and the rotor has sector blades corresponding one-to-one with the sector teeth. The sector teeth and sector blades are arranged alternately along the circumference of the actuator cylinder. The actuator cylinder, the stator, the sector teeth, the rotor, and the sector blades enclose and form multiple high-pressure chambers and multiple low-pressure chambers arranged alternately along the circumference of the actuator cylinder. The actuator cylinder has at least one high-pressure damping hole connecting the high-pressure chamber and the mud channel, and at least one low-pressure damping hole connecting the low-pressure chamber and the mud channel. The rotor has a mud hole that connects the connecting hole and each of the high-pressure chambers. The actuator cylinder is connected to the outer shaft sleeve through a middle layer tube, and the retaining shaft is connected to the inner shaft sleeve through the core inner tube.

6. The wireline coring drill bit based on flow control core extraction according to claim 5, characterized in that, The drive cylinder has multiple fan-shaped grooves arranged at intervals along its circumference. The retaining shaft is threadedly connected to a limiting screw that corresponds to each of the fan-shaped grooves. One end of the limiting screw extends into the corresponding fan-shaped groove. When the rotor rotates relative to the stator, the fan-shaped groove blocks the corresponding limiting screw to limit the rotation angle of the rotor.

7. The wireline coring drill bit based on flow control core extraction according to claim 6, characterized in that, The core inner tube includes a core receiving tube and a core tube end cap connected to one end of the core receiving tube. The retaining shaft has retaining holes extending through both ends. The core tube end cap is retained in the retaining holes. The core tube end cap has an end cap channel connecting the core receiving tube and the mud hole. The core tube end cap has a one-way overflow valve inside to limit the mud from flowing unidirectionally from the core receiving tube into the end cap channel.

8. The wireline coring drill bit based on flow control core extraction according to claim 7, characterized in that, When the core tube end cap is engaged in the engagement hole, the limiting screw moves axially to press against or stop pressing against the outer wall of the core tube end cap.

9. The wireline coring drill string based on flow control core extraction according to claim 8, characterized in that, Each of the cutting mechanisms includes a first pin and a second pin. One end of the cutting blade is sleeved on the corresponding first pin and the corresponding second pin through a pin hole and an arc-shaped hole, respectively. The two ends of the first pin and the two ends of the second pin are respectively connected to the two sides of the corresponding first receiving hole and the two sides of the corresponding second receiving hole.

10. A wireline coring method based on flow-controlled core fragmentation, characterized in that, It includes the following steps: The outer tube assembly of the wireline coring tool based on flow control core extraction as described in any one of claims 1 to 9 is placed into the borehole; The inner tube assembly of the wireline coring tool based on flow control core extraction as described in any one of claims 1 to 9 is lowered into the outer tube assembly; Control the mud flow rate through the flow adapter to be less than a preset value, and continue normal core drilling until the drilling depth of the cycle is reached. Stop drilling after the target core passes through the inner shaft sleeve and enters the core inner tube. Controlling the mud flow rate through the flow adapter to be above a preset value causes the torsion drive to rotate the outer shaft sleeve relative to the inner shaft sleeve, pushing each of the cutting blades to rotate synchronously and extend into the inner shaft sleeve to cut and support the rock core; After the inner tube assembly was retrieved, the core was taken out.

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