Oil field injection well test pipe column resistance dredging device

Abstract

The invention relates to the technical field of oil exploitation, in particular to an oil field injection well test tubular column blockage dredging device which comprises a mounting cylinder and a descaling head and is characterized by further comprising an anchoring mechanism and a telescopic mechanism, and the descaling head is mounted at the lower end of the telescopic mechanism; an anchor block is arranged in the anchoring mechanism, and the anchor block can be anchored on the inner wall of the underground pipeline after laterally stretching out, so that the device is integrally fixed on the inner wall of the underground pipeline; the telescopic mechanism can stretch out and draw back, and the descaling head is driven to move through the telescopic action, so that scale attached to the inner wall of the pipeline is scraped off. The method that anchoring is conducted firstly and then descaling is conducted is adopted, when the device is used, the device is integrally fixed in an underground pipeline through the anchoring mechanism, and then the telescopic mechanism drives the descaling head to conduct descaling. Compared with an existing gravity impact scraping descaling mode, the movement of the descaling head is more stable, the scraping force is softer, and therefore damage to the pipe wall is avoided.

Description

Technical Field

[0001] This invention relates to the field of petroleum extraction technology, specifically to a device for clearing obstructions in test tubing of oilfield injection wells. Background Technology

[0002] In oilfield production, the diameter of downhole pipelines can decrease due to factors such as rust, heavy oil, sand blockage, crystal adhesion, and polymer cementation. In certain special sections of downhole pipelines where the diameter is already small (such as the connection points of downhole tools), the diameter can become even smaller, making it impossible for test strings used for downhole testing to pass through, thus preventing the testing work from being completed smoothly.

[0003] Currently, common methods for descaling downhole tubing include chemical cleaning, high-pressure water jet cleaning, and gravity impact scraping. However, these methods all have certain limitations. While chemical cleaning can dissolve some scale, the use of chemicals may corrode the tubing, and in the complex downhole environment, the distribution of the chemicals is difficult to achieve evenly, easily leading to over- or under-cleaning in certain areas. High-pressure water jet cleaning is ineffective for some strongly adhered scale and requires a complex high-pressure water supply system, resulting in high costs. Gravity impact scraping is not only time-consuming and labor-intensive but can also easily damage the inner wall of the tubing. Summary of the Invention

[0004] The purpose of this invention is to provide a device for clearing obstructions in injection well test tubing, which aims to provide a completely new method for descaling downhole pipelines and solve problems such as easy corrosion and damage to the inner wall of pipelines in the existing technology.

[0005] This invention provides a device for clearing obstructions in test tubing of oilfield injection wells, including an installation cylinder and a descaling head, as well as an anchoring mechanism and a telescopic mechanism, wherein the descaling head is installed at the lower end of the telescopic mechanism; An anchoring mechanism is equipped with an anchor block. After the anchor block extends laterally, it can be anchored to the inner wall of the downhole pipeline, thereby fixing the entire device to the inner wall of the downhole pipeline. The telescopic mechanism can extend and retract, which drives the descaling head to move, thereby scraping away the scale adhering to the inner wall of the pipe.

[0006] As a preferred embodiment, the anchoring mechanism is installed inside the mounting cylinder. The anchoring mechanism specifically includes an anchoring motor, a lead screw, a wedge, and the anchor block. The output shaft of the anchoring motor is connected to one end of the lead screw, and the wedge is threaded to the other end of the lead screw. The side of the mounting cylinder is machined with a window, and the anchor block is slidably installed in the window along the radial direction of the mounting cylinder. The wedge is located inside the anchor block.

[0007] As a preferred embodiment, the telescopic mechanism is installed inside the mounting cylinder. Its structure includes a telescopic motor, a rotating sleeve, a sliding rod, and a cutter head. The rotating sleeve is connected to the output shaft of the telescopic motor. An axial slide is machined on the side of the rotating sleeve. The sliding rod is inserted into the rotating sleeve. A first limiting pin is provided at the upper end of the sliding rod. The end of the first limiting pin is inserted into the axial slide and can slide along the axial slide. A helical groove is machined on the outer side of the sliding rod. A second limiting pin is provided at the lower end of the mounting cylinder. The second limiting pin is inserted inward into the helical groove.

[0008] As a preferred embodiment, a micro-movement sleeve is provided at the lower end of the mounting cylinder, and the second limiting pin is fixedly disposed on the micro-movement sleeve, and the micro-movement sleeve is axially slidably connected to the lower end of the mounting cylinder; Two sets of springs are provided at the connection between the micro-motion sleeve and the mounting sleeve. The two sets of springs provide elastic support when the micro-motion sleeve slides up and down, respectively.

[0009] As a preferred embodiment, the slide bar includes an upper section and a lower section, with the joint between the two sections located at the upper part of the slide bar as a whole. The lower end face of the upper section of the slide rod and the upper end face of the lower section of the slide rod are respectively provided with matching one-way ratchet teeth. Under the action of the one-way ratchet teeth, when the upper section of the slide rod rotates in the forward direction, the lower section of the slide rod can rotate together. When the upper section of the slide rod rotates in the reverse direction, the one-way ratchet teeth can drive the lower section of the slide rod to slide axially.

[0010] The beneficial effects of this invention are as follows: 1. This invention employs a method of anchoring first, followed by descaling. In use, the entire device is first fixed inside the downhole pipeline using an anchoring mechanism, and then the descaling head is driven by a telescopic mechanism to remove scale. Compared to existing gravity impact scraping descaling methods, the movement of the descaling head is more stable, and the scraping force is gentler, thus avoiding damage to the pipe wall. It also avoids the corrosion of the pipe wall caused by chemical descaling methods.

[0011] 2. This invention uses a segmented slide rod structure, with the two segments connected by a one-way ratchet. Under normal conditions, the upper segment rotates clockwise, while the lower segment rotates synchronously under the influence of the ratchet. This, in conjunction with the spiral groove and the second limiting pin, pushes the descaling head downwards. When an abnormal increase in the current of the telescopic motor is detected, it indicates that the descaling head is encountering resistance. At this point, the telescopic motor is reversed automatically or manually, and the upper segment of the slide rod also reverses. After reversing, the lower segment of the slide rod undergoes a small-range axial reciprocating motion under the combined action of the ratchet and the spring, generating a vibration effect. This vibration provides a slight impact to the hardened scale, thereby enhancing the descaling force. After the telescopic motor reverses for a few seconds, it rotates clockwise again, allowing the descaling head to continue advancing. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0013] Figure 2 yes Figure 1 A partially enlarged view of the mating structure of the various parts at the lower end of the mounting cylinder.

[0014] Figure 3 This is a schematic diagram of the connection between the upper and lower sections of the slide rod.

[0015] Figure 4 It is a structural diagram of the lower end face of the upper section of the slide rod or the upper end face of the lower section of the slide rod.

[0016] In the diagram: 1. Anchor block, 2. Wedge block, 3. Lead screw, 4. Anchoring motor, 5. Mounting cylinder, 6. Telescopic motor, 7. Rotating sleeve, 8. First limit pin, 9. Axial slide, 10. Spiral groove, 11. Upper section of slide rod, 12. Lower section of slide rod, 13. Descaling head, 14. Second limit pin, 15. Micro-motion sleeve, 16. Spring. Detailed Implementation

[0017] like Figure 1 As shown, this embodiment includes an installation cylinder 5 and a descaling head 13. The installation cylinder 5 is used to install the descaling head 13, which slides along the inner wall of the downhole pipeline to achieve the purpose of descaling. The above structure is a structure that already exists in the prior art and will not be described in detail here.

[0018] like Figure 1 As shown, this embodiment also includes an anchoring mechanism and a telescopic mechanism, with the descaling head 13 installed at the lower end of the telescopic mechanism. In use, the entire device is first fixed inside the downhole pipeline by the anchoring mechanism, and then the descaling head 13 is driven by the telescopic mechanism to perform descaling.

[0019] like Figure 1 As shown, in this embodiment, the anchoring mechanism is installed inside the mounting cylinder 5. The anchoring mechanism includes an anchoring motor 4, a lead screw 3, a wedge 2, and an anchor block 1. The output shaft of the anchoring motor 4 is connected to one end of the lead screw 3, and the wedge 2 is threaded to the other end of the lead screw 3. A window is machined on the side of the mounting cylinder 5, and the anchor block 1 is slidably installed in the window along the radial direction of the mounting cylinder 5. The wedge 2 is located inside the anchor block 1. In this embodiment, the number of anchor blocks 1 is set to two.

[0020] During operation, the anchoring motor 4 drives the lead screw 3 to rotate. The rotational motion of the lead screw 3 is converted into the axial movement of the wedge block 2 through the threaded transmission pair, and then into the radial movement of the anchor block 1, causing the side of the anchor block 1 mounting cylinder 5 to extend out. Finally, the anchor block 1 is supported on the inner wall of the downhole pipeline, thereby fixing the entire invention on the inner wall of the downhole pipeline.

[0021] like Figure 1 , 2As shown, in this embodiment, the telescopic mechanism is installed inside the mounting cylinder 5, and its structure includes a telescopic motor 6, a rotating sleeve 7, a sliding rod, and a cutter head. The rotating sleeve 7 is connected to the output shaft of the telescopic motor 6, thereby driving the rotating sleeve 7 to rotate through the telescopic motor 6. An axial slide rail 9 is machined on the side of the rotating sleeve 7, and the sliding rod is inserted into the rotating sleeve 7 and can slide along the axis of the rotating sleeve 7. A first limiting pin 8 is provided at the upper end of the sliding rod, and the end of the first limiting pin 8 is located in the axial slide rail 9, which restricts the relative rotation between the rotating sleeve 7 and the sliding rod.

[0022] like Figure 1 , 2 As shown, in this embodiment, a spiral groove 10 is machined on the outer side of the slide rod, and a second limiting pin 14 is provided at the lower end of the mounting cylinder 5. The second limiting pin 14 is inserted inward into the spiral groove 10 to achieve a threaded transmission engagement between the slide rod and the mounting cylinder 5. During operation, the output shaft of the telescopic motor 6 drives the rotating sleeve 7 to rotate. The rotating sleeve 7 drives the slide rod to rotate through the first limiting pin 8, and the slide rod drives the descaling head 13 to rotate. At the same time, during the relative rotation of the mounting cylinder 5 and the slide rod, the slide rod extends downward under the action of the above-mentioned threaded transmission engagement, thereby causing the descaling head 13 to perform a descaling action.

[0023] like Figure 1 , 3 As shown in Figure 4, in this embodiment, the slide bar includes an upper section 11 and a lower section 12, with the connection point of the two sections located at the upper part of the slide bar. This invention sets the slide bar into a segmented structure and connects the two sections using a one-way ratchet. Under normal circumstances, the upper section 11 rotates forward, and the lower section 12 rotates synchronously under the drive of the one-way ratchet. Then, under the cooperation of the spiral groove 10 and the second limiting pin 14, it pushes the descaling head 13 spirally downward. When an abnormal increase in the current of the telescopic motor 6 is detected, it means that the descaling head 13 is obstructed. At this time, the telescopic motor 6 is reversed automatically or manually, and the upper section 11 also reverses. After reversing, the lower section 12 makes a small-range axial reciprocating motion under the combined action of the one-way ratchet and the spring 16, producing a vibration effect. This vibration slightly impacts the hard scale, thereby strengthening the descaling force. After the telescopic motor 6 reverses for a few seconds, it rotates forward again, allowing the descaling head 13 to continue advancing.

[0024] like Figure 1 , 2 As shown, in order to adapt the connection between the second limiting pin 14 and the spiral groove 10 to the axial vibration of the lower section 12 of the slide rod, the present invention provides a micro-movement sleeve 15 at the lower end of the mounting cylinder 5. The second limiting pin 14 is fixedly mounted on the micro-movement sleeve 15, and the micro-movement sleeve 15 is axially slidably connected to the lower end of the mounting cylinder 5. Two sets of springs 16 are provided at the connection between the micro-movement sleeve 15 and the mounting cylinder 5. The two sets of springs 16 provide elastic support when the micro-movement sleeve 15 slides upward and downward, respectively.

[0025] It should be noted that with the segmented structure described above, the slide bar can only extend by rotating in the forward direction and cannot retract by rotating in the reverse direction. In other words, it cannot be descaled by the up-and-down reciprocating motion of the descaling head 13. Therefore, this structure is only suitable for descaling using the scraping descaling head 13.

[0026] For the brush-type descaling head 13, a single extension of the descaling head 13 is insufficient for effective descaling; multiple reciprocating movements are required for effective descaling. To achieve reciprocating motion of the slide rod based on segmented slide rods, the technical solution can be improved as follows: An electromagnetic clutch mechanism can be installed at the joint between the upper section 11 and the lower section 12 of the slide rod. For example, an electromagnetic pin can be installed inside the upper section 11. When the lower section 12 and the upper section 11 need to rotate in opposite directions together, the electromagnetic pin is energized, causing its end to insert into the lower section 12, thereby transmitting the torque of the upper section 11 to the lower section 12 during reverse rotation. When vibration is required to be generated through the reverse rotation of the upper section 11 and the one-way ratchet, i.e., when rotation is not required, the electromagnetic pin retracts into the upper section 11.

Claims

1. A device for clearing obstructions in an oilfield injection well test tubing, comprising an installation cylinder (5) and a descaling head (13), characterized in that, It also includes an anchoring mechanism and a telescopic mechanism, with the descaling head (13) installed at the lower end of the telescopic mechanism; An anchor block (1) is provided inside the anchoring mechanism. After the anchor block (1) extends laterally, it can be anchored on the inner wall of the underground pipeline, thereby fixing the entire device on the inner wall of the underground pipeline. The telescopic mechanism can make telescopic movements, which drive the descaling head (13) to move, thereby scraping away the scale adhering to the inner wall of the pipe.

2. The oilfield injection well test tubing obstruction clearing device according to claim 1, characterized in that: The anchoring mechanism is installed inside the mounting cylinder (5). The anchoring mechanism specifically includes an anchoring motor (4), a lead screw (3), a wedge (2), and the anchor block (1). The output shaft of the anchoring motor (4) is connected to one end of the lead screw (3), and the wedge (2) is connected to the other end of the lead screw (3) by a thread. The side of the mounting cylinder (5) is machined with a window. The anchor block (1) is slidably installed in the window along the radial direction of the mounting cylinder (5), and the wedge (2) is set inside the anchor block (1).

3. The oilfield injection well test string obstruction clearing device according to claim 1, characterized in that: The telescopic mechanism is set inside the mounting cylinder (5). Its structure includes a telescopic motor (6), a rotating sleeve (7), a sliding rod, and a cutting head. The rotating sleeve (7) is connected to the output shaft of the telescopic motor (6). An axial slide (9) is machined on the side of the rotating sleeve (7). The sliding rod is inserted into the rotating sleeve (7). A first limiting pin (8) is provided at the upper end of the sliding rod. The end of the first limiting pin (8) is inserted into the axial slide (9) and can slide along the axial slide (9). A spiral groove (10) is machined on the outer side of the sliding rod. A second limiting pin (14) is provided at the lower end of the mounting cylinder (5). The second limiting pin (14) is inserted inward into the spiral groove (10).

4. The oilfield injection well test string obstruction clearing device according to claim 3, characterized in that: The lower end of the mounting cylinder (5) is provided with a micro-movement sleeve (15), and the second limiting pin (14) is fixedly disposed on the micro-movement sleeve (15). The micro-movement sleeve (15) is axially slidably connected to the lower end of the mounting cylinder (5). Two sets of springs (16) are provided at the connection between the micro-motion sleeve (15) and the mounting cylinder (5). The two sets of springs (16) provide elastic support when the micro-motion sleeve (15) slides up and down.

5. The oilfield injection well test string obstruction clearing device according to claim 4, characterized in that: The slide bar includes an upper section (11) and a lower section (12), with the joint between the two sections located at the upper part of the slide bar as a whole. The lower end face of the upper section (11) and the upper end face of the lower section (12) of the slide rod are respectively provided with matching one-way ratchet teeth. Under the action of the one-way ratchet teeth, when the upper section (11) of the slide rod rotates in the forward direction, the lower section (12) of the slide rod can rotate together. When the upper section (11) of the slide rod rotates in the reverse direction, the one-way ratchet teeth can drive the lower section (12) of the slide rod to slide axially.

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