Downhole packoff sand control tool

Abstract

The utility model discloses an underground filling sand prevention tool, from bottom to top includes float shoe, replacement mortar sealing cylinder, lower sand prevention screen pipe, lower filling sliding sleeve, open hole packer, upper sand prevention screen pipe and upper filling sliding sleeve in proper order, and the lower filling sliding sleeve includes: sliding sleeve upper joint, upper sealing cylinder is connected in the lower end of sliding sleeve upper joint, variable buckle joint is connected in the lower end of upper sealing cylinder, extension cylinder is connected in the lower end of variable buckle joint, filling cylinder is connected in the lower end of extension cylinder, and its below is equipped with the limiting sleeve, the upper end port of pressure transmission sleeve is connected with the lower end outer screw thread of filling cylinder and the outer screw thread of limiting sleeve, and the upper circumferential symmetry is equipped with a plurality of pressure transmission sleeve through -hole as filling channel, mechanical sliding sleeve blocks the inside passage of pressure transmission sleeve through -hole, and the upper end dog claw is embedded in the recess of limiting sleeve, lower sealing cylinder is located below pressure transmission sleeve.

Description

Technical Field

[0001] This utility model relates to the oil extraction industry, and in particular to a downhole filling and sand control tool, belonging to the technical field of filling and sand control equipment. Background Technology

[0002] With the development of drilling technology, horizontal well technology is now widely used in oil extraction. As geological steering technology becomes increasingly sophisticated, the length of horizontal sections can now exceed one kilometer. The original single-channel filling method at the bottom or top is no longer sufficient to meet the requirements for uniform stimulation and sand control throughout long horizontal wells. Furthermore, using multi-run tubing segmented filling technology cannot achieve rapid well completion and cannot meet the requirements for integrated drilling and completion.

[0003] To achieve efficient oilfield development, integrated and collaborative reservoir engineering construction is necessary to minimize secondary pollution to the reservoir caused by drilling and operations. Currently, the oilfield is promoting a combined drilling and completion model, replacing the previous model where the drilling team was responsible for drilling and completion, and the operations team for filling, with a turnkey project model where the drilling team is directly and comprehensively responsible for drilling, completion, filling, and sand control. Combined drilling and completion operations have high timeliness requirements. Existing single-channel filling at the bottom or top, and multi-run tubing segmented filling technologies cannot meet the functions of replacing open-hole mud in a single tubing run, segmented setting of open-hole packers, segmented filling, and segmented injection of plugging fluid, thus failing to meet the requirements of combined drilling and completion operations.

[0004] Therefore, it is necessary to develop a downhole sand control tool to address the problems of existing horizontal well sand control processes, such as the long drilling time and poor efficiency caused by multiple tripping of the tubing string under drilling and completion conditions. The goal is to achieve the following with a single trip of the filling service tubing: replacing open-hole mud, setting open-hole packers in stages, filling stage by stage, and injecting plugging fluid stage by stage. This allows for rapid mud replacement to protect the reservoir, while staged filling and injection of plugging fluid prevents formation collapse and filling failure. By utilizing a single long horizontal well, the production enhancement effect previously achieved with multiple short horizontal wells can be achieved, saving drilling costs and significantly reducing investment in production capacity construction. Utility Model Content

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, and such simplifications or omissions should not be construed as limiting the scope of the present invention.

[0006] In view of the problems existing in the above and / or prior art, this utility model is proposed.

[0007] The primary objective of this invention is to overcome the problems existing in the prior art and provide a downhole filling and sand control tool that can quickly replace open hole mud and fill sand by running a single completion string, thereby reducing mud soaking time and reducing reservoir contamination.

[0008] To solve the above technical problems, this utility model provides a downhole filling and sand control tool, which, from bottom to top, includes a float shoe, a slurry sealing cylinder, a lower sand control screen, a lower filling sliding sleeve, an open hole packer, an upper sand control screen, and an upper filling sliding sleeve. The lower filling sliding sleeve includes: upper connector on the sliding sleeve; The upper sealing cylinder is connected to the lower end of the upper joint on the sliding sleeve; The variable-thread connector is attached to the lower end of the upper sealing cylinder; The extension sleeve is connected to the lower end of the variable coupling. A filling cylinder is connected to the lower end of the extension cylinder, and a limiting sleeve is provided below it; The pressure transmission sleeve has its upper port connected to the lower end of the filling cylinder and the external thread of the limiting sleeve. Multiple pressure transmission sleeve through holes are symmetrically arranged on the upper circumference as filling channels. Mechanical sliding sleeve, which blocks the inner channel of the pressure transmission sleeve through hole, with the upper claw embedded in the groove of the limiting sleeve; The lower sealing cylinder is located below the pressure transmission sleeve.

[0009] Furthermore, a differential pressure sleeve is provided between the lower outer wall of the mechanical sleeve and the inner wall of the pressure transmission sleeve, with the upper end of the differential pressure sleeve located below the inner port of the through hole of the pressure transmission sleeve.

[0010] Furthermore, the bottom of the differential pressure sleeve abuts against the top of the sealing extension cylinder, and the upper end of the sealing extension cylinder is externally threaded into the lower port of the pressure transmission sleeve; the upper inner cavity of the sealing extension cylinder is provided with a sealing sleeve, the top of the sealing sleeve abuts against the lower inner step of the differential pressure sleeve, and the bottom of the sealing sleeve abuts against the upper inner step of the sealing extension cylinder.

[0011] Furthermore, the upper middle circumference of the sealing sleeve is provided with a radially penetrating sealing sleeve through hole that communicates with the hydraulic cavity between the differential pressure sliding sleeve and the sealing extension cylinder.

[0012] Furthermore, the upper inner wall of the pressure transmitting sleeve is provided with a reduced diameter section, and the inner wall of the reduced diameter section abuts against the mechanical sliding sleeve; a sealing ring is embedded in the upper outer periphery of the pressure transmitting sleeve to seal with the inner wall of the reduced diameter section, and a sealing ring is embedded in the lower outer periphery of the pressure transmitting sleeve to seal with the upper inner wall of the differential pressure sliding sleeve; multiple sealing rings are embedded in the outer periphery of the differential pressure sliding sleeve to seal with the inner wall of the pressure transmitting sleeve.

[0013] Furthermore, the inner wall of the middle section of the mechanical sliding sleeve is provided with two sliding sleeve grooves, and an annular step is formed between the two sliding sleeve grooves for the filling service tool to operate.

[0014] Furthermore, the inner wall of the middle section of the sealing extension cylinder is flush with the inner wall of the sealing sleeve, and is provided with an axially penetrating auxiliary through hole.

[0015] Furthermore, the lower end of the sealing extension cylinder is connected to a lower sealing cylinder, the lower end of the lower sealing cylinder is connected to the lower extension cylinder via a coupling, and the lower end of the lower extension cylinder is connected to a positioning coupling.

[0016] Furthermore, an anti-rotation pin is screwed onto the connection between the lower end of the variable buckle connector and the extension cylinder.

[0017] Furthermore, an anti-rotation pin is screwed into the threaded connection between the extension cylinder and the filling cylinder, and an anti-rotation pin is also screwed into the threaded connection between the differential pressure sleeve and the sealing extension cylinder.

[0018] Compared with existing technologies, this utility model achieves the following beneficial effects: 1. When used in conjunction with filling service tools, this utility model can achieve the requirements of replacing open-hole mud, setting open-hole packers in stages, filling sections one by one, and injecting plugging fluid section by section by section by section by section by section. It meets the requirements of rapid construction in drilling and completion operations and reduces the number of trips.

[0019] 2. During the lowering of the tubing string, the filling service tool pushes the mechanical sliding sleeve inside the lower filling sliding sleeve downwards to open the filling channel. Gravel filling is then carried out by injecting slurry into the drill string. After filling is completed, the manifold is switched to the reverse circulation process to flush excess slurry from the drill pipe to the surface.

[0020] 3. During the transition from the filling state to the backwashing state, the formation pressure is higher than the tubing pressure. The pressure difference will cause the pressure differential sleeve to move upward. Pre-closing the pressure transmission sleeve through hole, i.e. the filling channel, can effectively prevent the filling sand from being expelled and reduce the backwashing efficiency. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings are provided for reference and illustration only and are not intended to limit this utility model. Wherein: Figure 1 A schematic diagram of a downhole sand-control filling tool; Figure 2 This is a schematic diagram of the filling sleeve in this utility model; In the diagram: A. Floating shoe; B. Slurry replacement sealing cylinder; C. Lower sand-proof screen pipe; D. Lower filling sleeve; E. Open-hole packer; F. Upper sand-proof screen pipe; G. Upper filling sleeve; Lower filling sleeve: upper sleeve connector 1; upper sealing cylinder 2; variable thread connector 3; extension cylinder 4; filling cylinder 5; limiting sleeve 6; pressure transmission sleeve 7; mechanical sleeve 8; differential pressure sleeve 9; sealing sleeve 10; sealing extension cylinder 11; lower sealing cylinder 12; coupling 13; lower extension cylinder 14; positioning coupling 15. Detailed Implementation

[0022] In the following description of this utility model, the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not mean that the device must have a specific orientation.

[0023] To make the technical means, creative features, achieved objectives and effects of this utility model easier to understand, the present utility model will be further described below with reference to specific illustrations. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0025] like Figure 1 As shown, the downhole filling and sand control tool of this utility model includes, from bottom to top, a float shoe A, a slurry sealing cylinder B, a lower sand control screen C, a lower filling sliding sleeve D, an open hole packer E, an upper sand control screen F, and an upper filling sliding sleeve G.

[0026] Figure 2 Taking the lower filling sleeve D as an example. In the lower filling sleeve D, the lower end of the upper connector 1 of the sleeve is connected to the upper sealing cylinder 2 and they are sealed to each other. The lower end of the upper sealing cylinder 2 is connected to the variable thread connector 3. The lower end of the variable thread connector 3 is connected to the extension cylinder 4. The lower end of the extension cylinder 4 is connected to the filling cylinder 5. A limiting sleeve 6 is provided below the filling cylinder 5. The external thread at the lower end of the filling cylinder 5 and the external thread of the limiting sleeve 6 are both connected to the internal thread at the upper port of the pressure transmission sleeve 7. The bottom of the limiting sleeve 6 abuts against the inner step at the upper port of the limiting sleeve 6. The upper end of the limiting sleeve 6 is provided with a flared mouth that is wider at the top and narrower at the bottom. Below the flared mouth is a small-diameter limiting sleeve throat. Below the limiting sleeve throat is an annular limiting sleeve groove.

[0027] The upper inner wall of the pressure transmission sleeve 7 is provided with a reduced diameter section. The inner wall of the reduced diameter section abuts against the mechanical sliding sleeve 8 and they are sealed to each other. The claw at the upper end of the mechanical sliding sleeve 8 is embedded in the groove of the limiting sleeve. The middle inner wall of the mechanical sliding sleeve 8 is provided with two sliding sleeve grooves, and an annular step is formed between the two sliding sleeve grooves for the filling service tool to operate.

[0028] The upper circumference of the pressure-transmitting sleeve 7 is symmetrically provided with multiple pressure-transmitting sleeve through holes as filling channels. A differential pressure sleeve 9 is provided between the lower outer wall of the mechanical sliding sleeve 8 and the inner wall of the pressure-transmitting sleeve 7. The upper end of the differential pressure sleeve 9 is located below the inner port of the pressure-transmitting sleeve through hole. A sealing ring is embedded in the upper outer circumference of the pressure-transmitting sleeve 7 to achieve a seal with the inner wall of the reduced diameter section of the pressure-transmitting sleeve. A sealing ring is embedded in the lower outer circumference of the pressure-transmitting sleeve 7 to achieve a seal with the upper inner wall of the differential pressure sleeve 9. The outer circumference of the differential pressure sleeve 9 is embedded with multiple sealing rings to achieve a seal with the inner wall of the pressure-transmitting sleeve 7.

[0029] The bottom of the differential pressure sleeve 9 abuts against the top of the sealing extension cylinder 11, and the upper end of the sealing extension cylinder 11 is externally threaded into the lower port of the pressure transmission sleeve 7. The upper inner cavity of the sealing extension cylinder 11 is provided with a sealing sleeve 10, the top of the sealing sleeve 10 abuts against the lower inner step of the lower port of the differential pressure sleeve 9, and the bottom of the sealing sleeve 10 abuts against the upper inner step of the sealing extension cylinder 11.

[0030] The upper middle circumference of the sealing sleeve 10 is provided with a radially penetrating sealing sleeve through hole, which communicates with the hydraulic cavity between the differential pressure sliding sleeve 9 and the sealing extension cylinder 11. The formation pressure enters the hydraulic cavity below the differential pressure sliding sleeve 9 from the sealing sleeve through hole, which can push the differential pressure sliding sleeve 9 upward, thereby closing the pressure transmission sleeve through hole.

[0031] The inner wall of the middle section of the sealing extension cylinder 11 is flush with the inner wall of the sealing sleeve 10, and is provided with an axially penetrating auxiliary through hole, so that when there is a tool in the central channel, the axial penetration is maintained.

[0032] The lower end of the sealing extension cylinder 11 is connected to the lower sealing cylinder 12, and the lower end of the lower sealing cylinder 12 is connected to the lower extension cylinder 14 through the coupling 13. The lower end of the lower extension cylinder 14 is connected to the positioning coupling 15.

[0033] An anti-rotation pin is screwed into the connection between the lower end of the variable thread connector 3 and the extension cylinder 4. An anti-rotation pin is also screwed into the connection thread between the extension cylinder 4 and the filling cylinder 5. An anti-rotation pin is also screwed into the connection thread between the differential pressure sleeve 9 and the sealing extension cylinder 11 to prevent the threads from loosening.

[0034] During the lowering of the tubing, the filling switch tool on the filling service tool will push the mechanical sleeve 8 inside the lower filling sleeve D to move downward and open the filling channel.

[0035] At the filling position, the upper and lower seals of the filling service tool cooperate with the upper sealing cylinder 2 and the lower sealing cylinder 12 of the filling sliding sleeve to seal. Gravel filling is carried out by injecting mortar downwards into the drill. After filling is completed, the ground manifold is turned to the reverse circulation process to flush the excess mortar in the drill pipe to the ground.

[0036] During the transition from the filling state to the backwashing state, the formation pressure is higher than the tubing pressure. The pressure difference will cause the pressure differential sleeve 9 to move upward, thus pre-closing the pressure transmission sleeve through hole, i.e., the filling channel.

[0037] After the formation section is filled, when the tubing string is lifted, the filling service tool pulls the mechanical sliding sleeve 8 upwards, closing the filling channel. After the mechanical sliding sleeve 8 is closed, the upper locking claw will lock into the groove on the inner wall of the limiting sleeve 6. The small diameter part of the limiting sleeve will press down on the locking block of the filling switch tool, disengaging it from the mechanical sliding sleeve 8.

[0038] The working principle of this downhole sand-control filling tool is as follows: Slurry Replacement: The filling service string is inserted into the downhole filling and sand control tool. The slurry replacement switch on the filling service string pushes the mechanical sleeve inside the upper filling sleeve G downwards, opening the upper filling hole as a slurry return channel. This prevents mud from entering the annulus between the upper tubing and casing and causing blockage during the slurry replacement process. After slurry replacement is completed, the string is pulled up. The slurry replacement switch on the filling service string pulls the mechanical sleeve inside the upper filling sleeve G upwards, closing the slurry return channel.

[0039] The bottom of the slurry insertion sealing head on the filling service tubing has an open design to facilitate fluid outflow. The upper part of the filling service tubing is equipped with a slurry displacement switch tool. When in the slurry displacement position, the uppermost filling sleeve G is opened to circulate the open hole section slurry into the upper casing.

[0040] Completion fluid is injected into the drill pipe, flows out through the filling service tubing, then flows out through float shoe A into the horizontal open hole section, and then flows into the upper casing from the upper filling sleeve G. It then returns to the wellhead from the annulus between the tubing and the casing, continuing positive circulation until the bottom open hole section mud is replaced.

[0041] When the grout is being replaced, the filling hole of the filling service tool is sealed at the lower sealing cylinder of the lower filling sleeve D to prevent short circuits during grout replacement, which could result in incomplete grout replacement.

[0042] The filling service string is lifted up, causing the slurry insertion sealing head to disengage from the slurry sealing cylinder B. At the same time, the slurry switching tool at the top of the filling service string closes the upper filling sliding sleeve G during the lifting process.

[0043] Continue injecting completion fluid into the drill pipe, which flows out through the filling service tubing and returns from the annulus between the drill pipe and casing. Through positive circulation, the mud in the casing is displaced from the wellbore.

[0044] Setting the packer: After the slurry replacement is completed, the open-hole packer is set.

[0045] Filling of the lower and upper formations: Taking the lower section as an example, the filling service string is lowered to the lower filling position. During the lowering process, the filling service tool pushes the mechanical sleeve inside the lower filling sleeve D downwards, opening the lower filling channel. At the filling position, the upper and lower seals of the filling service tool cooperate with the upper and lower sealing cylinders of the lower filling sleeve D to seal. Gravel filling is performed by injecting slurry downwards through the drill string. After filling, the manifold is switched to the reverse circulation process to flush excess slurry from the drill pipe to the surface. After lower filling is completed, when the string is lifted, the filling service tool pulls the mechanical sleeve inside the lower filling sleeve D upwards, closing the lower filling channel.

[0046] The above description is merely a preferred embodiment of the present utility model, showing and describing the basic principles, main features, and advantages of the present utility model. It is not intended to limit the scope of patent protection of the present utility model. Those skilled in the art should understand that the present utility model is not limited to the above embodiments. In addition to the above embodiments, the present utility model may have other implementations without departing from the spirit and scope of the present utility model. Various changes and improvements to the present utility model are also possible. All technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by the present utility model. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents. Technical features not described in the present utility model can be implemented by or using existing technology, and will not be elaborated here.

Claims

1. A downhole sand control tool, comprising, from bottom to top, a float shoe (A), a slurry sealing cylinder (B), a lower sand control screen (C), a lower filling sliding sleeve (D), an open-hole packer (E), an upper sand control screen (F), and an upper filling sliding sleeve (G), characterized in that, The lower filling sleeve (D) includes: Sliding sleeve upper connector (1); The upper sealing cylinder (2) is connected to the lower end of the upper joint (1) of the sliding sleeve; The variable-length connector (3) is connected to the lower end of the upper sealing cylinder (2); The extension tube (4) is connected to the lower end of the variable coupling (3); The filling cylinder (5) is connected to the lower end of the extension cylinder (4), and a limiting sleeve (6) is provided below it. The pressure transmission sleeve (7) has its upper port connected to the lower end external thread of the filling cylinder (5) and the external thread of the limiting sleeve (6). Multiple pressure transmission sleeve through holes are symmetrically arranged on the upper circumference as filling channels. Mechanical sliding sleeve (8) blocks the inner channel of the pressure transmission sleeve through hole, and the upper claw is embedded in the groove of the limiting sleeve (6); The lower sealing cylinder (12) is located below the pressure transmission sleeve (7).

2. The downhole sand-control tool according to claim 1, characterized in that, A differential pressure sleeve (9) is provided between the lower outer wall of the mechanical sleeve (8) and the inner wall of the pressure transmission sleeve (7), and the upper end of the differential pressure sleeve (9) is located below the inner port of the through hole of the pressure transmission sleeve.

3. The downhole sand-control tool according to claim 2, characterized in that, The bottom of the differential pressure sleeve (9) abuts against the top of the sealing extension cylinder (11), and the upper end of the sealing extension cylinder (11) is externally threaded into the lower port of the pressure transmission sleeve (7); the upper inner cavity of the sealing extension cylinder (11) is provided with a sealing sleeve (10), the top of the sealing sleeve (10) abuts against the lower inner step of the lower port of the differential pressure sleeve (9), and the bottom of the sealing sleeve (10) abuts against the upper inner step of the sealing extension cylinder (11).

4. The downhole sand-control tool according to claim 3, characterized in that, The upper middle circumference of the sealing sleeve (10) is provided with a radially penetrating sealing sleeve through hole that communicates with the hydraulic cavity between the differential pressure sliding sleeve (9) and the sealing extension cylinder (11).

5. The downhole sand-control tool according to claim 3, characterized in that, The upper inner wall of the pressure transmission sleeve (7) is provided with a pressure transmission sleeve reduced diameter section, and the inner wall of the pressure transmission sleeve reduced diameter section abuts against the mechanical sliding sleeve (8); the upper outer periphery of the pressure transmission sleeve (7) is fitted with a sealing ring to achieve a seal with the inner wall of the pressure transmission sleeve reduced diameter section, and the lower outer periphery of the pressure transmission sleeve (7) is fitted with a sealing ring to achieve a seal with the upper inner wall of the differential pressure sliding sleeve (9); the outer periphery of the differential pressure sliding sleeve (9) is fitted with multiple sealing rings to achieve a seal with the inner wall of the pressure transmission sleeve (7).

6. The downhole sand-control tool according to claim 1, characterized in that, The mechanical sliding sleeve (8) has two sliding sleeve grooves on its inner wall at the middle end, and an annular step is formed between the two sliding sleeve grooves for the filling service tool to operate.

7. The downhole sand-control tool according to claim 3, characterized in that, The inner wall of the middle section of the sealing extension cylinder (11) is flush with the inner wall of the sealing sleeve (10) and is provided with an axially penetrating auxiliary through hole.

8. The downhole sand-control tool according to claim 3, characterized in that, The lower end of the sealing extension cylinder (11) is connected to the lower sealing cylinder (12), the lower end of the lower sealing cylinder (12) is connected to the lower extension cylinder (14) through the coupling (13), and the lower end of the lower extension cylinder (14) is connected to the positioning coupling (15).

9. The downhole sand-control tool according to claim 1, characterized in that, The lower end of the variable snap connector (3) is screwed with an anti-rotation pin at the connection between it and the extension cylinder (4).

10. The downhole sand-control tool according to claim 3, characterized in that, Anti-rotation pins are screwed into the connecting threads of the extension cylinder (4) and the filling cylinder (5), and anti-rotation pins are also screwed into the connecting threads of the differential pressure sleeve (9) and the sealing extension cylinder (11).

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