Pressure compensation and valve closing drive for a pressure-maintained wireline coring tool

Abstract

The application relates to the field of rope core drilling tools, and discloses a pressure compensation and valve-closing driving device of a pressure-maintaining rope core drilling tool, which comprises an outer cylinder and an inner cylinder assembled in the outer cylinder, the top of the inner cylinder is a high-pressure gas cylinder, a gas releasing mechanism is arranged at the bottom of the high-pressure gas cylinder, an isolation piston is arranged below the gas releasing mechanism, the bottom of the isolation piston is a throttling cavity, a valve driving mechanism is arranged below the throttling cavity, a pressure-maintaining cavity is in communication with the throttling cavity through a throttling and pressure compensation joint, a one-way valve is arranged on the throttling and pressure compensation joint, the liquid in the throttling cavity is driven to work under the pushing of high-pressure gas so as to drive the valve driving mechanism to close a sealing valve at the bottom of the pressure-maintaining cavity, and the throttling and pressure compensation joint provides pressure compensation for the pressure-maintaining cavity. The gas releasing mechanism releases high-pressure gas to push the isolation piston to work, thereby providing driving power for the sealing valve of the pressure-maintaining cavity to be closed, and meanwhile, the pressure compensation is provided for the pressure-maintaining cavity, so that the decomposition of hydrate samples in the pressure-maintaining cavity is effectively prevented.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wire-line coring drill, in particular to a pressure compensation and valve closing driving device of a pressure-maintaining wire-line coring drill. BACKGROUND

[0002] Natural gas hydrate is a potential energy resource, in order to accurately evaluate and master its storage condition, a large number of original hydrate samples are needed. One of the characteristics of natural gas hydrate is that it is very sensitive to temperature and pressure changes and is easily decomposed, so in order to obtain the required hydrate sample, the corresponding sampler needs to have perfect temperature and pressure maintaining function.

[0003] The hydrate sampler pressure maintaining technology is generally that the drill adopts inner and outer cylinder structure, after obtaining the sample, the sample is dragged and placed into the pressure maintaining cavity through the differential mode of the inner and outer cylinder, the upper and lower end sealing units of the pressure maintaining cavity are activated to realize the pressure maintaining of the sample, the upper end of the pressure maintaining cavity is generally sealed on the side, and the lower end generally adopts plate valve or ball valve sealing due to the need to set the sample passage. Generally, if the sampler pressure maintaining cavity sealing is not closed in time at the sampling site, with the decrease of the water depth of the fishing drill, the pressure in the pressure maintaining cylinder will decrease and thus the sample will be decomposed, therefore, the pressure maintaining cavity sealing is closed in time by using the controllable active mode, which can better realize the pressure maintaining of the sampler at the initial sampling position. At the same time, with the decrease of the water depth, the environmental pressure of the sampler becomes smaller, the pressure maintaining cavity of the sampler will slightly expand, which also leads to the decomposition of the hydrate sample.

[0004] Therefore, how to effectively prevent the decomposition of the hydrate sample in the pressure maintaining cavity is a problem to be solved by those skilled in the art. SUMMARY

[0005] The purpose of the present application is to provide a pressure compensation and valve closing driving device of a pressure-maintaining wire-line coring drill, which is used to solve the problem that with the decrease of the water depth, the environmental pressure of the sampler becomes smaller, the pressure maintaining cavity of the sampler will slightly expand, which leads to the decomposition of the hydrate sample.

[0006] To solve the above technical problems, the application provides a pressure compensation and valve closing driving device of a pressure-maintaining wireline coring drill, which comprises an outer cylinder and an inner cylinder assembled in the outer cylinder, the top of the inner cylinder is a high-pressure gas cylinder, a gas release mechanism is arranged at the bottom of the high-pressure gas cylinder, the gas release mechanism is used for blocking and releasing high-pressure gas in the high-pressure gas cylinder, an isolation piston is arranged below the gas release mechanism, the bottom of the isolation piston is a throttling cavity, a valve driving mechanism is arranged below the throttling cavity, a pressure-maintaining cavity is in communication with the throttling cavity through a throttling and pressure compensation joint, a one-way valve is arranged on the throttling and pressure compensation joint, the isolation piston moves to the throttling cavity under the pushing of the high-pressure gas, the liquid in the throttling cavity is driven to work to drive the valve driving mechanism to close a sealing valve at the bottom of the pressure-maintaining cavity, and the pressure-maintaining cavity is provided with pressure compensation through the throttling and pressure compensation joint.

[0007] Optionally, the high-pressure gas cylinder comprises a gas charging joint, a gas cylinder, a gas charging valve plug and a release valve core, the top of the gas cylinder is connected with the gas charging joint, the release valve core is inserted into a through hole at the bottom of the gas cylinder, the gas charging valve plug is arranged in the gas charging joint, and the through hole is provided with a hole seal.

[0008] Optionally, the outer cylinder is composed of a limiting sleeve, a top sealing shell and a pressure-maintaining cavity shell which are connected in sequence, the top sealing shell is detachably connected with the limiting sleeve and the pressure-maintaining cavity shell respectively, and the inner cylinder is composed of the gas charging joint, the gas cylinder, a release valve shell and a top sealing joint, when the inner cylinder moves axially along the outer cylinder, the gas release mechanism is triggered to release the high-pressure gas in the gas cylinder.

[0009] Optionally, the release valve core comprises a plunger and a locking block, the plunger is coaxially assembled at the top of the locking block, the plunger is used for blocking the through hole at the bottom of the gas cylinder, the diameter of the locking block is greater than that of the plunger, the inside of the locking block is provided with a gas release channel, the outer surface of the locking block is provided with a first locking groove and a first annular sealing groove, the first annular sealing groove is assembled with a first annular sealing element, the first annular sealing element abuts against the release valve shell, and when the plunger is separated from the through hole at the bottom of the gas cylinder, the high-pressure gas is released through the gas release channel.

[0010] Optionally, the gas release mechanism comprises a trigger sleeve, the release valve housing, a release valve lock block, a reset spring and the limiting sleeve, the upper part of the release valve housing is threadedly connected with the lower part of the gas cylinder, the outer circumferential surface of the release valve housing is sequentially sleeved with the trigger sleeve and the reset spring, the top of the trigger sleeve is abutted with the gas cylinder or the limiting sleeve, the bottom of the trigger sleeve is abutted with the top of the reset spring, the middle part of the outer circumferential surface of the release valve housing is provided with a support boss, the bottom of the reset spring is abutted with the support boss, the side wall of the release valve housing is provided with a lock block through hole, the release valve lock block is installed in the lock block through hole, the side of the trigger sleeve close to the release valve housing is provided with a release slot, when the release valve lock block is located in the first locking slot, the gas release mechanism is used for limiting the release valve core to make the plunger be inserted with the through hole at the bottom of the gas cylinder, when the release valve lock block is located in the release slot, the release valve core is moved under the action of the high-pressure gas to make the high-pressure gas be released through the gas release channel.

[0011] Optionally, the isolation piston comprises an isolation piston sleeve, an inner hole piston rod and a locking nut, the isolation piston sleeve is sleeved on the outer circumferential surface of the inner hole piston rod, the top of the inner hole piston rod is provided with a limiting boss, the tail of the inner hole piston rod is provided with an external thread, the external thread is matched with the internal thread of the locking nut to limit the isolation piston sleeve between the limiting boss and the locking nut, the outer circumferential surface of the inner hole piston rod from the limiting boss to the external thread is sequentially provided with a reset sealing surface and a limiting slot, the inner circumferential surface of the isolation piston sleeve close to the inner hole piston rod is provided with a second annular sealing groove, a second annular sealing element is assembled in the second annular sealing groove, the inner diameter of the second annular sealing element is matched with the outer diameter of the inner hole piston rod provided with the reset sealing surface, the inner diameter of the second annular sealing element is greater than the outer diameter of the inner hole piston rod provided with the limiting slot, when the locking nut is unlocked, the isolation piston sleeve moves towards the tail of the inner hole piston rod to make the second annular sealing element be located at the limiting slot, when the locking nut is locked, the isolation piston sleeve moves towards the head of the inner hole piston rod to make the second annular sealing element abut against the reset sealing surface, the outer circumferential surface of the isolation piston sleeve is provided with a third annular sealing groove, a third annular sealing element is assembled in the third annular sealing groove, and the third annular sealing element abuts against the release valve housing.

[0012] Optionally, the isolating piston sleeve is further provided with a mounting hole, a limiting screw is assembled in the mounting hole, a first limiting step and a second limiting step are sequentially arranged along the length direction of the limiting groove, the limiting screw is limited between the first limiting step and the second limiting step, when the limiting screw abuts against the second limiting step, the second annular seal is located at the limiting groove, and when the limiting screw abuts against the first limiting step, the second annular seal is located at the reset sealing surface.

[0013] Optionally, the throttling cavity is composed of a top seal, the top sealing joint and the throttling and pressure compensation joint, the upper part of the top sealing joint is threadedly connected with the lower part of the release valve shell, the lower part of the top sealing joint is connected with the throttling and pressure compensation joint, the two ends of the top sealing joint are provided with mounting grooves for assembling the top seal, and the middle part of the top sealing joint is an outlet channel of the liquid in the throttling cavity, and the top seal is used for sealing the top part of the pressure maintaining cavity when the inner cylinder moves axially along the outer cylinder.

[0014] Optionally, the valve closing driving mechanism is composed of a pawl lock sleeve, a pressure maintaining cavity shell, a top sealing shell, a pawl and a pre-pressing spring, the outer side of the pawl lock sleeve is sequentially provided with a sealing boss, an unlocking cylindrical surface and a locking cylindrical surface from top to bottom, the inner side of the pawl lock sleeve is a top sealing surface, the top sealing surface is matched with the top seal, the upper part of the pressure maintaining cavity shell is threadedly connected with the top sealing shell, a sealing cylindrical surface and a second locking groove are sequentially arranged downward from the upper part of the pressure maintaining cavity shell in a threaded manner, the outer peripheral surface of the top sealing joint is provided with a sealing ring, the sealing ring is located below the outlet channel, the sealing ring abuts against the sealing cylindrical surface of the pressure maintaining cavity shell and is located above the sealing boss, the top part of the pawl is an elastically deformable contact head, the contact head is located between the second locking groove and the unlocking cylindrical surface, the tail part of the pawl extends to between the locking cylindrical surfaces of the pressure maintaining cavity shell and the pawl lock sleeve and is connected with a valve closing cylinder, the valve closing cylinder is connected with a sealing valve of the pressure maintaining cavity, the unlocking cylindrical surface is sleeved with the pre-pressing spring, and the two ends of the pre-pressing spring abut against the sealing boss and the contact head of the pawl respectively.

[0015] Optionally, one side of the release valve lock block facing the trigger sleeve is a release contact surface, one side of the release valve lock block facing the release valve core is a locking contact surface, the release contact surface is a convex surface, and the locking contact surface is a concave surface.

[0016] The pressure compensation and valve closing driving device of the pressure-maintaining rope coring drill provided by the application comprises an outer cylinder and an inner cylinder assembled in the outer cylinder, the top of the inner cylinder is a high-pressure gas cylinder, a gas releasing mechanism is located at the bottom of the high-pressure gas cylinder, the gas releasing mechanism is used for blocking and releasing high-pressure gas in the high-pressure gas cylinder, an isolation piston is located below the gas releasing mechanism, the bottom of the isolation piston is a throttling cavity, a valve driving mechanism is located below the throttling cavity, a pressure-maintaining cavity is in communication with the throttling cavity through a throttling and pressure compensation joint, a one-way valve is arranged on the throttling and pressure compensation joint, the isolation piston moves to the throttling cavity under the pushing of the high-pressure gas, the liquid in the throttling cavity is driven to work to drive the valve driving mechanism to close the sealing valve at the bottom of the pressure-maintaining cavity, and the pressure-maintaining cavity is provided with pressure compensation through the throttling and pressure compensation joint. After the hydrate sample is collected in the pressure-maintaining cavity, the gas releasing mechanism releases the high-pressure gas to push the isolation piston to work, thereby providing driving power for closing the sealing valve of the pressure-maintaining cavity and providing pressure compensation for the pressure-maintaining cavity, which can effectively prevent the hydrate sample in the pressure-maintaining cavity from being decomposed. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the application, the drawings required to be used in the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings.

[0018] Figure 1 A cross-sectional view of the pressure compensation and valve closing driving device of the pressure-maintaining rope coring drill is provided for the embodiments of the application.

[0019] Figure 2 A cross-sectional view of another pressure compensation and valve closing driving device of the pressure-maintaining rope coring drill is provided for the embodiments of the application.

[0020] Figure 3 A cross-sectional view of the releasing valve core is provided for the embodiments of the application.

[0021] Figure 4 A cross-sectional view of the releasing valve lock block is provided for the embodiments of the application.

[0022] Figure 5 A cross-sectional view of the isolation piston is provided for the embodiments of the application.

[0023] Figure 6 A cross-sectional view of the elastic claw lock sleeve is provided for the embodiments of the application.

[0024] The reference signs are as follows: 1 is a limiting sleeve, 2 is an inflation joint, 3 is an inflation valve plug, 4 is a top sealing shell, 5 is a gas storage cylinder, 6 is a trigger sleeve, 7 is a release valve shell, 8 is a release valve lock block, 9 is a release valve core, 10 is a reset spring, 11 is an isolation piston, 12 is a pawl lock sleeve, 13 is a pressure maintaining cavity shell, 14 is a pawl, 15 is a top sealing element, 16 is a throttling cavity, 17 is a top sealing joint, 18 is a valve closing cylinder, 19 is a one-way valve, 20 is a throttling and pressure compensation joint, 21 is a pressure maintaining cavity, 801 is a release contact surface, 802 is a locking contact surface, 901 is a plunger, 902 is a gas release channel, 903 is a first locking groove, 904 is a first annular sealing element, 1101 is an inner hole piston rod, 1102 is a second annular sealing element, 1103 is a third annular sealing element, 1104 is a limiting screw, 1105 is an isolation piston sleeve, 1106 is a locking nut, 1201 is a sealing boss, 1202 is an unlocking cylindrical surface, 1203 is a locking cylindrical surface, 1204 is a top sealing surface. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the 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. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0026] The core of the present application is to provide a pressure compensation and valve closing driving device of a pressure maintaining wire line coring tool, which is used to effectively prevent the decomposition of hydrate samples in the pressure maintaining cavity.

[0027] In order to enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the drawings and specific embodiments. It should be understood that the terms "upper", "lower", "left", "right", "top", "bottom" and the like indicate the orientation or positional relationship shown in the drawings, and are only used for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0028] Figure 1 A cross-sectional view of a pressure compensation and valve closing driving device of a pressure maintaining wire line coring tool is provided for the embodiments of the present application, Figure 2 A cross-sectional view of another pressure compensation and valve closing driving device of a pressure maintaining wire line coring tool is provided for the embodiments of the present application, as shown in Figure 1 and Figure 2As shown, a pressure compensation and valve closing driving device of a pressure-maintaining wireline coring drill tool comprises an outer cylinder and an inner cylinder assembled in the outer cylinder, the top of the inner cylinder is a high-pressure gas cylinder, a gas release mechanism is located at the bottom of the high-pressure gas cylinder, the gas release mechanism is used for blocking and releasing high-pressure gas in the high-pressure gas cylinder, an isolation piston 11 is located below the gas release mechanism, the bottom of the isolation piston 11 is a throttling cavity 16, a valve driving mechanism is located below the throttling cavity 16, a pressure-maintaining cavity 21 is communicated with the throttling cavity 16 through a throttling and pressure compensation joint 20, a one-way valve 19 is arranged on the throttling and pressure compensation joint 20, the isolation piston 11 moves to the throttling cavity 16 under the push of the high-pressure gas, drives the liquid in the throttling cavity 16 to work to drive the valve closing driving mechanism to close the sealing valve at the bottom of the pressure-maintaining cavity 21, and the throttling and pressure compensation joint 20 provides pressure compensation for the pressure-maintaining cavity 21.

[0029] The outer cylinder and the inner cylinder are not specifically limited in the embodiment of the present application, the inner cylinder can be coaxially assembled in the outer cylinder, specifically, the outer cylinder is composed of a limiting sleeve 1, a top sealing shell 4 and a pressure-maintaining cavity shell 13 connected in sequence, the top sealing shell 4 is detachably connected with the limiting sleeve 1 and the pressure-maintaining cavity shell 13, specifically, the connection can be in the form of screw thread; the inner cylinder is composed of a gas charging joint 2, a gas cylinder 5, a release valve shell 7 and a top sealing joint 17. When the inner cylinder moves axially along the outer cylinder, the gas release mechanism is triggered to release the high-pressure gas in the gas cylinder 5, how the gas release mechanism blocks and releases the high-pressure gas in the gas cylinder 5 will be described in detail below.

[0030] The pressure compensation and valve closing driving device of the pressure-maintaining wireline coring drill tool provided by the embodiment of the present application comprises an outer cylinder and an inner cylinder assembled in the outer cylinder, the top of the inner cylinder is a high-pressure gas cylinder, a gas release mechanism is located at the bottom of the high-pressure gas cylinder, the gas release mechanism is used for blocking and releasing high-pressure gas in the high-pressure gas cylinder, an isolation piston is located below the gas release mechanism, the bottom of the isolation piston is a throttling cavity, a valve driving mechanism is located below the throttling cavity, a pressure-maintaining cavity is communicated with the throttling cavity through a throttling and pressure compensation joint, a one-way valve is arranged on the throttling and pressure compensation joint, the isolation piston moves to the throttling cavity under the push of the high-pressure gas, drives the liquid in the throttling cavity to work to drive the valve closing driving mechanism to close the sealing valve at the bottom of the pressure-maintaining cavity, and the throttling and pressure compensation joint provides pressure compensation for the pressure-maintaining cavity. After the pressure-maintaining cavity collects a hydrate sample, the gas release mechanism releases the high-pressure gas to push the isolation piston to work, provides driving power for the closing of the sealing valve of the pressure-maintaining cavity, and provides pressure compensation for the pressure-maintaining cavity, which can effectively prevent the decomposition of the hydrate sample in the pressure-maintaining cavity.

[0031] Based on the above embodiment, the high-pressure gas cylinder of the present application comprises a charging joint 2, a gas cylinder 5, a charging valve plug 3 and a release valve core 9. The top of the gas cylinder 5 is connected with the charging joint 2, the release valve core 9 is inserted into the through hole at the bottom of the gas cylinder 5, and the charging valve plug 3 is arranged in the charging joint 2. The through hole is provided with a hole seal.

[0032] The gas cylinder 5 in the embodiment of the present application is a cylindrical cavity, and the charging joint 2 is connected with the gas cylinder 5 through threads. The charging valve plug 3 blocks the hole of the charging joint 2 to prevent gas leakage. In addition, the through hole at the bottom of the gas cylinder 5 also has the function of preventing gas leakage.

[0033] Further, Figure 3 A cross-sectional view of the release valve core provided in the embodiment of the present application is shown in Figure 3 The release valve core 9 comprises a plunger 901 and a locking block. The plunger 901 is coaxially assembled at the top of the locking block. The plunger 901 is used to block the through hole at the bottom of the gas cylinder 5. The diameter of the locking block is larger than that of the plunger 901. The inside of the locking block is provided with a gas release channel 902. The outer surface of the locking block is provided with a first locking groove 903 and a first annular sealing groove. The first annular sealing groove is assembled with a first annular sealing element 904. The first annular sealing element 904 abuts against the release valve housing 7. When the plunger 901 is separated from the through hole at the bottom of the gas cylinder 5, the high-pressure gas is released through the gas release channel 902.

[0034] The diameter of the plunger 902 matches the diameter of the through hole at the bottom of the gas cylinder 5. The locking block is arranged inside the release valve housing 7. The outer surface of the locking block is provided with a first annular sealing groove. The first annular sealing element 904 assembled in the first annular sealing groove abuts against the release valve housing 7, so that the high-pressure gas in the gas cylinder 5 is smoothly released through the gas release channel 902, avoiding the leakage of high-pressure gas through the gap between the locking block and the release valve housing 7. As shown in Figure 3 The gas release channel 902 is divided into two ends. The gas release channel 902 close to the plunger 901 is a double-opening air channel. One end of the double-opening air channel is located on each side of the plunger 901. The gas release channel 902 far from the plunger 901 is a single air channel. One end of the single air channel communicates with the other end of the double-opening air channel.

[0035] Based on the above embodiment, the gas release mechanism of the embodiment of the application comprises a trigger sleeve 6, a release valve housing 7, a release valve locking block 8, a return spring 10 and a limiting sleeve 1, the upper part of the release valve housing 7 is threadedly connected with the lower part of the gas cylinder 5, the outer circumferential surface of the release valve housing 7 is sequentially sleeved with the trigger sleeve 6 and the return spring 10, the top of the trigger sleeve 6 abuts against the gas cylinder 5 or the limiting sleeve 1, the bottom of the trigger sleeve 6 abuts against the top of the return spring 10, the middle part of the outer circumferential surface of the release valve housing 7 is provided with a supporting boss, the bottom of the return spring 10 abuts against the supporting boss, the side wall of the release valve housing 7 is provided with a locking block through hole, the release valve locking block 8 is installed in the locking block through hole, the side of the trigger sleeve 6 close to the release valve housing 7 is provided with a release groove, when the release valve locking block 8 is located in the first locking groove 903, the gas release mechanism is used for limiting the release valve core 9 so that the plunger 901 is inserted into the through hole at the bottom of the gas cylinder 5, when the release valve locking block 8 is located in the release groove, the release valve core 9 is moved under the action of the high-pressure gas so that the high-pressure gas is released through the gas release channel 902.

[0036] The outer lateral cylindrical surface of the trigger sleeve 6 in the embodiment of the application is uniformly distributed with the axis direction flow channel, the inner side of the trigger sleeve 6 close to the release valve housing 7 is provided with a release groove, the release groove forms two sizes of cylindrical surfaces in the inner side of the trigger sleeve 6, the small size cylindrical surface is the radial limiting surface in the locking state of the release valve locking block 8, and the large size cylindrical surface (i.e. the side surface of the release groove) is the radial limiting surface in the release state of the release valve locking block 8, the trigger sleeve 6 is supported by the return spring 10, and the upper end surface of the trigger sleeve 6 is in contact with the lower end of the gas cylinder 5 or the limiting sleeve 1 for limiting. Figure 1 In the embodiment, when the inner cylinder is located in the outer cylinder, the upper end surface of the trigger sleeve 6 is in contact with the lower end of the gas cylinder 5 for limiting, at this time, the release valve locking block 8 is located in the first locking groove 903 provided on the outer surface of the release valve core 9, so as to limit the plunger 901 of the release valve core 9 in the through hole at the bottom of the gas cylinder 5. Figure 2In the middle, the inner cylinder is differential relative to the outer cylinder, that is, the inner cylinder moves upward along the axial direction, when the inflation connector 2 at the top of the inner cylinder is located outside the outer cylinder, because the whole inner cylinder moves upward, the release valve shell 7 as a part of the inner cylinder moves upward relative to the trigger sleeve 6, thereby generating a downward force on the trigger sleeve 6, the trigger sleeve 6 compresses the return spring 10 to move downward, so that the release valve lock block 8 enters the release slot inside the trigger sleeve 6, thereby the whole release valve core 9 moves downward under the action of high-pressure gas without the release valve lock block 8 limiting, so that the plunger 901 of the release valve core 9 is separated from the through hole in the gas cylinder, the high-pressure gas is released through the gas release channel 902, and the isolation piston 11 at the bottom of the release valve core 9 is pushed downward by the high-pressure gas. Specifically, the release valve shell 7 is a rotary body, the upper end of the release valve shell 7 is threadedly connected with the gas storage cylinder 5, the outer peripheral surface of the middle part of the release valve shell 7 is a support boss of the return spring 10, and the side wall of the release valve shell 7 can be provided with a plurality of lock block through holes which can be square. Correspondingly, the release valve lock block 8 is a block, and the middle part of the release valve shell 7 can be provided with a boss for limiting the release valve core 9 to prevent the release valve core 9 from always moving downward. Figure 4 A cross-sectional view of a release valve lock block provided by an embodiment of the present application is shown in Figure 4 As shown, the side of the release valve lock block 8 facing the trigger sleeve 6 is a release contact surface 801, and the side of the release valve lock block 8 facing the release valve core 9 is a locking contact surface 802. The release contact surface 801 is a convex surface, and the locking contact surface 802 is a concave surface. The design of the release valve lock block 8 can effectively ensure the release or locking of the release valve core 9.

[0037] Based on the above embodiment, Figure 5 A cross-sectional view of an isolation piston provided by an embodiment of the present application is shown in Figure 5As shown, the isolation piston 11 of the embodiment of the present application comprises an isolation piston sleeve 1105, an inner hole piston rod 1101 and a locking nut 1106, the isolation piston sleeve 1105 is sleeved on the outer circumferential surface of the inner hole piston rod 1101, the top of the inner hole piston rod 1101 is provided with a limiting boss, the tail of the inner hole piston rod 1101 is provided with an external thread, the external thread is matched with the internal thread of the locking nut 1106, so as to limit the isolation piston sleeve 1105 between the limiting boss and the locking nut 1106, the outer circumferential surface of the inner hole piston rod 1101 is sequentially provided with a reset sealing surface and a limiting slot from the limiting boss to the external thread, the inner circumferential surface of the isolation piston sleeve 1105 close to the inner hole piston rod 1101 is provided with a second annular sealing groove, the second annular sealing groove is assembled with a second annular sealing element 1102, the inner diameter of the second annular sealing element 1102 is matched with the outer diameter of the reset sealing surface of the inner hole piston rod 1101, and the inner diameter of the second annular sealing element 1102 is greater than the outer diameter of the limiting slot of the inner hole piston rod 1101, when the locking nut 1106 is unlocked, the isolation piston sleeve 1105 moves towards the tail of the inner hole piston rod 1101, so that the second annular sealing element 1102 is located at the limiting slot, when the locking nut 1106 is locked, the isolation piston sleeve 1105 moves towards the head of the inner hole piston rod 1101, so that the second annular sealing element 1102 abuts against the reset sealing surface, the outer circumferential surface of the isolation piston sleeve 1105 is provided with a third annular sealing groove, the third annular sealing groove is assembled with a third annular sealing element 1103, and the third annular sealing element 1103 abuts against the release valve shell 7.

[0038] In the embodiment of the present application, one end of the inner hole piston rod 1101 is a limiting boss, and the other end is provided with an external thread matched with the internal thread of the locking nut 1106. By adjusting the locking nut 1106, the isolation piston sleeve 1105 can freely move along the axial direction of the inner hole piston rod 1101, the lower side of the limiting boss is a reset sealing surface, and the limiting slot can be symmetrically arranged between the external thread and the reset sealing surface. When the locking nut 1106 is locked, the second annular sealing element 1102 abuts against the reset sealing surface, and the isolation piston 11 is not connected with the upper and lower parts for isolating high-pressure gas, so that the high-pressure gas pushes the isolation piston 11 to move downwards. If it is needed to move the isolation piston 11 upwards to reset, since the outer cylinder is detachably connected, after the outer cylinder is disassembled, the locking nut 1106 is unlocked, and the second annular sealing element 1102 is located at the limiting slot. Since the inner diameter of the second annular sealing element 1102 is greater than the outer diameter of the limiting slot of the inner hole piston rod 1101, after the isolation piston 11 is connected with the upper and lower parts, it is convenient to move the isolation piston 11 upwards to reset.

[0039] Further, the isolation piston sleeve 1105 is also provided with a mounting hole, a limiting screw 1104 is assembled in the mounting hole, a first limiting step and a second limiting step are sequentially arranged along the length direction of the limiting groove, so as to limit the limiting screw 1104 between the first limiting step and the second limiting step, when the limiting screw 1104 abuts against the second limiting step, the second annular sealing element 1102 is located at the limiting groove, when the limiting screw 1104 abuts against the first limiting step, the second annular sealing element 1102 is located at the reset sealing surface; wherein, the first limiting step is close to the reset sealing surface, and the second limiting step is close to the external thread. Through the cooperation of the limiting screw 1104, the first limiting step and the second limiting step, the operator can operate conveniently, and the nut can be locked and unlocked to a relatively accurate degree, respectively.

[0040] Based on the above embodiment, the throttling cavity 16 of the embodiment of the application is composed of a top sealing element 15, a top sealing joint 17 and a throttling and pressure compensation joint 20, the upper part of the top sealing joint 17 is threadedly connected with the lower part of the release valve shell 7, the lower part of the top sealing joint 17 is connected with the throttling and pressure compensation joint 20, both ends of the top sealing joint 17 are provided with mounting grooves for assembling the top sealing element 15, and the middle part of the top sealing joint 17 is an outlet channel of the liquid in the throttling cavity 16. The top sealing element 15 is used for sealing the top part of the pressure maintaining cavity 21 when the inner cylinder moves axially along the outer cylinder.

[0041] The lower part of the throttling and pressure compensation joint 20 in the embodiment of the application is threadedly connected with the sampling pipe, the upper end face has a throttling small hole, which communicates the throttling cavity 16 and the pressure maintaining cavity 21, the lower end is centrally provided with a one-way valve 19, and the middle part is uniformly provided with a plurality of flow channel holes. The one-way valve 19 can prevent the sample in the pressure maintaining cavity 21 from entering the throttling cavity 16, and also facilitates the isolation piston 11 to move downward to provide pressure compensation for the pressure maintaining cavity 21 through the throttling hole of the throttling and pressure compensation joint 20. The top sealing element 15 is used for sealing the top part of the pressure maintaining cavity 21 when the inner cylinder moves axially along the outer cylinder, so as to prevent the sample in the pressure maintaining cavity 21 from leaking and the pressure from fluctuating.

[0042] Based on the above embodiment, the valve closing driving mechanism of the embodiment of the application is composed of a claw lock sleeve 12, a pressure maintaining cavity shell 13, a top sealing shell 4, a claw 14 and a pre-pressing spring, Figure 6 A sectional view of the claw lock sleeve provided in the embodiment of the application is as follows, Figure 6As shown, the outer side of the pawl lock sleeve 12 is sequentially provided with a sealing boss 1201, an unlocking cylindrical surface 1202 and a locking cylindrical surface 1203 from top to bottom, and the inner side of the pawl lock sleeve 12 is provided with a top sealing surface 1204 which cooperates with the top sealing member 15, the upper part of the pressure maintaining cavity shell 13 is threadedly connected with the top sealing shell 4, and the upper part of the pressure maintaining cavity shell 13 is sequentially provided with a sealing cylindrical surface and a second locking groove in a threaded manner from top to bottom, the outer circumferential surface of the top sealing joint 17 is provided with a sealing ring which is located below the outlet passage, abuts against the sealing cylindrical surface of the pressure maintaining cavity shell 13 and is located above the sealing boss 1201, the top part of the pawl 14 is an elastically deformable contact head which is located between the second locking groove and the unlocking cylindrical surface 1202, the tail part of the pawl 14 extends between the pressure maintaining cavity shell 13 and the locking cylindrical surface 1203 of the pawl lock sleeve 12 and is connected with the valve closing cylinder 18, the valve closing cylinder 18 is connected with the sealing valve of the pressure maintaining cavity 21, the unlocking cylindrical surface is sleeved with a pre-pressing spring which abuts against the sealing boss 1201 and the contact head of the pawl 14 at two ends respectively.

[0043] When the locking cylindrical surface 1203 of the pawl lock sleeve 12 supports the inner side of the contact head of the pawl 14, the pawl 14 is hung in the second locking groove of the pressure maintaining cavity shell 13, when the unlocking cylindrical surface 1202 of the pawl lock sleeve 12 supports the inner side of the contact head of the pawl 14, the pawl 14 is unlocked from the second locking groove of the pressure maintaining cavity shell 13, the pawl lock sleeve 12 is driven by the high-pressure gas to move downward together with the pawl 14 to close the sealing valve of the pressure maintaining cavity 21, the lower end of the pre-pressing spring is supported by the radial end surface of the contact head of the pawl 14, and the upper end of the pre-pressing spring supports the sealing boss 1201 of the pawl lock sleeve 12, so that the entire valve closing driving mechanism is kept in a locked state. In addition, the outer circumferential surface of the top sealing joint 17 is provided with a sealing ring which is located below the outlet passage, abuts against the sealing cylindrical surface of the pressure maintaining cavity shell 13 and can prevent the leakage of liquid in the throttling cavity body 16, so that the liquid which flows out through the outlet passage can smoothly push the entire valve closing driving mechanism to move downward to close the sealing valve at the bottom of the pressure maintaining cavity 21.

[0044] In order to better understand the present application, the use method of the pressure compensation and valve closing driving device of the pressure maintaining wire-line coring tool will be introduced below.

[0045] After the pressure maintaining wire-line coring tool is prepared, the compressed gas is injected into the gas storage cylinder 3 through the inflation joint 2, and the state is as shown in Figure 1 When the wire rope is fished after the sampling is completed, the inner and outer barrels are differentially produced, and the final state is as shown in Figure 2The top sealing member 15 closes the top sealing of the pressure maintaining cavity 21, and the top sealing joint 17, the top sealing member 15, the throttling and pressure compensation joint 20 form a throttling cavity 16, which is communicated with the pressure maintaining cavity 21; the trigger sleeve 6 is blocked by the limiting sleeve 1 and the displacement of the release valve locking block 8 occurs, the release valve core 9 is unlocked and moves downward, the compressed gas is released, the high-pressure gas drives the isolation piston 11 to drive the liquid in the throttling cavity 16 to work, on the one hand, the pawl locking sleeve 12 is driven to move downward and unlock the pawl 14, and the valve closing cylinder 18 is driven to move downward together, the sealing valve at the bottom of the pressure maintaining cavity 21 is closed, on the other hand, the throttling hole of the throttling and pressure compensation joint 20 provides pressure compensation for the pressure maintaining cavity 21.

[0046] The pressure compensation and valve closing driving device of the pressure maintaining wire-line coring drill provided by the application can make the pressure maintaining wire-line coring drill close the sample pressure maintaining cavity in time at the sampling position and realize in-situ pressure maintaining by means of controllable driving force; meanwhile, the device provides real-time and continuous pressure compensation for the sample pressure maintaining cavity, maintains the pressure of the pressure maintaining cavity to be greater than the in-situ pressure, and protects the hydrate sample from being decomposed due to pressure change; and the whole device is restored quickly and efficiently after use.

[0047] The pressure compensation and valve closing driving device of the pressure maintaining wire-line coring drill provided by the application is described in detail above. The embodiments in the specification are described by means of progression, and each embodiment mainly describes the difference from other embodiments, and the same and similar parts of each embodiment can be referred to mutually. It should be pointed out that, for those skilled in the art, some improvements and modifications can be made to the application without departing from the principle of the application, and these improvements and modifications also fall within the protection scope of the claims of the application.

[0048] It should also be noted that, in the specification, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between the entities or operations. Moreover, the terms “include”, “contain” or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitation, the element defined by the statement “including a…” does not exclude the presence of another identical element in the process, method, article or device including the element.

Claims

1. A pressure compensation and valve closing drive device for a pressure-maintaining wireline coring drill, characterized in that, include: The outer cylinder and the inner cylinder assembled in the outer cylinder, the top of the inner cylinder is a high-pressure gas storage cylinder, the gas release mechanism is located at the bottom of the high-pressure gas storage cylinder, the gas release mechanism is used to block and release the high-pressure gas in the high-pressure gas storage cylinder, the isolation piston (11) is located below the gas release mechanism, the bottom of the isolation piston (11) is a throttling chamber (16), the throttling chamber (16) is provided with a valve drive mechanism below it, the pressure holding chamber (21) is connected to the throttling chamber (16) through the throttling and pressure compensation connector (20), the throttling and pressure compensation connector (20) is provided with a one-way valve (19), the isolation piston (11) moves towards the throttling chamber (16) under the push of the high-pressure gas, drives the liquid in the throttling chamber (16) to do work to drive the valve drive mechanism to close the sealing valve at the bottom of the pressure holding chamber (21), and provides pressure compensation to the pressure holding chamber (21) through the throttling and pressure compensation connector (20); The high-pressure gas storage cylinder includes an inflation connector (2), a gas storage cylinder (5), an inflation valve plug (3), and a release valve core (9). The top of the gas storage cylinder (5) is connected to the inflation connector (2), the release valve core (9) is inserted into the through hole at the bottom of the gas storage cylinder (5), the inflation valve plug (3) is located inside the inflation connector (2), and the through hole is provided with a hole seal. The outer cylinder is composed of a limiting sleeve (1), a top sealing shell (4), and a pressure holding chamber shell (13) connected in sequence. The top sealing shell (4) is detachably connected to the limiting sleeve (1) and the pressure holding chamber shell (13). The inner cylinder is composed of the air filling connector (2), the air storage cylinder (5), the release valve shell (7), and the top sealing connector (17). When the inner cylinder moves along the axial direction of the outer cylinder, the gas release mechanism is triggered to release the high-pressure gas in the air storage cylinder (5). The release valve core (9) includes a plunger (901) and a locking block. The plunger (901) is coaxially mounted on the top of the locking block. The plunger (901) is used to block the through hole at the bottom of the gas storage cylinder (5). The diameter of the locking block is larger than the diameter of the plunger (901). The locking block has a gas release channel (902) inside. The outer surface of the locking block has a first locking groove (903) and a first annular sealing groove. The first annular sealing groove is equipped with a first annular sealing element (904). The first annular sealing element (904) abuts against the release valve housing (7). When the plunger (901) disengages from the through hole at the bottom of the gas storage cylinder (5), the high-pressure gas is released through the gas release channel (902). The gas release mechanism includes a trigger sleeve (6), a release valve housing (7), a release valve locking block (8), a return spring (10), and a limiting sleeve (1). The upper part of the release valve housing (7) is threadedly connected to the lower part of the gas storage cylinder (5). The trigger sleeve (6) and the return spring (10) are sequentially fitted on the outer circumferential surface of the release valve housing (7). The top of the trigger sleeve (6) abuts against the gas storage cylinder (5) or the limiting sleeve (1), and the bottom of the trigger sleeve (6) abuts against the top of the return spring (10). A support boss is provided in the middle of the outer circumferential surface of the release valve housing (7), and the bottom of the return spring (10) abuts against the top of the return spring (10). The supporting boss abuts against the side wall of the release valve housing (7), which is provided with a locking block through hole. A release valve locking block (8) is installed in the locking block through hole. The trigger sleeve (6) is provided with a release groove on the side near the release valve housing (7). When the release valve locking block (8) is located in the first locking groove (903), the gas release mechanism is used to limit the release valve core (9) so that the plunger (901) is inserted into the through hole at the bottom of the gas storage cylinder (5). When the release valve locking block (8) is located in the release groove, the release valve core (9) moves under the action of the high-pressure gas so that the high-pressure gas is released through the gas release channel (902).

2. The pressure compensation and valve closing drive device for the pressure-maintaining wireline coring drill according to claim 1, characterized in that, The isolation piston (11) includes an isolation piston sleeve (1105), an inner piston rod (1101), and a locking nut (1106). The isolation piston sleeve (1105) is fitted onto the outer circumferential surface of the inner piston rod (1101). The top of the inner piston rod (1101) is provided with a limiting boss, and the tail of the inner piston rod (1101) is provided with an external thread. The external thread cooperates with the internal thread of the locking nut (1106) to limit the isolation piston sleeve (1105) between the limiting boss and the locking nut (1106). The outer circumferential surface of the inner piston rod (1101) is provided with a reset sealing surface and a limiting groove from the limiting boss to the external thread. The inner circumferential surface of the isolation piston sleeve (1105) near the inner piston rod (1101) is provided with a second annular sealing groove. A second annular sealing element (1102) is assembled in the second annular sealing groove. The inner diameter of the second annular seal (1102) matches the outer diameter of the inner piston rod (1101) at the location of the reset sealing surface. The inner diameter of the second annular seal (1102) is larger than the outer diameter of the inner piston rod (1101) at the location of the limiting groove. When the locking nut (1106) is unlocked, the isolation piston sleeve (1105) moves toward the tail of the inner piston rod (1101) so that the second annular seal (1102) is located at the limiting groove. When the locking nut (1106) is tightened, the isolation piston sleeve (1105) moves toward the head of the inner piston rod (1101) so that the second annular seal (1102) abuts against the reset sealing surface. The outer circumferential surface of the isolation piston sleeve (1105) is provided with a third annular sealing groove. A third annular seal (1103) is assembled in the third annular sealing groove. The third annular seal (1103) abuts against the release valve housing (7).

3. The pressure compensation and valve closing drive device for the pressure-maintaining wireline coring drill according to claim 2, characterized in that, The isolation piston sleeve (1105) is also provided with a mounting hole, in which a limiting screw (1104) is fitted. A first limiting step and a second limiting step are sequentially provided along the length direction of the limiting groove to limit the limiting screw (1104) between the first limiting step and the second limiting step. When the limiting screw (1104) abuts against the second limiting step, the second annular seal (1102) is located at the limiting groove. When the limiting screw (1104) abuts against the first limiting step, the second annular seal (1102) is located at the reset sealing surface.

4. The pressure compensation and valve closing drive device for the pressure-maintaining wireline coring drill according to claim 1, characterized in that, The throttling chamber (16) is composed of a top seal (15), a top sealing joint (17), and a throttling and pressure compensation joint (20). The upper part of the top sealing joint (17) is threaded to the lower part of the release valve housing (7), and the lower part of the top sealing joint (17) is connected to the throttling and pressure compensation joint (20). The two ends of the top sealing joint (17) are provided with mounting grooves for assembling the top seal (15). The middle part of the top sealing joint (17) is the outlet channel for the liquid in the throttling chamber (16). The top seal (15) is used to seal the top of the pressure-holding chamber (21) by moving the inner cylinder axially along the outer cylinder.

5. The pressure compensation and valve closing drive device for the pressure-maintaining wireline coring drill according to claim 4, characterized in that, The valve closing drive mechanism comprises a pawl lock sleeve (12), a pressure holding chamber housing (13), a top sealing housing (4), a pawl (14), and a preload spring. The outer side of the pawl lock sleeve (12) consists of a sealing boss (1201), an unlocking cylindrical surface (1202), and a locking cylindrical surface (1203) sequentially from top to bottom. The inner side of the pawl lock sleeve (12) is a top sealing surface (1204), which mates with the top sealing element (15). The upper part of the pressure holding chamber housing (13) is threadedly connected to the top sealing housing (4). A sealing cylindrical surface and a second locking groove are sequentially provided from the upper thread of the pressure holding chamber housing (13) downwards. A sealing ring is provided on the outer circumference of the top sealing joint (17). The sealing ring is located at the... Below the outlet channel, the sealing ring abuts against the sealing cylindrical surface of the pressure-holding chamber housing (13) and is located above the sealing boss (1201). The top of the spring claw (14) is an elastically deformable contact. The contact is located between the second locking groove and the unlocking cylindrical surface (1202). The tail of the spring claw (14) extends to the locking cylindrical surface (1203) of the pressure-holding chamber housing (13) and the spring claw lock sleeve (12), and is connected to the valve cylinder (18). The valve cylinder (18) is connected to the sealing valve of the pressure-holding chamber (21). The unlocking cylindrical surface (1202) is fitted with the preload spring. The two ends of the preload spring abut against the sealing boss (1201) and the contact of the spring claw (14), respectively.

6. The pressure compensation and valve closing drive device for the pressure-maintaining wireline coring drill according to claim 1, characterized in that, The side of the release valve locking block (8) facing the trigger sleeve (6) is the release contact surface (801), and the side of the release valve locking block (8) facing the release valve core (9) is the locking contact surface (802). The release contact surface (801) is a convex surface, and the locking contact surface (802) is a concave surface.

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