Gravel packing sand prevention device for oil exploitation well

Abstract

The invention discloses a gravel packing sand prevention device for an oil exploitation well, and relates to the field of gravel packing of the exploitation well, the gravel packing sand prevention device comprises a center cylinder with an oil inlet hole in the surface and a screen pipe arranged outside the center cylinder, a filling cavity is formed between the center cylinder and the screen pipe, a bottom filter is arranged at the bottom of the screen pipe, and an injection connecting pipe is arranged at the top of the screen pipe. Vibration vertical grooves are symmetrically formed in the two sides of the inner wall of the center cylinder, sliding blocks are slidably connected to the inner walls of the vibration vertical grooves, containing grooves are formed in the bottoms of the sliding blocks, vibration blocks are slidably connected to the inner side faces of the containing grooves, and fault-tolerant springs are installed between the vibration blocks and the sliding blocks. And a driving unit is arranged outside the sliding block. According to the gravel filling sand prevention device for the oil exploitation well, through mutual cooperation of the vibration vertical groove, the vibration block and the driving unit, gravel can be effectively driven to vibrate in the gravel filling process, gravel filling is more compact, and therefore the sand prevention effect of the gravel filling sand prevention device is better.

Description

Technical Field

[0001] The invention relates to a gravel packing technology for production wells, in particular to a gravel packing sand prevention device for oil production wells. Background Art

[0002] Sand production is a common and potentially detrimental phenomenon in oil wells, particularly in unconsolidated sandstone reservoirs. As formation sand enters the wellbore along with crude oil, it continuously accumulates, reducing the effective borehole diameter. In severe cases, it can even completely block the wellbore, forcing the interruption of production. Furthermore, the high-velocity flow of formation sand causes severe wear and tear on downhole equipment such as sucker rods and pumps. This not only shortens equipment lifespan and increases the frequency of replacement and repair, but also leads to significant economic losses due to equipment downtime. According to statistics, maintenance costs in wells with severe sand production can be 30%-50% higher than in normal wells, and production efficiency is reduced to only 60%-70% of normal levels. Gravel pack sand control technology, a mainstream approach to addressing sand production in oil wells, focuses on creating a reliable filtration barrier by filling the annular space between the wellbore and the formation with gravel of specific specifications. Ideally, this barrier effectively prevents formation sand from entering the wellbore while ensuring smooth passage of crude oil. However, current gravel pack sand control devices still suffer from numerous shortcomings in practical operation and use.

[0003] The Oil Production Technology Manual, published by the Petroleum Industry Press in March 1991, published a "vibratory gravel impact sand control tool." This tool features sliders installed at regular intervals on the impact pipe. When the downhole tubing rotates on the ground, the sliders strike the screen, causing it to vibrate. This aims to make the filled gravel solid and dense, achieving a good sand control effect. However, this tool has the disadvantages of requiring ground-generated power for the sliders to impact the screen, complex equipment, and inconvenient operation.

[0004] The utility model patent with announcement number CN2473332Y discloses a self-energy vibration filling tool. In actual application, the reflux liquid separated from the gravel is used as a driving force to drive the eccentric block inside the central tube to rotate, so that a vibration force is generated inside the central tube to assist the filling of the gravel, making the gravel filling more compact. However, during the rotation of the eccentric block, the water flow wraps it and flows out from bottom to top to the outside, so that the kinetic energy generated by the rotation of the eccentric block is easily weakened, so that the actual vibration force that the central tube can receive is small. Although it can play a certain vibration role on the central tube, the vibration force is too small, and it still cannot play a good vibration auxiliary role in gravel filling. Summary of the Invention

[0005] The object of the present invention is to provide a gravel packing sand control device for oil production wells to solve the above-mentioned deficiencies in the prior art.

[0006] In order to achieve the above-mentioned purpose, the present invention provides the following technical solution: a gravel filling and sand prevention device for oil production wells, comprising a central tube with an oil inlet hole on the surface and a screen pipe arranged on the outside thereof, a filling cavity is formed between the central tube and the screen pipe, a bottom filter is provided at the bottom of the screen pipe, an injection pipe is provided at the top of the screen pipe, vibration vertical grooves are symmetrically provided on both sides of the inner wall of the central tube, a sliding block is slidably connected to the inner wall of the vibration vertical groove, a receiving groove is provided at the bottom of the sliding block, a vibration block is slidably connected to the inner side surface of the receiving groove, a fault-tolerant spring is installed between the vibration block and the sliding block, and a driving unit is provided on the outside of the sliding block.

[0007] Furthermore, the drive unit includes a mounting frame installed inside the central tube, a reciprocating screw is installed at the bottom of the mounting frame, the external transmission of the reciprocating screw is connected to a lifting seat, and connecting rods are fixedly installed between the two sides of the lifting seat and the sliding block.

[0008] Furthermore, a driving block is coaxially mounted on the bottom of the reciprocating screw rod, and a plurality of spiral grooves are evenly spaced in a circular shape inside the driving block and run through the top and bottom. A connecting groove is provided at the bottom of the filling cavity to connect to the bottom end of the center tube.

[0009] Furthermore, the driving block is rotatably connected to the inner wall of the central tube, and the size specifications of the driving block are adapted to the inner wall of the central tube.

[0010] Furthermore, the outside of the central tube is rotatably connected to a guide tube, an adapting hole adapted to the oil inlet hole is provided on the guide tube, and a driving gear is installed on the outside of the guide tube.

[0011] Furthermore, an annular groove is provided on the outer surface of the central tube, a block is provided on the inner wall of the annular groove, a guide ring adapted to the annular groove is provided on the inner wall of the guide tube, and a limiting groove corresponding to the block is provided on the guide ring.

[0012] Furthermore, a convex ring adapted to the guide tube is provided on the outside of the central tube, two threaded grooves corresponding to the position of the limiting groove are opened on the top of the guide tube, and a through hole corresponding to the position of the block is opened on the top of the convex ring, and a locking screw is threadedly connected to the inside of one of the threaded grooves.

[0013] Furthermore, when the stop block abuts against the inner wall of one side of the limiting groove, the through hole corresponds to the position of the thread groove on the same side, and the adapter hole is connected to the oil inlet hole. When the stop block abuts against the inner wall of the other side of the limiting groove, the through hole corresponds to the position of the thread groove on the same side, and the adapter hole is staggered with the oil inlet hole.

[0014] Furthermore, receiving grooves are symmetrically provided at the upper and lower ends of the inner wall of the vibration vertical groove, and the width of the receiving groove is greater than the width of the vibration vertical groove. Closing plates are symmetrically installed at the upper and lower ends of the sliding block, and the closing plates are slidably connected to the inner side surfaces of the receiving groove, and the shape and size specifications of the closing plates are adapted to the receiving groove.

[0015] Compared with the prior art, the gravel packing sand control device for oil production wells provided by the present invention has the following beneficial effects: 1. The gravel filling and sand control device for oil production wells can effectively drive the gravel to vibrate during the gravel filling process through the mutual cooperation between the vibrating vertical trough, the vibrating block and the driving unit, making the gravel filling more compact, thereby achieving better sand control effect.

[0016] 2. The gravel filling sand prevention device for oil production wells can effectively guide the direction of the liquid during the gravel filling process through the mutual cooperation between the guide tube and the adapter hole, thereby ensuring the effective rotation of the driving block and making the vibration work of the vibration block proceed smoothly.

[0017] 3. The gravel filling and sand prevention device for oil production wells can effectively separate the vibration block and the liquid during operation through the mutual cooperation between the receiving groove and the closing plate, so that the flow of the liquid will not hinder the transmission of the vibration force of the vibration block, so that the gravel can withstand a greater vibration force and can be filled more compactly during the filling process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0019] Figure 1 A schematic diagram of the overall structure provided by an embodiment of the present invention; Figure 2 A schematic diagram of the overall longitudinal cross-sectional structure provided by an embodiment of the present invention; Figure 3 A schematic diagram of a partial cross-sectional structure of a guide tube and a central tube provided in an embodiment of the present invention; Figure 4 A schematic diagram of the structure of the central tube and the guide tube in the separated state provided by an embodiment of the present invention; Figure 5 This is a schematic diagram of the transverse cross-sectional structure of the central tube and the guide tube provided in an embodiment of the present invention.

[0020] Description of reference numerals: 1. Center tube; 101. Screen tube; 102. Filling chamber; 103. Bottom filter; 104. Injection pipe; 105. Oil inlet hole; 2. Vibration vertical groove; 21. Sliding block; 22. Vibration block; 23. Fault-tolerant spring; 3. Mounting frame; 31. Reciprocating screw; 32. Lifting seat; 33. Connecting rod; 34. Driving block; 35. Spiral groove; 36. Connecting groove; 4. Guide tube; 41. Adapter hole; 42. Driving gear; 5. Ring groove; 51. Stop block; 52. Guide ring; 53. Limiting groove; 54. Convex ring; 55. Threaded groove; 56. Through hole; 57. Locking screw; 6. Receiving groove; 61. Closing plate. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0022] See also Figures 1-5 A gravel packing and sand prevention device for oil production wells includes a central tube 1 with an oil inlet hole 105 on the surface and a screen tube 101 arranged on the outside thereof. A filling cavity 102 is formed between the central tube 1 and the screen tube 101. A bottom filter 103 is provided at the bottom of the screen tube 101, and an injection pipe 104 is provided at the top of the screen tube 101. Vibrating vertical grooves 2 are symmetrically provided on both sides of the inner wall of the central tube 1. A sliding block 21 is slidably connected to the inner wall of the vibrating vertical groove 2. A receiving groove is provided at the bottom of the sliding block 21. A vibrating block 22 is slidably connected to the inner side surface of the receiving groove. A fault-tolerant spring 23 is installed between the vibrating block 22 and the sliding block 21. A driving unit is provided on the outside of the sliding block 21.

[0023] During operation, liquid mixed with gravel is transported from the injection pipe 104 to the filling chamber 102. During this process, the driving unit drives the sliding block 21 to move up and down, so that the vibration block 22 collides with the bottom of the vibration vertical groove 2, so that the central tube 1 vibrates and drives the gravel inside the filling chamber 102 to vibrate, so that the gravel can be filled more compactly in the filling chamber 102.

[0024] The specific structure of the drive unit is described below. The drive unit includes a mounting frame 3 installed inside the central tube 1. A reciprocating screw 31 is installed at the bottom of the mounting frame 3. The external transmission of the reciprocating screw 31 is connected to a lifting seat 32. Connecting rods 33 are fixedly installed between the two sides of the lifting seat 32 and the sliding block 21. A driving block 34 is coaxially installed at the bottom of the reciprocating screw 31. The interior of the driving block 34 is in a circular shape and has multiple groups of spiral grooves 35 that are equidistantly spaced from top to bottom. A connecting groove 36 that is connected to the bottom end of the central tube 1 is provided at the bottom of the filling chamber 102.

[0025] It should be noted that the driving block 34 is rotatably connected to the inner wall of the central tube 1, and the size specifications of the driving block 34 are adapted to the inner wall of the central tube 1, so that the liquid flowing upward from the bottom can only pass through the spiral groove 35, thereby driving the driving block 34 to rotate effectively.

[0026] It should be further explained that the reciprocating screw 31 drives the driving block 34 to move in the vertical direction. The travel distance can meet the requirements for the driving block 34 to collide with the bottom of the inner wall of the vibration vertical groove 2, and the elastic coefficient of the fault-tolerant spring 23 is relatively large, so that it can compensate for the distance difference between the lifting seat 32 and the vibration block 22 during the movement of the lifting seat 32, but will not affect the impact force between the vibration block 22 and the inner wall of the vibration vertical groove 2 too much, so that the vibration force generated by the vibration block 22 when colliding is relatively large.

[0027] During operation, the liquid entering the filling chamber 102 enters the interior of the central tube 1 from the bottom connecting groove 36 thereof and flows upward from the bottom thereof. The upward-flowing liquid passes through the spiral groove 35, and in the process of passing through, it applies a continuous thrust to the inner wall of the spiral groove 35, so that the driving block 34 can rotate. The rotation of the driving block 34 drives the reciprocating screw 31 to rotate, so that the lifting seat 32 can continue to reciprocate up and down. In the process of moving downward, it can drive the vibration block 22 to collide with the bottom of the inner wall of the vibration vertical groove 2, so that the central tube 1 vibrates and transmits the vibration force to the gravel in the filling chamber 102.

[0028] Furthermore, the outside of the central tube 1 is rotatably connected to the guide tube 4, the screen tube 101 is connected to the outside of the guide tube 4, the guide tube 4 is provided with an adapter hole 41 adapted to the oil inlet hole 105, and a driving gear 42 is installed on the outside of the guide tube 4.

[0029] It should be noted that the driving gear 42 is driven by an external driving source, which can be a combination of an external motor and a transmission gear. The transmission method can be selected according to actual needs.

[0030] Through the cooperation of the guide tube 4, the oil inlet hole 105 can be closed during the gravel filling process, so that the liquid entering the filling chamber 102 can only enter from the bottom of the central tube 1 and be discharged from the top, thereby ensuring that the flow of liquid can drive the driving block 34 to rotate stably.

[0031] Further: an annular groove 5 is provided on the outer surface of the central tube 1, a stopper 51 is provided on the inner wall of the annular groove 5, a guide ring 52 adapted to the annular groove 5 is provided on the inner wall of the guide tube 4, a limiting groove 53 corresponding to the stopper 51 is provided on the guide ring 52, a convex ring 54 adapted to the guide tube 4 is provided on the outside of the central tube 1, two threaded grooves 55 corresponding to the positions of the limiting grooves 53 are provided on the top of the guide tube 4, a through hole 56 corresponding to the position of the stopper 51 is provided on the top of the convex ring 54, and a locking screw 57 is threadedly connected to the inside of one of the threaded grooves 55.

[0032] It should be noted that when the stopper 51 abuts against the inner wall of one side of the limiting groove 53, the through hole 56 corresponds to the position of the threaded groove 55 on the same side, and the adapter hole 41 is connected to the oil inlet hole 105. When the stopper 51 abuts against the inner wall of the other side of the limiting groove 53, the through hole 56 corresponds to the position of the threaded groove 55 on the same side, and the adapter hole 41 is staggered with the oil inlet hole 105.

[0033] During the gravel filling process or the subsequent formal work process, after the position adjustment of the guide tube 4 is completed, the guide tube 4 is fixedly connected to the center tube 1 through the cooperation between the locking screw 57 and the thread groove 55, so that the guide tube 4 has better stability during the actual work process.

[0034] Furthermore: accommodating grooves 6 are symmetrically opened at the upper and lower ends of the inner wall of the vibration vertical groove 2, the width of the accommodating groove 6 is greater than the width of the vibration vertical groove 2, and closing plates 61 are symmetrically installed at the upper and lower ends of the sliding block 21. The closing plate 61 is slidably connected to the inner side surface of the accommodating groove 6, and the shape and size specifications of the closing plate 61 are adapted to the accommodating groove 6.

[0035] In actual operation, the vibration vertical groove 2 is effectively closed by the closing plate 61 so that the vibration block 22 does not come into direct contact with the liquid, thereby effectively reducing the impact of the liquid flow on the vibration force transmission of the vibration block 22.

[0036] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A gravel packing and sand control device for oil production wells, comprising a central tube (1) with an oil inlet hole (105) on its surface and a screen tube (101) arranged outside the central tube (1), a filling cavity (102) being formed between the central tube (1) and the screen tube (101), a bottom filter (103) being provided at the bottom of the screen tube (101), and an injection nozzle (104) being provided at the top of the screen tube (101), characterized in that: Vibration vertical grooves (2) are symmetrically provided on both sides of the inner wall of the central tube (1); a sliding block (21) is slidably connected to the inner wall of the vibration vertical groove (2); a receiving groove is provided at the bottom of the sliding block (21); a vibration block (22) is slidably connected to the inner side surface of the receiving groove; a fault-tolerant spring (23) is installed between the vibration block (22) and the sliding block (21); and a driving unit is provided on the outside of the sliding block (21).

2. The gravel packing and sand control device for oil production wells according to claim 1, characterized in that: The driving unit comprises a mounting frame (3) mounted inside the central tube (1), a reciprocating screw rod (31) being mounted at the bottom of the mounting frame (3), a lifting seat (32) being connected to the external transmission of the reciprocating screw rod (31), and connecting rods (33) being fixedly mounted between the two sides of the lifting seat (32) and the sliding block (21).

3. The gravel packing and sand control device for oil production wells according to claim 2, characterized in that: A driving block (34) is coaxially mounted on the bottom of the reciprocating screw rod (31). The interior of the driving block (34) is provided with a plurality of groups of spiral grooves (35) extending vertically and equidistantly in an annular shape. A connecting groove (36) communicating with the bottom end of the central cylinder (1) is provided at the bottom of the filling cavity (102).

4. The gravel packing sand control device for oil production wells according to claim 3, characterized in that: The driving block (34) is rotatably connected to the inner wall of the central tube (1), and the size specifications of the driving block (34) are compatible with the inner wall of the central tube (1).

5. The gravel packing and sand control device for oil production wells according to claim 4, characterized in that: The outside of the central tube (1) is rotatably connected to a guide tube (4), and an adapting hole (41) adapted to the oil inlet hole (105) is provided on the guide tube (4). A driving gear (42) is installed on the outside of the guide tube (4).

6. The gravel packing and sand control device for oil production wells according to claim 5, characterized in that: An annular groove (5) is provided on the outer surface of the central tube (1), a stopper (51) is provided on the inner wall of the annular groove (5), a guide ring (52) adapted to the annular groove (5) is provided on the inner wall of the guide tube (4), and a limiting groove (53) corresponding to the stopper (51) is provided on the guide ring (52).

7. The gravel packing and sand control device for oil production wells according to claim 6, characterized in that: The center tube (1) is provided with a convex ring (54) adapted to the guide tube (4) on its exterior. The guide tube (4) is provided with two threaded grooves (55) corresponding to the positions of the limiting grooves (53) on its top. A through hole (56) corresponding to the position of the stopper (51) is provided on the top of the convex ring (54). A locking screw (57) is threadedly connected to the interior of one of the threaded grooves (55).

8. The gravel packing and sand control device for oil production wells according to claim 7, characterized in that: When the stopper (51) abuts against the inner wall of one side of the limiting groove (53), the through hole (56) corresponds to the position of the threaded groove (55) on the same side, and the adapting hole (41) is connected to the oil inlet hole (105); when the stopper (51) abuts against the inner wall of the other side of the limiting groove (53), the through hole (56) corresponds to the position of the threaded groove (55) on the same side, and the adapting hole (41) is staggered from the position of the oil inlet hole (105).

9. The gravel packing and sand control device for oil production wells according to claim 8, characterized in that: The upper and lower ends of the inner wall of the vibration vertical groove (2) are symmetrically provided with a receiving groove (6), the width of the receiving groove (6) is greater than the width of the vibration vertical groove (2), and the upper and lower ends of the sliding block (21) are symmetrically provided with a closing plate (61), the closing plate (61) is slidably connected to the inner side surface of the receiving groove (6), and the shape and size specifications of the closing plate (61) are adapted to the receiving groove (6).

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