Composite unblocking device for scaling well

Abstract

The utility model discloses a composite unblocking device for a scaling well, which comprises a shaft cleaning device, and the shaft cleaning device comprises a scale body fishing basket, a descending water pressing device and a pipe scraping device which are sequentially arranged from top to bottom; the pipe scraping device is provided with a central channel, and the central channel is communicated with the dirt body fishing basket; and under the action of the descending water pressing device, the scale body is pressed into the central channel along with the liquid and enters the scale body fishing basket. According to the utility model, automatic collection of dirt is realized. According to the utility model, the dirt can be thoroughly removed, and the effective period of blockage removal is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of oilfield development technology, specifically a composite unblocking device for scaled wells. Background Technology

[0002] Due to scaling near the wellbore, the permeability of oil and water wells decreases, and the levels of fluids and oil show a downward trend. For the decrease in fluid volume caused by scaling, the unblocking agent is generally directly injected in layers through the tubing or packer to remove the scale, which can have a certain effect, but the effective period is short and the scale removal and unblocking are not thorough.

[0003] Announcement No. CN219492268U discloses an oilfield workover tool, including an upper connector, an outer tube, and a central tube. The central tube is located inside the outer tube, and a sand sample channel is provided between the central tube and the outer tube. The upper connector is located at the upper end of the sand sample channel and is sealed to the central tube and the outer tube. A deformable cup is provided at the lower middle end of the central tube. The base of the cup is fixed to the central tube, the opening of the cup faces upward, and the upper edge of the cup is connected to the inner side of the outer tube. A movable scraper block is provided at the lower end of the outer tube, and a spring is provided at the lower end of the central tube, with the spring connected to the scraper block.

[0004] The existing technology uses a different method for setting up the sieve tube and the leather cup than this patent. The existing technology reduces the service life of the leather cup by collecting the scale.

[0005] Announcement No. CN108729879B discloses an integrated tool and method for scraping and cleaning the inner wall of oil and water well casing. The tool includes an impeller cylinder, an impeller, a guide cylinder, a wheel shaft, a tool holder, and a scraper. The impeller cylinder has a central shaft at its center, and the wheel shaft is sleeved on the outside of the central shaft. The impeller is mounted on the wheel shaft, and the entire impeller is located inside the impeller cylinder. The lower end of the impeller cylinder is sleeved inside the guide cylinder. At the same time, the central shaft and the wheel shaft pass through the central hole of the guide cylinder. A tool holder is also mounted on the wheel shaft. The entire tool holder is located below the guide cylinder, and a scraper is installed on the edge of the tool holder.

[0006] The existing screen tube setup method and the source of fluid flow power are different from those of this patent. The existing technology will carry some scale out of the tubing, which is not convenient for subsequent analysis of downhole scale and cannot obtain accurate downhole scaling information.

[0007] Announcement No. CN112523726B discloses a wax scraping cleaning tool for coiled tubing and its usage method. The tool includes a wax scraping structure, which comprises a branch inner tube. A forward spiral wax scraping section and a reverse spiral wax scraping section are axially spaced on the branch inner tube. Both the forward and reverse spiral wax scraping sections have an internal spiral hydraulic rotating tube inside, which drives the forward and reverse spiral wax scraping sections to rotate and scrape wax. A wax cleaning structure is abutting between the forward and reverse spiral wax scraping sections, used for axial and radial jet cleaning. A guide flushing structure is connected to the bottom of the branch inner tube, and a limiting sealing structure is connected to the top of the branch inner tube.

[0008] This existing technology is used for scraping wax and dirt, but it cannot recover the dirt.

[0009] In summary, the technical solutions, technical problems to be solved, and beneficial effects of the above-disclosed technologies are all different from those of this utility model. For more technical features, technical problems to be solved, and beneficial effects of this utility model, the above-disclosed technical documents do not provide any technical inspiration. Utility Model Content

[0010] In view of the above-mentioned defects in the existing technology, the purpose of this utility model is to provide a composite unblocking device for scaled wells.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] A composite unblocking device for scaled wells includes a well cleaning device, which comprises a scale retrieval basket, a downward pressure water device, and a scraper device arranged sequentially from top to bottom; the scraper device has a central channel that is connected to the scale retrieval basket; under the action of the downward pressure water device, the scale is pressed into the central channel along with the liquid and enters the scale retrieval basket.

[0013] Furthermore, the scale retrieval basket includes a screen tube and an inner tube; the central channel is connected to the inner tube;

[0014] Specifically, the inner tube is installed inside the screen tube, and the lower end of the annular space between the inner tube and the screen tube is closed;

[0015] Specifically, the inner tube wall is provided with a side opening, and the upper end of the inner tube is closed by an umbrella cap;

[0016] Specifically, the outer diameter of the umbrella cap is larger than the outer diameter of the inner tube, and the screen tube wall is provided with a flow port.

[0017] Furthermore, the umbrella cap is located above the flow port; the flow port is a slit or a sieve.

[0018] Furthermore, the downward pressure device is a cup sealer, which includes a central tube and a cup. The cup has its opening facing downwards, and the upper end of the central tube is connected to the lower end of the scale retrieval basket.

[0019] Furthermore, the scraping device is located at the lower end of the cup sealer, and a scraping block is provided on the outer wall of the scraping device.

[0020] Furthermore, the upper end of the screen tube is connected to a construction pipe.

[0021] In a preferred embodiment, the umbrella cap is located below the construction pipe, and the outer diameter of the umbrella cap is larger than the inner diameter of the construction pipe but smaller than the inner diameter of the screen pipe.

[0022] In another preferred embodiment, the umbrella cap is located inside the construction pipe, and the outer diameter of the umbrella cap is smaller than that of the construction pipe.

[0023] Furthermore, it also includes a borehole flushing device;

[0024] Specifically, the blast hole flushing device includes a flushing pipe and a connecting pipe;

[0025] Specifically, the outer wall of the flushing pipe is provided with a nozzle, and the lower end of the inner wall of the flushing pipe is connected to a check valve; the upper end of the connecting pipe is connected to the lower end of the flushing pipe, and the outer wall of the connecting pipe is connected to an iron chain.

[0026] Furthermore, the flushing pipe wall is provided with a flushing chamber corresponding to the nozzle, and the flushing chamber is frustoconical.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] 1. This utility model is equipped with a leather cup sealer, a screen tube and an inner tube. The scale is moved upward by the water flow and placed in the annular space of the screen tube and the inner tube, thus realizing the automatic collection of scale.

[0029] 2. This utility model is designed with an iron chain and a screw drill assembly, where the iron chain collidees with the well wall to achieve thorough cleaning of the blast hole and surrounding scale.

[0030] 3. This utility model achieves pulse jet cleaning through a nozzle, resulting in more thorough descaling.

[0031] 4. This invention can completely remove scale and extend the effective period of unblocking. Applying this invention can increase the fluid volume of a single well by 30% and extend the effective period by more than one year. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the well cleaning device in this utility model;

[0033] Figure 2 This is a schematic diagram of the hole flushing device in this utility model.

[0034] In the diagram: 1. Scraper device; 2. Sealing cup device; 3. Screen pipe; 4. Inner pipe; 5. Side opening; 6. Umbrella cap; 7. Construction pipe; 8. Connecting pipe; 9. Iron chain; 10. Flushing pipe; 11. Nozzle. Detailed Implementation

[0035] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0036] Example 1:

[0037] Please see Figures 1 to 2 This embodiment provides a composite unblocking device for scaled wells, including a well cleaning device, which includes a scale retrieval basket, a downward pressure water device, and a scraper device 1 arranged sequentially from top to bottom.

[0038] Furthermore, the scale removal basket includes a screen tube 3 and an inner tube 4. The inner tube 4 is disposed inside the screen tube 3, and the lower end of the annular space between the inner tube 4 and the screen tube 3 is closed. The inner tube 4 has a side opening 5 on its wall, and the upper end of the inner tube 4 is closed by an umbrella cap 6. The outer diameter of the umbrella cap 6 is larger than the outer diameter of the inner tube 4. The screen tube 3 has a flow port on its wall, and the umbrella cap 6 is located above the flow port.

[0039] Specifically, the flow outlet of the screen tube 3 is a slit or a sieve hole, and the screen tube 3 is both a liquid channel and a space for storing scale.

[0040] Specifically, the umbrella cap 6 is welded to the screen tube 3, and the umbrella cap 6 prevents the scale from falling back into the inner tube 4.

[0041] Specifically, two side openings are provided, symmetrically distributed, and the diameter of the side openings is 5mm.

[0042] Specifically, the inner tube 4 and the screen tube 3 are connected by a threaded ring.

[0043] Furthermore, the downward water pressure device is a cup sealer 2, which includes a central tube and a cup. The cup opening faces downward, and the upper end of the central tube is threadedly connected to the lower end of the outer wall of the screen tube 3 or the inner wall of the inner tube 4.

[0044] Specifically, the cup fits the inner wall of the casing with an interference fit. The cup packer 2 is used to separate the fluid above and below the packer and to compress the well fluid during the lowering of the tubing string to promote the flow of well fluid.

[0045] Furthermore, the scraping device 1 is located at the lower end of the cup sealer 2, the outer wall of the scraping device 1 is provided with scraping blocks, the scraping device 1 is provided with a central channel, and the central channel is connected to the inner tube 4.

[0046] Specifically, at least two scraping blocks are provided and are evenly distributed along the outer circumference of the scraping tube device 1. In this embodiment, four scraping blocks are provided.

[0047] Furthermore, the construction pipe 7 is connected to the inner wall of the upper end of the screen pipe 3.

[0048] In a preferred embodiment, the umbrella cap 6 is located below the construction pipe 7, and the outer diameter of the umbrella cap 6 is larger than the inner diameter of the construction pipe 7 but smaller than the inner diameter of the screen pipe 3.

[0049] In another preferred embodiment, the umbrella cap 6 is located inside the construction pipe 7, and the outer diameter of the umbrella cap 6 is smaller than that of the construction pipe 7.

[0050] All of the above solutions allow liquid to enter or exit the construction pipe 7 through the outside of the umbrella cap 6, and the umbrella cap 6 can interfere with the liquid flowing out from the side opening 5.

[0051] Specifically, in this embodiment, after assembling the above components from bottom to top and ensuring a tight threaded connection, the components are lowered into the well. During the lowering process, the scraper device 1 scrapes away the scale in the well shaft and near the borehole. Under the action of the cup packer 2, the liquid in the well is pressurized and automatically flows upward along the central channel of the scraper device 1 and the inner tube 4. Driven by the water flow, the scale flows out through the side opening 5 along the central channel of the scraper device 1 and the inner tube 4. The scale moves downward under the obstruction of the outer extension of the umbrella cap 6 and falls into the annulus between the screen tube 3 and the inner tube 4. The lengths of the inner tube 4 and the screen tube 3 are adjusted according to the scale buildup in the well shaft. After the treatment is completed, the construction pipe string and the well shaft cleaning device are pulled out, and the scale is brought to the surface, thus ending the physical descaling process. During the pulling process, the cup packer automatically opens, and the liquid column in the construction pipe 7 flows out from the outside of the umbrella cap 6, pressing the scale into the annulus between the screen tube 3 and the inner tube 4.

[0052] Example 2:

[0053] Based on Example 1, in order to thoroughly remove scale, clear oil flow channels, and extend the effective period of unblocking, a borehole flushing device is also included.

[0054] The borehole flushing device includes a flushing pipe 10 and a connecting pipe 8. The flushing pipe 10 is equipped with a nozzle 11 for forming a pulse jet. The nozzle 11 sprays liquid and unblocking agent to impact and remove scale from the borehole. A one-way valve is connected to the lower end of the inner wall of the flushing pipe 10 to ensure smooth flushing and enable backwashing. The upper end of the connecting pipe 8 is threaded to the lower end of the flushing pipe 10. An iron chain 9 is welded to the outer wall of the connecting pipe 8. The iron chain 9 rotates to clean the borehole and surrounding scale.

[0055] Specifically, the flushing pipe 10 has a flushing chamber on its wall corresponding to the nozzle 11, and the flushing chamber is frustoconical.

[0056] Specifically, the flushing pipe 10 has an outer diameter of 100mm, an inner diameter of 50mm, and a length of 50cm. The flushing chamber is 24mm long, has an inlet diameter of 20mm, and an outlet diameter of 10mm. The nozzle 11 is an accordion nozzle with an outer diameter of 10mm and an inner diameter of 3mm. Eight nozzles 11 are symmetrically distributed on the outer wall of the flushing pipe 10.

[0057] Specifically, the connecting pipe 8 has an outer diameter of 48mm and a length of 40cm. Iron chains 9 with a rotation diameter of up to 135mm are welded along the upper and lower ends of the connecting pipe 8 for further descaling.

[0058] In this embodiment, the hole flushing device is lowered into the well in conjunction with a screw pump. After the well-washing fluid has been used to flush the well normally, a de-clogging agent is pumped in and repeatedly flushes the area around the hole. Driven by the screw drill, the entire device rotates, and the iron chain 9 collidees with the well wall to further clean the hole and surrounding scale, ensuring thorough cleaning. Simultaneously, the de-clogging agent, along with the flushing tool, continuously impacts the hole through nozzle 11. This chemically removes scale, and the pulse jet shock wave generated by the nozzle further disperses the scale, accelerating the chemical reaction. After flushing, the construction tubing is pulled out.

[0059] Example 3:

[0060] Based on Example 2, this example provides a method for using a composite unclogging device for scaled wells, including the following steps:

[0061] The wellbore cleaning device used for physical descaling and the borehole flushing device used for a combination of physical and chemical descaling are implemented in a distributed manner to achieve thorough descaling and unblocking.

[0062] The first step is to lower the well cleaning device to use physical methods to clean the scale in the well and around the blast holes.

[0063] Assemble the well cleaning device according to the scheme of Example 1, and lower it into the well. During the lowering process, the scraper device 1 scrapes off the scale in the well and near the blast hole. Under the action of the cup packer 2, the liquid in the well is pressurized and automatically flows upward along the central channel and inner tube 4 of the scraper device 1. Driven by the water flow, the scale flows out through the side opening 5 along the central channel and inner tube 4 of the scraper device 1. The scale moves downward under the obstruction of the outer extension of the umbrella cap 6 and falls into the annulus between the screen tube 3 and the inner tube 4. Adjust the length of the inner tube 4 and the screen tube 3 according to the scale in the well. After the treatment is completed, pull out the construction pipe string and the well cleaning device. The scale is brought to the surface, and the physical descaling is completed. During the pulling process, the cup packer automatically opens, and the liquid column in the construction pipe 7 flows out from the outside of the umbrella cap 6. The liquid column in the construction pipe 7 presses the scale into the annulus between the screen tube 3 and the inner tube 4.

[0064] The second step involves lowering the borehole flushing device to clean the borehole and surrounding scale using a combination of physical and chemical methods.

[0065] The perforation flushing device, in conjunction with a screw pump, is lowered into the well. After the well-washing fluid is in place, a de-blocking agent is pumped in and repeatedly flushes the area around the perforation. Driven by the screw drill, the entire device rotates, and the iron chain 9 collidees with the well wall to further clean the perforation and surrounding scale, ensuring thorough cleaning. Simultaneously, the de-blocking agent, carried by the flushing tool, continuously impacts the perforation through nozzle 11. This serves two purposes: chemically removing scale and using the pulsed jet shock wave generated by the nozzle to further disperse the scale, thus accelerating the chemical reaction. The flushing time and de-blocking agent dosage are designed according to the length of the well section being treated. After flushing, the construction tubing is removed. The flushing flow rate is designed to be 0.3 m³ / min. The de-blocking agent consists of hydrochloric acid and terpineic acid, with a hydrochloric acid to terpineic acid ratio of 3:1, and the dosage of de-blocking agent is 1.5 m³ per meter.

[0066] All components not discussed in detail in this application, as well as the connection methods of these components, are well-known technologies in this field. They can be directly applied and will not be elaborated further.

[0067] In this utility model, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0068] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0069] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0070] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A composite unclogging device for scaled wells, comprising a wellbore cleaning device, characterized in that, The well cleaning device includes, from top to bottom, a scale retrieval basket, a downward pressure water device, and a scraper device; the scraper device is provided with a central channel, which is connected to the scale retrieval basket. Under the action of the downward pressure device, the scale is forced into the central channel along with the liquid and enters the scale retrieval basket.

2. The composite unblocking device for scaled wells according to claim 1, characterized in that, The scale retrieval basket includes a screen tube and an inner tube; the central channel is connected to the inner tube. The inner tube is installed inside the screen tube, and the lower end of the annular space between the inner tube and the screen tube is closed. The inner tube wall is provided with a side opening, and the upper end of the inner tube is closed by an umbrella cap; The outer diameter of the umbrella cap is larger than the outer diameter of the inner tube, and the screen tube wall is provided with a flow port.

3. The composite unblocking device for scaled wells according to claim 2, characterized in that, The umbrella cap is located above the flow outlet; the flow outlet is a slit or a sieve.

4. The composite unblocking device for scaled wells according to claim 1, characterized in that, The downward pressure device is a leather cup packer, which includes a central tube and a leather cup. The opening of the leather cup faces downward, and the upper end of the central tube is connected to the lower end of the scale retrieval basket.

5. A composite unblocking device for scaled wells according to claim 4, characterized in that, The scraping device is located at the lower end of the cup sealer, and a scraping block is provided on the outer wall of the scraping device.

6. A composite unblocking device for scaled wells according to claim 2, characterized in that, The upper end of the screen tube is connected to the construction pipe.

7. A composite unblocking device for scaled wells according to claim 6, characterized in that, The umbrella cap is located below the construction pipe, and the outer diameter of the umbrella cap is larger than the inner diameter of the construction pipe but smaller than the inner diameter of the screen pipe.

8. A composite unblocking device for scaled wells according to claim 6, characterized in that, The umbrella cap is located inside the construction pipe, and the outer diameter of the umbrella cap is smaller than that of the construction pipe.

9. A composite unclogging device for scaled wells according to any one of claims 1-8, characterized in that, It also includes a borehole flushing device; The blast hole flushing device includes a flushing pipe and a connecting pipe; The outer wall of the flushing pipe is equipped with a nozzle, and the lower end of the inner wall of the flushing pipe is connected to a check valve; the upper end of the connecting pipe is connected to the lower end of the flushing pipe, and the outer wall of the connecting pipe is connected to an iron chain.

10. A composite unblocking device for scaled wells according to claim 9, characterized in that, The flushing pipe wall is provided with a flushing chamber corresponding to the nozzle, and the flushing chamber is frustoconical.

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