Tool for screen hanging and sandstone filling

Abstract

This invention discloses a tool for suspending and filling a screen tube with sand and gravel, wherein: the upper end of the internal tube assembly extends into the interior of the upper connector and is threadedly fixedly connected to the upper connector; the internal tube assembly is provided with a first sand filling hole, and the internal tube assembly is detachably provided with a sealing sleeve and a first sealing ball for sealing the first sand filling hole at the first sand filling hole; the upper end of the piston cylinder is sleeved outside the upper connector and threadedly fixed to the upper connector, the piston is sleeved outside the internal tube assembly, and the piston, upper connector, internal tube assembly and piston cylinder form a hydraulic cavity, and the internal tube assembly is provided with an inlet hole communicating with the hydraulic cavity. The working fluid enters the hydraulic cavity through the inlet hole to drive the piston downward, the downward movement of the piston drives the pressure ring to cut off the setting pin, thereby driving the locking ring and the protective sleeve downward, the rubber sleeve is compressed by the downward movement of the protective sleeve and expands to the inner wall of the sleeve, the upper cone is driven by the downward movement of the protective sleeve to approach the lower cone and through the mating part with the cone surface, drives multiple meshing racks to pass through the clearance hole and bite into the inner wall of the sleeve.

Description

Technical Field

[0001] This invention relates to the field of drilling equipment design technology, and in particular to a tool for suspending screen pipes and filling them with sand and gravel. Background Technology

[0002] Screen pipes are crucial components in oil production. After cementing, perforations are made in the casing at a predetermined depth to connect oil seepage channels in the formation. The screen pipe is installed inside the casing at the predetermined depth. During crude oil production, crude oil flows from the seepage channels, passes through the perforations in the casing, and enters the space between the casing and the screen pipe. It then passes through even smaller perforations in the screen pipe and finally is extracted to the surface.

[0003] The diameter of the holes on the screen tube is smaller than that on the casing, so the screen tube can filter sand in the crude oil, preventing sand from entering the screen tube and ultimately improving the quality of the produced crude oil.

[0004] However, because the sand particles in crude oil are of different sizes, they are trapped between the screen tube and the casing. Over time, the sand particles of different sizes will form a dense sand layer between the screen tube and the casing, which will eventually block the crude oil in the seepage channel from passing through, making it difficult for crude oil to enter the screen tube and thus reducing crude oil production.

[0005] To address this issue, the relevant technology involves a tool capable of filling the space between the screen and the casing with uniformly sized sand and gravel. However, the screen needs to be fixed inside the casing at a predetermined depth using a specialized hanger. After the screen is suspended, a specialized sand and gravel filling tool is required to fill the space between the screen and the casing. In other words, the relevant technology requires different equipment for screen suspension and sand and gravel filling, necessitating multiple insertions and removals of the equipment from the wellbore, resulting in low operational efficiency. Summary of the Invention

[0006] This invention discloses a tool for suspending and filling screen tubes with sand and gravel, in order to solve the problem that the suspension of screen tubes and filling with sand and gravel in related technologies require different equipment, resulting in low work efficiency.

[0007] To address the aforementioned technical problems, the present invention discloses the following technical solutions:

[0008] A tool for suspending and filling a screen tube with sand and gravel is used to fix the screen tube and the sleeve and to fill the internal annulus formed between the screen tube and the sleeve with sand and gravel of uniform particle size. The tool for suspending and filling a screen tube with sand and gravel includes an upper connector, a piston cylinder, a piston, an internal tube assembly and an external tube assembly.

[0009] The upper end of the internal tube assembly extends into the interior of the upper connector and is threadedly fixedly connected to the upper connector; the internal tube assembly is provided with a first sand filling hole, and the internal tube assembly is detachably provided with a sealing sleeve for sealing the first sand filling hole and a first sealing ball for sealing the sealing sleeve at the first sand filling hole;

[0010] The upper end of the piston cylinder is sleeved outside the upper connector and threadedly fixed to the upper connector. The piston is sleeved outside the internal tube assembly. The piston, the upper connector, the internal tube assembly and the piston cylinder form a hydraulic cavity. The internal tube assembly has an inlet hole that communicates with the hydraulic cavity.

[0011] The external tube assembly includes a pressure ring, a sheath, a setting pin, a central tube, a lower cone, an upper cone, a release connector, a rubber sleeve, a locking ring, a slip cover, slips, and a first elastic element. The upper end of the central tube is detachably connected to the internal tube assembly. The lower cone is fitted outside the lower end of the central tube and is fixedly connected to the lower end of the central tube. The upper end of the pressure ring extends between the piston cylinder and the internal tube assembly and is used to cooperate with the piston to move downward with the piston. The lower end of the pressure ring is fitted outside the upper end of the release connector and is fixedly connected to the release connector through the setting pin. The release connector is fitted outside the upper end of the central tube and is fixedly connected to the central tube. The upper end of the sheath is fitted outside the lower end of the pressure ring and is fixedly connected to the lower end of the pressure ring. The locking ring is fitted outside the release connector.

[0012] The upper cone is slidably fitted outside the central tube, and the rubber sleeve is slidably fitted outside the central tube and located between the sheath and the upper cone;

[0013] The lower end of the slip cover is sleeved on the upper end of the lower cone and fixedly connected to the upper end of the lower cone. The upper end of the slip cover is sleeved on the upper cone. The upper cone and the slip cover are slidably fitted. The slip is disposed between the lower cone and the upper cone. The slip includes a plurality of conical mating parts distributed circumferentially along the central tube and a meshing rack connected to the conical mating parts. The slip cover has a plurality of clearance holes to avoid the plurality of meshing racks. The first elastic element is disposed between the slip cover and the conical mating parts.

[0014] When the working fluid flows into the internal tubing and reaches the first sealing ball, entering the first pressurized state, the working fluid enters the hydraulic chamber through the inlet hole to drive the piston downward. The downward movement of the piston drives the pressure ring to cut off the setting pin, thereby driving the locking ring and the sheath downward. The rubber sleeve is compressed by the downward-moving sheath and expands to the inner wall of the sleeve. The upper cone is driven by the downward movement of the sheath to approach the lower cone and, through its engagement with the cone surface, drives the plurality of meshing racks to pass through the corresponding clearance holes and bite against the inner wall of the sleeve. The locking ring and the unsealing connector mesh in the opposite direction to the downward movement of the locking ring to maintain the position of the sheath after it has moved downward.

[0015] The first elastic element is used to drive the engagement rack to retract from the corresponding clearance hole into the slip cover when the upper cone moves upward and away from the lower cone.

[0016] In one embodiment, the external pipe assembly further includes an upper filling sleeve, a lower filling sleeve, a sealing assembly, and a sliding sleeve switch valve; the upper end of the upper filling sleeve is fitted onto the lower end of the lower cone and threadedly fixed to the lower end of the lower cone; the sealing assembly is sealed between the upper filling sleeve and the internal pipe assembly; the lower end of the upper filling sleeve is fitted onto the upper end of the lower filling sleeve and fixedly connected to the upper end of the lower filling sleeve; the lower filling sleeve has a second sand filling hole, which is opposite to the first sand filling hole; the sliding sleeve switch valve is located between the internal pipe assembly and the lower filling sleeve and is kept in an open state by friction with the internal pipe assembly; when the internal pipe assembly is separated from the external pipe assembly, the internal pipe assembly drives the sliding sleeve switch valve to switch to a closed state that blocks the first and second sand filling holes through frictional engagement with the sliding sleeve switch valve.

[0017] In one embodiment, the external tube assembly further includes a second elastic element, an upper safety connector, and a lower safety connector; the lower end of the lower filling sleeve is sleeved outside the upper end of the upper safety connector and is threadedly fixedly connected to the upper end of the upper safety connector, the upper end of the lower safety connector is sleeved outside the lower end of the upper safety connector and is threadedly fixedly connected to the lower end of the upper safety connector, and the lower end of the lower safety connector is used to be fixedly connected to the screen tube.

[0018] The upper end of the upper safety connector protrudes from the inner wall of the lower filling sleeve. The second elastic element is elastically positioned between the end face of the upper safety connector and the sliding sleeve switch valve. The second elastic element is used to assist in driving the sliding sleeve switch valve to switch to the closed state.

[0019] In one embodiment, the outer wall of the sliding sleeve switch valve is provided with a connecting groove, and the internal pipe assembly includes an elastic sleeve located below the sliding sleeve switch valve. The elastic sleeve includes a connecting protrusion protruding from its outer wall. When the internal pipe assembly is separated from the external pipe assembly, the connecting protrusion can extend into the connecting groove and connect with it by elastic deformation when passing through a position opposite to the connecting groove. The sliding sleeve switch valve can be switched to the closed state by pulling the internal pipe assembly.

[0020] In one embodiment, the inner wall of the lower end of the upper filling sleeve is provided with a positioning protrusion, the upper end of the upper filling sleeve has a stepped threaded hole, the stepped threaded hole includes a small diameter threaded hole and a large diameter threaded hole, the lower end of the lower cone is threadedly fixedly connected to the large diameter threaded hole, the outer tube assembly also includes a locking ring, the locking ring is threadedly engaged with the small diameter threaded hole, a positioning space is formed between the locking ring and the positioning protrusion, and the sealing assembly is sleeved outside the upper filling sleeve and positioned between the positioning protrusion and the locking ring.

[0021] In one embodiment, the upper end of the upper filling sleeve and the lower end of the lower cone, the lower end of the upper filling sleeve and the upper end of the lower filling sleeve, and the lower end of the lower filling sleeve and the upper safety connector are all fixedly connected by fastening screws.

[0022] In one embodiment, the internal tube assembly includes a piston rod, a connecting sleeve, a flexible sleeve, a locking cap ring, a first spring seat, a second spring seat, a third elastic element, and an internal tube assembly body;

[0023] The upper end of the piston tube extends to the inner wall of the upper connector and is threadedly fixed to the upper connector. The liquid inlet is opened on the piston tube. The upper end of the connecting sleeve is threadedly fixed to the lower end of the piston tube. The lower end of the connecting sleeve is sleeved outside the upper end of the flexible sleeve and forms an annular groove between it and the upper end of the flexible sleeve. A portion of the locking cap ring extends into the annular groove and is threadedly fastened to the lower end of the connecting sleeve. The upper end of the flexible sleeve has an annular protrusion for forming the bottom wall of the annular groove. The annular protrusion overlaps with the locking cap ring. The inner wall of the locking cap ring and the inner wall of the lower end of the connecting sleeve are rotatably engaged with the flexible sleeve.

[0024] The upper end of the internal tube assembly body is fixedly connected to the lower end of the connecting sleeve by threads. The first spring seat is sleeved outside the connecting sleeve and makes limiting contact with the end face of the lower end of the piston tube. The second spring seat is sleeved outside the connecting sleeve. The outer wall of the connecting sleeve has an annular limiting surface facing the end face of the lower end of the piston tube. The second spring seat and the connecting sleeve are circumferentially limited by a spline engagement. The second spring seat can slide along the axial direction of the connecting sleeve. The third elastic element is sleeved outside the connecting sleeve and elastically positioned between the first spring seat and the second spring seat. The second spring seat makes limiting contact with the annular limiting surface.

[0025] The second spring seat is threadedly fixed to the upper end of the central tube;

[0026] When the upper connector drives the piston rod, the connecting sleeve and the locking cap ring to rotate relative to the movable sleeve, the second spring seat moves axially along the connecting sleeve while following the rotation of the upper connector to compress the third elastic element and achieve separation from the upper end of the central tube. The internal tube assembly is disconnected from the external tube assembly by separating the internal tube assembly from the central tube.

[0027] The internal tube assembly body is provided with the first sand filling hole, the sealing sleeve and the first sealing ball are disposed inside the internal tube assembly body, and the internal tube assembly body is in sealing contact with the sealing component.

[0028] In one embodiment, the internal tube assembly body includes an extension tube, a connecting tube, a double-through body, a ball seat cap, a fourth elastic element, a shear screw, a plug, a connecting tube, a ball stopper, a second sealing ball, and a lower ball seat;

[0029] The upper end of the extension tube is threadedly fixedly connected to the lower end of the flexible sleeve, and the lower end of the extension tube is threadedly fixedly connected to the upper end of the connecting tube. The double-through body includes an inner cylinder and an outer cylinder. The outer cylinder is sleeved outside the inner cylinder, and a liquid connection channel is formed between the two. The first sand filling hole passes through the inner cylinder and the outer cylinder and is isolated from the liquid connection channel.

[0030] The upper end of the inner cylinder extends beyond the upper end of the outer cylinder and is threadedly fixedly connected to the lower end of the connecting pipe. The lower end of the outer cylinder extends beyond the lower end of the inner cylinder and is threadedly fixedly connected to the connecting pipe. The sealing sleeve is fixedly connected to the inner and outer cylinders via the shear screw. The plug is fixed to the lower end of the inner cylinder. The ball stopper is fixed inside the connecting pipe via a threaded engagement. The upper end of the lower ball seat is threadedly fixedly connected to the lower end of the connecting pipe. The second sealing ball can engage with the lower ball seat in a direction away from the ball stopper, and the second sealing ball can engage with the ball stopper in a direction away from the lower ball seat. When the second sealing ball engages with the ball stopper, the lower ball seat communicates with the liquid connection channel through the ball stopper.

[0031] The ball seat cap is fixed inside the sealing sleeve. The fourth elastic element is elastically disposed between the ball seat cap and the first sealing ball. The fourth elastic element is used to elastically abut the first sealing ball against the sealing mating seat of the sealing sleeve. The ball seat cap, the plug and the ball stopper are all provided with through holes that coincide with or are parallel to the axial direction of the internal tube assembly.

[0032] In one embodiment, the internal tube assembly further includes a flushing connector, the upper end of which is threadedly fixedly connected to the lower ball seat, and the lower end of which is threadedly fixedly connected to the upper end of the flushing tube extending into the screen tube.

[0033] In one embodiment, the connecting pipe includes a pipe body and an annular rib disposed within the pipe body. The upper end of the inner cylinder is threadedly fixedly connected to the lower end of the pipe body, and the upper end of the pipe body is threadedly fixedly connected to the lower end of the extension pipe. The lower end of the extension pipe and the upper end of the inner cylinder both extend into the pipe body and abut against the opposite two surfaces of the annular rib.

[0034] The technical solutions disclosed in the embodiments of the present invention have the following technical effects:

[0035] As can be seen from the above working process, the tool for suspending and filling screen tubes with sand and gravel disclosed in the embodiments of the present invention can not only suspend the screen tubes, but also directly fill the internal annulus between the screen tubes and the sleeve with sand and gravel of uniform particle size after the screen tubes are suspended to solve the problem of low oil extraction efficiency caused by the formation of a dense sand layer. It can be seen that the tool for suspending and filling sand and gravel disclosed in the embodiments of the present invention can avoid the problem of low operation efficiency caused by using different equipment for suspending screen tubes and filling sand and gravel in related technologies. Attached Figure Description

[0036] Figures 1 to 5These are schematic diagrams of the sequentially connected parts of the tool for suspending screen tubes and filling sand and gravel disclosed in the embodiments of the present invention.

[0037] The components in the diagram are labeled as follows:

[0038] 10-Upper connector, 21-Piston cylinder, 22-Piston,

[0039] 30-Internal tube assembly, 31-Piston column tube, 32-Connecting sleeve, 321-Annular limiting surface, 33-Swivel sleeve, 331-Annular protrusion, 34-Locking cap ring, 35-First spring seat, 36-Second spring seat, 37-Third elastic element, 38-Internal tube assembly body, 381-Extension tube, 382-Connecting tube, 3821-Pipe body, 3822-Annular rib, 383-Double body, 3831-Inner cylinder, 3832-Outer cylinder, 384-Ball seat cap, 385-Fourth elastic element, 386-Shear screw, 387-Plug, 388-Connecting tube, 389-Ball stopper, 390-Second sealing ball, 391-Lower ball seat, 39-Punching connector, 310-Elastic sleeve, 311-Connecting protrusion

[0040] 40-External tube assembly, 41-Pressure ring, 401-Connecting hole, 42-Sheath, 43-Setting pin, 44-Lower safety connector, 45-Center tube, 46-Lower cone, 47-Upper cone, 48-Unsealing connector, 49-Roll sleeve, 410-Locking ring, 411-Slip cover, 412-Slip, 4121-Conical mating part, 4122-Interlocking rack, 413-First elastic element, 414-Upper filling sleeve, 4141-Positioning protrusion, 415-Lower filling sleeve, 416-Sealing assembly, 417-Locking ring, 418-Sliding sleeve switch valve, 4181-Connecting groove, 419-Second elastic element, 420-Upper safety connector.

[0041] 51-Blocking sleeve, 511-Blocking mating seat, 52-First blocking ball,

[0042] 01-First sand filling hole, 02-Hydraulic cavity, 03-Liquid inlet hole, 04-Second sand filling hole. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0044] The technical solutions disclosed in the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0045] Please refer to Figures 1 to 5 This invention discloses a tool for suspending and filling a screen tube with sand and gravel. This tool is used to fix the screen tube to a sleeve, thereby suspending the screen tube within the sleeve. Furthermore, after the screen tube is suspended, it is used to fill the internal annulus formed between the screen tube and the sleeve with sand and gravel of uniform particle size.

[0046] The tool for suspending and filling sand and gravel in the screen tube disclosed in the embodiments of the present invention includes an upper connector 10, a piston cylinder 21, a piston 22, an internal tube assembly 30, and an external tube assembly 40.

[0047] The upper connector 10 is the connecting piece for the entire screen suspension and sand-filling tool to connect with the tubing. It also forms the basis for setting up other components of the tool. Specifically, the upper connector 10 is a hollow threaded connector that connects to the tubing via a threaded engagement. After connection, during tubing descent, the tubing pulls the entire screen suspension and sand-filling tool down into the wellbore. In this paper, the wellbore is a cylindrical structure formed by sequentially connecting casing pipes. After the tubing is connected to the upper connector 10, communication between the tubing and the entire screen suspension and sand-filling tool is achieved, enabling the input of subsequent working fluids (such as water or water carrying sand).

[0048] Both piston cylinder 21 and piston 22 are cylindrical structures. The upper end of piston cylinder 21 is sleeved outside upper connector 10, and the upper end of piston cylinder 21 is threadedly fixed to upper connector 10. The inner tube assembly 30 and the outer tube assembly 40 are nested, and both the inner tube assembly 30 and the outer tube assembly 40 are important components of the tool for screening, suspending, and filling sand and gravel disclosed in the embodiments of this application.

[0049] The upper end of the internal tube assembly 30 extends into the interior of the upper connector 10 and is threadedly fixed to the upper connector 10. The internal tube assembly 30 is provided with a first sand filling hole 01, which is used to fill sand and gravel into the internal annulus between the screen tube and the sleeve after the subsequent screen tube suspension is completed. The internal tube assembly 30 is detachably provided with a sealing sleeve 51 and a first sealing ball 52 at the first sand filling hole 01 to seal the first sand filling hole 01. Specifically, the first sealing ball 52 makes limiting contact with the sealing sleeve 51 in a direction away from the upper connector 10, and simultaneously seals the sealing sleeve 51.

[0050] Piston 22 is fitted outside the internal tube assembly 30. As mentioned above, both piston cylinder 21 and piston 22 are cylindrical structures. The upper end of piston cylinder 21 is fitted outside the upper connector 10, and piston cylinder 21 is also fitted outside the upper end of the internal tube assembly 30, thus forming an annular gap between piston cylinder 21 and internal tube assembly 30. Piston 22 is fitted outside the internal tube assembly 30. Piston 22, upper connector 10, internal tube assembly 30, and piston cylinder 21 form a hydraulic cavity 02. The internal tube assembly 30 has an inlet hole 03 that communicates with the hydraulic cavity 02. During the suspension of the screen tube, the working fluid (e.g., water) transported by the oil pipe enters the upper connector 10 and enters the hydraulic cavity 02 through the inlet hole 03. Once the working fluid enters the hydraulic cavity 02, the piston 22 will move downward along the internal tube assembly 30 under the hydraulic drive of the working fluid.

[0051] The lower end of the external tube assembly 40 is connected to the screen tube to be suspended. The external tube assembly 40 includes a pressure ring 41, a sheath 42, a setting pin 43, a locking ring 410, a central tube 45, a lower cone 46, an upper cone 47, a release joint 48, a rubber sleeve 49, a slip cover 411, a slip 412, and a first elastic element 413.

[0052] The upper end of the central tube 45 is detachably connected to the internal tube assembly 30. The lower cone 46 is sleeved outside the lower end of the central tube 45 and is fixedly connected to the lower end of the central tube 45, meaning that the lower cone 46 cannot move relative to the central tube 45. Specifically, the lower cone 46 is fixedly connected to the lower end of the central tube 45 by a threaded connection.

[0053] The upper end of the pressure ring 41 extends between the piston cylinder 21 and the internal tube assembly 30, and is used to cooperate with the piston 22 to move downward with the piston 22. Specifically, after the working fluid enters the hydraulic chamber 02, with the continuous input of the working fluid, the pressure of the working fluid in the hydraulic chamber 02 increases, which in turn drives the piston 22 to move downward. The downward movement of the piston 22 will hit the pressure ring 41, which will then push the pressure ring 41 to move downward together.

[0054] The lower end of the pressure ring 41 is sleeved over the upper end of the unsealing connector 48 and fixedly connected to the unsealing connector 48 via a setting pin 43. The unsealing connector 48 is also a cylindrical structure, sleeved over the upper end of the central tube 45 and fixedly connected to the central tube 45. Specifically, the unsealing connector 48 and the central tube 45 can be fixedly connected by a threaded connection or by a fastening screw; this embodiment of the invention is not limited to this.

[0055] The upper end of the sheath 42 is fitted over the lower end of the pressure ring 41 and is fixedly connected to the lower end of the pressure ring 41. Specifically, the upper end of the sheath 42 and the lower end of the pressure ring 41 are fixedly connected by a threaded connection.

[0056] The locking ring 410 is fitted outside the unsealing connector 48. When the locking ring 410 is subjected to a driving force in the same direction as the downward movement, it can move downward along the unsealing connector 48. The locking ring 410 will only move downward along the unsealing connector 48 when subjected to driving force; it cannot move backward or upward during the downward movement. The engagement between the locking ring 410 and the unsealing connector 48 is similar to a ratchet and pawl mechanism. Various structures can achieve this. For example, the outer surface of the unsealing connector 48 can have an inclined toothed structure, similar to barbs. When the locking ring 410 is subjected to force, it will move downward. If the angle between the downward direction of the locking ring 410 and the inclined direction of the toothed structure is small (e.g., an acute angle), then the toothed structure will not cause much interference during the downward movement of the locking ring 410. The locking ring 410, when subjected to a certain driving force, can overcome the resistance of the toothed structure and thus move downward. Conversely, when the locking ring 410 moves upward, the toothed structure will cause greater resistance, making it more difficult for the locking ring 410 to move upward. In this embodiment of the invention, the locking ring 410 performs a locking function. After the locking ring 410 moves downward, it can perform a locking function to ensure that the suspension connection of the screen tube described later is maintained after suspension.

[0057] The upper cone 47 is slidably fitted outside the central tube 45, and the rubber sleeve 49 is slidably fitted outside the central tube 45. The rubber sleeve 49 expands after compression deformation, allowing it to tightly adhere to the inner wall of the opposite sleeve, thus sealing the inner wall of the sleeve at the opposite position. Ultimately, this seals the tool and sleeve used for suspending the screen tube and filling sand and gravel, isolating the tool and sleeve in the upper and lower annular spaces of the rubber sleeve 49 respectively. The internal annular space between the screen tube and the sleeve mentioned above is substantially connected to the lower annular space. The rubber sleeve 49 is located between the sheath 42 and the upper cone 47.

[0058] The lower end of the slip cover 411 is fitted onto the upper end of the lower cone 46 and is fixedly connected to the upper end of the lower cone 46. For example, the lower end of the slip cover 411 can be fixedly connected to the lower cone 46 by a threaded connection. The upper end of the slip cover 411 is fitted onto the upper cone 47, and the upper cone 47 and the slip cover 411 are in sliding fit. Specifically, the upper cone 47 can slide axially relative to the slip cover 411. It should be noted that, in this article, axial direction refers to the axial direction of the tool used for suspending the screen tube and filling sand and gravel, and can also be the axial direction of the internal tube assembly 30 or the axial direction of the external tube assembly 40. In this article, the upward and downward directions are parallel to the axial direction.

[0059] The upper cone 47 and the lower cone 46 are cylindrical structures, with their opposite ends being tapered ends, the surfaces of which are conical. The conical surfaces are essentially wedge-shaped surfaces. A locking mechanism 412 is located between the lower cone 46 and the upper cone 47. The locking mechanism 412 includes multiple conical mating parts 4121 and multiple meshing racks 4122. The multiple conical mating parts 4121 are distributed circumferentially along the central tube 45, and the multiple meshing racks 4122 are connected to corresponding conical mating parts 4121. Specifically, the multiple meshing racks 4122 are fixedly connected to the corresponding conical mating parts 4121. The multiple meshing racks 4122 and the multiple conical mating parts 4121 are fixedly connected in a one-to-one correspondence; this embodiment of the invention is not limited. It should be noted that, in this text, the meshing rack 4122 refers to a structure with multiple meshing teeth arranged in rows; this structure does not perform a transmission function, but only a meshing function.

[0060] The slip cover 411 has multiple clearance holes for accommodating multiple meshing racks 4122, allowing the racks 4122 to extend beyond or retract into the slip cover 411 through the corresponding clearance holes. A first elastic element 413 is disposed between the slip cover 411 and the multiple conical mating parts 4121. The first elastic element 413 can apply a restoring force to the conical mating parts 4121, causing them to move closer to the central tube 45, thereby pulling the meshing racks 4122 through the clearance holes and retracting them into the slip cover 411. The first elastic element 413 can be a coil spring, leaf spring, etc., and the specific type of the first elastic element 413 is not limited in this embodiment of the invention.

[0061] After the meshing rack 4122 extends out of the clearance hole, it can approach the inner wall of the sleeve and, as it continues to extend, it can mesh with the inner wall of the sleeve, thereby realizing the connection between the outer tube assembly 40 and the sleeve, and finally realizing the suspension of the screen tube connected to the lower end of the outer tube assembly 40 on the sleeve.

[0062] A portion of the working process of the tool for suspending screen tubes and filling them with sand and gravel disclosed in this embodiment of the invention is as follows:

[0063] During suspension, the working fluid enters the internal pipe assembly 30 from the oil pipe through the upper connector 10 and flows downwards along the internal pipe assembly 30. When the working fluid flows into the internal pipe assembly 30 and reaches the first sealing ball 52, the pressure of the working fluid drives the first sealing ball 52 to make limited contact with the sealing sleeve 51 in a direction away from the upper connector 10, thereby sealing the sealing sleeve 51. In this case, since the working fluid (e.g., water) cannot continue to flow downwards, it will gradually accumulate in the internal pipe assembly 30, increasing the pressure and entering the first pressure-locked state. In the first pressure-locked state, the working fluid will enter the hydraulic chamber 02 through the inlet hole 03 to drive the piston 22 downwards. It should be noted that the working fluid must be in the first pressure-locked state to drive the piston 22 downwards. When the working fluid enters the internal pipe assembly 30, it can also be considered that a certain amount of working fluid enters the hydraulic chamber 02 through the inlet hole 03, but since the internal pipe assembly 30 can still hold the working fluid, the working fluid entering the hydraulic chamber 02 is insufficient to drive the piston 22 downwards.

[0064] Next, the downward movement of piston 22 drives pressure ring 41 to cut off setting pin 43, thereby driving locking ring 410 and sheath 42 downward. At this time, the downward movement of sheath 42 is not restricted by release joint 48. Rubber sleeve 49 is compressed by the downward-moving sheath 42 and expands to the inner wall of the sleeve, sealing against the inner wall of the sleeve to form the upper and lower annulus as described above.

[0065] During the compression of the rubber sleeve 49, the sheath 42 also pushes the upper cone 47 downward along the central tube 45 via the rubber sleeve 49. In other words, during this process, the upper cone 47 is driven by the downward movement of the sheath 42 to approach the lower cone 46, and through the contact part 4121 with the cone surface, it drives multiple meshing racks 4122 to pass through corresponding clearance holes and bite against the inner wall of the sleeve, ultimately achieving a suspended connection with the sleeve. Since the lower end of the outer tube assembly 40 is connected to the screen tube, and the meshing racks 4122 are part of the outer tube assembly 40, the outer tube assembly 40 ultimately achieves a suspended connection between the screen tube and the sleeve, thus achieving the suspended installation of the screen tube. Therefore, the tool for suspending screen tubes and filling sand and gravel disclosed in this embodiment of the invention can achieve the suspension of the screen tube.

[0066] Because the locking ring 410 and the unsealing connector 48 engage in the opposite direction to the downward direction of the locking ring 410 (i.e., the upward direction), the position of the sheath 42 after its downward movement is maintained. Maintaining the position of the sheath 42 after its downward movement allows the rubber sleeve 49 to be in a compressed and expanded state, ensuring a tight seal with the sleeve. Simultaneously, it ensures that the upper cone 47 does not move upward but engages with the lower cone 46 to drive the conical mating part 4121 to push the engagement rack 4122 through the clearance hole and engage with the sleeve, ultimately ensuring the maintenance of the suspension.

[0067] The first elastic element 413 is used to drive the meshing rack 4122 to retract from the corresponding clearance hole into the slip cover 411 when the upper cone 47 moves upward and away from the lower cone 46, thereby achieving the separation of the outer tubing assembly 40 from the casing. Of course, the upward movement of the upper cone 47 occurs when the outer tubing assembly 40 needs to be removed from the wellbore as a whole for replacement or maintenance. Once the screen pipe is suspended in place, the outer tubing assembly 40 will remain inside the wellbore.

[0068] The sand and gravel backfilling work takes place after the suspension work is completed. That is, the sand and gravel backfilling work can be carried out after the screen tube suspension is completed. The sand and gravel backfilling process is as follows:

[0069] The working fluid carrying sand and gravel enters the internal pipe assembly 30. As the pressure continues, the working fluid with higher pressure will drive the sealing sleeve 51 to separate from the internal pipe assembly 30, thereby causing the first sealing ball 52 and the sealing sleeve 51 to move downward together. The downward movement of the sealing sleeve 51 will open the seal on the first sand filling hole 01, and the working fluid carrying sand and gravel will flow out from the first sand filling hole 01. Due to the sealing of the rubber sleeve 49, the working fluid carrying sand and gravel can only pass through the external pipe assembly 40 and enter the lower annulus, and then enter the internal annulus between the screen tube and the sleeve to achieve filling in the internal annulus, but will not enter the upper annulus. Of course, during this process, the sand and gravel particles carried in the working fluid are too large to pass through the screen tube and are instead retained in the internal annulus for gradual filling. The working fluid, on the other hand, passes through the screen tube and eventually returns through other channels in the tool disclosed in this application. These other channels are different from the channels through which the working fluid carrying sand and gravel enters the internal annulus, thus preventing them from interfering with each other.

[0070] In current oil production processes, crude oil in the formation carries sand (essentially gravel, but referred to as sand in this text for clarity) of varying particle sizes. This sand passes through the perforations in the casing and enters the annulus between the casing and the screen. Because the perforations in the casing are larger than those in the screen, the screen effectively prevents sand from entering, ensuring crude oil quality. However, the varying particle sizes of the sand in the formation's crude oil allow smaller particles to fill the gaps between larger particles, gradually accumulating in the annulus to form a dense sand layer. Since these dense sand layers have virtually no gaps for oil passage, this significantly reduces the well's crude oil production. In other words, crude oil in the formation cannot pass through the dense sand layer in the annulus and enter the screen.

[0071] The tool disclosed in this application for suspending and filling screen tubes with sand and gravel can fill the internal annulus with uniformly sized sand and gravel during the filling process. This prevents smaller sand and gravel from blocking the gaps between the particles, thus forming a non-dense sand layer within the annulus. This non-dense sand layer prevents sand and gravel of varying sizes from entering the annulus, preventing the formation of a dense sand layer. This non-dense sand layer creates a stable gap for oil passage, allowing crude oil to pass through the gap and into the screen tube, ensuring continuous production of high-quality crude oil. It should be noted that this invention does not limit the specific particle size of the sand and gravel used. Designers can determine the particle size of the sand and gravel based on the crude oil parameters of different oil fields (e.g., the particle size range of sand in the crude oil) to achieve the goal of forming a stable, non-dense sand layer, ultimately achieving the purpose of using sand to block sand.

[0072] As can be seen from the above working process, the tool for suspending and filling screen tubes with sand and gravel disclosed in the embodiments of the present invention can not only suspend the screen tubes, but also directly fill the internal annulus between the screen tubes and the sleeve with sand and gravel of uniform particle size after the screen tubes are suspended to solve the problem of low oil extraction efficiency caused by the formation of a dense sand layer. It can be seen that the tool for suspending and filling sand and gravel disclosed in the embodiments of the present invention can avoid the problem of low operation efficiency caused by using different equipment for suspending screen tubes and filling sand and gravel in related technologies.

[0073] In one embodiment, the external pipe assembly 40 disclosed in this invention may further include an upper filling sleeve 414, a lower filling sleeve 415, a sealing assembly 416, and a sliding sleeve switch valve 418.

[0074] The upper end of the upper filling sleeve 414 is fitted onto the lower end of the lower cone 46 and threadedly fixed to the lower end of the lower cone 46. The sealing assembly 416 is disposed between the upper filling sleeve 414 and the inner tube assembly 30, thereby preventing communication between the upper tube assembly gap and the lower tube assembly gap formed on both sides of the sealing assembly 416 between the outer tube assembly 40 and the inner tube assembly 30. Both the upper and lower tube assembly gaps are gaps between the tube assemblies formed between the outer tube assembly 40 and the inner tube assembly 30, with the upper tube assembly gap located above the lower tube assembly gap.

[0075] The lower end of the upper filling sleeve 414 is fitted onto the upper end of the lower filling sleeve 415 and is fixedly connected to the upper end of the lower filling sleeve 415. Optionally, the lower end of the upper filling sleeve 414 and the upper end of the lower filling sleeve 415 are fixedly connected by threads. The lower filling sleeve 415 has a second sand filling hole 04, which is opposite to the first sand filling hole 01. During the sand filling process, the cavity of the internal pipe assembly 30 is sequentially connected to the first sand filling hole 01 and the second sand filling hole 04. The first sand filling hole 01 and the second sand filling hole 04 can be considered to be located on both sides of the gap of the lower pipe assembly and are connected through the gap of the lower pipe assembly. The sealing component 416 effectively prevents the first sand filling hole 01 and the second sand filling hole 04 from being connected to the gap of the upper pipe assembly, thus preventing the working fluid carrying sand and gravel from entering the gap of the upper pipe assembly during the sand filling process. It also ensures the independence and isolation of the gap of the upper pipe assembly when it is used as other flow channels.

[0076] The sliding sleeve switch valve 418 is located between the inner tube assembly 30 and the lower filling sleeve 415, and is kept in the open state by friction with the inner tube assembly 30. When assembling the tool for suspending screen tubes and filling sand and gravel disclosed in the embodiment of the present invention, after the outer tube assembly 40 and the inner tube assembly 30 are assembled, the sliding sleeve switch valve 418 is in the open state due to the assembly clamping force.

[0077] Of course, after the sand and gravel backfilling operation is completed or the backflushing operation mentioned later is completed, only the outer tubing assembly 40 will remain in the wellbore. Other components such as the inner tubing assembly 30, the upper connector 10, the piston 22, and the piston cylinder 21 will be lifted out of the well. During this process, the inner tubing assembly 30 and the outer tubing assembly 40 will separate. Based on this, when the inner tubing assembly 30 separates from the outer tubing assembly 40, the inner tubing assembly 30 can drive the sliding sleeve switch valve 418 to switch to the closed state of blocking the first sand filling hole 01 and the second sand filling hole 04 through the sliding friction with the sliding sleeve switch valve 418. This achieves the isolation of the lumen of the outer tubing assembly 40 from the space between the outer tubing assembly 40 and the casing (including the upper annulus, lower annulus, and internal annulus mentioned above), thereby preventing crude oil from entering the space between the outer tubing assembly 40 and the casing during the subsequent crude oil extraction process.

[0078] In a further embodiment, the external pipe assembly 40 disclosed in this embodiment of the invention may further include a second elastic member 419, an upper safety connector 420, and a lower safety connector 44.

[0079] The lower end of the lower filling sleeve 415 is fitted over the upper end of the upper safety connector 420 and is threadedly fixedly connected to the upper end of the upper safety connector 420. The upper end of the lower safety connector 44 is fitted over the lower end of the upper safety connector 420 and is threadedly fixedly connected to the lower end of the upper safety connector 420. The lower end of the lower safety connector 44 is used for fixed connection to the screen tube. Specifically, the lower end of the lower safety connector 44 can be threadedly fixedly connected to the screen tube.

[0080] The upper end of the upper safety connector 420 protrudes from the inner wall of the lower filling sleeve 415, and the second elastic element 419 is elastically positioned between the end face of the upper safety connector 420 and the sliding sleeve switch valve 418. The second elastic element 419 is used to assist in driving the sliding sleeve switch valve 418 to switch to the closed state. In the assembly of the tool for suspending screen pipes and filling sand and gravel disclosed in the embodiments of the present invention, after the outer pipe assembly 40 and the inner pipe assembly 30 are assembled, the sliding sleeve switch valve 418 is in the open state due to the assembly clamping force. At this time, the assembly clamping force on the sliding sleeve switch valve 418 will also overcome the elastic force of the second elastic element 419, so that the sliding sleeve switch valve 418 is in the open state. When the inner pipe assembly 30 and the outer pipe assembly 40 are separated, the friction force generated by the inner pipe assembly 30 on the sliding sleeve switch valve 418 is combined with the elastic force applied by the second elastic element 419 on the sliding sleeve switch valve 418, so that the sliding sleeve switch valve 418 can switch to the closed state more stably.

[0081] To better ensure that the sliding sleeve switch valve 418 switches to the closed state when the internal pipe assembly 30 and the external pipe assembly 40 separate, in a further embodiment, the outer wall of the sliding sleeve switch valve 418 of the present invention may be provided with a connecting groove 4181. The internal pipe assembly 30 may include an elastic sleeve 310, which may be located below the sliding sleeve switch valve 418. The elastic sleeve 310 may include a connecting protrusion 311 protruding from its outer wall. When the internal pipe assembly 30 and the external pipe assembly 40 separate, the connecting protrusion 311 will move upward with the elastic sleeve 310, and then, when passing a position opposite to the connecting groove 4181, the connecting protrusion 311 will extend into the connecting groove 4181 through elastic deformation and connect with the connecting groove 4181. It should be noted that when the connecting protrusion 311 is misaligned with the connecting groove 4181, it is in a state of being compressed and contracted by the external pipe assembly 40. The sliding sleeve switch valve 418 can be switched to the closed state by pulling the internal pipe assembly 30. Of course, since the connecting protrusion 311 can be elastically deformed, during the process of the sliding sleeve switch valve 418 being closed and the internal pipe assembly 30 continuing to move upward, the connecting protrusion 311 can then be elastically deformed and disengaged from the connecting groove 4181, so as not to affect the subsequent continued upward movement of the internal pipe assembly 30.

[0082] To improve the stability of the sealing assembly 416 during installation, in other embodiments, the inner wall of the lower end of the upper filling sleeve 414 may be provided with a positioning protrusion 4141. The upper end of the upper filling sleeve 414 may have a stepped threaded hole, which may include a small-diameter threaded hole and a large-diameter threaded hole. The lower end of the lower cone 46 may be threadedly fixedly connected to the large-diameter threaded hole. The outer tube assembly 40 may also include a locking ring 417, which is threadedly engaged with the small-diameter threaded hole. A positioning space may be formed between the locking ring 417 and the positioning protrusion 4141. The sealing assembly 416 is sleeved outside the upper filling sleeve 414 and positioned between the positioning protrusion 4141 and the locking ring 417. In this structure, since the two sides of the sealing assembly 416 can be restricted by the positioning protrusion 4141 and the locking ring 417 respectively, the installation position of the sealing assembly 416 is relatively fixed, avoiding sealing problems caused by the movement of the sealing assembly 416.

[0083] To further improve the stability of the connection, in other embodiments, the upper end of the upper filling sleeve 414 is connected to the lower end of the lower cone 46, the lower end of the upper filling sleeve 414 is connected to the upper end of the lower filling sleeve 415, and the lower end of the lower filling sleeve 415 is connected to the upper safety connector 420 by fastening screws. In this structure, they are not only fixedly connected by threaded engagement, but also further fixed by fastening screws to avoid loosening of the fit due to possible relative rotation.

[0084] In this embodiment of the invention, the internal tube assembly 30 may further include a piston rod tube 31, a connecting sleeve 32, a flexible sleeve 33, a locking cap ring 34, a first spring seat 35, a second spring seat 36, a third elastic element 37, and an internal tube assembly body 38.

[0085] The upper end of the piston tube 31 extends into the interior of the upper connector 10 and is threadedly fixedly connected to the upper connector 10, thereby achieving a threaded fixed connection between the upper end of the internal tube assembly 30 and the upper connector 10. In this case, the upper end of the piston tube 31 constitutes the upper end of the internal tube assembly 30. The liquid inlet 03 is opened on the piston tube 31, and the piston 22 is sleeved on the piston tube 31. The piston 22, the upper connector 10, the piston tube 31, and the piston cylinder 21 form a hydraulic cavity 02.

[0086] The upper end of the connecting sleeve 32 is threadedly fixedly connected to the lower end of the piston rod tube 31. The lower end of the connecting sleeve 32 is sleeved outside the upper end of the connecting sleeve 33, forming an annular groove between them. A portion of the locking cap ring 34 extends into the annular groove and is threadedly fastened to the lower end of the connecting sleeve 32. The upper end of the connecting sleeve 33 has an annular protrusion 331 for forming the bottom wall of the annular groove. The annular protrusion 331 overlaps and engages with the locking cap ring 34. The inner wall of the locking cap ring 34 and the interior of the lower end of the connecting sleeve 32 are rotatably engaged with the connecting sleeve 33. This allows the upper connector 10, piston cylinder 21, piston rod tube 31, connecting sleeve 32, locking cap ring 34, and the second spring seat 36 mentioned later to rotate when the oil pipe rotates. However, components at least including the connecting sleeve 33 and the internal tube assembly 30 located downstream of the connecting sleeve 33 will not rotate.

[0087] The internal tube assembly body 38 can be considered as a component of the internal tube assembly 30 located downstream of the connecting sleeve 33. The internal tube assembly body 38 is provided with the first sand filling hole 01, and the sealing sleeve 51 and the first sealing ball 52 are disposed within the internal tube assembly body 38. The internal tube assembly body 38 is in sealing contact with the sealing component 416, thereby achieving the sealing fit between the sealing component 416 and the internal tube assembly 30 as described above. As can be seen from the above, the first sand filling hole 01, the second sand filling hole 04, etc., are all located below the sealing component 416.

[0088] The upper end of the internal tube assembly body 38 is fixedly connected to the lower end of the connecting sleeve 33 by threads. The first spring seat 35 is sleeved outside the connecting sleeve 32 and makes limiting contact with the end face of the lower end of the piston tube 31. The second spring seat 36 is sleeved outside the connecting sleeve 32. The outer wall of the connecting sleeve 32 has an annular limiting surface 321 facing the end face of the lower end of the piston tube 31. The second spring seat 36 and the connecting sleeve 32 are circumferentially limited by a spline engagement. The second spring seat 36 can slide along the axial direction of the connecting sleeve 32. That is, the spline engagement allows the second spring seat 36 to rotate axially with the connecting sleeve 32, but it cannot rotate independently relative to the connecting sleeve 32. Simultaneously, it allows the second spring seat 36 to move axially relative to the connecting sleeve 32.

[0089] The third elastic element 37 is sleeved outside the connecting sleeve 32 and elastically positioned between the first spring seat 35 and the second spring seat 36. The second spring seat 36 is in limiting contact with the annular limiting surface 321. The second spring seat 36 is threadedly fixedly connected to the upper end of the central tube 45. Specifically, the second spring seat 36 extends into the upper end of the central tube 45 and is threadedly fixedly connected to the upper end of the central tube 45. The connection between the second spring seat 36 and the central tube 45 realizes the connection between the internal tube assembly 30 and the external tube assembly 40. Correspondingly, when the connection between the second spring seat 36 and the central tube 45 is released, the connection between the internal tube assembly 30 and the external tube assembly 40 is released, so that when the tubing is pulled through the upper connector 10, the internal tube assembly 30 can be pulled out of the wellbore.

[0090] When the upper connector 10 drives the piston rod tube 31, connecting sleeve 32, and locking cap ring 34 to rotate relative to the movable sleeve 33, the second spring seat 36 rotates along the upper connector 10 and moves axially along the connecting sleeve 32 to compress the third elastic element 37, thereby separating it from the upper end of the central tube 45. The internal tube assembly 30 is disconnected from the external tube assembly 40 by separating the second spring seat 36 from the central tube 45.

[0091] As mentioned above, after the sand and gravel filling operation is completed, the screen pipe suspension and sand and gravel filling operations are also completed, and the internal pipe assembly 30 can then be pulled out of the wellbore. During the sand and gravel filling process, sand and gravel carried by the working fluid may enter the tool for screen pipe suspension and sand and gravel filling disclosed in this application. The sand and gravel may seep between the internal pipe assembly 30 and the external pipe assembly 40, causing them to jam due to the presence of sand and gravel. As mentioned above, the internal pipe assembly 30 and the external pipe assembly 40 are connected through the connection between the second spring seat 36 and the central pipe 45. When the internal pipe assembly 30 and the external pipe assembly 40 are separated, the tubing pulls the internal pipe assembly 30 upward through the upper connector 10. In some abnormal situations, the internal pipe assembly 30 and the external pipe assembly 40 may become stuck due to sand and gravel, or they may be unable to separate due to the failure to disconnect the connection between them. This poses a significant challenge to the removal of subsequent components such as the internal pipe assembly 30 from the wellbore after the screen pipe is suspended. However, the tool for suspending the screen pipe and filling sand and gravel disclosed in this application allows the screen pipe and the external pipe assembly 40 to remain in the wellbore after filling or the subsequent backflushing operation. Other components of the tool for suspending the screen pipe and filling sand and gravel, such as the upper connector 10, piston cylinder 21, piston 22, and internal pipe assembly 30, need to be removed from the wellbore to avoid occupying space within the wellbore and ultimately provide conditions for subsequent normal crude oil production.

[0092] Since the working fluid does not carry sand and gravel during the screen tube suspension process, but does during the sand and gravel filling process, the tool for screen tube suspension and sand and gravel filling disclosed in this embodiment of the invention can rotate the upper connector 10, piston column tube 31, piston cylinder 21, connecting sleeve 32, and locking cap ring 34 via an oil pipe after the screen tube suspension is completed and before the sand and gravel filling process. Simultaneously, the second spring seat 36 will also rotate with the connecting sleeve 32. As the second spring seat 36 rotates, the threaded engagement between the second spring seat 36 and the upper end of the central tube 45 will be released, thereby allowing the second... As the connecting sleeve 32 rotates, the spring seat 36 moves along the axial direction of the connecting sleeve 32 toward the first spring seat 35 until the second spring seat 36 is completely separated from the central tube 45. During this process, the third elastic element 37 is compressed by the second spring seat 36. The third elastic element 37 elastically connects the first spring seat 35 and the second spring seat 36, while the first spring seat 35 is sleeved outside the connecting sleeve 32, thereby ensuring that the second spring seat 36 is connected to the connecting sleeve 32 through the third elastic element 37 and the first spring seat 35, and thus realizes the connection between the second spring seat 36 and other components of the internal tube assembly 30.

[0093] The tool for suspending screen pipes and filling sand and gravel disclosed in this invention can disconnect the internal pipe assembly 30 and the external pipe assembly 40 before the sand and gravel filling operation. If difficulty in lifting the internal pipe assembly 30 into the wellbore occurs, it can be accurately determined that the difficulty in separating the internal pipe assembly 30 and the external pipe assembly 40 is caused by sand and gravel jamming, rather than by the failure to disconnect the internal pipe assembly 30 and the external pipe assembly 40. This allows for pinpointing the problem and facilitating subsequent targeted disassembly.

[0094] Meanwhile, as can be seen from the above working process, during the separation of the inner tube assembly 30 and the outer tube assembly 40, only a few components such as the piston column tube 31, connecting sleeve 32, locking cap ring 34, and second spring seat 36 in the inner tube assembly 30 need to rotate, while the inner tube assembly body 38 below the inner tube assembly 30 will not rotate. This ensures that the inner tube assembly body 38 will not rotate or move relative to the sealing component 416 before the sand filling work begins, thus ensuring sealing performance. It also prevents the sealing problem caused by sand carried in the working fluid entering the sealing surface during subsequent sand filling due to relative movement between the sealing component 416 and the inner tube assembly body 38.

[0095] In a further specific embodiment, the internal pipe assembly body 38 disclosed in the present invention may include an extension pipe 381, a connecting pipe 382, ​​a double-through body 383, a ball seat cap 384, a fourth elastic element 385, a shear screw 386, a plug 387, a connecting pipe 388, a ball stopper 389, a second sealing ball 390, and a lower ball seat 391.

[0096] The upper end of the extension tube 381 is threadedly fixedly connected to the lower end of the connecting sleeve 33, and the lower end of the extension tube 381 is threadedly fixedly connected to the upper end of the connecting tube 382. The double-through body 383 includes an inner cylinder 3831 and an outer cylinder 3832. The outer cylinder 3832 is sleeved outside the inner cylinder 3831, and a liquid connection channel is formed between the two, which can extend from one end of the double-through body 383 to the other end. The outer cylinder 3832 and the inner cylinder 3831 can be an integral structure or a separate structure. This embodiment of the invention is not limited.

[0097] The first sand filling hole 01 connects the inner cylinder 3831 and the outer cylinder 3832 and is isolated from the liquid connection channel. In other words, during the sand filling process, the working fluid containing sand flowing out of the first sand filling hole 01 will not enter the liquid connection channel.

[0098] The upper end of the inner cylinder 3831 extends beyond the upper end of the outer cylinder 3832 and is threadedly fixedly connected to the lower end of the connecting pipe 382. The lower end of the outer cylinder 3832 extends beyond the lower end of the inner cylinder 3831 and is threadedly fixedly connected to the upper end of the connecting pipe 388.

[0099] The sealing sleeve 51 is fixedly connected to the inner cylinder 3831 and the outer cylinder 3832 by shear screws 386. Specifically, the shear screws 386 pass through the outer cylinder 3832 and the inner cylinder 3831 in sequence and are locked in place with the threaded holes on the sealing sleeve 51. When the sealing sleeve 51 is subjected to a preset liquid pressure, the sealing sleeve 51 will cut the shear screws 386, thereby causing the sealing sleeve 51 to drive the first sealing ball 52 and the fourth elastic element 385 downward together, eventually reaching the plug 387, where it is blocked. The plug 387 is fixed to the lower end of the inner cylinder 3831. The ball stopper 389 is fixed inside the connecting pipe 388 by a threaded engagement. The upper end of the lower ball seat 391 is threadedly fixedly connected to the lower end of the connecting pipe 388. The second sealing ball 390 can engage with the lower ball seat 391 for limiting and sealing in a direction away from the ball stopper 389. The second sealing ball 390 can be limited and matched with the ball stopper 389 in a direction away from the lower ball seat 391, but the second sealing ball 390 will not block the ball stopper 389. The ball stopper 389 can still connect the spaces on both sides to ensure the normal flow of working fluid.

[0100] With the second sealing ball 390 and the ball stopper 389 in a limiting engagement, the lower ball seat 391 is connected to the liquid connection channel through the ball stopper 389. The ball seat cap 384 is fixed inside the sealing sleeve 51. The fourth elastic element 385 is elastically disposed between the ball seat cap 384 and the first sealing ball 52. The fourth elastic element 385 is used to elastically abut the first sealing ball 52 against the sealing mating seat 511 of the sealing sleeve 51. The ball seat cap 384, the plug 387, and the ball stopper 389 are all provided with through holes that coincide with or are parallel to the axial direction of the internal pipe assembly 30. Alternatively, the through holes may not coincide with or be parallel to the axial direction. The through holes only need to be able to connect the spaces on the opposite sides of the corresponding components.

[0101] The working process of the tool for suspending screen tubes and filling sand and gravel disclosed in this embodiment of the invention is as follows:

[0102] During the sand and gravel filling process, the working fluid carrying sand and gravel enters the upper connector 10 through the oil pipe, and then passes sequentially through the piston rod tube 31, connecting sleeve 32, movable sleeve 33, extension tube 381, connecting tube 382, ​​and inner cylinder 3831, driving the first sealing ball 52 to seal with the sealing mating seat 511 of the sealing sleeve 51. As the working fluid carrying sand and gravel accumulates in the inner cylinder 3831 and cannot flow away, pressure buildup occurs. Since the screen tube has been suspended at this time, the pressure of the working fluid is even greater, thus entering the second pressure buildup state. The working fluid in the second pressure buildup state will drive the sealing sleeve 51 to cut the shear screw 386, thereby causing the sealing sleeve 51 to drive the ball seat cap 384, the fourth elastic element 385, and the first sealing ball 52 downward until they are blocked by the plug 387. It should be noted that when the device descends to the position blocked by the plug 387, the first plugging ball 52 still cooperates with the plugging mating seat 511 to seal the inner cylinder 3831. As the plugging sleeve 51 descends, it releases the seal on the first sand filling hole 01. The working fluid carrying sand and gravel will flow out from the inner cylinder 3831 and then flow through the first sand filling hole 01 and the second sand filling hole 04 in sequence to exit the lower annulus outside the outer pipe assembly 40. Finally, it flows from the lower annulus into the inner annulus between the screen pipe and the sleeve. Because the opening of the screen pipe wall is small, the sand and gravel will be blocked and remain in the inner annulus. The working fluid will pass through the opening in the wall of the screen tube and enter the screen tube. The bottom end of the screen tube is the sealing end. The fluid entering the screen tube will enter the lower ball seat 391 or enter the lower ball seat 391 through the flushing pipe connected to the flushing pipe joint 39 as described later. The working fluid entering the lower ball seat 391 will push the second sealing ball 390 to make it engage with the ball stopper 389. At this time, the limiting sealing engagement between the second sealing ball 390 and the lower ball seat 391 is released. The working fluid passes through the lower ball seat 391 and the ball stopper 389 and enters the lower side of the plug 387 opposite to the first sealing ball 52. The space above the ball stopper 389 in the connecting pipe 388 (i.e., the side facing the first sealing ball 52) is connected to the liquid connection channel. The liquid then enters the upper pipe assembly gap between the outer pipe assembly 40 and the inner pipe assembly 30, located above the sealing assembly 416, until it flows into the upper annular space through the gap between the pressure ring 41 and the piston cylinder 21. Finally, it is transported to the ground from the upper annular space, thus completing the sand and gravel filling cycle. To facilitate the flow from the upper pipe assembly gap into the gap between the pressure ring 41 and the piston cylinder 21, a connecting hole 401 can be provided on the side wall of the pressure ring 41. The connecting hole 401 connects the upper pipe assembly gap and the gap between the pressure ring 41 and the piston cylinder 21.

[0103] It should be noted that during the sand and gravel filling process, the working fluid carrying the sand and gravel is pressurized and input into the oil pipe, and then enters the tool for suspending the screen pipe and filling sand and gravel disclosed in this embodiment of the invention through the oil pipe, ultimately achieving the filling of sand and gravel. During the flow of the working fluid carrying sand and gravel, the pressure of the working fluid will be lost. Therefore, the working fluid flowing to the lower side of the plug 387 has a lower pressure than the working fluid carrying sand and gravel located on the upper side of the plug 387. Therefore, when the working fluid flowing back to the ground reaches the lower side of the plug 387, it will not pass through the plug 387 and push open the first sealing ball 52.

[0104] As the filling operation proceeds, sand and gravel accumulate in the annulus between the screen pipe and the casing, forming a loose sand layer as described above. After the filling operation is completed, the upstream pipe of the annulus between the screen pipe and the casing remains filled with working fluid carrying sand and gravel. To prevent this residual working fluid carrying sand and gravel from affecting subsequent lifting operations (internal pipe assembly 30, upper connector 10, piston cylinder 21, piston 22, etc.), the tool for suspending the screen pipe and filling it with sand and gravel disclosed in this embodiment can also perform backwashing operations. The specific backwashing operation workflow is as follows:

[0105] A working fluid (e.g., water) free of sand and gravel can be injected from the ground into the upper annulus. After entering the upper annulus, the working fluid will press against the gap between the ring 41 and the piston cylinder 21 and flow back into the upper pipe assembly gap. Then, it will flow back into the liquid connection channel. The working fluid flowing out of the liquid connection channel will enter the connecting pipe 388. The working fluid has pressure, which will push the second sealing ball 390 to separate from the ball stopper 389 and roll down to the lower ball seat 391, thereby sealing the lower ball seat 391. This prevents the working fluid from passing through the lower ball seat 391. At this time, since there is no newly injected working fluid carrying sand and gravel on the upper side of the plug 387 facing away from the ball stopper 389, the working fluid carrying sand and gravel on the upper side of the plug 387 is only residual working fluid with pressure. The working fluid, being relatively small, can pass through the plug 387 and push the first sealing ball 52. Since a fourth elastic element 385 is provided between the first sealing ball 52 and the ball seat cap 384 connected to the sealing sleeve 51, and the ball seat cap 384 is fixed to the sealing sleeve 51 by, for example, a threaded connection, the high-pressure, sand-free working fluid will push the first sealing ball 52 and the fourth elastic element 385, causing the ball seat cap 384 to rise and cover the first sand-filling hole 01. The working fluid will pass through the ball seat cap 384 and rise along the inner cylinder 3831, eventually passing sequentially through the connecting pipe 382, ​​extension pipe 381, flexible sleeve 33, connecting sleeve 32, piston rod tube 31, and upper connector 10 into the oil pipe, and finally flow back to the ground through the oil pipe. During the backwashing process, the sand-free working fluid, in its reverse flow, will push out the previously residual sand-carrying working fluid, causing it to eventually return to the ground from the oil pipe, achieving the purpose of backwashing.

[0106] It should be noted that in this article, "reverse" refers to the direction in which the working fluid flows in the opposite direction to the direction in which the working fluid carrying sand and gravel flows during sand and gravel backfilling operations.

[0107] In the tool for suspending and filling sand and gravel in the embodiment of the present invention, the internal tube assembly 30 may further include a punching joint 39, the upper end of which is threadedly fixedly connected to the lower ball seat 391, and the lower end of which is threadedly fixedly connected to the upper end of the punching pipe extending into the screen tube.

[0108] The connecting pipe 382 can have various structures. In one embodiment, the connecting pipe 382 may include a pipe body 3821 and an annular rib 3822. The annular rib 3822 may be disposed within the pipe body 3821. Specifically, the annular rib 3822 may be fixed to the pipe body 3821 by welding, interference fit, or other methods. In other embodiments, the annular rib 3822 may also be an integral structure with the pipe body 3821. The upper end of the inner cylinder 3831 may be threadedly fixedly connected to the lower end of the pipe body 3821. The upper end of the pipe body 3821 may be threadedly fixedly connected to the lower end of the extension pipe 381. The lower end of the extension pipe 381 and the upper end of the inner cylinder 3831 both extend into the pipe body 3821 and abut against the opposite side surfaces of the annular rib 3822, respectively. In this structure, the annular rib 3822 not only enhances the overall strength of the connecting pipe 382, ​​but also prevents the extension pipe 381 and the inner cylinder 3831 from directly colliding and potentially being damaged during the threading process.

[0109] After sand and gravel backfilling or backflushing is completed, the upper connector 10, piston cylinder 21, piston 22, and internal tubing assembly 30 can be lifted out of the wellbore via tubing, leaving the external tubing assembly 40 with the screen pipe inside the wellbore. The screen pipe is suspended by the engagement of slips 412 between the external tubing assembly 40 and the casing. Over time, if the screen pipe is damaged and needs to be pulled out of the wellbore, the engagement between the slips 412 and the casing can be released. In one embodiment, the release connector 48 may have an annular groove 431, and a locking ring 410 is fitted onto the release connector 48 and located in the annular groove 431. When the screen pipe is suspended, the locking ring 410 descends along the bottom wall of the annular groove 431. As mentioned above, the locking ring 410 cannot retract during its descent. The upper end of the unsealing connector 48 is provided with an internal thread. The retrieval tool can fall into the upper end of the unsealing connector 48 under the drive of the oil pipe and be threadedly connected to the internal thread of the upper end of the unsealing connector 48 (for example, the rotation of the oil pipe drives the retrieval tool to rotate, thereby achieving threaded connection with the internal thread). The retrieval tool can lift the unsealing connector 48.

[0110] The sidewall of the annular groove 431 located below the locking ring 410 is an inclined sidewall. As the unsealing connector 48 moves upward, the inclined sidewall gradually drills into the locking ring 410, thereby enlarging the diameter of the locking ring 410. This causes the locking ring 410 to separate from the toothed structure of the bottom wall of the annular groove 431. Once the locking ring 410 fails to engage with the unsealing connector 48, the rubber sleeve 49 will elastically recover and separate from the casing. The first elastic element 413 will also push the slip 412 through the clearance hole and retract, thereby releasing the engagement between the slip 412 and the casing. The elastic recovery of the rubber sleeve 49 and the repositioning of the slip 412 ultimately release the connection between the external tubing assembly 40 and the casing. Finally, the retrieval tool can pull the unsealing connector 48 to retrieve the external tubing assembly 40 and the screen pipe connected to it out of the wellbore, thus preparing for subsequent maintenance or replacement of the screen pipe.

[0111] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A tool for suspending and filling a screen tube with sand and gravel, used to fix the screen tube to a sleeve and to fill the internal annulus formed between the screen tube and the sleeve with sand and gravel of uniform particle size, characterized in that, The tool for suspending the screen tube and filling it with sand and gravel includes an upper connector (10), a piston cylinder (21), a piston (22), an internal tube assembly (30), and an external tube assembly (40); The upper end of the internal tube assembly (30) extends into the interior of the upper connector (10) and is threadedly fixed to the upper connector (10); the internal tube assembly (30) is provided with a first sand filling hole (01), and the internal tube assembly (30) is detachably provided with a sealing sleeve (51) for sealing the first sand filling hole (01) and a first sealing ball (52) for sealing the sealing sleeve (51); The upper end of the piston cylinder (21) is sleeved outside the upper connector (10) and threadedly fixed to the upper connector (10). The piston (22) is sleeved outside the internal tube assembly (30). The piston (22), the upper connector (10), the internal tube assembly (30) and the piston cylinder (21) form a hydraulic cavity (02). The internal tube assembly (30) has an inlet hole (03) that communicates with the hydraulic cavity (02). The external tube assembly (40) includes a pressure ring (41), a sheath (42), a setting pin (43), a central tube (45), a lower cone (46), an upper cone (47), a release connector (48), a rubber sleeve (49), a locking ring (410), a slip cover (411), a slip (412), and a first elastic element (413); the upper end of the central tube (45) is detachably connected to the internal tube assembly (30), the lower cone (46) is sleeved outside the lower end of the central tube (45) and fixedly connected to the lower end of the central tube (45), and the upper end of the pressure ring (41) extends to the piston cylinder (21) and the... Between the internal tube assemblies (30), and for cooperating with the piston (22) to move downward with the piston (22); the lower end of the pressure ring (41) is sleeved outside the upper end of the unsealing connector (48) and fixedly connected to the unsealing connector (48) through the setting pin (43); the unsealing connector (48) is sleeved outside the upper end of the central tube (45) and fixedly connected to the central tube (45); the upper end of the sheath (42) is sleeved outside the lower end of the pressure ring (41) and fixedly connected to the lower end of the pressure ring (41); the locking ring (410) is sleeved outside the unsealing connector (48); The upper cone (47) is slidably sleeved outside the central tube (45), and the rubber sleeve (49) is slidably sleeved outside the central tube (45) and located between the sheath (42) and the upper cone (47); The lower end of the slip cover (411) is sleeved on the upper end of the lower cone (46) and fixedly connected to the upper end of the lower cone (46). The upper end of the slip cover (411) is sleeved on the upper cone (47). The upper cone (47) and the slip cover (411) are slidably engaged. The slip (412) is disposed between the lower cone (46) and the upper cone (47). The slip (412) includes a plurality of conical mating parts (4121) distributed circumferentially along the central tube (45) and a meshing rack (4122) connected to the conical mating parts (4121). The slip cover (411) has a plurality of clearance holes to avoid the plurality of meshing racks (4122). The first elastic element (413) is disposed between the slip cover (411) and the conical mating parts (4121). When the working fluid flows into the internal tubing assembly (30) and reaches the first sealing ball (52) to enter the first pressure-locking state, the working fluid enters the hydraulic chamber (02) through the inlet hole (03) to drive the piston (22) downward. The downward movement of the piston (22) drives the pressure ring (41) to cut off the setting pin (43), thereby driving the locking ring (410) and the sheath (42) downward. The rubber sleeve (49) is pressed by the downward-moving sheath (42). The expansion extends to the inner wall of the sleeve. The upper cone (47) is driven by the downward movement of the sheath (42) to approach the lower cone (46) and, through the engagement with the cone surface mating part (4121), drives the plurality of biting racks (4122) to pass through the corresponding clearance holes and bite against the inner wall of the sleeve. The locking ring (410) and the unsealing connector (48) engage in the opposite direction to the downward movement of the locking ring (410) to maintain the position of the sheath (42) after its downward movement. The first elastic element (413) is used to drive the engagement rack (4122) to retract from the corresponding clearance hole into the slip cover (411) when the upper cone (47) moves upward away from the lower cone (46).

2. The tool for suspending and filling sand and gravel in a screen tube according to claim 1, characterized in that, The external pipe assembly (40) further includes an upper filling sleeve (414), a lower filling sleeve (415), a sealing assembly (416), and a sliding sleeve switch valve (418); the upper end of the upper filling sleeve (414) is fitted onto the lower end of the lower cone (46) and threadedly fixed to the lower end of the lower cone (46); the sealing assembly (416) is sealed between the upper filling sleeve (414) and the internal pipe assembly (30); the lower end of the upper filling sleeve (414) is fitted onto the upper end of the lower filling sleeve (415) and fixedly connected to the upper end of the lower filling sleeve (415); the lower filling sleeve (415) has an opening... The second sand filling hole (04) is opposite to the first sand filling hole (01). The sliding sleeve switch valve (418) is located between the internal pipe assembly (30) and the lower filling sleeve (415) and is kept in the open state by friction with the internal pipe assembly (30). When the internal pipe assembly (30) is separated from the external pipe assembly (40), the internal pipe assembly (30) drives the sliding sleeve switch valve (418) to switch to the closed state of blocking the first sand filling hole (01) and the second sand filling hole (04) by frictional cooperation with the sliding sleeve switch valve (418).

3. The tool for suspending and filling sand and gravel in a screen tube according to claim 2, characterized in that, The external tube assembly (40) also includes a second elastic element (419), an upper safety connector (420), and a lower safety connector (44); the lower end of the lower filling sleeve (415) is sleeved outside the upper end of the upper safety connector (420) and is threadedly fixedly connected to the upper end of the upper safety connector (420); the upper end of the lower safety connector (44) is sleeved outside the lower end of the upper safety connector (420) and is threadedly fixedly connected to the lower end of the upper safety connector (420); the lower end of the lower safety connector (44) is used to be fixedly connected to the screen tube. The upper end of the upper safety connector (420) protrudes from the inner wall of the lower filling sleeve (415). The second elastic element (419) is elastically positioned between the end face of the upper safety connector (420) and the sliding sleeve switch valve (418). The second elastic element (419) is used to assist in driving the sliding sleeve switch valve (418) to switch to the closed state.

4. The tool for suspending and filling sand and gravel in a screen tube according to claim 3, characterized in that, The outer wall of the sliding sleeve switch valve (418) is provided with a connecting groove (4181). The internal pipe assembly (30) includes an elastic sleeve (310). The elastic sleeve (310) is located below the sliding sleeve switch valve (418). The elastic sleeve (310) includes a connecting protrusion (311) protruding from its outer wall. When the internal pipe assembly (30) is separated from the external pipe assembly (40), the connecting protrusion (311) can extend into the connecting groove (4181) and connect with it by elastic deformation when passing through the position opposite to the connecting groove (4181). The sliding sleeve switch valve (418) can be switched to the closed state by pulling the internal pipe assembly (30).

5. The tool for suspending and filling sand and gravel in a screen tube according to claim 2, characterized in that, The lower end of the upper filling sleeve (414) has a positioning protrusion (4141) on its inner wall. The upper end of the upper filling sleeve (414) has a stepped threaded hole, which includes a small-diameter threaded hole and a large-diameter threaded hole. The lower end of the lower cone (46) is threadedly fixed to the large-diameter threaded hole. The outer tube assembly (40) also includes a locking ring (417). The locking ring (417) is threadedly engaged with the small-diameter threaded hole. A positioning space is formed between the locking ring (417) and the positioning protrusion (4141). The sealing assembly (416) is sleeved outside the upper filling sleeve (414) and positioned between the positioning protrusion (4141) and the locking ring (417).

6. The tool for suspending and filling sand and gravel in a screen tube according to claim 3, characterized in that, The upper end of the upper filling sleeve (414) and the lower end of the lower cone (46), the lower end of the upper filling sleeve (414) and the upper end of the lower filling sleeve (415), and the lower end of the lower filling sleeve (415) and the upper safety connector (420) are all fixedly connected by fastening screws.

7. The tool for suspending and filling sand and gravel in a screen tube according to claim 2, characterized in that, The internal tube assembly (30) includes a piston rod tube (31), a connecting sleeve (32), a flexible sleeve (33), a locking cap ring (34), a first spring seat (35), a second spring seat (36), a third elastic element (37), and an internal tube assembly body (38). The upper end of the piston tube (31) extends into the interior of the upper connector (10) and is threadedly fixedly connected to the upper connector (10). The liquid inlet (03) is opened on the piston tube (31). The upper end of the connecting sleeve (32) is threadedly fixedly connected to the lower end of the piston tube (31). The lower end of the connecting sleeve (32) is sleeved outside the upper end of the movable sleeve (33) and forms an annular groove between it and the upper end of the movable sleeve (33). A portion of the locking cap ring (34) extends into the annular groove and is threadedly fastened to the lower end of the connecting sleeve (32). The upper end of the movable sleeve (33) has an annular protrusion (331) for forming the bottom wall of the annular groove. The annular protrusion (331) overlaps with the locking cap ring (34). The inner wall of the locking cap ring (34) and the inner wall of the lower end of the connecting sleeve (32) are rotatably engaged with the movable sleeve (33). The upper end of the internal tube assembly body (38) is fixedly connected to the lower end of the movable sleeve (33) by a thread. The first spring seat (35) is sleeved outside the connecting sleeve (32) and makes a limiting contact with the end face of the lower end of the piston tube (31). The second spring seat (36) is sleeved outside the connecting sleeve (32). The outer wall of the connecting sleeve (32) has an annular limiting surface (321) facing the end face of the lower end of the piston tube (31). The second spring seat (36) and the connecting sleeve (32) are circumferentially limited by a spline engagement. The second spring seat (36) can slide along the axial direction of the connecting sleeve (32). The third elastic element (37) is sleeved outside the connecting sleeve (32) and elastically positioned between the first spring seat (35) and the second spring seat (36). The second spring seat (36) makes a limiting contact with the annular limiting surface (321). The second spring seat (36) is threadedly fixed to the upper end of the central tube (45); When the upper connector (10) drives the piston rod tube (31), the connecting sleeve (32) and the locking cap ring (34) to rotate relative to the movable sleeve (33), the second spring seat (36) rotates along the upper connector (10) and moves along the axial direction of the connecting sleeve (32) to compress the third elastic element (37) and achieve separation from the upper end of the central tube (45). The inner tube assembly (30) is disconnected from the outer tube assembly (40) by separating from the central tube (45) through the separation of the second spring seat (36) from the central tube (45). The internal tube assembly body (38) is provided with the first sand filling hole (01), the sealing sleeve (51) and the first sealing ball (52) are located inside the internal tube assembly body (38), and the internal tube assembly body (38) is in sealed contact with the sealing component (416).

8. The tool for suspending and filling sand and gravel in a screen tube according to claim 7, characterized in that, The internal tube assembly body (38) includes an extension tube (381), a connecting tube (382), a double-through body (383), a ball seat cap (384), a fourth elastic element (385), a shear screw (386), a plug (387), a connecting tube (388), a ball stopper (389), a second sealing ball (390), and a lower ball seat (391); The upper end of the extension tube (381) is threadedly fixedly connected to the lower end of the flexible sleeve (33), and the lower end of the extension tube (381) is threadedly fixedly connected to the upper end of the connecting tube (382). The double-through body (383) includes an inner cylinder (3831) and an outer cylinder (3832). The outer cylinder (3832) is sleeved outside the inner cylinder (3831), and a liquid connection channel is formed between the two. The first sand filling hole (01) passes through the inner cylinder (3831) and the outer cylinder (3832) and is isolated from the liquid connection channel. The upper end of the inner cylinder (3831) extends beyond the upper end of the outer cylinder (3832) and is threadedly fixed to the lower end of the connecting pipe (382). The lower end of the outer cylinder (3832) extends beyond the lower end of the inner cylinder (3831) and is threadedly fixed to the connecting pipe (388). The sealing sleeve (51) is fixedly connected to the inner cylinder (3831) and the outer cylinder (3832) by the shear screw (386). The plug (387) is fixed to the lower end of the inner cylinder (3831). The ball stopper (389) is fixed by threaded engagement. Inside the connecting pipe (388), the upper end of the lower ball seat (391) is threadedly fixedly connected to the lower end of the connecting pipe (388). The second sealing ball (390) can be limited and sealed with the lower ball seat (391) in a direction away from the ball stopper (389). The second sealing ball (390) can be limited and sealed with the ball stopper (389) in a direction away from the lower ball seat (391). When the second sealing ball (390) is limited and sealed with the ball stopper (389), the lower ball seat (391) is connected to the liquid connection channel through the ball stopper (389). The ball seat cap (384) is fixed inside the sealing sleeve (51). The fourth elastic element (385) is elastically disposed between the ball seat cap (384) and the first sealing ball (52). The fourth elastic element (385) is used to elastically abut the first sealing ball (52) against the sealing mating seat (511) of the sealing sleeve (51). The ball seat cap (384), the plug (387) and the ball stopper (389) are all provided with through holes that coincide with or are parallel to the axial direction of the internal tube assembly (30).

9. The tool for suspending and filling sand and gravel in a screen tube according to claim 8, characterized in that, The internal tube assembly (30) also includes a punching connector (39), the upper end of which is threadedly fixedly connected to the lower ball seat (391), and the lower end of which is threadedly fixedly connected to the upper end of the punching tube extending into the screen tube.

10. The tool for suspending and filling sand and gravel in a screen tube according to claim 8, characterized in that, The connecting pipe (382) includes a pipe body (3821) and an annular rib (3822) disposed inside the pipe body (3821). The upper end of the inner cylinder (3831) is threadedly fixedly connected to the lower end of the pipe body (3821). The upper end of the pipe body (3821) is threadedly fixedly connected to the lower end of the extension pipe (381). The lower end of the extension pipe (381) and the upper end of the inner cylinder (3831) both extend into the pipe body (3821) and abut against the opposite two surfaces of the annular rib (3822).

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