A clampless continuous tubing injector and its usage method

Abstract

This invention relates to the field of petroleum equipment technology, and particularly to a clamp-free coiled tubing injector and its usage method. The technical solution is as follows: multiple sets of active friction wheels, driven friction shafts, and intermediate wheels are installed inside the injector housing. The multiple active friction wheels are connected by intermediate wheel drives. A driven friction shaft is installed in a driven friction shaft mounting slot on one side of each active friction wheel. A friction rubber component is installed in the middle of the active friction wheel. The coiled tubing to be injected is clamped through the cavity formed between the active friction wheel and the driven friction shaft. The output end of a hydraulic motor meshes with a set of active friction wheels through gears, driving the coiled tubing to move and achieve injection downhole or retrieval to the reel. This invention uses multiple active friction wheels and driven friction shafts to clamp the coiled tubing, allowing each set of gears to clamp the coiled tubing, meeting the lifting requirements of heavier coiled tubing. Furthermore, replacing the friction rubber component is convenient, reducing safety hazards.

Description

Technical Field

[0001] This invention relates to the field of petroleum equipment technology, and in particular to a non-clamping block continuous tubing injector and its usage method. Background Technology

[0002] Coiled tubing, also known as flexible tubing or coiled tubing, is a coiled, jointless tubing made of low-carbon alloy steel. It is a core piece of equipment in oil and gas field operations. Compared to traditional tubing, it supports continuous tripping under pressure, eliminating the need for repeated splicing of individual sections. It boasts advantages such as high operational efficiency, small footprint, low formation damage, and low cost, earning it the reputation of being an all-purpose workover machine for oil and gas fields. It is widely used in well workover and petroleum development. The coiled tubing injection head is the core assembly of the coiled tubing operation equipment. It is the key power component for sending and retrieving coiled tubing downhole. Its main function is to continuously deliver the coiled tubing downhole to complete the operation and then smoothly retrieve it afterward. The clamping drive, as the core component of the injection head, adjusts the clamping force of the clamping blocks according to the working conditions. This force, via a chain, drives the clamped coiled tubing, enabling continuous insertion and removal from the well. The problems are as follows: First, the clamping blocks in the existing coiled tubing injector can damage the surface of the coiled tubing, causing corrugations and indentations, which affects the wellhead seal and service life of the coiled tubing, thus creating certain safety hazards. Second, the chain rotates around the drive and driven wheels. The clamping blocks corresponding to the chain at the drive and driven wheels should forcefully clamp the coiled tubing. However, due to the preload of the chain, the clamping blocks on the chain between the drive and driven wheels cannot achieve a strong clamping action. Therefore, it is necessary to design a new action that can continuously clamp the coiled tubing. For example, a 2-meter chain-type coiled tubing injector can meet the lifting requirements of 60-ton coiled tubing, but it cannot meet the lifting requirements of coiled tubing with greater weight. Third, the workload of replacing clamping blocks is large. The clamping blocks of the existing technology wear out quickly and need to be replaced regularly. Moreover, most of the existing ones are one-piece structures, and the injector weighs several tons. The weight of each chain link is large, which makes replacement difficult and prone to safety hazards.

[0003] Additionally, Chinese patent number 201610478185.6, entitled "Coiled Tube Injector Apparatus and Method," describes a coiled tube injector apparatus for inserting and / or retrieving coiled tube from a wellhead. It includes a first injection head and a second injection head, forming a central channel within a frame. Each of the first and second injection heads includes an inner belt and an outer belt. The outer belt includes multiple rolling elements that engage the coiled tube, and the inner belt provides the driving force applied to the outer belt. The inner belt further includes a wear-resistant plate designed to withstand most wear, thus reducing maintenance and replacement costs for the injection head. The problems with this patent are: it still uses a chain drive, resulting in insufficient preload on the clamping blocks of the chain between the drive and driven sprockets; and the heavy weight of each chain link makes replacing the clamping blocks difficult.

[0004] Furthermore, Chinese Patent No. 202121857348.4, entitled "A Clamping Device for an Injection Head of Continuous Tubing," includes a housing and continuous tubing. The outer sides of the tensioning ratchet and the driven ratchet are connected via a transmission chain. Multiple clamping blocks are fixedly connected to the outer sides of the transmission chain. Fixing plates are fixedly connected to the middle of the left and right sides inside the housing. Clamping cylinders are fixedly connected to the top center of each fixing plate. Multiple pushing elements are fixedly connected to the middle of the inner side of each pushing block. Multiple fixing clamping blocks are fixedly connected to the middle of the inner side of each clamping block. Telescopic clamping blocks are slidably connected inside the mounting groove. In this invention, the tensioning ratchet is driven together with the driven ratchet via the transmission chain. The control device continues to control the clamping cylinder drive, causing the pushing blocks and pushing elements to press against the transmission chain. This achieves clamping of the continuous tubing while simultaneously allowing for extension and retraction of the continuous tubing, facilitating subsequent continuous tubing entry and exit from the well and improving work efficiency. However, the problem with this patent is that it still uses a chain drive, which means there is still insufficient preload on the clamping blocks on the chain between the drive wheel and the driven wheel. In addition, each chain link is heavy, making it difficult to replace the clamping blocks. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned deficiencies in the existing technology by providing a non-clamping continuous tubing injector and its usage method. This invention employs multiple active friction wheels and multiple driven friction shafts to clamp the continuous tubing, ensuring that each set of gears can clamp the continuous tubing. This allows the same-sized continuous tubing injector to meet the lifting requirements of heavier continuous tubing. Furthermore, this invention makes it easier to replace the friction rubber components, improving the service life of the continuous tubing and reducing safety hazards.

[0006] The present invention discloses a non-clamping block coiled tubing injector, the technical solution of which includes an injector housing, an input end cover, and an output end cover. The input end cover is installed at the input end of the injector housing, and the output end cover is installed at the output end of the injector housing. It also includes an active friction wheel, a driven friction shaft, a driven friction shaft mounting groove, a hydraulic motor, an intermediate wheel, and friction rubber components. Multiple sets of active friction wheels, driven friction shafts, and intermediate wheels are installed inside the injector housing. The multiple active friction wheels are connected to each other via intermediate wheel transmission. A driven friction shaft is installed in the driven friction shaft mounting groove on one side of each active friction wheel. A friction rubber component is installed in the middle of the active friction wheel. The coiled tubing to be injected is clamped by the cavity formed between the friction rubber component in the middle of the active friction wheel and the driven friction shaft. The output end of the hydraulic motor meshes with a set of active friction wheels via gears. The hydraulic motor drives the active friction wheels and intermediate wheels to rotate, thereby moving the coiled tubing to achieve injection downhole or retrieval to the reel.

[0007] Preferably, the active friction wheel includes a power tooth, an active wheel body, a mounting hole, and a mounting groove. The power tooth is installed on both sides of the active wheel body. Multiple evenly distributed mounting grooves are provided on the outer wall of the active wheel body. A mounting hole is provided in the center of the active wheel body for the active friction wheel to be installed and fixed by passing a connecting shaft through the side wall of the injector housing.

[0008] Preferably, the mounting groove of the aforementioned drive wheel body is used to install a friction rubber component, the inner side of which is provided with a protrusion for cooperating with the mounting groove, and the outer surface of the friction rubber component has an arc-shaped structure.

[0009] Preferably, the outer wall of the injector housing is provided with a mediator mounting hole, a hydraulic motor mounting hole, a driven friction shaft mounting groove, and a driving friction wheel shaft hole. The hydraulic motor mounting hole is located in the middle of the outer wall of the injector housing. The driving friction wheel shaft hole corresponds to the position of the driven friction shaft mounting groove. A mediator mounting hole is provided on one side of the driving friction wheel shaft hole.

[0010] Preferably, the driven friction shaft mounting groove is an elongated groove structure, and the mounting position of the driven friction shaft is adjusted along the elongated groove structure.

[0011] Preferably, the driven friction shaft includes a driven shaft body and a driven shaft mounting groove. A ring of driven shaft mounting grooves is evenly distributed on the outer wall of the driven shaft body, and the friction rubber component is fixed to the outer ring of the driven friction shaft through the driven shaft mounting grooves.

[0012] Preferably, the input end cover has a continuous oil pipe inlet hole at its center, and the output end cover has a continuous oil pipe injection hole at its center, and the diameters of the continuous oil pipe inlet hole and the continuous oil pipe injection hole are larger than the outer diameter of the continuous oil pipe.

[0013] The method of using the clampless continuous tubing injector mentioned in this invention includes the following steps: First, the friction rubber component is installed and fixed in the middle of the active friction wheel, and the friction rubber component is fixed on the outer wall of the driven friction shaft. Then, multiple active friction wheels are fixed in the active friction wheel shaft holes of the injector housing. Power is transmitted between the active friction wheels by installing intermediate wheels. Next, multiple driven friction shafts are fixed in the driven friction shaft mounting groove. Then, the continuous oil pipe is passed through the continuous oil pipe inlet hole and sent to the position between the active friction wheel and the driven friction shaft, and extends a distance along the continuous oil pipe injection hole. The position of the driven friction shaft is adjusted according to the outer diameter of the continuous oil pipe so that the active friction wheel and the driven friction shaft can clamp the continuous oil pipe. Then, the hydraulic motor is installed in the hydraulic motor mounting hole, and the output shaft of the hydraulic motor is engaged with the active friction wheel through gear meshing to transmit rotational power. Then, the non-clamping coiled tubing injector is moved to the wellhead. The coiled tubing from the coiled tubing injection port is fed into the wellhead casing. The rotation speed of the hydraulic motor is controlled to drive the active friction wheel to rotate, so that the coiled tubing moves between the middle of the active friction wheel and the driven friction shaft. Under the action of the friction rubber parts, the coiled tubing is clamped and continuously fed into the downhole casing. When it is necessary to lift the coiled tubing, the hydraulic motor outputs power in the opposite direction to lift the coiled tubing out of the wellhead.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: I. This invention employs multiple active friction wheels and multiple driven friction shafts to clamp the coiled tubing. The force is applied via a friction wheel kinematic pair. The positions of the active friction wheels and multiple driven friction shafts are adjustable, enabling each set of active friction wheels and driven friction shafts to apply clamping force to the coiled tubing. Furthermore, replacing the friction rubber components is convenient, improving the service life of the coiled tubing and reducing safety hazards. In contrast, existing coiled tubing injectors using clamping blocks rely on a track system, avoiding insufficient clamping force from the intermediate clamping blocks. This allows coiled tubing injectors of the same size to meet the lifting requirements of heavier coiled tubing. Second, the clamp-free coiled tubing injector mentioned in this invention ensures uniform stress on the surface of the coiled tubing, eliminating clamp marks. In contrast, existing coiled tubing injectors with clamping blocks cause uneven stress on the surface of the coiled tubing, resulting in clamp marks. These clamp marks can lead to poor wellhead sealing and oil leakage. This invention eliminates clamp marks on the surface of the coiled tubing, thus improving wellhead sealing and preventing oil leakage. Furthermore, it avoids clamp marks and damage to the surface of the coiled tubing, extending its service life. Third, the present invention installs and fixes the friction rubber component in the middle of the active friction wheel and fixes the friction rubber component on the outer wall of the driven friction shaft. Furthermore, the inner side of the friction rubber component is provided with a protrusion for cooperating with the mounting groove of the active friction wheel and the driven shaft mounting groove of the driven friction shaft, so as to prevent the friction rubber component from slipping. This allows the active friction wheel and the driven friction shaft to better clamp the continuous oil pipe and drive the continuous oil pipe to move. Attached Figure Description

[0015] Figure 1 This is a front structural diagram of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention viewed from the left. Figure 3 This is a top-view schematic diagram of the internal structure of the present invention; Figure 4 This is a three-dimensional structural schematic diagram of the present invention; Figure 5 This is a structural schematic diagram of the present invention from one angle; Figure 6 This is a structural schematic diagram of the present invention from another angle; Figure 7 This is a schematic diagram of the internal structure of the present invention; Figure 8 This is a schematic diagram of the active friction wheel; Figure 9 This is a schematic diagram of the active friction wheel's structure along direction A. Figure 10 This is a schematic diagram of the driven friction shaft; Figure 11 This is a schematic diagram of the cross-section of the driven friction shaft; Figure 12 This is a schematic diagram of the structure of a friction rubber component; In the diagram: Injector housing 1, Input end cover 2, Output end cover 3, Driving friction wheel 4, Driven friction shaft 5, Driven friction shaft mounting groove 6, Driving friction wheel shaft hole 7, Hydraulic motor 8, Intermediate wheel 9, Continuous oil pipe 10, Friction rubber component 11, Intermediate wheel mounting hole 1.1, Hydraulic motor mounting hole 1.2, Continuous oil pipe inlet hole 2.1, Continuous oil pipe injection hole 3.1, Power gear 4.1, Driving wheel body 4.2, Mounting hole 4.3, Mounting groove 4.4, Driven shaft body 5.1, Driven shaft mounting groove 5.2, Protrusion 11.1. Detailed Implementation

[0016] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0017] Example 1, referring to Figures 1-12The present invention discloses a continuous tubing injector without clamping blocks, comprising an injector housing 1, an input end cover 2, and an output end cover 3. The input end cover 2 is installed at the input end of the injector housing 1, and the output end cover 3 is installed at the output end of the injector housing 1. It also includes an active friction wheel 4, a driven friction shaft 5, a driven friction shaft mounting groove 6, a hydraulic motor 8, a mediator 9, and friction rubber components 11. Multiple sets of active friction wheels 4, driven friction shafts 5, and mediator 9 are installed inside the injector housing 1, and the multiple active friction wheels 4 are respectively driven by the mediator 9. A driven friction shaft 5 is installed in the driven friction shaft mounting groove 6 on one side of each active friction wheel 4. A friction rubber component 11 is installed in the middle of the active friction wheel 4. The continuous tubing 10 to be injected is clamped through the cavity formed between the friction rubber component 11 in the middle of the active friction wheel 4 and the driven friction shaft 5. The output end of the hydraulic motor 8 is engaged with a set of active friction wheels 4 through gears. The hydraulic motor 8 drives the active friction wheel 4 and the intermediate wheel 9 to rotate, thereby driving the continuous tubing 10 to move its position to achieve injection downhole or retrieval into the reel.

[0018] Reference Figures 8-9 The active friction wheel 4 mentioned in this invention includes a power tooth 4.1, an active wheel body 4.2, a mounting hole 4.3, and a mounting groove 4.4. The power tooth 4.1 is installed on both sides of the active wheel body 4.2. Multiple evenly distributed mounting grooves 4.4 are provided on the outer wall of the active wheel body 4.2. The mounting hole 4.3 is provided in the center of the active wheel body 4.2 for mounting and fixing the active friction wheel 4 by passing a connecting shaft through the side wall of the injector housing 1.

[0019] The friction rubber component 11 is installed in the mounting groove 4.4 of the aforementioned drive wheel body 4.2. The inner side of the friction rubber component 11 is provided with a protrusion 11.1 for cooperating with the mounting groove 4.4. The outer surface of the friction rubber component 11 has an arc-shaped structure.

[0020] Reference Figures 1-7 The injector housing 1 mentioned in this invention has an intermediate wheel mounting hole 1.1, a hydraulic motor mounting hole 1.2, a driven friction shaft mounting groove 6, and an active friction wheel shaft hole 7 on its outer wall. The hydraulic motor mounting hole 1.2 is located in the middle of the outer wall of the injector housing 1. The active friction wheel shaft hole 7 corresponds to the position of the driven friction shaft mounting groove 6. An intermediate wheel mounting hole 1.1 is provided on one side of the active friction wheel shaft hole 7.

[0021] The driven friction shaft mounting groove 6 is an elongated groove structure, and the mounting position of the driven friction shaft 5 is adjusted along the elongated groove structure.

[0022] Reference Figures 10-11The driven friction shaft 5 mentioned in this invention includes a driven shaft body 5.1 and a driven shaft mounting groove 5.2. The driven shaft body 5.1 has a ring of driven shaft mounting grooves 5.2 evenly distributed on its outer wall. The friction rubber component 11 is fixed to the outer ring of the driven friction shaft 5 through the driven shaft mounting grooves 5.2.

[0023] In addition, the center of the input end cover 2 is provided with a continuous oil pipe inlet 2.1, and the center of the output end cover 3 is provided with a continuous oil pipe injection hole 3.1. The diameters of the continuous oil pipe inlet 2.1 and the continuous oil pipe injection hole 3.1 are larger than the outer diameter of the continuous oil pipe 10.

[0024] The method of using the clampless continuous tubing injector mentioned in this invention includes the following steps: First, the friction rubber component 11 is installed and fixed in the middle of the active friction wheel 4, and the friction rubber component 11 is fixed on the outer wall of the driven friction shaft 5. Then, multiple active friction wheels 4 are fixed in the active friction wheel shaft hole 7 of the injector housing 1. Power is transmitted between the active friction wheels 4 by installing the intermediate wheel 9. Then, multiple driven friction shafts 5 are fixed in the driven friction shaft mounting groove 6. Then, the continuous oil pipe 10 is passed through the continuous oil pipe inlet hole 2.1 and sent to the position between the active friction wheel 4 and the driven friction shaft 5, and extends a distance along the continuous oil pipe injection hole 3.1. The position of the driven friction shaft 5 is adjusted according to the outer diameter of the continuous oil pipe 10 so that the active friction wheel 4 and the driven friction shaft 5 can clamp the continuous oil pipe 10. Then, the hydraulic motor 8 is installed in the hydraulic motor mounting hole 1.2, and the output shaft of the hydraulic motor 8 is meshed with the active friction wheel 4 through gears to transmit rotational power. Then, the non-clamping block coiled tubing injector is moved to the wellhead. The coiled tubing 10 from the coiled tubing injection port 3.1 is fed into the wellhead casing. The rotation speed of the hydraulic motor 8 is controlled to drive the active friction wheel 4 to rotate, so that the coiled tubing 10 moves between the middle of the active friction wheel 4 and the driven friction shaft 5. Under the action of the friction rubber component 11, the coiled tubing 10 is clamped and continuously fed into the downhole casing. When it is necessary to lift the coiled tubing 10, the hydraulic motor 8 outputs power in the opposite direction to lift the coiled tubing 10 out of the wellhead.

[0025] Example 2: The clamp-free continuous tubing injector mentioned in this invention includes an injector housing 1, an input end cover 2, and an output end cover 3. The input end cover 2 is installed at the input end of the injector housing 1, and the output end cover 3 is installed at the output end of the injector housing 1. It also includes an active friction wheel 4, a driven friction shaft 5, a driven friction shaft mounting groove 6, a hydraulic motor 8, a mediator 9, and friction rubber components 11. Multiple sets of active friction wheels 4, driven friction shafts 5, and mediators 9 are installed inside the injector housing 1. The multiple active friction wheels 4 are respectively connected by mediators 9. The transmission connection includes a driven friction shaft 5 installed in the driven friction shaft mounting groove 6 on one side of each active friction wheel 4. A friction rubber component 11 is installed in the middle of the active friction wheel 4. The continuous tubing 10 to be injected is clamped through the cavity formed between the friction rubber component 11 in the middle of the active friction wheel 4 and the driven friction shaft 5. The output end of the hydraulic motor 8 is engaged with a set of active friction wheels 4 through gears. The hydraulic motor 8 drives the active friction wheel 4 and the intermediate wheel 9 to rotate, thereby driving the continuous tubing 10 to move its position to achieve injection downhole or retrieval into the reel.

[0026] The difference from Example 1 is: In this embodiment, the outer wall of the driven shaft body 5.1 is uniformly distributed with a ring of driven shaft mounting grooves 5.2, which are trapezoidal in shape; the outer wall of the driving wheel body 4.2 is provided with multiple uniformly distributed mounting grooves 4.4, which are also trapezoidal in shape, to facilitate installation and also to prevent the friction rubber parts 11 from falling off.

[0027] The above description is merely a partial preferred embodiment of the present invention. Any person skilled in the art can modify the above-described technical solutions or modify them into equivalent technical solutions. Therefore, any simple modifications or equivalent transformations made based on the technical solutions of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A continuous tubing injector without clamping blocks, comprising an injector housing (1), an input end cover (2), and an output end cover (3), wherein the input end cover (2) is installed at the input end of the injector housing (1), and the output end cover (3) is installed at the output end of the injector housing (1), characterized in that: It also includes an active friction wheel (4), a driven friction shaft (5), a driven friction shaft mounting groove (6), a hydraulic motor (8), an intermediate wheel (9), and a friction rubber component (11). Multiple sets of active friction wheels (4), driven friction shafts (5), and intermediate wheels (9) are installed in the injector housing (1). The multiple active friction wheels (4) are connected to each other through the intermediate wheel (9). A driven friction shaft (5) is installed in the driven friction shaft mounting groove (6) on one side of each active friction wheel (4). A friction rubber component (11) is installed in the middle of the active friction wheel (4). The cavity formed between the friction rubber component (11) in the middle of the active friction wheel (4) and the driven friction shaft (5) clamps the coiled tubing (10) to be injected. The output end of the hydraulic motor (8) meshes with a set of active friction wheels (4) through gears. The hydraulic motor (8) drives the active friction wheels (4) and the intermediate wheel (9) to rotate, thereby driving the coiled tubing (10) to move to achieve injection downhole or recovery into the reel.

2. The clampless continuous tubing injector according to claim 1, characterized in that: The active friction wheel (4) includes a power tooth (4.1), an active wheel body (4.2), a mounting hole (4.3), and a mounting groove (4.4). The power tooth (4.1) is installed on both sides of the active wheel body (4.2). Multiple evenly distributed mounting grooves (4.4) are provided on the outer wall of the active wheel body (4.2). The mounting hole (4.3) is provided in the center of the active wheel body (4.2) for mounting and fixing the active friction wheel (4) by passing the connecting shaft through the side wall of the injector housing (1).

3. The clampless continuous tubing injector according to claim 2, characterized in that: The friction rubber component (11) is installed in the mounting groove (4.4) of the drive wheel body (4.2). The inner side of the friction rubber component (11) is provided with a protrusion (11.1) for cooperating with the mounting groove (4.4). The outer surface of the friction rubber component (11) is an arc-shaped structure.

4. The clampless continuous tubing injector according to claim 3, characterized in that: The outer wall of the injector housing (1) is provided with a median mounting hole (1.1), a hydraulic motor mounting hole (1.2), a driven friction shaft mounting groove (6), and an active friction wheel shaft hole (7). The hydraulic motor mounting hole (1.2) is located in the middle of the outer wall of the injector housing (1). The active friction wheel shaft hole (7) is positioned corresponding to the driven friction shaft mounting groove (6). A median mounting hole (1.1) is provided on one side of the active friction wheel shaft hole (7).

5. The clampless continuous tubing injector according to claim 4, characterized in that: The driven friction shaft mounting groove (6) is a long strip groove structure, and the mounting position of the driven friction shaft (5) is adjusted along the long strip groove structure.

6. The clampless continuous tubing injector according to claim 5, characterized in that: The driven friction shaft (5) includes a driven shaft body (5.1) and a driven shaft mounting groove (5.2). A ring of driven shaft mounting grooves (5.2) is evenly distributed on the outer wall of the driven shaft body (5.1). The friction rubber component (11) is fixed to the outer ring of the driven friction shaft (5) through the driven shaft mounting groove (5.2).

7. The clampless continuous tubing injector according to claim 6, characterized in that: The input end cover (2) has a continuous oil pipe inlet hole (2.1) at its center, and the output end cover (3) has a continuous oil pipe injection hole (3.1) at its center. The diameters of the continuous oil pipe inlet hole (2.1) and the continuous oil pipe injection hole (3.1) are larger than the outer diameter of the continuous oil pipe (10).

8. A method of using the clampless continuous tubing injector as described in claim 7, characterized in that: Includes the following processes: First, the friction rubber component (11) is installed and fixed in the middle of the active friction wheel (4), and the friction rubber component (11) is fixed on the outer wall of the driven friction shaft (5). Then, multiple active friction wheels (4) are fixed in the active friction wheel shaft hole (7) of the injector housing (1). Power is transmitted between the active friction wheels (4) by installing intermediate wheels (9). Then, multiple driven friction shafts (5) are fixed in the driven friction shaft mounting groove (6). Then, the continuous oil pipe (10) is passed through the continuous oil pipe inlet hole (2). 1) Insert it into the position between the active friction wheel (4) and the driven friction shaft (5), and extend it a distance along the injection hole (3.1) of the continuous oil pipe. Adjust the position of the driven friction shaft (5) according to the outer diameter of the continuous oil pipe (10) so that the active friction wheel (4) and the driven friction shaft (5) can clamp the continuous oil pipe (10). Then install the hydraulic motor (8) in the hydraulic motor mounting hole (1.2) and make the output shaft of the hydraulic motor (8) mesh with the active friction wheel (4) through gears to transmit the rotational power. Then, the non-clamping block coiled tubing injector is moved to the wellhead. The coiled tubing (10) from the coiled tubing injection hole (3.1) is fed into the wellhead casing. The rotation speed of the hydraulic motor (8) is controlled to drive the active friction wheel (4) to rotate, so that the coiled tubing (10) moves between the middle of the active friction wheel (4) and the driven friction shaft (5). Under the action of the friction rubber part (11), the coiled tubing (10) is clamped and continuously fed into the downhole casing. When it is necessary to lift the coiled tubing (10), the hydraulic motor (8) outputs power in the opposite direction, so that the coiled tubing (10) is lifted out of the wellhead.

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