Multi-section suction type sand prevention device
By using a multi-stage suction-type sand control device, the problem of sand bridge formation in horizontal wells for pre-extraction of coalbed methane was solved, enabling continuous liquid supply under low flow pressure and low permeability conditions, increasing production and extending the stable operation time of downhole pumps.
Patent Information
- Application Number
- CN202421902471.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-07
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2034-08-07
AI Technical Summary
In horizontal wells for pre-extraction of coalbed methane, as the drainage time increases, sand bridges are easily formed at the downhole pump hanger, affecting the drainage effect. Furthermore, the reservoir energy is not fully released, and existing sand control devices cannot ensure continuous fluid supply under low flow pressure and low permeability conditions, resulting in unstable operation of the downhole pump.
A multi-stage suction-type sand control device is adopted, including a horizontally arranged outer pipe and an inner pipe. A flow guiding channel is formed between the outer pipe and the inner pipe. The two ends of the outer pipe are densely covered with screen holes, and the middle of the inner pipe is densely covered with screen holes. The inner wall of the outer pipe has an annular groove as a sand control step, which extends to the depth of the horizontal section. The accumulated liquid is discharged through the screen holes of the outer pipe and the screen holes of the inner pipe, avoiding the influence of sand bridge and optimizing the working environment of the pump.
It effectively removes accumulated liquid deep in the horizontal section, increases coalbed methane production, extends well workover cycle, reduces the frequency of downhole pump replacement, lowers well workover costs, and increases production capacity.
Smart Images
Figure CN223647794U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a multi-stage suction-type sand control device, belonging to the technical field of sand control devices for horizontal well coalbed methane extraction. Background Technology
[0002] As the production time increases, the gas volume of a single well in a coalbed methane pre-drainage horizontal well gradually decreases. In order to further release the reservoir energy, it is necessary to further lower the pump hanger. However, after the pump hanger is lowered, the discharge of powder and sand in the well affects the continuous and stable operation of the downhole pump. Moreover, the horizontal section is undulating, and as time goes by, sand bridges are easily formed at the troughs, affecting the extraction effect. Currently, the lowest position of the pump hanger in the horizontal well that has been put into operation is located at 80~85° of the horizontal well inclination, which is still 0.1~0.15MPa of flowing pressure away from the coal seam. The reservoir energy has not been fully released, and the well workover cycle is short. Utility Model Content
[0003] To address the shortcomings of existing technologies, the purpose of this utility model is to provide a sand-prevention device that, when the pump hanger is lowered to the landing point or extended to the horizontal section, solves the problem of excessive impact of coal dust and sand in the wellbore on the downhole pump, optimizes the working environment of the downhole pump, and ensures continuous liquid supply under conditions of low flow pressure, low permeability, and low pump hanger, thus preventing pump burnout.
[0004] To achieve the above objectives, the present invention adopts the following technical solution: a multi-stage suction sand control device, comprising a horizontally arranged outer tube and an inner tube, the front end of the outer tube being open and the rear end being connected to an outer tube plug, the front end of the inner tube being open and the rear end being connected to an inner tube plug, the outer tube being fitted over the outer tube, the inner wall of the outer tube and the outer wall of the inner tube being a flow channel, the walls at both ends of the outer tube being densely covered with outer tube screen holes, and the wall in the middle of the inner tube being densely covered with inner tube screen holes;
[0005] The inner wall of the outer tube is evenly distributed with multiple annular grooves, which serve as sand-proof steps;
[0006] The front end of the inner tube is flush with the front end of the outer tube, and the tail end is located at the screen hole of the outer tube at the tail end of the outer tube.
[0007] In this invention, the outer tube may have screen holes densely distributed only on the tube wall at the tail end, while the inner tube screen holes are densely distributed on the tube wall at the front end of the inner tube.
[0008] Preferably, the outer tube includes a first oil pipe, a second oil pipe, and an outer screen pipe. Multiple first oil pipes are arranged in a row from front to back. A second oil pipe is connected between each pair of adjacent first oil pipes. The outer diameter of the second oil pipe is adapted to the inner diameter of the first oil pipe. The two ends of the second oil pipe are respectively fitted into the ends of the adjacent first oil pipes. The two first oil pipes at both ends are respectively connected to an outer screen pipe. The outer screen pipe is densely covered with outer pipe screen holes. The outer screen pipe at the tail end is connected to the outer pipe plug. The inner wall of the first oil pipe and the pipe thickness of the two adjacent second oil pipes form a sand-proof step.
[0009] Preferably, the total length of the outer tube is 100m, the first oil tube is an 89 oil tube with an outer diameter of 88.9mm and a length of 5.5m, the second oil tube is a 73 oil tube with an outer diameter of 73mm and a length of 0.5m, and the outer screen tube is a 73 oil tube with an outer diameter of 73mm and a length of 2m.
[0010] Preferably, the inner tube includes a third oil pipe, a fourth oil pipe, and an inner screen pipe. One end of the third oil pipe is the front end, and the other end is connected to one end of the inner screen pipe. The other end of the inner screen pipe is connected to one end of the fourth oil pipe, and the other end of the fourth oil pipe is the tail end, which is connected to the inner tube plug. The inner screen pipe is densely covered with inner tube screen holes.
[0011] Preferably, the third oil pipe, the fourth oil pipe, and the inner screen pipe are all oil pipes with an outer diameter of 36 mm.
[0012] Preferably, the third and fourth oil pipes are composed of multiple oil pipes connected in sequence.
[0013] Preferably, the diameter of the outer tube sieve hole is 6-10 mm, and the diameter of the inner tube sieve hole is 4-8 mm.
[0014] Preferably, the diameter of the outer tube sieve hole is 8 mm, and the diameter of the inner tube sieve hole is 5 mm.
[0015] Preferably, both the inner tube and the outer tube are flexible tubes.
[0016] Compared with the prior art, the present invention has the following beneficial effects.
[0017] 1. This utility model is connected to a pump. After the pump is placed at the landing point of the horizontal section, this utility model can extend to a deeper part of the horizontal section. It draws in the accumulated liquid in the horizontal section through both ends of the outer pipe, especially the tail end, so that the pump's suction port extends to a deeper part of the horizontal section and discharges the accumulated liquid in the deeper part of the horizontal section. This further releases the coalbed methane in the horizontal well and greatly increases the production.
[0018] 2. In this utility model, a flow channel is formed between the outer pipe and the inner pipe. The accumulated liquid entering from both ends of the outer pipe enters the inner pipe through the flow channel, thus avoiding the impact of sand bridges in the horizontal section on the pumping effect.
[0019] 3. In this utility model, after the accumulated liquid enters the guide channel from both ends of the outer pipe, the flow rate of the accumulated liquid in the guide channel is slow and unaffected by gas disturbance, which is conducive to the settling of sand. At the same time, it will pass through multiple sand-proof steps to settle sand, effectively preventing sand from entering the working pump, optimizing the working environment of the pump, providing technical support for the discharge of mixed sand accumulated liquid in deeper horizontal sections, improving production capacity, extending the well workover cycle, and reducing the frequency of replacing the working pump. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in 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.
[0021] Figure 1 This is a structural schematic diagram of Embodiment 1 of the present utility model.
[0022] In the diagram: 1 is the outer tube, 11 is the outer tube screen hole, 12 is the first oil tube, 13 is the second oil tube, 14 is the outer screen tube, 2 is the inner tube, 21 is the inner tube screen hole, 22 is the third oil tube, 23 is the fourth oil tube, 24 is the inner screen tube, 3 is the outer tube plug, 4 is the inner tube plug, 5 is the flow guide channel, and 6 is the sand control step. Detailed Implementation
[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.
[0024] It should be noted that the structures, proportions, sizes, etc. shown in the accompanying drawings of this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which this utility model can be implemented. Therefore, they have no substantial technical significance. Any modification to the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed in this utility model, provided that it does not affect the effects and purposes that this utility model can produce. It should be noted that in this specification, relational terms such as "first" and "second" are only used to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.
[0025] The present invention provides the following embodiments.
[0026] Example 1
[0027] like Figure 1 As shown, this utility model discloses a multi-stage suction sand control device, which includes a horizontally arranged outer tube 1 and inner tube 2. The front end of the outer tube 1 is open and the tail end is connected to the outer tube plug 3. The front end of the inner tube 2 is open and the tail end is connected to the inner tube plug 4. The outer tube 1 is fitted outside the inner tube 2. The inner wall of the outer tube 1 and the outer wall of the inner tube 2 form a flow guiding channel 5. The tube walls at both ends of the outer tube 1 are densely covered with outer tube screen holes 11, and the tube wall in the middle of the inner tube 2 is densely covered with inner tube screen holes 21.
[0028] The length of the pipe wall occupied by the outer tube sieve hole 11 and the inner tube sieve hole 21 is 1-3m;
[0029] The inner wall of the outer tube 1 is evenly distributed with multiple annular grooves, which are sand-proof steps 6;
[0030] The front end of the inner tube 2 is flush with the front end of the outer tube 1, and the tail end is located at the outer tube sieve hole 11 at the tail end of the outer tube 1.
[0031] In order to drain the accumulated fluid from deeper parts of the horizontal well, this utility model can be made in different lengths depending on the situation. In the case of total length, in order to facilitate installation and prevent the inner tube 2 from being subjected to axial pressure, the inner tube 2 can be a few meters or more than ten meters shorter than the outer tube 1. That is, the tail end of the inner tube 2 can be a few meters or more than ten meters away from the tail end of the outer tube 1 and the outer tube screen hole 11. All of these should be within the protection scope of this utility model.
[0032] The inner tube screen hole 21 should be located in the middle of the two outer tube screen holes 11, with a deviation of a few meters or more than ten meters. In order to achieve a better gas prevention effect, the vertical depth of the inner tube screen hole 21 should be lower than the vertical depth of the two outer tube screen holes 11, based on the actual drilling trajectory data of the horizontal well.
[0033] The outer tube 1 includes a first oil pipe 12, a second oil pipe 13, and an outer screen pipe 14. Multiple first oil pipes 12 are arranged in a row from front to back. A second oil pipe 13 is connected between each two adjacent first oil pipes 12. The outer diameter of the second oil pipe 13 is adapted to the inner diameter of the first oil pipe 12. The two ends of the second oil pipe 13 are respectively fitted into the ends of the adjacent first oil pipes 12. The two first oil pipes 12 at both ends are respectively connected to an outer screen pipe 14. The outer screen pipe 14 is densely covered with outer screen holes 11. The outer screen pipe 14 at the tail end is connected to the outer screen plug 3. The inner wall of the first oil pipe 12 and the pipe thickness of the two adjacent second oil pipes 13 form a sand-proof step 6.
[0034] The outer pipe 1 has a total length of 100m. The first oil pipe 12 is an 89 oil pipe with an outer diameter of 88.9mm and a length of 5.5m. The second oil pipe 13 is a 73 oil pipe with an outer diameter of 73mm and a length of 0.5m. The outer screen pipe 14 is a 73 oil pipe with an outer diameter of 73mm and a length of 2m.
[0035] The inner tube 2 includes a third oil pipe 22, a fourth oil pipe 23 and an inner screen pipe 24. One end of the third oil pipe 22 is the front end, and the other end is connected to one end of the inner screen pipe 24. The other end of the inner screen pipe 24 is connected to one end of the fourth oil pipe 23. The other end of the fourth oil pipe 23 is the tail end, which is connected to the inner tube plug 4. The inner screen pipe 24 is densely covered with inner tube screen holes 21.
[0036] The third oil pipe 22 and the fourth oil pipe 23 are both composed of multiple oil pipes connected in sequence.
[0037] The third oil pipe 22, the fourth oil pipe 23, and the inner screen pipe 24 are all oil pipes with an outer diameter of 36 mm.
[0038] The diameter of the outer tube sieve hole 11 can be 6mm, 7mm, 8mm, 9mm, or 10mm, preferably 8mm, and the diameter of the inner tube sieve hole 21 can be 4mm, 5mm, 6mm, 7mm, or 8mm, preferably 5mm.
[0039] Both the inner tube 2 and the outer tube 1 are flexible tubes.
[0040] The installation and operation process of this embodiment is as follows.
[0041] The present invention is assembled on the ground and connected to the bottom of the hydraulic tubular pump (rodless pump). It is then smoothly lowered into the horizontal well. The pump hanger is placed at the landing point of the horizontal section. The present invention extends to the depth of the horizontal section. The tail end of the outer screen pipe 14 passes through the first perforation section near the well. After the whole assembly is installed and debugged, the pump works to pump water. The accumulated liquid enters the guide channel 5 through the outer pipe screen holes 11 at the front and rear ends. The accumulated liquid flows slowly in the guide channel 5. The silt mixed in the accumulated liquid is deposited into the sand-prevention step 6 under the action of gravity. Then it enters the inner pipe 2 through the inner pipe screen hole 21 and is finally pumped out to the ground and discharged.
[0042] Example 2
[0043] In this embodiment, the outer tube 1 has a dense array of outer tube sieve holes 11 on the tube wall at its tail end, while the inner tube sieve holes 21 are densely distributed on the tube wall at the front end of the inner tube 2.
[0044] In the specific structure of the outer tube 1, only one outer screen tube 14 is needed, which is connected between the first oil tube 12 at the tail end and the outer tube plug 3;
[0045] In the specific structure of the inner tube 2, the inner screen tube 24 is located at the front end, the third oil tube 22 and the fourth oil tube 23 are connected to the inner screen tube 24 in sequence, and the inner tube plug 4 is connected to the tail end of the fourth oil tube 23.
[0046] The other structures in this embodiment are the same as those in Embodiment 1.
[0047] The installation and operation process of this embodiment is the same as that in embodiment one. However, when the pump is pumping water, the accumulated liquid only enters the guide channel 5 through the outer pipe screen hole 11 at the tail end, and then is pumped out of the ground and discharged through the inner pipe screen hole 21.
[0048] The above two embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0049] This invention effectively avoids the influence of silt, extends the pump inlet deep into the horizontal section, discharges the accumulated liquid in the horizontal section, further releases coalbed methane, effectively improves the production of horizontal wells, extends the well workover cycle, reduces the frequency of replacing downhole pumps, and saves well workover and pump replacement costs.
[0050] This invention can be used to build new horizontal wells and is even more suitable for the renovation of existing horizontal wells. Currently, this invention has been used to renovate multiple existing horizontal wells in the Zhengzhuang mining area of Jincheng, Shanxi. After the renovation, the gas production of a single well has been significantly increased, the well repair rate has been reduced by 20%, the replacement of multiple downhole pumps has been reduced, the annual increase in gas production profit is more than 200,000 yuan, and the annual cost savings are more than 2 million yuan.
[0051] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.
Claims
1. A multi-stage suction-type sand control device, characterized in that: It includes a horizontally arranged outer tube (1) and inner tube (2). The front end of the outer tube (1) is open and the tail end is connected to the outer tube plug (3). The front end of the inner tube (2) is open and the tail end is connected to the inner tube plug (4). The outer tube (1) is fitted outside the inner tube (2). The inner wall of the outer tube (1) and the outer wall of the inner tube (2) form a flow channel (5). The walls at both ends of the outer tube (1) are densely covered with outer tube screen holes (11), and the walls in the middle of the inner tube (2) are densely covered with inner tube screen holes (21). The inner wall of the outer tube (1) is evenly distributed with multiple annular grooves, which are sand-proof steps (6). The front end of the inner tube (2) is flush with the front end of the outer tube (1), and the tail end is located at the outer tube sieve hole (11) at the tail end of the outer tube (1).
2. The multi-stage suction-type sand control device according to claim 1, characterized in that: The outer tube (1) has sieve holes (11) densely distributed on the tube wall at the tail end, while the inner tube sieve holes (21) are densely distributed on the tube wall at the front end of the inner tube (2).
3. The multi-stage suction-type sand control device according to claim 1, characterized in that: The outer tube (1) includes a first oil pipe (12), a second oil pipe (13) and an outer screen pipe (14). Multiple first oil pipes (12) are arranged in a row from front to back. A second oil pipe (13) is connected between each two adjacent first oil pipes (12). The outer diameter of the second oil pipe (13) is adapted to the inner diameter of the first oil pipe (12). The two ends of the second oil pipe (13) are respectively fitted into the ends of the adjacent first oil pipes (12). The two first oil pipes (12) at both ends are respectively connected to an outer screen pipe (14). The outer screen pipe (14) is densely covered with outer screen holes (11). The outer screen pipe (14) at the tail end is connected to the outer screen plug (3). The inner wall of the first oil pipe (12) and the pipe thickness of the two adjacent second oil pipes (13) form a sand-proof step (6).
4. A multi-stage suction-type sand control device according to claim 3, characterized in that: The outer pipe (1) has a total length of 100m. The first oil pipe (12) is an 89 oil pipe with an outer diameter of 88.9mm and a length of 5.5m. The second oil pipe (13) is a 73 oil pipe with an outer diameter of 73mm and a length of 0.5m. The outer screen pipe (14) is a 73 oil pipe with an outer diameter of 73mm and a length of 2m.
5. A multi-stage suction-type sand control device according to claim 1, characterized in that: The inner tube (2) includes a third oil pipe (22), a fourth oil pipe (23) and an inner screen pipe (24). One end of the third oil pipe (22) is the front end, and the other end is connected to one end of the inner screen pipe (24). The other end of the inner screen pipe (24) is connected to one end of the fourth oil pipe (23). The other end of the fourth oil pipe (23) is the tail end, which is connected to the inner tube plug (4). The inner screen pipe (24) is densely covered with inner tube screen holes (21).
6. A multi-stage suction-type sand control device according to claim 5, characterized in that: The third oil pipe (22), the fourth oil pipe (23) and the inner screen pipe (24) are all oil pipes with an outer diameter of 36 mm.
7. A multi-stage suction-type sand control device according to claim 5, characterized in that: The third oil pipe (22) and the fourth oil pipe (23) are both composed of multiple oil pipes connected in sequence.
8. A multi-stage suction-type sand control device according to claim 1, characterized in that: The diameter of the outer tube sieve hole (11) is 6-10 mm, and the diameter of the inner tube sieve hole (21) is 4-8 mm.
9. A multi-stage suction-type sand control device according to claim 8, characterized in that: The diameter of the outer tube sieve hole (11) is 8 mm, and the diameter of the inner tube sieve hole (21) is 5 mm.
10. A multi-stage suction-type sand control device according to claim 1, characterized in that: Both the inner tube (2) and the outer tube (1) are flexible tubes.