Drilling tool inner pipe assembly in-place informing mechanism

Abstract

The invention discloses a drilling tool inner pipe assembly in-place informing mechanism, and relates to the technical field of geological reconnaissance, the drilling tool inner pipe assembly in-place informing mechanism comprises a drilling fluid pressure detection device, a hollow sleeve assembly, a hollow valve core assembly and an elastic supporting assembly, the valve core assembly is arranged in the sleeve assembly, the outer side wall of the valve core assembly is in sealing contact with the inner side wall of the sleeve assembly, and the elastic supporting assembly is arranged in the sleeve assembly. The rear end of the valve element assembly is provided with a first water passing opening communicated with the water inlet of the sleeve assembly, and the side wall of the front end of the valve element assembly is provided with a second water passing opening. The elastic supporting assembly can enable the valve element assembly to be located at the first position, after the hanging ring and the clamping ring abut against each other for sealing, drilling fluid can push the valve element assembly to slide forwards from the first position to the second position in the axial direction of the sleeve assembly, and it can be judged that the sleeve assembly is lowered in place after the pressure of the drilling fluid is gradually increased and suddenly decreased; the mode is not interfered by noise, the coring failure condition is reduced, and the coring production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geological exploration, and particularly relates to a mechanism for reporting that a drill pipe inner tube assembly is in place. BACKGROUND

[0002] With the rapid development of domestic geological drilling, the wire-line coring drilling technology has also been widely applied. Even if a drill rod is connected with an outer pipe, the outer pipe is driven to rotate to break rocks, and an inner tube assembly is arranged in the outer pipe to store rock cores. The inner tube assembly is driven by a steel wire rope to ascend and descend in the drill rod to realize rock core extraction, without the need to ascend and descend the entire drill rod. Meanwhile, drilling fluid is used to cool and remove slag during the drilling process. When the inner tube assembly is lowered in the outer pipe, a hanging ring is arranged on the outer sidewall of the inner tube assembly, and a snap ring is arranged on the inner sidewall of the outer pipe. When the hanging ring and the snap ring abut, that is, the inner tube assembly is lowered to the position, the metal impact sound of the hanging ring and the snap ring after the inner tube assembly is lowered to the position is usually used to determine whether the inner tube assembly is lowered to the position in the prior art. However, the determination is easily interfered by noise, and thus misjudgment is easily caused. As a result, drilling is started before the inner tube assembly is in place, which causes a production accident of core extraction failure and affects the production efficiency of core extraction. SUMMARY

[0003] The present application aims to provide a mechanism for reporting that a drill pipe inner tube assembly is in place, so as to solve the problems in the prior art and improve the production efficiency of core extraction.

[0004] To achieve the above object, the present application provides the following solutions. The present application provides a drilling tool inner tube assembly in-place signaling mechanism, comprising: a drilling fluid pressure monitoring device for monitoring the drilling fluid pressure into the outer tube of the drilling tool; a hollow sleeve assembly, a water inlet is formed on the rear end side wall of the sleeve assembly, a water outlet is formed on the front end side wall of the sleeve assembly, a suspension ring is further fixedly sleeved on the outer side wall of the sleeve assembly, the suspension ring is located between the water inlet and the water outlet, and is used for abutting and sealing with the snap ring on the inner wall of the outer tube to block the flow of the drilling fluid between the outer side wall of the sleeve assembly and the inner side wall of the outer tube; a hollow valve core assembly, the valve core assembly is arranged inside the sleeve assembly, the outer side wall of the valve core assembly is in sealing contact with the inner side wall of the sleeve assembly and can slide along the inner side wall of the sleeve assembly, a first water passage is formed on the rear end of the valve core assembly and is communicated with the water inlet of the sleeve assembly, a second water passage is formed on the front end side wall of the valve core assembly and is communicated with the first water passage; and a resilient support assembly, the resilient support assembly is arranged between the valve core assembly and the sleeve assembly, the resilient support assembly can make the valve core assembly be in a first position, in the first position, the second water passage is disconnected with the water outlet, as the drilling fluid pressure at the rear end of the valve core assembly gradually increases, the drilling fluid can push the valve core assembly to slide along the axial direction of the sleeve assembly from the first position to a second position, in the second position, the second water passage is communicated with the water outlet, and the drilling fluid can flow from the water inlet to the water outlet inside the sleeve assembly.

[0005] In some embodiments, the sleeve assembly comprises a spring frame, a suspension joint and a mandrel, the spring frame is connected with the rear end of the suspension joint, the suspension joint is sleeved with a suspension ring on the outer side wall, the front end of the suspension joint is connected with the mandrel, the water inlet is formed on the side wall of the spring frame, and the water outlet is formed on the outer side wall of the mandrel.

[0006] In some embodiments, the inner side wall of the suspension joint has an annular protrusion, the outer side wall of the valve core assembly is in sealing contact with the inner side wall of the suspension joint and slides along the inner side wall of the protrusion, so as to divide the sleeve assembly into a first chamber and a second chamber, the first chamber is enclosed by the inner side wall of the spring frame and the inner side wall of the suspension joint, the second chamber is enclosed by the inner side wall of the mandrel and the inner side wall of the suspension joint, the valve core assembly can slide along the inner side wall of the suspension joint from a first position to a second position, in the first position, the first water passage and the second water passage are both located in the first chamber, and the first chamber and the second chamber are not communicated, in the second position, the first water passage is located in the first chamber, the second water passage is located in the second chamber, and the first chamber and the second chamber are communicated through the first water passage and the second water passage.

[0007] In some embodiments, the valve core assembly comprises a water passing sleeve and a valve core, the elastic support assembly comprises a positioning sleeve and a locking sleeve, the water passing sleeve and the valve core are hollow structures, the water passing sleeve is arranged inside the elastic holder and can slide along the axial direction of the elastic holder, the valve core is arranged in the water passing sleeve, the rear end of the valve core has a protruding part, the outer side wall of the protruding part is connected with the inner side wall of the rear end of the water passing sleeve, the positioning sleeve and the locking sleeve are connected with the suspension joint, the inner side wall of the positioning sleeve is in sealing contact with the outer side wall of the valve core, and the locking sleeve is arranged outside the positioning sleeve, the locking sleeve and the positioning sleeve form a circumferential positioning space, when the water passing sleeve and the valve core move forward along the axial direction of the sleeve assembly, the front end of the water passing sleeve can extend into and be locked in the positioning space, so that the valve core is kept in the second position.

[0008] In some embodiments, the inner side wall of the front end of the water passing sleeve is embedded with a steel ball, the front end of the positioning sleeve is fixedly connected with the inner side wall of the suspension joint, the front end of the locking sleeve is connected with the inner side wall of the suspension joint through a first elastic element, a groove is formed in the outer side wall of the positioning sleeve, when the water passing sleeve and the valve core move forward along the axial direction of the sleeve assembly, the front end of the water passing sleeve extends into the positioning space, the steel ball abuts against the outer side wall of the positioning sleeve on the inner side of the water passing sleeve, the steel ball abuts against the rear end of the locking sleeve on the outer side of the water passing sleeve to drive the locking sleeve to move forward, at the same time, the first elastic element is compressed, until the steel ball is embedded into the groove in the outer side wall of the positioning sleeve, the steel ball no longer abuts against the rear end of the locking sleeve, the locking sleeve locks the steel ball in the inner side wall of the locking sleeve and the groove in the positioning sleeve under the restoring force of the first elastic element.

[0009] In some embodiments, the rear end of the valve core is provided with a first water passing opening in communication with the water inlet, and the front end of the valve core is provided with a second water passing opening, when the second water passing opening is located in the second chamber, the drilling fluid flows into the interior of the valve core through the water inlet and the first water passing opening, and flows out through the second water passing opening and the water outlet.

[0010] In some embodiments, the elastic support assembly further comprises a support frame arranged between the outer wall of the valve core and the inner wall of the water passing sleeve, the support frame is connected with the convex part of the valve core through a second elastic element, when the water passing sleeve and the valve core move forward along the axial direction of the sleeve assembly, the front end of the support frame first abuts against the rear end of the positioning sleeve, the second elastic element is compressed, then the water passing sleeve and the valve core continue to move forward along the axial direction of the sleeve assembly until the front end of the water passing sleeve extends into and is locked in the positioning space.

[0011] In some embodiments, the outer wall of the water passing sleeve is provided with a centralizing block, the outer wall of the centralizing block is in contact with the inner wall of the elastic clamping frame to enable the water passing sleeve to slide along the axial direction of the elastic clamping frame.

[0012] In some embodiments, the front end of the positioning sleeve is fixedly connected with the inner wall of the suspension joint through screw threads, the side wall of the positioning sleeve is provided with a step surface arranged forward, when the positioning sleeve is tightened, the step surface can apply pressure to the front end of the locking sleeve and compress the first elastic element.

[0013] In some embodiments, the rear end of the positioning sleeve is provided with a guide surface inclined from the front end to the rear end towards the locking sleeve, when the water passing sleeve and the valve core move forward along the axial direction of the sleeve assembly, the steel ball abuts against the guide surface on the inner side of the water passing sleeve to enable the steel ball to move outward along the radial direction of the water passing sleeve and abut against the rear end of the locking sleeve.

[0014] The present application has the following technical effects compared with the prior art: The present application provides a drilling tool inner tube assembly in place signaling mechanism, before the suspension ring is in abutment with the snap ring, drilling fluid flows through the gap between the casing assembly and the inner wall of the outer tube, the pressure of the drilling fluid remains constant, the pressure of the drilling fluid flowing into the casing assembly through the water inlet is less than the support force of the elastic support assembly on the valve core assembly, the elastic support assembly makes the valve core assembly in the first position, the second water inlet is not in communication with the water outlet, after the suspension ring is in abutment with the snap ring, the drilling fluid cannot flow between the outer wall of the casing assembly and the inner wall of the outer tube, the drilling fluid flows into the casing assembly through the water inlet, the pressure of the drilling fluid at the rear end of the valve core assembly gradually increases, until the pressure of the drilling fluid is greater than the support force of the elastic support assembly on the valve core assembly, the drilling fluid can push the valve core assembly to slide along the axial direction of the casing assembly from the first position to the second position, so that the second water inlet is in communication with the water outlet, the drilling fluid can flow from the water inlet to the water outlet in the casing assembly, in this process, the drilling fluid pressure is monitored through the drilling fluid pressure monitoring device, when the drilling fluid pressure is gradually increased and suddenly becomes small, it can be judged that the casing assembly is lowered in place, this way of judging whether the casing assembly is lowered in place through the change of the drilling fluid pressure will not be disturbed by noise, has higher accuracy, so as to ensure that drilling is started after the casing assembly is in place, reduces the occurrence of core taking failure, improves the production efficiency of core taking. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings described in the following are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0016] Fig. 1 The structure diagram of the drilling tool inner tube assembly in place signaling mechanism when the valve core is in the first position; Fig. 2 The structure diagram of the drilling tool inner tube assembly in place signaling mechanism when the valve core moves from the first position to the second position; Fig. 3 The structure diagram of the drilling tool inner tube assembly in place signaling mechanism when the valve core is in the second position.

[0017] In the figure: 1-cannula assembly; 11-poppet frame; 12-hanging joint; 13-core shaft; 14-water inlet; 15-water outlet; 16-hanging ring; 17-first chamber; 18-second chamber; 2-valve core assembly; 21-water passing sleeve; 211-steel ball; 212-centralizing block; 22-valve core; 221-first water passing opening; 222-second water passing opening; 23-positioning sleeve; 231-groove; 232-guiding surface; 233-step surface; 24-locking sleeve; 25-first elastic element; 26-second elastic element; 27-support frame. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0019] The present application aims to provide a drill pipe inner tube assembly in-place signaling mechanism to solve the problems existing in the prior art and improve the production efficiency of coring.

[0020] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] The present application provides a drill pipe inner tube assembly in-place signaling mechanism, such as Figs. 1-3As shown, it comprises: a drilling fluid pressure detection device, a hollow casing assembly 1, a hollow valve core assembly 2 and an elastic support assembly, the drilling fluid pressure detection device is used for monitoring the drilling fluid pressure flowing into the outer pipe of the drilling tool; the rear end side wall of the casing assembly 1 is provided with a water inlet 14, the front end side wall of the casing assembly 1 is provided with a water outlet 15, the outer side wall of the casing assembly 1 is further provided with a hanging ring 16, the hanging ring 16 is located between the water inlet 14 and the water outlet 15, and is used for abutting and sealing with the snap ring on the inner wall of the outer pipe to block the flow of drilling fluid between the outer side wall of the casing assembly 1 and the inner side wall of the outer pipe; the inside of the casing assembly 1 is provided with the valve core assembly 2, the outer side wall of the valve core assembly 2 is in sealing contact with the inner side wall of the casing assembly 1 and can slide along the inner side wall of the casing assembly 1, the valve core assembly 2 is a hollow structure, the rear end of the valve core assembly 2 is provided with a first water passage 221 which is in communication with the water inlet 14 of the casing assembly 1, and the front end side wall of the valve core assembly 2 is provided with a second water passage 222 which is in communication with the first water passage 221; the elastic support assembly is arranged between the valve core assembly 2 and the casing assembly 1, the elastic support assembly can make the valve core assembly 2 be in a first position, in the first position, the second water passage 222 is disconnected with the water outlet 15, as the drilling fluid pressure at the rear end of the valve core assembly 2 gradually increases, the drilling fluid can push the valve core assembly 2 to slide along the axial direction of the casing assembly 1 from the first position to a second position, in the second position, the second water passage 222 is in communication with the water outlet 15, and the drilling fluid can flow from the water inlet 14 to the water outlet 15 in the casing assembly; before the hanging ring 16 abuts against the snap ring, the drilling fluid flows through the gap between the casing assembly 1 and the inner wall of the outer pipe, the pressure of the drilling fluid remains constant, the drilling fluid flowing into the casing assembly 1 through the water inlet 14 has a pressure smaller than the support force of the elastic support assembly on the valve core assembly 2, the elastic support assembly makes the valve core assembly be in the first position, and the second water passage 222 is not in communication with the water outlet 15, after the hanging ring 16 abuts against and seals with the snap ring, the drilling fluid cannot flow between the outer side wall of the casing assembly 1 and the inner side wall of the outer pipe, the drilling fluid flowing into the casing assembly 1 through the water inlet 14, the drilling fluid pressure at the rear end of the valve core assembly 2 gradually increases, until the drilling fluid pressure is greater than the support force of the elastic support assembly on the valve core assembly 2, the drilling fluid can push the valve core assembly 2 to slide along the axial direction of the casing assembly 1 from the first position to the second position, so that the second water passage 222 is in communication with the water outlet 15, and the drilling fluid can flow from the water inlet 14 to the water outlet 15 in the casing assembly 1, in this process, the drilling fluid pressure is monitored through the drilling fluid pressure detection device, when it is monitored that the drilling fluid pressure gradually increases and suddenly becomes small, it can be judged that the casing assembly 1 is lowered in place, this way of judging whether the casing assembly 1 is lowered in place through the change of the drilling fluid pressure will not be disturbed by noise, has higher accuracy, so that it can be ensured that the drilling is started after the casing assembly 1 is in place, the occurrence of core taking failure is reduced, and the production efficiency of core taking is improved.

[0022] Specifically, the front end is the end close to the bottom of the drill hole, i.e. the end for taking the core, and the rear end is the end close to the ground surface.

[0023] In some embodiments of the present application, the casing assembly 1 comprises a snap frame 11, a hanging joint 12 and a core shaft 13, the snap frame 11 is connected with the rear end of the hanging joint 12, the hanging joint 12 is sleeved with a hanging ring 16 on the outer side wall, the front end of the hanging joint 12 is connected with the core shaft 13, the side wall of the snap frame 11 is provided with a water inlet 14, and the outer side wall of the core shaft 13 is provided with a water outlet 15; when the hanging ring 16 and the snap ring abut, i.e. the casing assembly 1 and the valve core assembly 2 are lowered into place, the drilling fluid cannot flow between the outer side wall of the casing assembly 1 and the inner side wall of the outer pipe, and thus enters the casing assembly 1 through the water inlet 14 on the snap frame 11; when the drilling fluid pressure pushes the valve core assembly 2 to slide along the axial direction of the casing assembly 1 from the first position to the second position, the second water passage 222 is in communication with the water outlet 15, and the drilling fluid returns to the space between the outer side wall of the casing assembly 1 and the inner side wall of the outer pipe through the water outlet 15 on the core shaft 13, so as to realize pressure relief.

[0024] In some embodiments of the present application, the inner side wall of the hanging joint 12 has an annular protrusion, the outer side wall of the valve core assembly 2 is in sealing contact with the inner side wall of the hanging joint 12 and slides along the inner side wall of the protrusion, so as to divide the casing assembly 1 into a first chamber 17 and a second chamber 18; the first chamber 17 is enclosed by the inner side wall of the snap frame 11 and the inner side wall of the hanging joint 12, and the second chamber 18 is enclosed by the inner side wall of the core shaft 13 and the inner side wall of the hanging joint 12; the valve core assembly 2 can slide along the inner side wall of the hanging joint 12 from the first position to the second position; in the first position, the first water passage 221 and the second water passage 222 are both located in the first chamber 17, and the first chamber 17 and the second chamber 18 are not in communication; at this time, due to the sealing contact between the outer side wall of the valve core assembly 2 and the inner side wall of the hanging joint 12, the drilling fluid flowing into the first chamber 17 through the water inlet 14 cannot enter the second chamber 18; in the second position, the first water passage 221 is located in the first chamber 17, the second water passage 222 is located in the second chamber 18, and the first chamber 17 and the second chamber 18 are in communication through the first water passage 221 and the second water passage 222, so that the drilling fluid in the first chamber 17 flows into the second chamber 18 through the first water passage 221, the inside of the valve core assembly 2 and the second water passage 222, and then flows out from the water outlet 15 of the second chamber 18 to realize pressure relief of the drilling fluid.

[0025] In some embodiments of the present application, the valve core assembly 2 comprises a water passing sliding sleeve 21 and a valve core 22, and the elastic support assembly comprises a positioning sleeve 23 and a locking sleeve 24, the water passing sliding sleeve 21 and the valve core 22 are both hollow structures, the water passing sliding sleeve 21 is arranged inside the snap frame 11 and can slide along the axial direction of the snap frame 11, the valve core 22 is arranged in the water passing sliding sleeve 21, the rear end of the valve core 22 has a protruding part, the outer side wall of the protruding part is connected with the inner side wall of the rear end of the water passing sliding sleeve 21, the positioning sleeve 23 and the locking sleeve 24 are both connected with the suspension joint 12, the inner side wall of the positioning sleeve 23 is in sealing contact with the outer side wall of the valve core 22, and the locking sleeve 24 is arranged outside the positioning sleeve 23, the locking sleeve 24 and the positioning sleeve 23 enclose a positioning space in the circumferential direction, when the water passing sliding sleeve 21 and the valve core 22 move forward along the axial direction of the sleeve assembly 1, the front end of the water passing sliding sleeve 21 can extend into and be locked in the positioning space, so that the valve core 22 is kept in the second position and avoids returning to the first position, thereby in the subsequent drilling sampling process, the drilling fluid does not need to be kept at a pressure capable of pushing the valve core 22 to slide forward from the first position to the second position, so as to reduce the burden of the drilling fluid pump, improve the service life of the pump, and avoid the negative impact of high drilling fluid pressure on the subsequent drilling process.

[0026] In some embodiments of the present application, the inner side wall of the front end of the water passing sliding sleeve 21 is embedded with a steel ball 211, the front end of the positioning sleeve 23 is fixedly connected with the inner side wall of the suspension joint 12, the front end of the locking sleeve 24 is connected with the inner side wall of the suspension joint 12 through a first elastic element 25, a groove 231 is formed in the outer side wall of the positioning sleeve 23, when the water passing sliding sleeve 21 and the valve core 22 move forward along the axial direction of the sleeve assembly 1 under the action of the drilling fluid pressure, the front end of the water passing sliding sleeve 21 extends into the positioning space, the steel ball 211 abuts against the outer side wall of the positioning sleeve 23 on the inner side of the water passing sliding sleeve 21, the steel ball 211 abuts against the rear end of the locking sleeve 24 on the outer side of the water passing sliding sleeve 21 to drive the locking sleeve 24 to move forward, and at the same time, the first elastic element 25 is compressed, until the steel ball 211 is embedded into the groove 231 in the outer side wall of the positioning sleeve 23, the steel ball 211 no longer abuts against the rear end of the locking sleeve 24, and the locking sleeve 24 locks the steel ball 211 in the inner side wall of the locking sleeve 24 and the groove 231 in the positioning sleeve 23 under the restoring force of the first elastic element 25, so as to realize the locking of the water passing sliding sleeve 21 and the valve core 22, and further keep the valve core 22 in the second position and avoid the valve core 22 returning to the first position.

[0027] In some embodiments of the present application, the rear end of the valve core 22 is provided with a first water passage 221 communicating with the water inlet 14, and the front end of the valve core 22 is provided with a second water passage 222. Under the pressure of the drilling fluid, the valve core 22 is slid forward from the first position to the second position, and the second water passage 222 is located in the second chamber 18. The drilling fluid flows into the interior of the valve core 22 through the water inlet 14 and the first water passage 221, and flows out through the second water passage 222 and the water outlet 15 to achieve pressure relief.

[0028] In some embodiments of the present application, the elastic support assembly further comprises a support frame 27 arranged between the outer sidewall of the valve core 22 and the inner sidewall of the water passing sleeve 21. The support frame 27 is connected to the protruding portion of the valve core 22 by the second elastic element 26. When the water passing sleeve 21 and the valve core 22 move forward along the axial direction of the casing assembly 1 under the pressure of the drilling fluid, the front end of the support frame 27 first abuts against the rear end of the positioning sleeve 23. Then, the pressure of the drilling fluid causes the second elastic element 26 to compress, and the water passing sleeve 21 and the valve core 22 continue to move forward along the axial direction of the casing assembly 1 until the front end of the water passing sleeve 21 extends into and is locked in the positioning space, so that the second elastic element 26 remains in a compressed state and the valve core 22 remains in the second position. Specifically, the second elastic element 26 is a spring.

[0029] In some embodiments of the present application, the outer sidewall of the water passing sleeve 21 is provided with a centralizing block 212, and the outer sidewall of the centralizing block 212 is in contact with the inner sidewall of the elastic clamping frame 11 to enable the water passing sleeve 21 to slide along the axial direction of the elastic clamping frame 11, thereby preventing the sliding direction of the water passing sleeve 21 and the valve core 22 from deviating along the radial direction of the valve core 22.

[0030] In some embodiments of the present application, the front end of the positioning sleeve 23 is fixedly connected to the inner sidewall of the hanger sub 12 by screwing, and the sidewall of the positioning sleeve 23 is provided with a step face 233 arranged forward. When the positioning sleeve 23 is tightened, the step face 233 can exert pressure on the front end of the locking sleeve 24 and cause the first elastic element 25 to compress. Specifically, the first elastic element 25 is a gradually hardening spring, i.e., the spring stiffness coefficient k increases with the increase of the deformation variable. By controlling the number of turns when screwing the threaded connection, the initial deformation variable of the first elastic element 25 can be changed, and thus the pressure of the drilling fluid when the water passing sleeve 21 and the valve core 22 are locked can be adjusted. When the number of turns is large, the initial deformation variable of the first elastic element 25 is large, and the drilling fluid pressure required for the first elastic element 25 to deform is also increased accordingly. When the number of turns is small, the initial deformation variable of the first elastic element 25 is small, and the drilling fluid pressure required for the first elastic element 25 to deform is also decreased accordingly. Through this arrangement, the pressure of the drilling fluid when the water passing sleeve 21 and the valve core 22 are locked can be adapted to the drilling fluid pressure that the drilling fluid pump can provide. Specifically, the gradually hardening spring can be a variable diameter / variable pitch spring or a composite spring.

[0031] In some embodiments of the present application, the rear end outer side wall of the positioning sleeve 23 has a guide surface 232 inclined from the front end to the rear end towards the locking sleeve 24. When the water passing sleeve 21 and the valve core 22 move along the axial direction of the sleeve assembly 1 to the front end, the steel ball 211 abuts against the guide surface 232 at the inner side of the water passing sleeve 21, so that the steel ball 211 moves along the radial direction of the water passing sleeve 21 to the outside and abuts against the rear end of the locking sleeve 24, thereby avoiding the steel ball 211 from being stuck at the rear end of the positioning sleeve 23 and unable to move forward.

[0032] In use, as the casing assembly 1 and the inner valve core assembly 2 are lowered in the outer pipe, before the hanging ring 16 abuts against the snap ring, the drilling fluid flows through the gap between the casing assembly 1 and the inner wall of the outer pipe, the pressure of the drilling fluid remains constant, the pressure of the drilling fluid flowing into the casing assembly 1 through the water inlet 14 is not enough to push the valve core assembly 2 to move, then the casing assembly 1 and the inner valve core assembly 2 are lowered in the outer pipe to the position, the hanging ring 16 abuts against the snap ring to seal, the pressure of the drilling fluid gradually increases at the rear end of the hanging ring and the snap ring, the drilling fluid flows into the casing assembly 1 through the water inlet 14, at this time the valve core 22 is in the first position, the first water passage 221 and the second water passage 222 on the valve core 22 are both in the first chamber 17 of the casing assembly 1, and the first chamber 17 and the second chamber 18 are not connected, that is, the second water passage 222 has not yet communicated with the water outlet 15 of the second chamber 18 of the casing assembly 1, as the pressure of the drilling fluid in the first chamber 17 gradually increases, the water-crossing sliding sleeve 21 and the valve core 22 move forward along the axial direction of the casing assembly 1 under the pressure of the drilling fluid, the front end of the support frame 27 first abuts against the rear end of the positioning sleeve 23, then the pressure of the drilling fluid makes the second elastic element 26 compress, the water-crossing sliding sleeve 21 and the valve core 22 continue to move forward along the axial direction of the casing assembly 1, the front end of the water-crossing sliding sleeve 21 extends into the positioning space, the steel ball 211 abuts against the outer side wall of the positioning sleeve 23 on the inner side of the water-crossing sliding sleeve 21, guided by the guide surface 232, the steel ball 211 moves outward along the radial direction of the water-crossing sliding sleeve 21, so that the steel ball 211 abuts against the rear end of the locking sleeve 24 on the outer side of the water-crossing sliding sleeve 21 to drive the locking sleeve 24 to move forward, and at the same time the first elastic element 25 compresses, until the steel ball 211 is embedded into the groove 231 of the outer side wall of the positioning sleeve 23, the steel ball 211 no longer abuts against the rear end of the locking sleeve 24, the locking sleeve 24 locks the steel ball 211 in the inner side wall of the locking sleeve 24 and the groove 231 of the positioning sleeve 23 under the restoring force of the first elastic element 25, thereby realizing the locking of the water-crossing sliding sleeve 21 and the valve core 22, at this time the valve core 22 moves to the second position, the second water passage 222 communicates with the water outlet 15 of the second chamber 18 of the casing assembly 1, thereby making the drilling fluid return to the space between the outer side wall of the casing assembly 1 and the inner side wall of the outer pipe through the water outlet 15 on the mandrel 13, so as to realize pressure relief; the operator can judge that the casing assembly 1 is lowered to the position through the sudden decrease of the gradually increasing pressure of the drilling fluid, this way of judging whether the casing assembly 1 is lowered to the position through the change of pressure will not be disturbed by noise, has higher accuracy, so as to ensure that drilling is started after the casing assembly 1 is in position, reduce the occurrence of core taking failure, and improve the production efficiency of core taking.

[0033] The principles and implementation manners of the present application are described by using specific examples in the present application, and the above examples are only used for helping to understand the method of the present application and its core idea; meanwhile, for the general technical personnel in the art, according to the idea of the present application, the specific implementation manners and application ranges will be changed. In conclusion, the content of the present specification should not be understood as the limitation of the present application.

Claims

1. A drill string inner tube assembly positioning signaling mechanism, characterized in that: include: Drilling fluid pressure monitoring device, used to monitor the pressure of drilling fluid introduced into the outer casing of the drill string; A hollow casing assembly has an inlet on its rear sidewall and an outlet on its front sidewall. A suspension ring is also fixedly fitted on the outer sidewall of the casing assembly. The suspension ring is located between the inlet and the outlet and is used to abut against a retaining ring on the inner wall of the outer tube to seal and block the flow of drilling fluid between the outer sidewall of the casing assembly and the inner sidewall of the outer tube. A hollow valve core assembly is disposed inside a sleeve assembly. The outer wall of the valve core assembly is in sealing contact with the inner wall of the sleeve assembly and can slide along the inner wall of the sleeve assembly. A first water inlet communicating with the water inlet of the sleeve assembly is provided at the rear end of the valve core assembly, and a second water inlet communicating with the first water inlet is provided on the front side wall of the valve core assembly. An elastic support assembly is disposed between the valve core assembly and the casing assembly. The elastic support assembly enables the valve core assembly to be in a first position, in which the second water inlet is disconnected from the water outlet. As the drilling fluid pressure at the rear end of the valve core assembly gradually increases, the drilling fluid can push the valve core assembly to move along the axial direction of the casing assembly from the first position to a second position. In the second position, the second water inlet is connected to the water outlet, and the drilling fluid can flow from the inlet to the outlet from inside the casing assembly.

2. The drill string inner tube assembly positioning signaling mechanism according to claim 1, characterized in that: The sleeve assembly includes a spring clip, a suspension connector, and a mandrel. The spring clip is connected to the rear end of the suspension connector. A suspension ring is fitted on the outer side wall of the suspension connector. The front end of the suspension connector is connected to the mandrel. The spring clip has an inlet on its side wall, and the mandrel has an outlet on its outer side wall.

3. The drill string inner tube assembly positioning signaling mechanism according to claim 2, characterized in that: The inner wall of the suspension connector has an annular protrusion. The outer wall of the valve core assembly is in sealing contact with the inner wall of the suspension connector and slides along the inner wall of the protrusion to divide the sleeve assembly into a first chamber and a second chamber. The first chamber is enclosed by the inner wall of the spring clip and the inner wall of the suspension connector. The second chamber is enclosed by the inner wall of the mandrel and the inner wall of the suspension connector. The valve core assembly can slide forward along the inner wall of the suspension connector from a first position to a second position. In the first position, both the first water inlet and the second water inlet are located in the first chamber, and the first chamber and the second chamber are not connected. In the second position, the first water inlet is located in the first chamber, the second water inlet is located in the second chamber, and the first chamber and the second chamber are connected through the first water inlet and the second water inlet.

4. The drill string inner tube assembly positioning signaling mechanism according to claim 3, characterized in that: The valve core assembly includes a water-passing sliding sleeve and a valve core. The elastic support assembly includes a positioning sleeve and a locking sleeve. Both the water-passing sliding sleeve and the valve core are hollow structures. The water-passing sliding sleeve is disposed inside the spring clip and can slide along the axial direction of the spring clip. The valve core is disposed inside the water-passing sliding sleeve. The rear end of the valve core has a protrusion. The outer side wall of the protrusion is connected to the inner side wall of the rear end of the water-passing sliding sleeve. Both the positioning sleeve and the locking sleeve are connected to the suspension joint. The inner side wall of the positioning sleeve is in sealing contact with the outer side wall of the valve core, and the locking sleeve is disposed outside the positioning sleeve. The locking sleeve and the positioning sleeve enclose a circumferential positioning space. When the water-passing sliding sleeve and the valve core move forward along the axial direction of the sleeve assembly, the front end of the water-passing sliding sleeve can extend into and be locked in the positioning space, so that the valve core is held in the second position.

5. The drill string inner tube assembly positioning signaling mechanism according to claim 4, characterized in that: A steel ball is embedded in the side wall of the front end of the water-passing sleeve. The front end of the positioning sleeve is fixedly connected to the inner side wall of the suspension joint. The front end of the locking sleeve is connected to the inner side wall of the suspension joint through a first elastic element. A groove is formed on the outer side wall of the positioning sleeve. When the water-passing sleeve and the valve core move forward along the axial direction of the sleeve assembly, the front end of the water-passing sleeve extends into the positioning space. The steel ball abuts against the outer side wall of the positioning sleeve on the inner side of the water-passing sleeve. The steel ball abuts against the rear end of the locking sleeve on the outer side of the water-passing sleeve to drive the locking sleeve forward. At the same time, the first elastic element is compressed until the steel ball is embedded in the groove of the outer side wall of the positioning sleeve. The steel ball no longer abuts against the rear end of the locking sleeve. Under the restoring force of the first elastic element, the locking sleeve locks the steel ball in the inner side wall of the locking sleeve and the groove of the positioning sleeve.

6. The drill string inner tube assembly positioning signaling mechanism according to claim 4, characterized in that: The valve core has a first water inlet at its rear end, which is connected to the water inlet, and a second water inlet at its front end. When the second water inlet is located in the second chamber, the drilling fluid flows into the interior of the valve core through the water inlet and the first water inlet, and flows out through the second water inlet and the water outlet.

7. The drill string inner tube assembly positioning signaling mechanism according to claim 4, characterized in that: The elastic support assembly further includes a support frame disposed between the outer wall of the valve core and the inner wall of the water-passing sleeve. The support frame is connected to the protrusion of the valve core through a second elastic element. When the water-passing sleeve and the valve core move forward along the axial direction of the sleeve assembly, the front end of the support frame first abuts against the rear end of the positioning sleeve, the second elastic element is compressed, and then the water-passing sleeve and the valve core continue to move forward along the axial direction of the sleeve assembly until the front end of the water-passing sleeve extends into and is locked in the positioning space.

8. The drill string inner tube assembly positioning signaling mechanism according to claim 4, characterized in that: A straightening block is provided on the outer side wall of the water-passing sliding sleeve. The outer side wall of the straightening block contacts the inner side wall of the spring clip frame, so that the water-passing sliding sleeve slides along the axial direction of the spring clip frame.

9. The drill string inner tube assembly positioning signaling mechanism according to claim 5, characterized in that: The front end of the positioning sleeve is fixedly connected to the inner side wall of the suspension joint by a thread. The side wall of the positioning sleeve has a stepped surface facing forward. When the positioning sleeve is tightened, the stepped surface can apply pressure to the front end of the locking sleeve and compress the first elastic element.

10. The drill string inner tube assembly positioning signaling mechanism according to claim 5, characterized in that: The outer rear wall of the positioning sleeve has a guide surface that slopes from the front end to the rear end toward the locking sleeve. When the water-passing sliding sleeve and the valve core move toward the front end along the axial direction of the sleeve assembly, the steel ball abuts against the guide surface on the inner side of the water-passing sliding sleeve, so that the steel ball moves radially outward along the water-passing sliding sleeve and abuts against the rear end of the locking sleeve.

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