Sand washing equipment for clamping and sealing of packer of coal-bed gas well
By using packer-sealed sand flushing equipment, combined with packer setting, dual-pipe reverse circulation, and coal breaking knife, the problem of damage to coal seams caused by hydraulic sand flushing is solved. This achieves efficient removal of coal blockage, reduces water consumption and costs, and improves the production continuity and gas production of coalbed methane wells.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2025-06-06
- Publication Date
- 2026-04-17
AI Technical Summary
Existing hydraulic sand flushing technology causes significant damage to coal seams, leading to waterlogging of coal seam channels and the formation of "water locks," resulting in reduced production. Furthermore, conventional sand flushing methods consume large amounts of water and have long recovery times, affecting the production continuity and capacity of coalbed methane wells.
The packer-sealed sand flushing equipment uses a combination of packer setting, double-pipe reverse circulation, and coal crushing knife to efficiently remove coal chunks and sediment from the wellbore. Soluble balls and coal crushing knives are used to reduce damage to the coal seam. Small and large oil pipes are used in combination for sand flushing fluid injection and sediment return.
It effectively removes coal blockage and interlayer interference in coalbed methane wells, adapts to low dynamic fluid levels, reduces water consumption, lowers costs, improves production continuity and gas production, and the packer can be reused.
Smart Images
Figure CN224134611U_ABST
Abstract
Description
Technical Field
[0001] This utility model specifically relates to the field of mine sand flushing technology, and more specifically to a packer sealing and sand flushing device for coalbed methane wells. Background Technology
[0002] Currently, coalbed methane wells are mainly put into production using large-scale fracturing. While fracturing increases production capacity, it also brings production problems. The return of fracturing sand and coal particles, along with coal dust settling into the wellbore, causes the sand surface to rise continuously, burying the coal seam and reducing gas production. Therefore, it is necessary to deal with the sand and coal dust in the wellbore. In the mid-to-late stages of production, with low fluid production, it is impossible to effectively carry the fracturing sand and coal dust generated during the drainage process to the surface, resulting in high coal dust concentration in the wellbore. This ultimately leads to pump maintenance, interrupting production continuity, increasing development costs, and affecting gas well production capacity.
[0003] The existing sand mining method mainly uses hydraulic flushing. Due to the continuous decline in formation energy and severe formation depletion, ordinary hydraulic flushing causes great damage to the coal seam. A large amount of well washing fluid enters the coal seam, resulting in large water consumption and long recovery time. In severe cases, the coal seam channel is filled with water, which prevents gas from moving and forms a "water lock", which greatly reduces production. Utility Model Content
[0004] Therefore, this utility model proposes a packer sealing and sand flushing device for coalbed methane wells to solve the problems mentioned in the background art.
[0005] To achieve the above objectives, this utility model provides the following technical solution: a packer sealing and sand flushing device for coalbed methane wells, comprising:
[0006] The large oil pipe is placed inside the well.
[0007] The packer, which is a K341 packer, is installed at the bottom end of the main tubing;
[0008] Soluble balls are placed inside the large oil pipe and sit on the packer. The large oil pipe is pressurized by a pump truck to drive the soluble balls to squeeze the ball seat of the packer until the ball seat falls off and the rubber sleeve of the packer expands and sets.
[0009] A small oil pipe is installed inside the large oil pipe, and multiple evenly distributed coal shredders are installed at the bottom end of the small oil pipe.
[0010] The straightening mechanism is provided in multiple units and is arranged at equal intervals on the side wall of the small oil pipe. The multiple straightening mechanisms can work together to ensure that the small oil pipe and the large oil pipe are always coaxially aligned.
[0011] And a mining small four-way valve, which is equipped with a main channel and a side channel. One end of the main channel is connected to the large oil pipe, and the other end of the main channel is connected to the pump truck through the injection channel. One end of the side channel is connected to the small oil pipe, and the other end of the side channel is connected to the sedimentation tank through the return pipe.
[0012] Furthermore, as a preferred embodiment, the bottom end of the small oil pipe is fixed with a filter screen located above the coal crusher.
[0013] Furthermore, as a preferred embodiment, the diameter of the large oil pipe is set to 73 mm, and the diameter of the small oil pipe is set to 48 mm.
[0014] Furthermore, as a preferred embodiment, the packer is disposed below the underground coal seam, and the distance between the packer and the coal seam is set to 2m.
[0015] Furthermore, as a preferred embodiment, the pressure value of the pump truck pressurization is set to 15 MPa.
[0016] Furthermore, preferably, the straightening mechanism includes:
[0017] A retaining collar is fixed to the side wall of the small oil pipe;
[0018] A slip ring is slidably disposed in an annular groove on the outer wall of the fixed collar, and a plurality of movable handles are arranged in a circumferential array on the side wall of the slip ring.
[0019] Multiple fixing handles are provided and arranged in a circumferential array on the side wall of the fixing collar;
[0020] The support arm is the same number as the moving handle and the fixed handle. One end of each support arm can be rotatably connected to the corresponding fixed handle. The other end of each support arm is fixed with a wheel seat, and a roller is installed on the wheel seat. The middle of each support arm is fixed with an ear seat, and an adjusting arm is rotatably connected between the ear seat and the moving handle.
[0021] Furthermore, as a preferred embodiment, a telescopic rod is connected between the moving handle and the fixed handle, and a spring is wound around the side wall of the telescopic rod.
[0022] This utility model adopts the above technology and has the following beneficial effects compared with the existing technology: The device of this utility model, through the combination of packer setting, double-pipe reverse circulation, and coal breaking knife protection, efficiently solves the problems of coal blockage and inter-layer interference in the sand flushing of coalbed methane wells. It is suitable for very low coalbed pneumatic liquid level, does not damage the coalbed, has a simple and conventional process, low water consumption, relatively low cost, low impact on gas production, and the packer can be reused, only the soluble ball seat needs to be replaced. Attached Figure Description
[0023] Figure 1 A schematic diagram of a packer sealing and sand flushing device for a coalbed methane well.
[0024] Figure 2 This is a schematic diagram of the straightening mechanism in a packer sealing and sand flushing device for a coalbed methane well.
[0025] Figure 3 for Figure 2 An enlarged schematic diagram of part A in the middle.
[0026] In the diagram: 1. Mining small four-way valve; 2. Small oil pipe; 3. Centralizing mechanism; 4. Packer; 5. Coal crusher; 6. Filter screen; 7. Large oil pipe; 301. Roller; 302. Wheel seat; 303. Support arm; 304. Ear seat; 305. Fixing handle; 306. Fixing collar; 307. Moving handle; 308. Adjusting arm; 309. Slip ring; 310. Annular groove. Detailed Implementation
[0027] With reference to the accompanying drawings of the embodiments of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below.
[0028] Example: Please refer to the appendix. Figure 1-3 This utility model provides a technical solution: a packer sealing and sand flushing device for coalbed methane wells, comprising:
[0029] The main oil pipe 7 is placed inside the well.
[0030] Packer 4, which adopts K341 packer, is installed on the bottom end of the main tubing 7;
[0031] Soluble balls are placed inside the large oil pipe 7 and sit on the packer 4. The large oil pipe 7 is pressurized by a pump truck to drive the soluble balls to squeeze the ball seat of the packer 4 until the ball seat falls off and the rubber sleeve of the packer 4 expands and sets.
[0032] Small oil pipe 2 is installed inside large oil pipe 7, and multiple evenly distributed coal shredders 5 are installed at the bottom end of small oil pipe 2.
[0033] The straightening mechanism 3 is provided in multiples and is arranged at equal intervals on the side wall of the small oil pipe 2. The multiple straightening mechanisms 3 can work together to ensure that the small oil pipe 2 and the large oil pipe 7 are always coaxially arranged.
[0034] And the mining small four-way valve 1, which is equipped with a main channel and a side channel. One end of the main channel is connected to the large oil pipe 7, and the other end of the main channel is connected to the pump truck through the injection channel. One end of the side channel is connected to the small oil pipe 2, and the other end of the side channel is connected to the sedimentation tank through the return pipe.
[0035] In this embodiment, a filter screen 6 located above the coal shredder 5 is fixed at the bottom end of the small oil pipe 2.
[0036] In this embodiment, the diameter of the large oil pipe 7 is set to 73mm, and the diameter of the small oil pipe 2 is set to 48mm.
[0037] In this embodiment, the packer 4 is located below the underground coal seam, and the distance between the packer 4 and the coal seam is set to 2m.
[0038] In this embodiment, the pressure value of the pump truck pressurization is set to 15MPa.
[0039] In this embodiment, the straightening mechanism 3 includes:
[0040] The retaining collar 306 is fixed to the side wall of the small oil pipe 2;
[0041] The slip ring 309 is matched and slidably disposed in the annular groove 310 on the outer wall of the fixed collar 306, and the side wall of the slip ring 309 has a plurality of moving handles 307 arranged in a circular array.
[0042] Multiple fixing handles 305 are provided and arranged in a circumferential array on the side wall of the fixing collar 306;
[0043] And support arms 303, which are the same number as moving handles 307 and fixed handles 305. One end of each support arm 303 can be rotatably connected to the corresponding fixed handle 305. The other end of each support arm 303 is fixed with a wheel seat 302, and a roller 301 is installed on the wheel seat 302. The middle part of each support arm 303 is fixed with an ear seat 304, and an adjusting arm 308 is rotatably connected between the ear seat 304 and the moving handle 307.
[0044] In this embodiment, a telescopic rod is connected between the movable handle 307 and the fixed handle 305, and a spring is wound around the side wall of the telescopic rod.
[0045] In practice, the following steps are included:
[0046] S1: Connect the packer to the 73mm tubing and lower it to 2m below the bottom of the coal seam (ensure that the packer is set below the target seam to avoid disturbing the coal seam).
[0047] S2: Drop the soluble ball into the main oil pipe. The soluble ball falls into the ball seat of the packer. Pressurize the pump to 15MPa. The pressure pushes the soluble ball to seal the ball seat. The hydraulic action causes the packer rubber sleeve to expand and set. Continue to pressurize until the ball seat shears off (falls off), and establish the oil pipe channel (at this time, the packer is fixed and the oil pipe is restored to its original diameter). Test the pressure at 15MPa to verify the packer's sealing performance (to ensure effective interlayer isolation).
[0048] S3: Install a small oil pipe and use a straightening mechanism to center the small oil pipe inside the large oil pipe. The small oil pipe serves as a channel for flushing fluid return (forming a cycle of "fluid injection in the large pipe and return in the small pipe").
[0049] S4: The flushing fluid (such as water or sand-carrying fluid) is injected through the large oil pipe. After passing through the coal seam, the fluid carries coal slurry and sediment, and is discharged back to the surface through the small oil pipe.
[0050] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.
Claims
1. A packer sealing and sand flushing device for coalbed methane wells, characterized in that, It includes: The large oil pipe (7) is placed inside the well; Packer (4), which adopts K341 packer, is installed on the bottom end of the large oil pipe (7); Soluble balls are placed inside the large oil pipe (7) and placed on the packer (4). The large oil pipe (7) is pressurized by a pump truck to drive the soluble balls to squeeze the ball seat of the packer (4) until the ball seat falls off and the rubber sleeve of the packer (4) expands and sets. Small oil pipe (2) is installed inside the large oil pipe (7), and multiple evenly distributed coal shredders (5) are installed at the bottom end of the small oil pipe (2). The straightening mechanism (3) is provided in multiple ways and is arranged at equal intervals on the side wall of the small oil pipe (2). The multiple straightening mechanisms (3) can work together to ensure that the small oil pipe (2) and the large oil pipe (7) are always coaxially arranged. And a mining small four-way valve (1), which is provided with a main channel and a side channel. One end of the main channel is connected to the large oil pipe (7), and the other end of the main channel is connected to the pump truck through the injection channel. One end of the side channel is connected to the small oil pipe (2), and the other end of the side channel is connected to the sedimentation tank through the return pipe.
2. The coal bed gas well packer and sand washing device of claim 1, wherein: The bottom end of the small oil pipe (2) is fixed with a filter screen (6) located above the coal shredder (5).
3. The coal bed gas well packer and sand washing device of claim 1, wherein: The diameter of the large oil pipe (7) is set to 73 mm, and the diameter of the small oil pipe (2) is set to 48 mm.
4. The coal bed gas well packer and sand washing device of claim 1, wherein: The packer (4) is located below the coal seam underground, and the distance between the packer (4) and the coal seam is set to 2m.
5. The coal bed gas well packer and sand washing device of claim 1, wherein: The pressure value for pressurizing the pump truck is set to 15 MPa.
6. The coal bed gas well packer and sand washing device of claim 1, wherein: The straightening mechanism (3) includes: A retaining collar (306) is fixed to the side wall of the small oil pipe (2); A slip ring (309) is slidably disposed in an annular groove (310) on the outer wall of the fixed collar (306), and a plurality of movable handles (307) are arranged in a circumferential array on the side wall of the slip ring (309). Multiple fixing handles (305) are provided and arranged in a circumferential array on the side wall of the fixing collar (306); And support arms (303), which are the same number as moving handles (307) and fixed handles (305). One end of each support arm (303) can be rotatably connected to the corresponding fixed handle (305). The other end of each support arm (303) is fixed with a wheel seat (302), and a roller (301) is installed on the wheel seat (302). The middle part of each support arm (303) is fixed with an ear seat (304), and an adjusting arm (308) is rotatably connected between the ear seat (304) and the moving handle (307).
7. The coal bed gas well packer and sand washing device of claim 6, wherein: A telescopic rod is connected between the movable handle (307) and the fixed handle (305), and a spring is wound around the side wall of the telescopic rod.