A marine hydrate cementation particle collision breaking and separation device

Abstract

The present invention discloses a device for collision and gel breaking and separation of marine hydrate cemented particles, comprising a lower outer tube, an inner tube assembly located inside the lower outer tube, the inner tube assembly comprising a lower inner tube; a gel breaking sleeve is arranged inside the lower inner tube, the bottom of the gel breaking sleeve is closed, a plurality of radially opposite jet holes are provided on the side wall of the gel breaking sleeve, and an annulus is provided between the gel breaking sleeve and the lower inner tube; the device also comprises a driving mechanism that slides and fits inside the gel breaking sleeve to push a shaft and drives the shaft to perform axial reciprocating motion. The present invention provides a device for collision and gel breaking and separation of marine hydrate cemented particles to solve the problems of relatively small gel breaking force and insufficient gel breaking and separation effect on cemented particles in the prior art, thereby achieving the purpose of improving the gel breaking efficiency of cemented particles and thus improving hydrate recovery efficiency.

Description

Technical Field

[0001] The present invention relates to the field of hydrate mining, and in particular to a device for separating marine hydrate cemented particles by collision and gel breaking. Background Art

[0002] Natural gas hydrates, also known as combustible ice, are ice-like solid compounds formed by hydrocarbon gases, primarily methane, and water under certain temperature and pressure conditions. Global reserves of natural gas hydrates are vast, and as a clean, high-quality energy source, they play a crucial role in future energy strategies.

[0003] Based on the reservoir characteristics of non-diagenetic natural gas hydrates in the South my country Sea, such as weak cementation, poor stability, and the absence of dense caprock, a new solid-state fluidized bed recovery method has been proposed, with successful natural gas hydrate trial production conducted in 2017. The core concept of solid-state fluidized bed recovery is to use water jets to disrupt the hydrate reservoir and fluidize it into a slurry, without changing temperature and pressure conditions. The hydrates are then recovered, separated, and lifted to a platform.

[0004] Due to the cementing properties of hydrate deposits, the hydrate slurry formed after fluidized crushing contains a large number of cementing particles. The mutual cementation between hydrate and sand particles causes a large number of hydrate particles to be carried in the sand backfilled to the bottom of the well, and a large number of sand particles to be entrained in the recovered hydrate slurry, which greatly reduces the hydrate recovery efficiency. Therefore, how to achieve debonding and separation of hydrate and sand is a key step in the fluidized mining process.

[0005] In the prior art, Chinese Patent Publication No. CN109882147A discloses a large-capacity, integrated, downhole, in-situ hydrate separation parallel device, which primarily addresses the problems of severe sand production and low separation efficiency of existing separators during hydrate extraction. However, this device separates dispersed hydrate and sand particles, without considering the agglomeration between the two. Chinese Patent Publication No. CN113090244A discloses a natural gas hydrate cyclone self-rotation gel breaking and separation method and separation device. The separation device, consisting of a preliminary gel breaker, a cyclone gel breaking cylinder, and a cyclone separation cylinder, achieves gel breaking and separation of the natural gas hydrate sediment slurry. However, this device increases the wellbore diameter, leading to an increase in the drilling wellbore diameter, reducing reservoir stability and increasing the risk of wellbore reservoir collapse. Chinese Patent Publication No. CN214091833U discloses a gel breaking and separation mechanism and a natural gas hydrate-sand agglomerated particle gel breaking and separation device. However, the gel breaking force generated by this centrifugal method is relatively small, and the gel breaking efficiency of the agglomerated particles is still low.

[0006] In summary, the existing hydrate recovery technologies all generate relatively small breaking forces, which are insufficient in breaking and separating the cemented particles in the hydrate slurry, resulting in low hydrate recovery efficiency. Summary of the Invention

[0007] The present invention provides a device for collision breaking and separating marine hydrate cemented particles to solve the problems of small breaking force and insufficient breaking and separating effect on cemented particles in the prior art, thereby achieving the purpose of improving the breaking efficiency of cemented particles and further improving the hydrate recovery efficiency.

[0008] The present invention is achieved through the following technical solutions:

[0009] A device for collision breaking and separating marine hydrate cemented particles comprises a lower outer tube and an inner tube assembly located inside the lower outer tube, wherein the inner tube assembly comprises a lower inner tube; a breaking sleeve is arranged inside the lower inner tube, the bottom of the breaking sleeve is closed, and a plurality of radially opposite jet holes are provided on the side wall of the breaking sleeve, with an annulus between the breaking sleeve and the lower inner tube; and the device also comprises a driving mechanism which is slidably fitted in the inside of the breaking sleeve to push a shaft for driving the pushing shaft to perform axial reciprocating motion.

[0010] In order to solve the problems in the prior art of low breaking force and insufficient breaking and separating effect on cemented particles, the present invention proposes a marine hydrate cemented particle collision breaking and separating device. Based on the double-layer tube technology in hydrate mining, the present application has structures such as a lower outer tube and an inner tube assembly. The inner tube assembly in the present application includes a breaking sleeve, which has a closed bottom and jet holes on the side wall. The driving shaft performs axial reciprocating motion inside the breaking sleeve under the drive of the driving mechanism. The specific driving method of the driving mechanism for the driving shaft is not specifically limited here. Any linear driving method that can be achieved by those skilled in the art based on the prior art can be applied to the present application.

[0011] When the present application is in operation, it is connected above the downhole power drill, and the high-pressure fluid flows downward from the annulus between the lower outer tube and the inner tube assembly into the downhole power drill, driving the downhole power drill to rotate and synchronously performing jet crushing, and the obtained hydrate slurry returns to the existing inner tube and enters the lower inner tube in the present application; in this process, the driving mechanism drives the propulsion shaft to perform axial reciprocating motion, and each upward movement of the propulsion shaft will generate a suction force in the breaker sleeve. Under the action of the suction force, the hydrate slurry recovered to the inside of the lower inner tube is periodically sucked into the inside of the breaker sleeve through each jet hole. Since the jet holes are opposite to each other in radial direction, the hydrate slurry jetted in will undergo strong convection collision in the breaker sleeve, and under the action of the strong collision force, the hydrate cementing particles are broken and dispersed. The present application enables the recovered hydrate slurry to continuously undergo jet collision under the action of suction, thereby achieving a collision-crushing debonding effect, significantly optimizing the debonding effect on cemented hydrate particles and sand particles, and improving the debonding efficiency of cemented particles, which is beneficial to improving the recovery rate of natural gas hydrates.

[0012] Furthermore, the outer diameter of the driving shaft is equal to the inner diameter of the rubber-breaking sleeve, and thus part of the jet hole can be blocked by the driving shaft;

[0013] When the driving shaft is at the top of the stroke, all the jet holes are connected with the interior of the rubber-breaking sleeve, that is, all the jet holes are open;

[0014] When the propulsion shaft is at the bottom of its travel, some of the jet holes are disconnected from the interior of the breaker sleeve, meaning some are open and others are closed. This arrangement ensures that some of the jet holes are always open, ensuring unobstructed internal flow during hydrate extraction and preventing temporary well shut-ins or tool self-locking.

[0015] Furthermore, the inner layer tube assembly further comprises an intermediate joint connected above the lower inner layer tube, and a middle inner layer tube connected above the intermediate joint;

[0016] The driving mechanism includes a piston head that slides axially in the middle inner layer tube, a first elastic member connected between the piston head and the intermediate joint, and an excitation component for generating pressure fluctuations inside the middle inner layer tube and in the space above the piston head; the piston head is connected to the driving shaft.

[0017] When the driving mechanism needs to work, the excitation component generates pressure fluctuations in the area inside the middle inner layer tube and on the top of the piston head: when the pressure increases, the high pressure drives the piston head to move downward, driving the push shaft to move downward synchronously. During this process, the first elastic member is compressed; when the pressure decreases, the first elastic member releases the elastic force, and under the action of its elastic restoring force, it pushes the piston head upward, driving the push shaft to move upward synchronously.

[0018] The excitation component in this solution can be implemented using any existing technology that can provide pressure fluctuations or pressure pulses, and is not specifically limited here. In addition, those skilled in the art will understand that in order to ensure smooth flow, the piston head in this solution is a hollow structure.

[0019] Furthermore, the inner layer tube assembly further includes an upper inner layer tube connected above the middle inner layer tube;

[0020] The excitation assembly includes an inner sleeve arranged inside the upper inner tube, a throttling sleeve axially slidingly fitted in the inner sleeve, and a second elastic member connected between the throttling sleeve and the inner sleeve. The throttling sleeve is used to generate a throttling pressure drop from bottom to top.

[0021] When the present application is working, there is always fluid flowing back inside the inner tube assembly. Therefore, the present solution utilizes the energy of the flowing fluid to set a certain area of the inner tube assembly as a throttling sleeve, so that a pressure drop is generated when the hydrate slurry passes through the throttling sleeve from bottom to top. Under the throttling effect, the pressure at the upstream end of the throttling sleeve (bottom space) increases and the pressure at the downstream end of the throttling sleeve (top space) decreases. The high-pressure area at the bottom of the throttling sleeve can drive the piston head to move downward and the throttling sleeve to move upward at the same time until the pressure in the high-pressure area is released. At this time, the piston head is reset upward under the action of the first elastic member, and the throttling sleeve is reset downward under the action of the second elastic member. The above process is repeated continuously during the working process of the present application, thereby achieving the effect of providing the required pressure fluctuation.

[0022] It can be seen that this solution utilizes the energy of the hydrate slurry that returns during the hydrate extraction process. The required pressure fluctuation can be obtained through ingenious structural design without the need for an additional pressure source or power source. This significantly improves the operability of collision breaking and avoids problems such as the bulky and bloated device that is inconvenient to put into the well.

[0023] In addition, the throttling sleeve in this solution can be implemented by any existing structure that has a throttling pressure drop function and can generate a pressure difference at both ends. The throttling pressure drop structure / equipment / tools / valves, etc. in the fluid transportation process in the prior art can be applied to this application, such as installing a throttling valve therein.

[0024] Preferably, the interior of the throttling sleeve includes a main cavity, a variable diameter cavity, a throttling hole and a variable diameter hole which are connected in sequence from bottom to top; the inner diameter of the throttling hole is smaller than the inner diameter of the main cavity; the inner diameter of the variable diameter cavity gradually decreases from bottom to top; the inner diameter of the variable diameter hole gradually increases from top to bottom.

[0025] This solution clearly defines the specific structure of the throttling sleeve to ensure that the required pressure difference is stably generated at both ends of the throttling sleeve.

[0026] Furthermore, a pressure relief annulus is provided between the inner sleeve and the upper inner tube; a plurality of pressure relief holes are provided on the side wall of the inner sleeve, and the pressure relief holes are connected to the pressure relief annulus;

[0027] When the throttle sleeve is at the top of its stroke, the pressure relief hole is connected to the interior of the inner sleeve; at this time, the pressure in the high-pressure area below the throttle sleeve enters the pressure relief annulus through the pressure relief hole to release the pressure, causing the piston head and the throttle sleeve to begin to reset;

[0028] When the throttling sleeve is at the bottom of the stroke, the pressure relief hole is not connected to the interior of the inner sleeve; at this time, the pressure in the high-pressure area below the throttling sleeve rises rapidly, ensuring that the piston head starts to move downward and the throttling sleeve starts to move upward.

[0029] Furthermore, the inner layer pipe assembly also includes a suspension joint connected above the upper inner layer pipe; the pressure relief annulus is communicated with the interior of the suspension joint.

[0030] The interior of the suspension joint and the interior of the upper inner layer pipe are normal fluid return channels. At the same time, this solution ensures that the pressure relief annulus is always connected to the interior of the suspension joint to provide a more efficient and stable pressure relief space, avoiding pressure buildup in the pressure relief annulus that may cause tool jamming or self-locking.

[0031] Furthermore, it also includes a double-layer pipe joint connected to the top of the lower outer layer pipe and the inner layer pipe assembly, an upper outer layer pipe and a separator sleeve connected above the double-layer pipe joint, and the separator sleeve is located inside the upper outer layer pipe; a downward flow channel and an upward flow channel are set in the double-layer pipe joint;

[0032] The top end of the descending flow channel is in communication with the annulus between the upper outer layer pipe and the separator sleeve, and the bottom end of the descending flow channel is in communication with the annulus between the lower outer layer pipe and the inner layer pipe assembly;

[0033] The top end of the upward flow channel is communicated with the interior of the separator sleeve, and the bottom end of the upward flow channel is communicated with the interior of the inner layer pipe assembly.

[0034] This solution clearly defines the structure of the top of the lower outer tube and inner tube assembly, which is convenient for adapting to the existing double-layer drill pipe in the hydrate production string, ensuring smooth flow of high-pressure fluid and hydrate slurry and ensuring the versatility of this application.

[0035] Furthermore, it also includes an upper joint connected to the top of the separator sleeve and a cyclone arranged inside the separator sleeve; a tangential inlet is set on the side of the cyclone, an overflow port is set on the top, and an underflow port is set on the bottom. The tangential inlet is connected to the interior of the separator sleeve, the overflow port passes through the upper joint, and the underflow port is connected to the sand discharge channel. The sand discharge channel is located in the double-layer pipe joint and extends to the side wall of the double-layer pipe joint.

[0036] After the hydrate slurry is processed by jet collision and gel breaking through the jet hole, it returns to the inside of the separator sleeve step by step and enters the cyclone through the tangential inlet. The separated mud and sand particles enter the sand discharge channel through the bottom flow port and are discharged. The separated hydrate continues to return upward through the overflow port.

[0037] Furthermore, the outer diameter of the cyclone gradually decreases from top to bottom.

[0038] The cross-sectional area of the annulus between the cyclone and the separator sleeve gradually decreases from bottom to top, thereby accelerating the upward flow of the fluid after entering the separator sleeve and entering the tangential inlet at a faster flow rate. This has a greater initial velocity in the cyclone, which is conducive to the hydrate slurry obtaining a greater centrifugal force in the cyclone, thereby improving the separation ability of hydrate particles and mud and sand particles. At the same time, the centrifugal force can be used to break the gel again, further improving the gel breaking ability of the present application.

[0039] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0040] 1. The present invention provides a marine hydrate cementing particle collision breaking and separation device, which causes the recovered hydrate slurry to continuously undergo jet collision under the action of suction, thereby achieving a collision and crushing breaking effect, significantly optimizing the breaking effect of cemented hydrate particles and sand particles, and improving the breaking efficiency of cemented particles, which is conducive to improving the recovery rate of natural gas hydrates.

[0041] 2. The present invention provides a marine hydrate cementing particle collision breaking and separation device, which utilizes the energy of the hydrate slurry returned during the hydrate mining process. The required pressure fluctuation can be obtained through ingenious structural design without the need for additional pressure source or power source, which significantly improves the operability of collision breaking and avoids the problem of bulky and bloated device that is inconvenient to put into the well.

[0042] 3. The marine hydrate agglomerated particle collision debonding and separation device of the present invention can make the hydrate slurry have a greater initial velocity in the cyclone, which is beneficial for the hydrate slurry to obtain a greater centrifugal force in the cyclone, improve the separation ability of hydrate particles and mud and sand particles, and at the same time, the centrifugal force can be used to debond again, further improving the debonding ability of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0044] Figure 1 This is a schematic diagram of a driving shaft at the bottom end of a stroke in a specific embodiment of the present invention;

[0045] Figure 2 This is a schematic diagram of a driving shaft at the top of its travel in a specific embodiment of the present invention;

[0046] Figure 3 It is a cross-sectional view of a throttling sleeve in a specific embodiment of the present invention.

[0047] Markings and corresponding parts names in the accompanying drawings:

[0048] 1-upper outer tube, 2-double-layer pipe joint, 201-downward flow channel, 202-upward flow channel, 203-sand discharge channel, 3-lower outer tube, 4-lower joint, 5-lower inner tube, 6-rubber breaking sleeve, 601-jet hole, 7-first sealing ring, 8-propelling shaft, 9-middle joint, 10-first elastic member, 11-piston head, 12-middle inner tube, 13-second sealing ring, 14-upper inner tube, 15-third sealing ring, 16-fourth sealing ring, 17-inner sleeve, 1701-pressure relief hole, 18-second elastic member, 19-throttling sleeve, 1901-throttling hole, 20-limiting sleeve, 21-suspension joint, 22-separator, 2201-tangential inlet, 2202-overflow port, 2203-bottom flow port, 23-separator sleeve, 24-upper joint. DETAILED DESCRIPTION

[0049] In order to make the objects, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the examples and drawings. The schematic embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention. In the description of this application, it should be understood that the orientations or positional relationships indicated by terms such as "front", "back", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of this application.

[0050] Example 1:

[0051] like Figure 1 and Figure 2The device for separating marine hydrate aggregate particles by collision and gel breaking is shown, comprising a lower outer tube 3, an inner tube assembly located within the lower outer tube 3, the inner tube assembly comprising a lower inner tube 5; a gel breaking sleeve 6 disposed within the lower inner tube 5, the gel breaking sleeve 6 having a closed bottom and a plurality of radially opposed jet holes 601 formed on the sidewall of the gel breaking sleeve 6, with an annulus formed between the gel breaking sleeve 6 and the lower inner tube 5; and a driving mechanism for driving the driving shaft 8 to perform axial reciprocating motion, the outer diameter of the driving shaft 8 being equal to the inner diameter of the gel breaking sleeve 6.

[0052] When the driving shaft 8 is at the top of the stroke, all the jet holes 601 are connected to the interior of the rubber-breaking sleeve 6;

[0053] When the driving shaft 8 is located at the bottom of its stroke, part of the jet holes 601 are not connected to the interior of the rubber-breaking sleeve 6 .

[0054] The inner layer pipe assembly in this embodiment further includes an intermediate joint 9 connected above the lower inner layer pipe 5, a middle inner layer pipe 12 connected above the intermediate joint 9, an upper inner layer pipe 14 connected above the middle inner layer pipe 12, and a hanging joint 21 connected above the upper inner layer pipe 14;

[0055] The driving mechanism includes a piston head 11 that slides axially in the middle inner layer tube 12, a first elastic member 10 connected between the piston head 11 and the intermediate joint 9, and an excitation component for generating pressure fluctuations inside the middle inner layer tube 12 and in the top space of the piston head 11; the piston head 11 is connected to the driving shaft 8.

[0056] The excitation assembly in this embodiment includes an inner sleeve 17 arranged inside the upper inner tube 14, a throttling sleeve 19 axially slidingly fitted in the inner sleeve 17, and a second elastic member 18 connected between the throttling sleeve 19 and the inner sleeve 17, and the throttling sleeve 19 is used to generate a throttling pressure drop from bottom to top.

[0057] In this embodiment, the first elastic member 10 and the second elastic member 18 are preferably disc springs.

[0058] In addition, there is a pressure relief annulus between the inner sleeve 17 and the upper inner pipe 14; a plurality of pressure relief holes 1701 are opened on the side wall of the inner sleeve 17, and the pressure relief holes 1701 are connected to the pressure relief annulus, and the pressure relief annulus is connected to the interior of the suspension joint 21.

[0059] When the throttle sleeve 19 is at the top of its stroke, the pressure relief hole 1701 is in communication with the interior of the inner sleeve 17;

[0060] When the throttle sleeve 19 is located at the bottom of its stroke, the pressure relief hole 1701 is not connected to the interior of the inner sleeve 17 .

[0061] When in use, the upper and lower ends of the device can be connected to the existing natural gas hydrate extraction string, and the gel breaking and separation device of the present application only needs to be above the downhole power drill. Preferably, the gel breaking and separation device of the present application can be as close to the downhole power drill as possible.

[0062] In a more preferred embodiment, the throttle sleeve 19 is as follows Figure 3 As shown, the interior includes a main cavity 1903, a variable diameter cavity 1902, a throttling hole 1901 and a variable diameter hole 1904 which are connected in sequence from bottom to top; the inner diameter of the throttling hole 1901 is smaller than the inner diameter of the main cavity 1903; the inner diameter of the variable diameter cavity 1902 gradually decreases from bottom to top; the inner diameter of the variable diameter hole 1904 gradually increases from top to bottom.

[0063] In a more preferred embodiment: a first sealing ring 7 is provided between the rubber-breaking sleeve 6 and the driving shaft 8; a second sealing ring 13 is provided between the piston head 11 and the middle inner tube 12; a third sealing ring 15 is provided between the inner sleeve 17 and the upper inner tube; and a fourth sealing ring 16 is provided between the inner sleeve 17 and the throttling sleeve.

[0064] Example 2:

[0065] A marine hydrate cementing particle collision debonding and separation device, based on Example 1, further comprising a double-layer pipe joint 2 connected to the lower outer pipe 3 and the top of the suspension joint 21, an upper outer pipe 1 connected above the double-layer pipe joint 2 and a separator sleeve 23, the separator sleeve 23 being located inside the upper outer pipe 1; a downward flow channel 201 and an upward flow channel 202 being provided in the double-layer pipe joint 2;

[0066] The top end of the downflow channel 201 is connected to the annulus between the upper outer layer pipe 1 and the separator sleeve 23, and the bottom end of the downflow channel 201 is connected to the annulus between the lower outer layer pipe 3 and the suspension joint 21;

[0067] The top end of the upward flow channel 202 is communicated with the interior of the separator sleeve 23 , and the bottom end of the upward flow channel 202 is communicated with the interior of the suspension joint 21 .

[0068] This embodiment further includes an upper joint 24 connected to the top of the separator sleeve 23 and a cyclone 22 disposed inside the separator sleeve 23; the cyclone 22 is provided with a tangential inlet 2201 on the side, an overflow port 2202 on the top, and an underflow port 2203 on the bottom. The tangential inlet 2201 is communicated with the interior of the separator sleeve 23, the overflow port 2202 passes through the upper joint 24, and the underflow port 2203 is connected to a sand discharge channel 203. The sand discharge channel 203 is located inside the double-layer pipe joint 2 and extends to the side wall of the double-layer pipe joint 2.

[0069] In addition, the outer diameter of the cyclone 22 gradually decreases from top to bottom.

[0070] Example 3:

[0071] A marine hydrate cemented particle collision breaking and separation device, based on Example 2, has a working process comprising:

[0072] In the initial state of not turning on the pump, if Figure 2 As shown, the push shaft 8 is located at the top end of the stroke and the throttle sleeve 19 is located at the bottom end of the stroke.

[0073] After the wellhead pump is started, the high-pressure fluid is pumped from top to bottom to the annulus between the upper outer layer pipe 1 and the upper joint 24, enters the annulus between the lower outer layer pipe 3 and the inner layer pipe assembly through the downward flow channel 201 inside the double-layer pipe joint 2, and continues to flow downward until it enters the downhole power drill, causing the downhole power drill to rotate, and synchronously performing high-pressure jet crushing on the seabed hydrate during the drilling process.

[0074] The hydrate slurry obtained by drilling and high-pressure jet crushing enters the lower joint 4 under the action of lifting, and then enters the annulus between the lower inner layer pipe 5 and the breaker sleeve 6, enters the hollow flow channel inside the breaker sleeve 6 through the jet hole 601 of the breaker sleeve 6, and then passes through the hollow flow channel inside the push shaft 8, the hollow flow channel inside the piston head 11, the hollow flow channel inside the middle inner layer pipe 12, the hollow flow channel inside the inner sleeve 17, the hollow flow channel inside the throttling sleeve 19 and the hollow flow channel inside the suspension joint 21 in turn, and then enters the separator sleeve 23 through the upward flow channel 202 of the double-layer pipe joint 2, and then enters the separator 22 through the tangential inlet 2201. The separated mud and sand enter the sand discharge channel 203 through the bottom flow port 2203 and are discharged. The separated hydrate enters the internal flow channel of the upper joint 24 through the overflow port 2202 and continues to be transported upward to the next link.

[0075] In the above process, the following collision and gel breaking process is automatically completed:

[0076] When the upward-returning hydrate slurry passes through the throttling sleeve 19, a pressurized area is formed at the lower end of the throttling hole 1901 and a pressure drop area is formed at the upper end of the throttling hole 1901 due to the throttling pressure reduction, resulting in a pressure difference between the upper and lower end faces of the throttling sleeve 19. The high-pressure fluid at the lower end pushes the throttling sleeve 19 to move upward and compresses the second elastic member 18; at the same time, the high-pressure fluid pushes the piston head 11 to move downward, and the piston head 11 pushes the driving shaft 8 downward to move and compress the first elastic member 10, pushing the shaft 8 to press against the inner wall of the rubber-breaking sleeve 6 and squeeze the rubber-breaking sleeve 6 cavity downward; during this process, the throttling sleeve 19 always blocks the communication between the pressure relief hole 1701 and the inside of the inner sleeve 17.

[0077] When the throttle sleeve 19 continues to move upward to the top of the stroke, the bottom end of the throttle sleeve 19 moves to above the pressure relief hole 1701. Figure 1 As shown, at this time, the pressure relief hole 1701 is connected to the interior of the inner sleeve 17, the area below the throttling sleeve 19 is depressurized, and the high-pressure fluid returns through the pressure relief hole 1701 and the pressure relief annulus; therefore, the pressure difference above and below the throttling sleeve 19 quickly disappears, and the compressed second elastic member 18 releases its elastic force, pushing the throttling sleeve 19 to move axially downward; at the same time, the compressed first elastic member 10 releases its elastic force, pushing the piston head 11 to drive the driving shaft 8 to move axially upward, and the driving shaft 8 moves upward against the inner wall of the breaking sleeve 6, forming a suction effect in the cavity of the breaking sleeve 6. Under the action of the suction force, the recovered hydrate slurry is radially ejected through the jet holes 601 of the breaking sleeve 6 into the hollow flow channel of the breaking sleeve 6. Since the jet holes 601 are symmetrically arranged in the radial direction, the fluid injected will collide with each other, and under the action of the collision force, the hydrate cementing particles are broken and dispersed.

[0078] The above collision breaking process is circulated, and the driving shaft 8 can automatically realize axial reciprocating motion inside the breaking sleeve 6, so that the recovered hydrate slurry continuously undergoes jet collision under the action of suction to achieve the collision breaking effect until the pump is stopped at the wellhead.

[0079] Those skilled in the art should understand that the up / top direction in this application refers to the direction toward the wellhead after the device enters the well; conversely, the down / bottom direction in this embodiment refers to the direction toward the bottom of the well after the device enters the well.

[0080] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0081] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises", or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In addition, the term "connected" as used in this document, unless otherwise specified, may refer to a direct connection or an indirect connection via other components.

Claims

1. A marine hydrate cementation particle collision breaking and separation device, comprising a lower outer layer tube (3), and an inner layer tube assembly located inside the lower outer layer tube (3), characterized in that: The inner layer tube assembly comprises a lower inner layer tube (5); a rubber-breaking sleeve (6) is arranged in the lower inner layer tube (5); the bottom of the rubber-breaking sleeve (6) is closed, and a plurality of radially opposite jet holes (601) are provided on the side wall of the rubber-breaking sleeve (6); an annulus is provided between the rubber-breaking sleeve (6) and the lower inner layer tube (5); and the assembly further comprises a driving shaft (8) that is slidably fitted inside the rubber-breaking sleeve (6) and is used to drive the driving shaft (8) to perform axial reciprocating motion; The inner layer tube assembly further comprises an intermediate joint (9) connected above the lower inner layer tube (5), and a middle inner layer tube (12) connected above the intermediate joint (9); The driving mechanism comprises a piston head (11) axially slidingly fitted in the middle inner tube (12), a first elastic member (10) connected between the piston head (11) and the intermediate joint (9), and an excitation component for generating pressure fluctuations in the space inside the middle inner tube (12) and at the top of the piston head (11); the piston head (11) is connected to the driving shaft (8); The inner layer tube assembly further includes an upper inner layer tube (14) connected above the middle inner layer tube (12); The excitation assembly comprises an inner sleeve (17) arranged inside the upper inner tube (14), a throttling sleeve (19) axially slidingly fitted in the inner sleeve (17), and a second elastic member (18) connected between the throttling sleeve (19) and the inner sleeve (17), wherein the throttling sleeve (19) is used to generate a throttling pressure drop from bottom to top; The throttling sleeve (19) includes a main cavity (1903), a diameter-reducing cavity (1902), a throttling hole (1901), and a diameter-reducing hole (1904) that are sequentially connected from bottom to top; the inner diameter of the throttling hole (1901) is smaller than the inner diameter of the main cavity (1903); the inner diameter of the diameter-reducing cavity (1902) gradually decreases from bottom to top; and the inner diameter of the diameter-reducing hole (1904) gradually increases from top to bottom; A pressure relief annulus is provided between the inner sleeve (17) and the upper inner tube (14); a plurality of pressure relief holes (1701) are provided on the side wall of the inner sleeve (17), and the pressure relief holes (1701) are connected to the pressure relief annulus; When the throttling sleeve (19) is located at the top of the stroke, the pressure relief hole (1701) is in communication with the interior of the inner sleeve (17); When the throttling sleeve (19) is located at the bottom of the stroke, the pressure relief hole (1701) is not connected to the interior of the inner sleeve (17).

2. The marine hydrate cementing particle collision breaking and separation device according to claim 1 is characterized in that: The outer diameter of the driving shaft (8) is equal to the inner diameter of the rubber-breaking sleeve (6); When the driving shaft (8) is at the top of the stroke, all the jet holes (601) are in communication with the interior of the rubber-breaking sleeve (6); When the driving shaft (8) is located at the bottom of the stroke, part of the jet holes (601) are not connected to the interior of the rubber-breaking sleeve (6).

3. The marine hydrate cementing particle collision breaking and separation device according to claim 1 is characterized in that: The inner layer pipe assembly further comprises a hanging joint (21) connected above the upper inner layer pipe (14); the pressure relief annulus is communicated with the interior of the hanging joint (21).

4. The marine hydrate cementing particle collision breaking and separation device according to claim 1, characterized in that: It also includes a double-layer pipe joint (2) connected to the top of the lower outer layer pipe (3) and the inner layer pipe assembly, an upper outer layer pipe (1) connected above the double-layer pipe joint (2) and a separator sleeve (23), wherein the separator sleeve (23) is located inside the upper outer layer pipe (1); a downward flow channel (201) and an upward flow channel (202) are provided in the double-layer pipe joint (2); The top end of the downward flow channel (201) is in communication with the annulus between the upper outer layer pipe (1) and the separator sleeve (23), and the bottom end of the downward flow channel (201) is in communication with the annulus between the lower outer layer pipe (3) and the inner layer pipe assembly; The top end of the upward flow channel (202) is in communication with the interior of the separator sleeve (23), and the bottom end of the upward flow channel (202) is in communication with the interior of the inner layer pipe assembly.

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