Oil pipe unblocking tool

Abstract

The present invention provides an oil pipe unblocking tool, comprising: an upper joint; a core shaft, rotatably connected to the lower part of the upper joint, the core shaft having an inner cavity connected to the upper joint, a rotation generator for driving the core shaft to rotate is installed on the core shaft; a rotating lower nozzle, fixed on the core shaft to rotate synchronously with the core shaft, the core shaft is provided with a connecting structure connecting the inner cavity of the core shaft and the inner cavity of the rotating lower nozzle, the rotating lower nozzle is provided with a spray hole for flushing the blockage on the inner wall of the oil pipe; a grinding and milling brush, arranged on the outside of the core shaft and located above the rotating lower nozzle, the grinding and milling brush rotates together with the core shaft and the rotating lower nozzle to grind the blockage on the inner wall of the oil pipe. The present invention adopts the form of a combination of a rotating lower nozzle and a grinding and milling brush, which can first soften the blockage on the inner wall of the oil pipe and remove the blockage with a soft surface, and then grind the hard blockage, which can not only achieve a better unblocking effect, but also will not affect the smooth development of subsequent production.

Description

Technical Field

[0001] The invention relates to the technical field of oil pipe unblocking, and in particular to an oil pipe unblocking tool. Background Art

[0002] The oil pipe is the production channel of the gas well. The size of the oil pipe flow channel directly affects the production of the gas well and is also a prerequisite for the implementation of gas well operations. Due to the high content of hydrogen sulfide in high-sulfur gas wells, as the gas field is developed, the gas reservoir pressure gradually decreases, a large amount of elemental sulfur is precipitated and adsorbed on the inner wall of the wellbore, resulting in increasingly serious sulfur deposition in the wellbore. Some gas wells have obvious wellbore throttling, which seriously affects the gas well production.

[0003] Currently, the commonly used methods for wellbore unblocking are chemical unblocking and mechanical unblocking.

[0004] The main principle of chemical agent unblocking is to inject agents into the wellbore, and the agents react with the blockage to achieve the purpose of unblocking. At present, through field experiments, it is found that the effect of agent injection unblocking is not obvious. The main reason is that the oil pipe is not blocked before the agent is injected, and the agent injected into the wellbore flows directly to the bottom of the well. The contact time between the agent and the blockage is short, resulting in poor unblocking effect.

[0005] Commonly used methods for mechanical unblocking include hydraulic flushing of continuous tubing and scraping unblocking. Among them, hydraulic flushing of continuous tubing uses a conventional nozzle to flush the inner wall of the tubing, such as the rotary sand flushing head disclosed in the Chinese utility model patent with authorization announcement number CN204571888U, which is mainly composed of a guide head, a rotary flushing cylinder and a connecting sleeve. The rotary flushing cylinder is eccentrically provided with a flushing hole, so that the rotary flushing cylinder can rotate quickly under the action of the flushing liquid while spraying liquid to flush sand, thereby ensuring the flushing effect. However, since this tool is mainly used for wellbore sand removal operations, for hard scale and sulfur deposits attached to the inner wall of the tubing, simple flushing is difficult to remove the hard deposits on the inner wall of the tubing, and only removes the soft deposits on the surface, and the unblocking effect is not ideal.

[0006] In addition, the Chinese utility model patent with the authorization announcement number CN210152614U discloses a wax scraping tool for oil pipes, which is mainly composed of a center rod and a wax scraping head arranged on the center rod, and is mainly used for wax removal of oil pipes. However, for high-sulfur natural gas wells with serious sulfur deposition in the wellbore, due to the small residual flow path of the oil pipe and the high hardness of the deposits on the wall of the oil pipe, the use of the wax scraping tool for oil pipes can easily lead to further compaction of the wellbore channel, making it smaller or even completely blocked. At the same time, the blocky deposits produced by scraping fall into the wellbore and are carried to the production process after the well is opened for production, which can easily cause blockage of the process pipeline.

[0007] In summary, the unblocking methods in the prior art all have the problem of unsatisfactory unblocking effects, and therefore an oil pipe unblocking tool with better unblocking effects is urgently needed. Summary of the invention

[0008] The purpose of the present invention is to provide an oil pipe unblocking tool with better unblocking effect.

[0009] To achieve the above purpose, the oil pipe unblocking tool of the present invention adopts the following technical solution:

[0010] A tool for unblocking an oil pipe, comprising:

[0011] An upper joint, used for connecting below the coiled tubing;

[0012] A core shaft is rotatably connected to the lower part of the upper joint, the core shaft has an inner cavity connected to the upper joint, and a rotation generator for driving the core shaft to rotate is installed on the core shaft;

[0013] The rotating lower nozzle is fixed on the core shaft to rotate synchronously with the core shaft. The core shaft is provided with a connecting structure connecting the inner cavity of the core shaft and the inner cavity of the rotating lower nozzle. The rotating lower nozzle is provided with a spray hole for flushing the blockage on the inner wall of the oil pipe.

[0014] The grinding and milling brush is arranged outside the core shaft and above the rotating lower nozzle. The grinding and milling brush rotates together with the core shaft and the rotating lower nozzle to grind the blockage on the inner wall of the oil pipe.

[0015] The beneficial effect of the above technical solution is that the rotating generator installed on the mandrel can drive the mandrel to rotate, the rotating lower nozzle is fixed on the mandrel and can rotate synchronously with the mandrel, and a liquid spray hole is arranged on the rotating lower nozzle, so that the rotating lower nozzle can rotate and spray liquid to flush the blockage on the inner wall of the oil pipe, soften the blockage on the inner wall of the oil pipe, remove the blockage with soft surface, and pre-treat the blockage. The grinding and milling brush is located above the rotating lower nozzle, and the grinding and milling brush rotates with the mandrel and the rotating lower nozzle, and can grind the blockage on the inner wall of the oil pipe, further remove the hard blockage on the inner wall of the oil pipe, and the use of a grinding and milling brush can make the milled particles relatively small, so that even if the particles enter the production process in subsequent production, it will not cause blockage of the process pipeline.

[0016] Therefore, the oil pipe unblocking tool of the present invention adopts the form of a combination of a rotating lower nozzle and a grinding and milling brush, which can first soften the blockage on the inner wall of the oil pipe and remove the soft blockage on the surface, and then grind the hard blockage, which can not only achieve a better unblocking effect, but also will not affect the smooth progress of subsequent production.

[0017] Furthermore, the rotating lower nozzle is threadedly connected to the bottom of the core shaft, the inner cavity of the core shaft is composed of a through hole that passes through the core shaft from top to bottom, and the connecting structure is formed by the bottom end opening of the through hole.

[0018] The beneficial effect of the above technical solution is that it is convenient to connect the rotating lower nozzle, and the formation of the connecting structure is convenient by arranging a through hole that passes through the core shaft from top to bottom.

[0019] Furthermore, a bearing sleeve is threadedly connected to the lower part of the upper joint, the bearing sleeve is located on the outside of the core shaft, and the lower end of the bearing sleeve is provided with an inwardly turned edge extending inward. A ring platform is protruded from the outside of the core shaft, and the upper and lower surfaces of the ring platform respectively constitute an upper annular step and a lower annular step. A first thrust bearing is installed between the upper annular step and the bottom end surface of the upper joint, and a second thrust bearing is installed between the lower annular step and the inward turned edge. The core shaft is rotatably suspended on the upper joint and the bearing sleeve through the ring platform, the first thrust bearing and the second thrust bearing.

[0020] The beneficial effects of the above technical solution are: by protruding an annular platform on the outside of the core shaft, a lower annular step and an upper annular step are formed, which facilitates the installation of the first thrust bearing, and by providing an inward-turned edge at the lower end of the bearing sleeve, the installation of the second thrust bearing is facilitated. The core shaft hanging type rotating installation method is realized through the annular platform, the first thrust bearing and the second thrust bearing. The structure is simple and compact, and it is convenient to process, manufacture and assemble. At the same time, the thrust bearing can withstand a large axial force, and the use effect is better.

[0021] Furthermore, the rotation generator includes an upper end cover fixed to the upper end of the core shaft, a fixing column arranged on the upper end cover and extending downward, and a spiral blade fixed on the fixing column. The spiral blade is located in the inner cavity of the core shaft. The upper end cover is provided with a through hole corresponding to the spiral blade for passing the well washing fluid, so that the spiral blade drives the core shaft to rotate under the impact force of the well washing fluid.

[0022] The beneficial effect of the above technical solution is that the rotation generator is arranged at the upper end of the core shaft, including an upper end cover, a fixed column and a spiral blade, and the upper end cover is provided with a through hole, so that the entering well washing fluid can impact the spiral blade at the first time, so that the spiral blade drives the core shaft to rotate under the action of the impact force. This form of rotation generator has a simple structure, is easy to install and reliable to use.

[0023] Furthermore, the oil pipe unblocking tool also includes a rotating upper nozzle arranged outside the core shaft and located above the grinding and milling brush. A connecting hole connecting the inner cavity of the core shaft and the inner cavity of the rotating upper nozzle is opened on the core shaft. The rotating upper nozzle is provided with a plurality of upper flow holes extending obliquely upward and distributed in a spiral shape, so that the well washing fluid passing through the upper flow holes can drive the rotating upper nozzle to rotate.

[0024] The beneficial effect of the above technical solution is that multiple upper flow holes extend obliquely upward and are distributed in a vortex shape, so that the well washing fluid passing through the upper flow holes can drive the rotating upper nozzle to rotate, realizing rotation and spraying, and the sprayed liquid forms a vortex, which can clean the inner wall of the oil pipe, and at the same time prevent the solid particles on the upper part of the grinding and milling brush from being deposited above the grinding and milling brush and causing blockage.

[0025] Furthermore, the rotating upper nozzle is also provided with a lower flow hole extending obliquely downward, and the orifice of the lower flow hole corresponds to the grinding and milling brush, so that the well washing fluid passing through the lower flow hole can spray the grinding and milling brush to cool it down and assist the grinding and milling brush to break the blockage.

[0026] The beneficial effect of the above technical solution is that the orifice of the lower flow hole corresponds to the grinding and milling brush, which can be sprayed to cool the grinding and milling brush and increase the service life of the grinding and milling brush. At the same time, it can also assist the grinding and milling brush to break up blockages and improve grinding efficiency.

[0027] Furthermore, the rotating upper nozzle is installed on the outside of the core shaft through the third thrust bearing and the fourth thrust bearing arranged up and down. A bearing is fixed on the outer surface of the core shaft. The bearing is located between the third thrust bearing and the fourth thrust bearing, and the bearing is located on the inner side of the rotating upper nozzle. A bearing flow hole connecting the connecting hole and the inner cavity of the rotating upper nozzle is opened on the bearing.

[0028] The beneficial effect of the above technical solution is that the third thrust bearing and the fourth thrust bearing are used to facilitate the rotational installation of the rotating upper nozzle. At the same time, a bearing is fixed on the outer surface of the core shaft, and the bearing is located on the inner side of the rotating upper nozzle. The bearing protects the core shaft to prevent the rotating upper nozzle from directly contacting the core shaft, thereby preventing the high-speed rotation of the rotating upper nozzle from causing wear on the core shaft surface.

[0029] Furthermore, the outer sleeve of the core shaft is provided with an upper adjustment sleeve and a lower adjustment sleeve. The upper adjustment sleeve is located below the rotating upper nozzle, and the upper adjustment sleeve is provided with an installation groove for installing the fourth thrust bearing. The lower adjustment sleeve is located above the rotating lower nozzle, and the grinding and milling brush clamp is fixed between the upper adjustment sleeve and the lower adjustment sleeve.

[0030] The beneficial effect of the above technical solution is that the clamping installation of the grinding and milling brush is realized through the upper adjustment sleeve and the lower adjustment sleeve, so that the grinding and milling brush has a bulging effect, so that it can better contact with the blockage and improve the grinding effect. At the same time, by installing upper adjustment sleeves and lower adjustment sleeves of different specifications, the clamping degree of the grinding and milling brush can be adjusted to achieve an ideal fixing effect and grinding effect.

[0031] Furthermore, the milling brush includes conical parts at upper and lower ends and a cylindrical part in the middle.

[0032] The beneficial effects of the above technical solution are: the tapered part at the lower end gradually contacts the blockage as the milling brush moves downward, and the contact area gradually increases, thereby achieving gradual and uniform grinding of the blockage, avoiding excessive grinding, which causes rapid wear of the milling brush and uneven rotation speed; the middle cylindrical part achieves uniform grinding and milling of the blockage, further removing hard blockages on the inner wall of the oil pipe; the tapered part at the upper end mainly facilitates some particles milled off the cylindrical part to pass through the milling brush smoothly, avoiding the deposition of particles in the cylindrical part and causing blockage.

[0033] Furthermore, the interior of the grinding and milling brush is a hollow structure, and an elastic member is provided between the cylindrical portion and the core shaft.

[0034] The beneficial effect of the above technical solution is that the cylindrical part can be elastically deformed, and can be in close contact with blockages of different degrees, thereby achieving a better grinding effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of the oil pipe unblocking tool in the present invention;

[0036] Figure 2 for Figure 1 Middle AA section view;

[0037] Figure 3 for Figure 1 Middle BB section view.

[0038] In the figure: 1-upper joint; 2-bearing sleeve; 3-rotating upper nozzle; 301-upper flow hole; 302-lower flow hole; 4-milling brush; 401-transition line; 5-rotating lower nozzle; 501-spray hole; 6-upper sealing assembly; 7-first thrust bearing; 8-second thrust bearing; 9-lower sealing assembly; 10-third thrust bearing; 11-fourth thrust bearing; 12-compression spring; 13-lower adjustment sleeve; 14-upper adjustment sleeve; 15-bearing shell; 151-bearing shell flow hole; 16-rotating generator; 161-through hole; 162-spiral blade; 163-upper end cover; 164-fixed column; 17-core shaft; 171-connecting hole; 172-ring platform. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0041] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0042] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0043] Embodiment 1 of the oil pipe unblocking tool of the present invention is as follows Figure 1 As shown, it mainly includes upper joint 1, bearing sleeve 2, rotating upper nozzle 3, milling brush 4, rotating lower nozzle 5, mandrel 17 and other components, wherein the upper joint 1 is used to be connected to the bottom of the continuous oil pipe, the mandrel 17 is connected to the bottom of the upper joint 1, and the upper part of the mandrel 17 is rotatably installed inside the bearing sleeve 2 and the upper joint 1. The mandrel 17 has an inner cavity connected with the upper joint 1, so that the well washing fluid passes through the continuous oil pipe and the upper joint 1 and enters the inner cavity of the mandrel. Specifically, the inner cavity of the mandrel is composed of a through hole that passes through the mandrel from top to bottom.

[0044] The bearing sleeve 2 is threadedly connected to the lower part of the upper joint 1. The bearing sleeve 2 is located outside the core shaft 17. The lower end of the bearing sleeve 2 is provided with an inwardly extending inwardly turned edge. The inner diameter of the part above the inwardly turned edge of the bearing sleeve 2 is larger than the inner diameter of the upper joint 1. The outer part of the core shaft 17 is provided with a ring platform 172. The upper surface of the ring platform 172 constitutes an upper annular step, and the lower surface constitutes a lower annular step. The lower annular step faces downward and is arranged opposite to the inwardly turned edge of the bearing sleeve 2. A second thrust bearing 8 is installed between them. At the same time, the upper annular step faces upward and is arranged opposite to the bottom end surface of the upper joint 1. A first thrust bearing 7 is installed between them. The core shaft 17 is rotatably installed inside the bearing sleeve 2 and the upper joint 1 through the first thrust bearing 7 and the second thrust bearing 8, and a hanging installation mode is formed.

[0045] To ensure sealing, an upper sealing component 6 is provided between the core shaft 17 and the upper joint 1 , and a lower sealing component 9 is provided between the core shaft 17 and the bearing sleeve 2 .

[0046] In order to realize the rotation of the core shaft 17, a rotation generator 16 is installed at the upper end of the core shaft 17, and the rotation generator 16 includes an upper end cover 163 fixed on the upper end surface of the core shaft 17, a fixing column 164 fixed on the upper end cover 163 and extending downward, and a spiral blade 162 fixed on the fixing column 164. The spiral blade 162 is located in the inner cavity of the core shaft, and a plurality of through holes corresponding to the spiral blade 162 for the well washing fluid to pass through are opened on the upper end cover 163, so that the well washing fluid can impact the spiral blade 162, and the spiral blade 162 can drive the core shaft 17 to rotate under the impact of the water flow. In this embodiment, six through holes are evenly arranged.

[0047] The rotating lower nozzle 5 is threadedly connected to the bottom of the core shaft 17, and is fixedly installed on the outside of the core shaft 17, and is directly driven to rotate by the core shaft 17. The inner cavity of the rotating lower nozzle 5 is a stepped cavity, and the bottom end opening of the through hole in the core shaft 17 forms a connecting structure connecting the inner cavity of the core shaft and the inner cavity of the rotating lower nozzle. The rotating lower nozzle 5 is provided with a plurality of spray holes 501 extending obliquely downward. In this embodiment, four spray holes 501 are evenly distributed. The rotating lower nozzle 5 is used to rotate and spray liquid along with the core shaft 17 to flush the blockage on the inner wall of the oil pipe, soften the blockage on the inner wall of the oil pipe, and remove the blockage with soft surface, so as to pre-treat the blockage.

[0048] The grinding and milling brush 4 is arranged outside the core shaft 17 and located above the rotating lower nozzle 5. The grinding and milling brush 4 can be a wire brush or a brush made of other wear-resistant materials to grind the blockage on the inner wall of the oil pipe while rotating, thereby further removing the hard blockage on the inner wall of the oil pipe.

[0049] Specifically, the outer sleeve of the mandrel 17 is provided with an upper adjustment sleeve 14 and a lower adjustment sleeve 13, the upper adjustment sleeve 14 is located below the rotating upper nozzle 3, the lower adjustment sleeve 13 is located above the rotating lower nozzle 5, and the grinding and milling brush 4 is clamped and fixed between the upper adjustment sleeve 14 and the lower adjustment sleeve 13, so the upper adjustment sleeve 14, the lower adjustment sleeve 13 and the grinding and milling brush 4 clamped in the middle can rotate with the mandrel 17 and the rotating lower nozzle 5. The clamping installation of the grinding and milling brush is realized by the upper adjustment sleeve and the lower adjustment sleeve, so that the grinding and milling brush produces a bulging effect, so that it can better contact with the blockage and improve the grinding effect. At the same time, by installing upper adjustment sleeves and lower adjustment sleeves of different specifications, the clamping degree of the grinding and milling brush can be adjusted, so as to achieve an ideal fixing effect and grinding effect.

[0050] Furthermore, the grinding and milling brush 4 includes conical parts at the upper and lower ends and a cylindrical part in the middle. The conical part at the lower end gradually contacts the blockage as the grinding and milling brush descends, and the contact area gradually increases, thereby achieving gradual and uniform grinding of the blockage to avoid excessive grinding, which causes rapid wear of the grinding and milling brush and uneven rotation speed; the cylindrical part in the middle achieves uniform grinding and milling of the blockage to further remove hard blockages on the inner wall of the oil pipe; the conical part at the upper end mainly facilitates some particles milled down by the cylindrical part to pass through the grinding and milling brush smoothly, thereby avoiding particles from being deposited in the cylindrical part and causing blockage.

[0051] The interior of the milling brush 4 is a hollow structure, and an elastic member is arranged between the cylindrical portion and the core shaft 17. The elastic member in this embodiment is a compression spring 12. Figure 3 As shown, six groups of compression springs 12 are evenly arranged, and six grooves are evenly arranged on the mandrel 17 to position the compression springs 12. By arranging the compression springs 12, the cylindrical part can be elastically deformed, and can be in close contact with blockages of different degrees, thereby achieving a better grinding effect.

[0052] The rotating upper nozzle 3 is located between the bearing sleeve 2 and the upper adjustment sleeve 14, and is independently rotatably installed on the outside of the core shaft 17 through the third thrust bearing 10 and the fourth thrust bearing 11 arranged up and down. The upper end surface of the upper adjustment sleeve 14 is provided with a mounting groove for installing the fourth thrust bearing 11, and the lower end surface of the bearing sleeve 2 is provided with a mounting groove for installing the third thrust bearing 10.

[0053] The core shaft 17 is provided with a connecting hole 171 connecting the core shaft inner cavity and the rotating upper nozzle inner cavity. Figure 2 As shown, three connecting holes 171 are evenly arranged. A bearing bush 15 is fixed on the outer surface of the mandrel 17. The bearing bush 15 is located between the first thrust bearing 10 and the second thrust bearing 11, and the bearing bush 15 is located on the inner side of the rotating upper nozzle 3. The bearing bush 15 protects the mandrel 17 to prevent the rotating upper nozzle 3 from directly contacting the mandrel 17, thereby preventing the rotating upper nozzle 3 from rotating at high speed and causing wear on the surface of the mandrel 17. The bearing bush 15 is provided with a bearing bush flow hole 151 connecting the above-mentioned connecting hole 171 and the inner cavity of the rotating upper nozzle. There are also three corresponding bearing bush flow holes 151 evenly arranged, and the aperture is larger than the aperture of the connecting hole 171.

[0054] like Figure 1 As shown, the rotating upper nozzle 3 is provided with a plurality of upper flow holes 301 extending obliquely upward and distributed in a vortex shape. Specifically, the central axis of the upper flow hole 301 is at an angle of 45 degrees to the central axis of the rotating upper nozzle 3. Figure 2As shown, and distributed obliquely at 45 degrees in the radial direction, the well washing fluid passing through the upper flow hole 301 can drive the rotating upper nozzle 3 to rotate, realize rotation and spraying, and the sprayed liquid forms a vortex, which can clean the inner wall of the oil pipe, and at the same time prevent the solid particles on the upper part of the grinding and milling brush from being deposited on the grinding and milling brush, causing blockage.

[0055] like Figure 1 As shown, the rotating upper nozzle 3 is also provided with a lower flow hole 302 extending obliquely downward, and the orifice of the lower flow hole 302 corresponds to the grinding and milling brush 4. Specifically, the central axis of the lower flow hole 302 intersects with the transition line 401 between the conical part and the cylindrical part at the upper end of the grinding and milling brush 4, so that the grinding and milling brush 4 can be sprayed to cool down the grinding and milling brush 4 and increase the service life of the grinding and milling brush 4. At the same time, it can also assist the grinding and milling brush 4 to break the blockage and improve the grinding and milling efficiency.

[0056] The working process of the oil pipe unblocking tool of the present invention is as follows:

[0057] When unblocking the inner wall of the oil pipe, the continuous oil pipe is connected to the upper joint 1 through a thread, and then the tool is lowered to the target depth, and the well washing fluid is pumped. The fluid flows in from the upper joint 1, and then flows into the mandrel 17 through the through hole 161 and the spiral blade 162 of the rotating generator 16. When the fluid passes through the spiral blade 162, it can drive the mandrel 17 to rotate, and the mandrel 17 drives the milling brush 4 and the rotating lower nozzle 5 to rotate together, and a part of the fluid flows out through the spray hole 501 on the rotating lower nozzle 5, pre-flushing the sediment on the inner wall of the oil pipe to make it soft, and at the same time removing the soft sediment on the surface. As the tool is lowered, the lower conical surface of the rotating milling brush 4 realizes the gradual and uniform milling of the blockage, and the cylindrical surface realizes the full grinding of the hard blockage. Part of the grinded material falls directly to the bottom of the well, and part of the grinded material enters the top of the tool through the upper conical surface of the milling brush 4 as the tool is lowered.

[0058] Six groups of compression springs 12 are evenly distributed between the milling brush 4 and the core shaft 17, and the compression amount is adjusted according to the severity of the blockage, so as to ensure that the milling brush is always close to the oil pipe wall and improve the milling effect. And the use of a milling brush in the form of a milling brush can make the milled particles relatively small, so that even if the particles enter the production process in subsequent production, it will not cause blockage of the process pipeline. Therefore, the oil pipe unblocking tool of the present invention adopts the form of a combination of a rotating lower nozzle and a milling brush, which can first soften the blockage on the inner wall of the oil pipe and remove the soft blockage on the surface, and then grind the hard blockage, which can not only achieve a better unblocking effect, but also will not affect the smooth progress of subsequent production.

[0059] At the same time, another part of the fluid enters the inner cavity of the rotating upper nozzle 3 through the connecting hole 171 and the bearing bush flow hole 151, and then flows out through the upper flow hole 301 and the lower flow hole 302 of the rotating upper nozzle 3. Under the action of hydraulic force, the rotating upper nozzle 3 forms self-rotation to clean the pipe wall again, and at the same time effectively avoids the solid particles on the upper end surface of the grinding and milling brush 4 from being deposited on the upper end surface of the grinding and milling brush 4, causing blockage. The fluid through the lower flow hole 302 realizes the spray cooling of the grinding and milling brush 4 and assists in breaking the sediment, which protects the tool and improves the unblocking effect.

[0060] Embodiment 2 of the oil pipe unblocking tool in the present invention is different from the above embodiments in that an angular contact ball bearing capable of withstanding a certain axial force is used between the core shaft and the bearing sleeve to achieve rotational fit, and in this case, a ring platform is not required on the core shaft.

[0061] Embodiment 3 of the oil pipe unblocking tool in the present invention is different from the above embodiments in that no bearing sleeve is provided, and the core shaft is directly rotatably mounted on the inner wall of the upper joint through an angular contact ball bearing.

[0062] Embodiment 4 of the oil pipe unblocking tool in the present invention: The difference from the above embodiments is that the rotating lower nozzle is not fixedly connected to the bottom of the core shaft, but is closer to it. A guide head is connected to the bottom of the core shaft, and the rotating lower nozzle is located above the guide head. At this time, a connecting hole is provided on the pipe wall of the core shaft as a connecting structure.

[0063] Embodiment 5 of the oil pipe unblocking tool in the present invention is different from the above embodiments in that no lower flow holes are provided on the rotating upper nozzle, but only upper flow holes are provided.

[0064] Embodiment 6 of the oil pipe unblocking tool in the present invention is different from the above embodiments in that an upper adjustment sleeve and a lower adjustment sleeve are not provided, the lower part of the grinding and milling brush is directly pressed on the rotating lower nozzle, and an installation groove for installing a second thrust bearing is provided on the upper part.

[0065] Embodiment 7 of the oil pipe unblocking tool of the present invention is different from the above embodiments in that the bearing is not fixed on the outer surface of the core shaft, and the rotating upper nozzle is in clearance fit with the outer wall of the core shaft.

[0066] Embodiment 8 of the oil pipe unblocking tool in the present invention is different from the above embodiments in that the rotating upper nozzle is rotatably mounted on the outside of the core shaft through an angular contact ball bearing that can withstand a certain axial force.

[0067] Embodiment 9 of the oil pipe unblocking tool of the present invention is different from the above embodiments in that no rotating upper nozzle is provided, and the unblocking work is achieved only by the milling brush and the rotating lower nozzle.

[0068] Embodiment 10 of the oil pipe unblocking tool of the present invention is different from the above embodiments in that the elastic member between the cylindrical part and the core shaft can also be a spring sheet.

[0069] Embodiment 11 of the oil pipe unblocking tool in the present invention is different from the above embodiments in that no elastic member is arranged between the cylindrical part and the core shaft. In this case, a material having elasticity itself can be selected to manufacture the grinding and milling brush so that the grinding and milling brush itself has a certain elasticity.

[0070] Embodiment 12 of the oil pipe unblocking tool in the present invention is different from the above embodiments in that only a conical part is provided at the lower part of the grinding and milling brush, and the grinding and milling brush is composed of an upper cylindrical part and a lower conical part.

[0071] Embodiment 13 of the oil pipe unblocking tool of the present invention is different from the above embodiments in that the grinding and milling brush is cylindrical as a whole.

[0072] Embodiment 14 of the oil pipe unblocking tool of the present invention is different from the above embodiments in that the rotary generator is a spiral blade directly fixed on the inner wall of the core shaft.

[0073] 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 contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. A tool for unblocking oil pipes, characterized in that: include: A connector, used for connecting below the coiled tubing; A mandrel is rotatably connected to the lower part of the joint, the mandrel has an inner cavity connected to the joint, a rotation generator for driving the mandrel to rotate is installed on the mandrel, the rotation generator includes an end cap fixed to the upper end of the mandrel, a fixing column arranged on the end cap and extending downward, a spiral blade located in the inner cavity of the mandrel is fixed on the fixing column, and a through hole corresponding to the spiral blade for passing the well washing fluid is arranged on the end cap; The rotating lower nozzle is fixed on the core shaft to rotate synchronously with the core shaft. The core shaft is provided with a connecting structure connecting the inner cavity of the core shaft and the inner cavity of the rotating lower nozzle. The rotating lower nozzle is provided with a spray hole for flushing the blockage on the inner wall of the oil pipe. A grinding and milling brush is arranged outside the mandrel and above the rotating lower nozzle. The grinding and milling brush rotates together with the mandrel and the rotating lower nozzle to grind the blockage on the inner wall of the oil pipe; The oil pipe unblocking tool also includes a rotating upper nozzle arranged outside the core shaft and located above the grinding and milling brush. A connecting hole connecting the inner cavity of the core shaft and the inner cavity of the rotating upper nozzle is opened on the core shaft. The rotating upper nozzle is provided with a plurality of upper flow holes extending obliquely upward and distributed in a vortex shape, so that the well washing fluid passing through the upper flow holes can drive the rotating upper nozzle to rotate.

2. The oil pipe unblocking tool according to claim 1, characterized in that: The rotating lower nozzle is threadedly connected to the bottom of the core shaft, the inner cavity of the core shaft is composed of a through hole that passes through the core shaft from top to bottom, and the connecting structure is formed by the bottom end opening of the through hole.

3. The oil pipe unblocking tool according to claim 1 or 2, characterized in that: A bearing sleeve is threadedly connected to the lower part of the joint, and the bearing sleeve is located on the outside of the core shaft. An inward-turned edge extending inward is provided at the lower end of the bearing sleeve. A ring platform is convexly provided on the outside of the core shaft, and the upper and lower surfaces of the ring platform respectively constitute an upper annular step and a lower annular step. A first thrust bearing is installed between the upper annular step and the bottom end surface of the joint, and a second thrust bearing is installed between the lower annular step and the inward-turned edge. The core shaft is rotatably mounted on the joint and the bearing sleeve through the ring platform, the first thrust bearing and the second thrust bearing.

4. The oil pipe unblocking tool according to claim 1 or 2, characterized in that: The spiral blade drives the core shaft to rotate under the impact force of the well washing fluid.

5. The oil pipe unblocking tool according to claim 1 or 2, characterized in that: The rotating upper nozzle is also provided with a lower flow hole extending obliquely downward, and the orifice of the lower flow hole corresponds to the grinding and milling brush, so that the well washing fluid passing through the lower flow hole can spray the grinding and milling brush to cool it down and assist the grinding and milling brush to break the blockage.

6. The oil pipe unblocking tool according to claim 1 or 2, characterized in that: The rotating upper nozzle is installed on the outside of the core shaft through the third thrust bearing and the fourth thrust bearing arranged up and down. A bearing is fixed on the outer surface of the core shaft. The bearing is located between the third thrust bearing and the fourth thrust bearing, and the bearing is located on the inner side of the rotating upper nozzle. A bearing flow hole connecting the connecting hole and the inner cavity of the rotating upper nozzle is opened on the bearing.

7. The oil pipe unblocking tool according to claim 6, characterized in that: The outer sleeve of the core shaft is provided with an upper adjustment sleeve and a lower adjustment sleeve. The upper adjustment sleeve is located below the rotating upper nozzle, and the upper adjustment sleeve is provided with an installation groove for installing the fourth thrust bearing. The lower adjustment sleeve is located above the rotating lower nozzle, and the grinding and milling brush clamp is fixed between the upper adjustment sleeve and the lower adjustment sleeve.

8. The oil pipe unblocking tool according to claim 1 or 2, characterized in that: The milling brush comprises conical parts at upper and lower ends and a cylindrical part in the middle.

9. The oil pipe unblocking tool according to claim 8, characterized in that: The interior of the grinding and milling brush is a hollow structure, and an elastic member is arranged between the cylindrical part and the core shaft.

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