Oil pipe paraffin scraping and sampling device

Abstract

The utility model belongs to the technical field of borehole or well cleaning methods or devices, and provides an oil pipe paraffin scraping and sampling device which comprises a paraffin scraping cylinder and a paraffin collecting cylinder, and the periphery of the paraffin scraping cylinder is provided with a scraper which is arranged downwards and used for scraping off accumulated paraffin on the inner wall of an oil pipe. A wax inlet allowing scraped accumulated wax to enter the wax scraping cylinder is formed in the position, corresponding to the scraper, of the cylinder wall of the wax scraping cylinder, a wax guiding wall used for guiding the accumulated wax to move towards the wax inlet is formed in the inner wall of the scraper, and an electric heating device used for heating and melting the accumulated wax is arranged in the wax scraping cylinder. The wax collecting cylinder is fixedly connected to the lower portion of the wax scraping cylinder, and a communicating structure is arranged between the wax collecting cylinder and the wax scraping cylinder so that molten wax in the wax scraping cylinder can flow into the wax collecting cylinder. The accumulated wax is guided into the wax scraping cylinder through the cooperation of the scraper and the wax inlet, then the accumulated wax is heated by the electric heating device to be melted and then flows into the wax collecting cylinder, compared with the prior art, the scraped accumulated wax can be melted in time and flows into the wax collecting cylinder, and the problem that the cleaning efficiency is low due to the fact that the accumulated wax is accumulated at the scraper is solved.

Description

Technical Field

[0001] The utility model relates to an oil pipe wax scraping sampling device, belonging to the technical field of methods or devices for cleaning wellbores or wells. Background Art

[0002] During the development of natural gas wells, since the natural gas components in some reservoirs contain a large amount of wax, as the pressure and temperature decrease when flowing from the wellbore to the ground, the solubility of the wax decreases, and solid wax will precipitate and deposit on the inner wall of the wellbore, causing the wellbore diameter to decrease and the gas well production to decrease. As the production time increases, the deposited wax will increase and may even block the wellbore and cause the gas well to stop production.

[0003] At present, the main technical means to remove wax on the inner wall of the wellbore are chemical wax cleaning, electric heating wax cleaning, heat carrier circulation wax cleaning and mechanical wax cleaning. The two methods of chemical wax cleaning and heat carrier circulation wax cleaning are to pump solvent into the wellbore to soak and dissolve the wax on the inner wall of the wellbore when the gas well is shut down. This method has high requirements on the effect of the agent and the construction process. Electric heating wax cleaning easily causes the melted wax to adhere to the uncleaned wax, resulting in low wax cleaning efficiency. Mechanical removal uses steel wire operation to send a scraper tool into the wellbore to scrape the deposited wax. It has the advantages of simple method and low cost, and is a commonly used wax cleaning method.

[0004] The Chinese utility model patent with the authorization announcement number CN212689995U discloses a wax scraping device for a petroleum wellbore, including a storage column, a motor is arranged in the storage column, the output end of the motor is connected to a rotating shaft, a plurality of arc-shaped scraping leaves are arranged obliquely on the outer side wall of the rotating shaft, and a heat conducting sheet is arranged obliquely on the bottom side wall of the scraping leaf. A storage cavity is also arranged in the storage column, an opening penetrating the side wall is arranged at the top of the storage cavity, a collecting device is arranged in the opening, the collecting device includes a rotating groove arranged at the opening, the rotating groove includes a rotating ring and a heating ring at the bottom of the rotating ring, the rotating ring is located at the bottom of the scraping leaf and the top of the rotating ring is connected to the side wall of the scraping leaf, and a spiral extrusion leaf is also arranged on the outer side wall of the spiral shaft at the opening for extruding the accumulated wax at the rotating groove into the storage cavity. A battery is also arranged in the storage column for heating the motor and the heating ring. By setting a heating ring and conducting heat from a rotating ring and a heat conducting sheet to the scraping blade, the scraping blade is heated up. After the scraping blade scrapes the wax accumulated in the barrel, the wax attached to the scraping blade melts and enters the storage chamber for collection with the action of the heat conducting sheet and the spiral extrusion blade. Although this device can scrape off the wax accumulated inside the wellbore well, an additional motor needs to be set up to drive the scraping blade and the spiral extrusion blade to rotate. The overall structure is complex and the cost is high.

[0005] The Chinese utility model patent with the authorization announcement number CN208633805U discloses a wax cleaning machine for oilfield well washing (i.e., a wax scraping device), including scraping teeth arranged on the outside of the baffle and a brush head (i.e., a wax scraping cylinder) under the scraping teeth, a wax storage box (i.e., a wax collecting cylinder), and a heating chamber. The barrel wall is roughly cleaned and finely cleaned by the scraping teeth on the baffle and the brush head under the scraping teeth, and the cleaned wax accumulation is recovered through the wax storage box and the heating chamber. The wax cleaning machine for oilfield well washing avoids the setting of additional motors and other mechanisms, simplifies the structural setting, reduces the cost, and the wax cleaned by the scraper and the brush head is heated and stored in the wax storage box and the heating chamber, which can accommodate more wax accumulation. However, since the wax accumulation on the pipe wall is soft and sticky, the wax accumulation is easy to accumulate at the scraping teeth during the wax cleaning operation, resulting in low cleaning efficiency. Utility Model Content

[0006] The utility model aims to provide an oil pipe wax scraping sampling device to solve the problem that the existing wax scraping device uses scraping teeth and a brush head to scrape wax, which causes the wax to easily accumulate at the scraping teeth and thus leads to low cleaning efficiency.

[0007] In order to achieve the above purpose, the oil pipe wax scraping sampling device in the utility model adopts the following technical scheme:

[0008] A wax scraping sampling device for an oil pipe comprises a wax scraping cylinder and a wax collecting cylinder. A scraper arranged downwards on the outer periphery of the wax scraping cylinder is provided for scraping off wax accumulated on the inner wall of the oil pipe. A wax inlet is provided on the wall of the wax scraping cylinder at a position corresponding to the scraper for allowing the accumulated wax scraped off by the scraper to enter the wax scraping cylinder. The inner wall of the scraper forms a wax guide wall for guiding the accumulated wax to move toward the wax inlet. An electric heating device for heating and melting the accumulated wax is provided in the wax scraping cylinder. The wax collecting cylinder is fixedly connected to the bottom of the wax scraping cylinder. A connecting structure is provided between the wax collecting cylinder and the wax scraping cylinder so that the melted accumulated wax in the wax scraping cylinder can flow into the wax collecting cylinder.

[0009] The beneficial effect of the above technical scheme is that: the utility model belongs to an improved invention, by arranging a downwardly arranged scraper on the outer periphery of the wax scraper cylinder, the scraper is used to scrape the accumulated wax in the oil pipe when the oil pipe wax scraping sampling device descends, the accumulated wax enters the wax scraper cylinder from the wax inlet through the wax guide wall and is heated and melted by the electric heating device inside the wax scraper cylinder, and the melted accumulated wax flows into the wax collecting cylinder through the connecting structure. The scraped accumulated wax is guided to move toward the wax inlet by the wax guide wall on the scraper, which facilitates the accumulated wax to enter the wax scraper cylinder and prevents the accumulated wax from accumulating at the scraper. Through the cooperation of the electric heating device, the accumulated wax in the wax scraper cylinder is heated and melted in time, which facilitates its flow into the wax collecting cylinder, and prevents the accumulated wax from accumulating in the wax scraper cylinder and affecting the subsequent accumulated wax from entering the wax scraper cylinder, thereby improving the cleaning efficiency.

[0010] Furthermore, the overall diameter of the wax scraping cylinder gradually decreases from top to bottom, and at least two levels of scrapers are provided on the outer circumference of the wax scraping cylinder.

[0011] Furthermore, the wax scraping cylinder comprises at least two cylindrical sections whose diameters gradually decrease from top to bottom, the cylindrical sections are connected by conical sections, and each cylindrical section is provided with a primary scraper.

[0012] Furthermore, the wax scraping cylinder comprises an inner cylinder and an outer cylinder, the scraper and the wax inlet are arranged on the outer cylinder, the electric heating device is arranged on the inner cylinder, and an inner cavity for the accumulated wax to pass through is formed between the inner cylinder and the outer cylinder.

[0013] Furthermore, the electric heating device is a heating cable, and the wax scraping cylinder is also provided with a shaping cylinder for pressing the heating cable against the inner wall of the inner cylinder of the wax scraping cylinder.

[0014] Furthermore, each level of scrapers is provided with at least two groups of scrapers, and each group of scrapers is evenly distributed in the circumference of the wax scraping cylinder.

[0015] Furthermore, the oil pipe wax scraping sampling device also includes a connecting cylinder arranged above the wax scraping cylinder and fixedly connected to the wax scraping cylinder, and a battery for providing electric energy to the electric heating device is arranged in the connecting cylinder.

[0016] Furthermore, the connecting tube includes a connecting tube body and an upper joint connected to the top of the connecting tube body, a support plate for supporting the battery is provided at the bottom of the connecting tube body, a through hole is provided on the support plate, and the battery and the electric heating device are connected by a wire and the wire passes through the through hole.

[0017] Furthermore, the wax guiding wall is arc-shaped.

[0018] Furthermore, the wax collecting cylinder is in an inverted cone shape from top to bottom. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is an implementation method of an oil pipe wax scraping sampling device of the utility model;

[0020] Figure 2 Another embodiment of the oil pipe wax scraping sampling device of the utility model;

[0021] In the figure: 1. connecting cylinder; 11. upper joint; 12. connecting cylinder body; 13. through hole; 14. support plate; 2. battery; 3. wax scraping cylinder; 31. scraper; 310. wax guide wall; 32. wax inlet; 33. inner cylinder; 34. cavity; 35. heating cable; 36. shaping cylinder; 37. outer cylinder; 38. wax scraping cylinder flow hole; 4. wax collecting cylinder; 41. wax collecting cavity; 42. wax collecting hole; 43. wax collecting cylinder connector; 44. wax collecting cylinder flow hole. DETAILED DESCRIPTION

[0022] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0023] First, the technical solution of the utility model is generally described as follows:

[0024] In view of the technical problems existing in the prior art, the basic technical concept of the utility model is that a scraper arranged downward is provided on the circumference of the wax scraping cylinder, a wax inlet is provided below the scraper to allow the scraped wax to enter the wax scraping cylinder, the inner wall of the scraper forms a wax guide wall for guiding the wax to move toward the wax inlet, an electric heating device for heating and melting the wax in the wax scraping cylinder is provided in the wax scraping cylinder, a wax collecting cylinder is fixedly connected to the bottom of the wax scraping cylinder, and a connecting structure is provided between the wax collecting cylinder and the wax scraping cylinder to allow the melted wax in the wax scraping cylinder to flow into the wax collecting cylinder. During the descent of the oil pipe wax scraping sampling device, the wax is directly scraped off by the scraper arranged downward on the wax scraping cylinder, and moves toward the wax inlet under the guidance of the wax guide wall, so that the wax can enter the wax scraping cylinder from the wax inlet, and prevent the wax from accumulating at the scraper. The electric heating device in the wax scraping cylinder melts the wax entering the wax scraping cylinder, and the wax melts and flows into the wax collecting cylinder, so as to avoid the wax accumulation in the wax scraping cylinder and affecting the subsequent wax accumulation entering the wax scraping cylinder, thereby improving the cleaning efficiency.

[0025] Based on the above concept, the embodiment of the oil pipe wax scraping sampling device of the utility model is as follows:

[0026] like Figure 1 As shown, the oil pipe wax scraping sampling device includes a wax scraping cylinder 3 and a wax collecting cylinder 4. The outer periphery of the wax scraping cylinder 3 is provided with a scraper 31 arranged downward for scraping off the wax accumulated on the inner wall of the oil pipe. A wax inlet 32 ​​is provided on the wall of the wax scraping cylinder 3 at a position corresponding to the scraper 31 for the accumulated wax scraped by the scraper 31 to enter the wax scraping cylinder 3. The inner wall of the scraper 31 forms a wax guide wall 310 for guiding the accumulated wax to move toward the wax inlet 32. An electric heating device for heating and melting the accumulated wax in the wax scraping cylinder 3 is provided in the wax scraping cylinder 3. The wax collecting cylinder 4 is fixedly connected to the bottom of the wax scraping cylinder 3. A connecting structure is provided between the wax scraping cylinder 3 and the wax collecting cylinder 4 to allow the melted accumulated wax in the wax scraping cylinder 3 to flow into the wax collecting cylinder 4.

[0027] Specifically, in this embodiment, the wax scraping cylinder 3 includes an inner cylinder 33 and an outer cylinder 37, the scraper 31 and the wax inlet 32 ​​are arranged on the outer cylinder 37, and the wax introducing wall 310 is arc-shaped. The arc-shaped wax introducing wall 310 scrapes off the wax accumulation as the oil pipe wax scraping sampling device descends, and at the same time provides a radial component of force to the wax accumulation, so that the wax accumulation is guided by the wax introducing wall 310 and enters the wax scraping cylinder 3 from the wax inlet 32, so that the wax scraping cylinder 3 can collect the wax accumulation more smoothly, and avoid the wax accumulation from being blocked at the scraper 31.

[0028] The overall diameter of the wax scraper cylinder 3 gradually decreases from top to bottom, and the outer cylinder of the wax scraper cylinder 3 is provided with at least two levels of scrapers 31. In this embodiment, the outer cylinder 37 is specifically a three-layer cylindrical section with a gradually decreasing diameter from top to bottom. The wax scraper cylinders of each cylindrical section with different diameters are connected and transitioned by a conical section. Each layer of the cylindrical section of the outer cylinder 37 is provided with a first-level scraper 31, that is, the outer cylinder 37 is provided with a total of three levels of scrapers 31, so as to achieve layered multiple scraping of the accumulated wax attached to the cylinder wall, and avoid the oil pipe wax scraping sampling device from being slow to scrape wax or even stuck due to the large resistance caused by the excessive thickness of the accumulated wax scraped in a single scraping. At the same time, the conical section transition set between the cylindrical sections also has the function of guiding the oil pipe wax scraping sampling device when the oil pipe wax scraping sampling device descends, making the overall descent smoother.

[0029] In order to further reduce the resistance of the scraper 31 when scraping the wax accumulation, at least two groups of scrapers are provided at each level. In this embodiment, three groups of scrapers 31 are provided at each level, and each group of scrapers 31 has three scrapers 31 arranged obliquely. The three groups of scrapers 31 are evenly distributed in the circumference of the outer cylinder 37, and the total effective scraping range covers one circle of the cylinder wall to be cleaned. By arranging multiple groups of scrapers 31 in groups, the area of ​​wax accumulation scraped by each scraper 31 in a single time is further reduced, thereby reducing the resistance of the scraper 31 to wax accumulation.

[0030] The electric heating device is arranged on the inner cylinder 33, and an inner cavity 34 for the wax accumulation to pass through is formed between the inner cylinder 33 and the outer cylinder 37. In actual operation, the electric heating device is energized to generate heat and transfers the heat from the inner cylinder 33 to the wax accumulation in the inner cavity 34, thereby melting the wax accumulation and preventing the wax accumulation from accumulating in the inner cavity 34 and affecting the subsequent wax accumulation from entering the inner cavity 34. In this embodiment, the electric heating device is specifically a heating cable 35, and a shaping cylinder 36 is also provided in the inner cylinder 33. The shaping cylinder 36 presses the heating cable 35 against the inner wall of the inner cylinder 33, thereby ensuring that the heat generated by the heating cable 35 when it is energized can be more efficiently transferred to the cavity 34 through the inner cylinder 33, thereby avoiding the heating cable 35 not being close to the inner cylinder 33, resulting in poor heat transfer effect.

[0031] The oil pipe wax scraping sampling device also includes a connecting tube 1 disposed above the wax scraping tube 3 and fixedly connected to the wax scraping tube 3. The connecting tube 1 includes a connecting tube body 12 and an upper joint 11 connected to the top of the connecting tube body 12. A support plate 14 for supporting the battery 2 is disposed at the bottom of the connecting tube body 12. A through hole 13 is disposed on the support plate 14. The battery 2 and the heating cable 35 are connected by a wire (not shown in the figure). The wire passes through the through hole 13 to connect the battery 2 and the heating cable 35. The through hole 13 is disposed to cover the wire between the battery 2 and the heating cable 35 inside the oil pipe wax scraping sampling device to prevent the wire from being damaged. Specifically, the battery 2 is loaded into the connecting tube body 12 and supported by the support plate 14. The upper joint 11 is threadedly assembled with the connecting tube body 12 to press the battery 2 onto the support plate 14. The upper part of the upper joint 11 has an external thread to connect with the oil pipe or oil rod to form a wax scraping pipe column. The connection tube 1 and the wax scraping tube 3 are also threadedly assembled, and the overall connection is set as a threaded assembly to facilitate the disassembly and replacement of parts.

[0032] The wax collecting cylinder 4 of the oil pipe wax scraping sampling device is arranged below the wax scraping cylinder 3 and is threadedly connected to the wax scraping cylinder 3. The wax collecting cylinder 4 is specifically in an inverted cone shape, including a wax collecting cavity 41 and a wax collecting hole 42. The wax collecting hole 42 is arranged at the threaded connection between the wax collecting cylinder 4 and the wax scraping cylinder 3 to allow the melted accumulated wax in the wax scraping cylinder 3 to flow from the cavity 34 into the wax collecting cavity 41. Since the accumulated wax in the wax collecting cavity 41 needs to be discharged after the wax scraping operation is completed, it is more convenient to disassemble by setting the wax collecting cylinder 4 and the wax scraping cylinder 3 to be threadedly connected. At the same time, the wax collecting cavity 41 is set as an inverted cone shape as a whole, which has a guiding effect during actual operation, preventing the oil pipe wax scraping sampling device from tilting when descending, and making the overall descent smoother.

[0033] In other embodiments, Figure 2 As shown, the shaping cylinder may not be provided, and the heating cable 35 may be directly arranged on the inner wall of the inner cylinder 33. The wax scraping cylinder 3 and the wax collecting cylinder 4 may no longer be directly connected. The wax scraping cylinder 3 and the wax collecting cylinder 4 are connected through a wax collecting cylinder connector 43. A wax scraping cylinder flow hole 38 is provided below the wax scraping cylinder 3, and a wax collecting cylinder flow hole 44 is provided at a corresponding position of the wax collecting cylinder 4. The aperture of the wax collecting cylinder flow hole 44 is larger than the wax scraping cylinder flow hole 38, so that the melted accumulated wax can easily flow from the wax scraping cylinder flow hole 38 into the wax collecting cylinder flow hole 44. The wax scraping cylinder flow hole 38 and the wax collecting cylinder flow hole 44 can be round holes, square holes, or holes of any other shape, as long as the accumulated wax can flow from the wax scraping cylinder flow hole 38 into the wax collecting cylinder flow hole 44.

[0034] In other embodiments, the wax scraping cylinder can be a truncated cone with a gradually decreasing overall diameter from top to bottom. In other embodiments, the scraper on the outer periphery of the wax scraping cylinder can be set to two levels, four levels, five levels or even more, and of course only one level can be set. In other embodiments, the wax scraping cylinder can no longer be set to a structure with a gradually decreasing overall diameter from top to bottom, but can be set as a cylinder as a whole.

[0035] In other embodiments, the wax scraping cylinder may also be two, four, five, six or more cylindrical segments with gradually decreasing diameters from top to bottom, each cylindrical segment being connected by a conical segment. In other embodiments, each cylindrical segment may no longer be connected by a conical segment, but by a horizontal segment perpendicular to the upper and lower cylindrical segments, that is, the wax scraping cylinder as a whole is a stepped cylinder.

[0036] In other embodiments, the inner cylinder may also be configured as a cylindrical structure. In other embodiments, the inner cylinder may also be a stepped structure with a diameter gradually decreasing from top to bottom.

[0037] In other embodiments, the electric heating device may also be an electric heating rod. In this case, there is no need to provide an inner cylinder to fix the electric heating rod. That is, the wax scraping cylinder is only composed of an outer cylinder, and the electric heating rod is arranged in the outer cylinder.

[0038] In other embodiments, each stage of scrapers may be provided with two groups, four groups or even more groups of scrapers. Of course, each stage of scrapers may also be provided with a group, where a group has multiple scrapers and are arranged at intervals along the same circumference.

[0039] In other embodiments, the oil pipe wax scraping sampling device may no longer be provided with a connecting tube and a battery, and the electric heating device may be directly connected to an external long wire for power supply and heating.

[0040] In other embodiments, the wax introducing wall may no longer be configured as an arc, but as a plane inclined downward. In other embodiments, the wax scraping cylinder is configured as a truncated cone, the wax introducing wall is configured vertically downward, and the wax introducing hole is configured on the cylinder wall of the wax scraping cylinder, that is, the wax introducing hole is inclined and gradually away from the wax introducing wall. In other embodiments, the wax introducing wall is configured as an inverted "L" shaped structure consisting of a horizontal section and a vertical section.

[0041] In other embodiments, the wax collecting cylinder can also be configured as a truncated cone structure or a stepped columnar structure that gradually decreases from top to bottom. In other embodiments, the wax collecting cylinder can also be configured as a cylindrical shape with equal diameters.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the description and drawings of the present invention shall be included in the protection scope of the present invention.

Claims

1. A wax scraping sampling device for oil pipes, comprising a wax scraping cylinder and a wax collecting cylinder, characterized in that: The outer periphery of the wax scraper cylinder is provided with a scraper arranged downward for scraping off the wax accumulated on the inner wall of the oil pipe. A wax inlet is provided on the wall of the wax scraper cylinder at a position corresponding to the scraper for the accumulated wax scraped off by the scraper to enter the wax scraper cylinder. The inner wall of the scraper forms a wax guide wall for guiding the accumulated wax to move toward the wax inlet. An electric heating device for heating and melting the accumulated wax is provided in the wax scraper cylinder. The wax collecting cylinder is fixedly connected to the bottom of the wax scraper cylinder. A connecting structure is provided between the wax collecting cylinder and the wax scraper cylinder so that the melted accumulated wax in the wax scraper cylinder can flow into the wax collecting cylinder.

2. The oil pipe wax scraping sampling device according to claim 1, characterized in that: The overall diameter of the wax scraping cylinder gradually decreases from top to bottom, and at least two levels of scrapers are arranged on the outer circumference of the wax scraping cylinder.

3. The oil pipe wax scraping sampling device according to claim 2, characterized in that: The wax scraping cylinder comprises at least two cylindrical sections whose diameters gradually decrease from top to bottom, the cylindrical sections are connected by cone sections, and each cylindrical section is provided with a primary scraper.

4. The oil pipe wax scraping sampling device according to claim 1, 2 or 3, characterized in that: The wax scraping cylinder comprises an inner cylinder and an outer cylinder, the scraper and the wax inlet are arranged on the outer cylinder, the electric heating device is arranged on the inner cylinder, and an inner cavity for the accumulated wax to pass through is formed between the inner cylinder and the outer cylinder.

5. The oil pipe wax scraping sampling device according to claim 4, characterized in that: The electric heating device is a heating cable, and a shaping cylinder for pressing the heating cable onto the inner wall of the inner cylinder is arranged in the inner cylinder.

6. The oil pipe wax scraping sampling device according to claim 2 or 3, characterized in that: Each level of scrapers is provided with at least two groups of scrapers, and each group of scrapers is evenly distributed in the circumference of the wax scraping cylinder.

7. The oil pipe wax scraping sampling device according to claim 1, 2 or 3, characterized in that: The oil pipe wax scraping sampling device also includes a connecting cylinder which is arranged above the wax scraping cylinder and fixedly connected to the wax scraping cylinder. A storage battery for providing electric energy to the electric heating device is arranged in the connecting cylinder.

8. The oil pipe wax scraping sampling device according to claim 7, characterized in that: The connecting cylinder includes a connecting cylinder body and an upper joint connected to the top of the connecting cylinder body. A supporting plate for supporting the battery is provided at the bottom of the connecting cylinder body. A through hole is provided on the supporting plate. The battery and the electric heating device are connected by a wire and the wire passes through the through hole.

9. The oil pipe wax scraping sampling device according to claim 1, 2 or 3, characterized in that: The wax introducing wall is arc-shaped.

10. The oil pipe wax scraping sampling device according to claim 1, 2 or 3, characterized in that: The wax collecting cylinder is in an inverted cone shape from top to bottom.

Images