Segmented jet flow plug removal tubular column for horizontal well

Abstract

The utility model discloses a horizontal well subsection jet flow plug removal pipe column which comprises an outer pipe column and an inner pipe column, and the outer pipe column comprises an upper packer, an upper jet flow plug removal pipe, at least one lower jet flow unit and a check valve which are sequentially connected from top to bottom; the inner pipe column comprises a conversion connector and at least one layered jet flow conversion assembly which are connected in sequence; the number of the jet conversion assemblies is the same as that of the lower jet units; each layered jet flow conversion assembly corresponds to one lower jet flow unit; and the upper end of the upper packer is connected with the outer wall of the lower end of the adapter. According to the utility model, one pipe column is used for selectively removing blocking in sections, jet flow blocking removal is carried out section by section from bottom to top, different discharge capacities, different treatment radiuses and different blocking remover types are selected for each section, jet flow blocking removal is selectively carried out, and formation jet flow blocking removal construction parameters are selectively optimized.

Description

Technical Field

[0001] The utility model relates to the technical field of oil well unblocking, in particular to a horizontal well segmented jet unblocking pipe column. Background Art

[0002] Horizontal well technology has been widely used in oil fields and has become an important supporting technology for the stable development of oil fields. The sand control methods currently used in horizontal wells are open-hole screen sand control and gravel filling in perforated pipes. Before production, it is necessary to carry out unblocking measures for inorganic and organic blockages. The horizontal sections encountered often have problems such as heterogeneous oil layers, mudstones, dry layers, high water-bearing layers, and formation collapse. The commonly used unblocking methods are general unblocking of the entire well section or dragging the pipe string to unblock. The general unblocking of the entire well section of the horizontal well will cause interference between layers, and a large amount of unblocking fluid will enter the high-permeability and high-porosity oil layers, and the low-permeability layer will not be effectively unblocked. The unblocking method of dragging the pipe string requires dismantling the wellhead to trip a single pipe or use a continuous oil pipe, which is highly dangerous and costly. After reasonable segmented isolation, differentiated unblocking measures can be carried out according to the specific reservoir characteristics of each section, and the construction parameters of formation jet unblocking can be selectively optimized, which is of great significance for realizing the fine development of horizontal wells and giving full play to the production capacity of horizontal wells.

[0003] Publication (Announcement) No.: CN114458210A, discloses an integrated process string for jet unblocking and negative pressure return and a method of use, including a negative pressure mechanism and a jet mechanism; the upper end of the jet mechanism is connected to the lower end of the negative pressure mechanism; the negative pressure mechanism is externally provided with a top packer, and the jet mechanism is externally provided with at least two jet unblocking segmented packers located at different levels. The invention can complete the integrated construction of jet unblocking and negative pressure return of sand control screens in oil wells, lower the tool into the sand control screen, use the packer to evenly segment the screen, first seal the top packer of the integrated process string for jet unblocking and negative pressure return, and then perform jet unblocking. After jet unblocking, negative pressure return is performed. The invention can achieve uniform unblocking and return of each section of the screen, improve operating efficiency, reduce operating costs, and improve construction safety.

[0004] This prior art can evenly remove blockage, but cannot achieve selective segmented removal of blockage in the entire well section.

[0005] Publication (announcement) number: CN110685622A, discloses a uniform jet unblocking and filling integrated process string and method, wherein the string includes a uniform jet unblocking and filling outer string and an inner string. Among them, the outer string includes an oil pipe, a walled outer pipe of a liquid flow wall conversion tool, a pressure difference flow blocking packer, and a jet unblocking tool connected in sequence from top to bottom. The inner string includes a walled inner pipe of a liquid flow wall conversion tool, an inner filling pipe, and an acid washing and filling inner tool. The uniform jet unblocking and filling outer string and the inner string are connected through a liquid flow wall conversion tool and lowered into the well. An annulus can be formed between the inner and outer strings to provide a liquid flow channel for acid washing, extrusion and circulation filling. This process string can realize the screen jetting, near-well uniform acid washing and unblocking, extrusion, and circulation filling sand control construction of a long well section of a horizontal well in one trip.

[0006] The prior art uses a differential pressure blocking packer to perform uniform unblocking, but cannot achieve selective segmented unblocking of the entire well section.

[0007] Publication (Announcement) No.: CN116517506B, discloses a reciprocating rotary jet unblocking device and a method of using the device. The technical solution is: the lower end of the central tube is connected to a reciprocating motion conduit, the outer wall is provided with a first spiral track and a second spiral track, and the pitch of the second spiral track is greater than the pitch of the first spiral track, and the lower end of the reciprocating motion conduit is connected to a lower connecting seat; a rotating cylinder is installed on the outer wall, and the rotating cylinder is connected and matched with the first spiral track and the second spiral track through a crescent guide pin; the upper end of the rotating cylinder is movably connected to the upper rotating outer tube, and the lower end is movably connected to the lower rotating outer tube; the beneficial effects are: on the one hand, it reciprocates up and down while rotating to unblock the corresponding wellbore wall section with a rotary jet, and on the other hand, it generates a wellbore liquid water hammer impact effect, forms an impact vibration on the casing wall and the perforation blasthole, enhances the unblocking and dredging effect on the perforation blasthole, further improves the seepage capacity of the near-wellbore formation, and achieves the purpose of better reservoir transformation.

[0008] The prior art uses rotating jets to uniformly remove blockages, but cannot achieve selective segmented blockage removal of the entire well section.

[0009] In short, the technical solutions of the above-disclosed technologies, the technical problems to be solved and the beneficial effects produced are all different from the present utility model. Regarding more technical features, technical problems to be solved and the beneficial effects of the present utility model, there is no technical inspiration in the above-disclosed technical documents. Utility Model Content

[0010] In view of the above-mentioned defects in the prior art, the purpose of the utility model is to provide a horizontal well segmented jet unblocking string. According to the heterogeneity of physical properties, oil, gas and water content, mud content, type of blockage, degree of blockage and other characteristics of each section of the formation, a differentiated unblocking string design is carried out. In one trip of the string, selective segmented unblocking is carried out, and jet unblocking is carried out section by section from bottom to top. There is no need to drag the string during construction, so the safety is high, segmentation can be achieved without using continuous oil pipes, and the construction cost is low. The horizontal section can be divided into the required number of sections according to the actual situation of the oil well.

[0011] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0012] A horizontal well segmented jet unblocking string comprises an outer string and an inner string, wherein the outer string comprises an upper packer, an upper jet unblocking pipe, at least one lower jet unit, and a check valve connected in sequence from top to bottom; the inner string comprises a conversion joint, an unblocking inner pipe, and at least one stratified jet conversion assembly connected in sequence; the number of the jet conversion assemblies is the same as that of the lower jet units; each stratified jet conversion assembly corresponds to a lower jet unit; the upper end of the upper packer is connected to the outer wall of the lower end of the conversion joint.

[0013] Furthermore, the lower jet unit comprises an upper sealing joint, a lower packer, a lower sealing joint, and a lower jet unblocking pipe which are connected in sequence.

[0014] Further, the stratified jet conversion assembly includes a stratified jet conversion tube, a ball seat sleeve, a return spring, and a return spring stop ring;

[0015] Specifically, the stratified jet conversion tube is sealed with an upper sealing joint and a lower sealing joint;

[0016] Specifically, the ball seat sleeve is connected to the stratified jet conversion tube through a pin; the return spring stop ring is arranged at the lower end of the inner wall of the stratified jet conversion tube; the return spring is arranged between the ball seat sleeve and the return spring stop ring;

[0017] Specifically, the stratified jet conversion tube is provided with a plugging-removing liquid conversion outlet above the sealing area with the upper sealing joint; the stratified jet conversion tube is provided with an internal pressure transmission hole between the sealing areas with the upper sealing joint and the lower sealing joint;

[0018] Specifically, when the ball seat sleeve is at the initial position, the ball seat sleeve closes the deblocking liquid conversion outlet, and the internal pressure transmission hole is located below the ball seat sleeve; when the ball seat sleeve is at the lowest point, the deblocking liquid conversion outlet is connected, and the internal pressure transmission hole is above the ball seat sleeve.

[0019] Furthermore, at least two of the stratified jet conversion assemblies are provided;

[0020] Specifically, the upper end of the stratified jet conversion pipe of the uppermost stratified jet conversion assembly is connected to the inner wall of the lower end of the conversion joint through the unblocking inner pipe;

[0021] The upper end of the stratified jet conversion tube of the stratified jet conversion assembly located below is connected to the lower end of the stratified jet conversion tube of the stratified jet conversion assembly located above;

[0022] Specifically, the inner diameter of the ball seat sliding sleeve gradually decreases from top to bottom.

[0023] Furthermore, the upper sealing joint and the lower sealing joint are sealed and matched with the lower jet unblocking pipe by providing a sealing ring.

[0024] Furthermore, at least two lower jet units are provided;

[0025] Specifically, the upper sealing joint of the uppermost lower jet unit is connected to the lower end of the upper jet unblocking pipe;

[0026] Specifically, the upper sealing joint of the lower jet unit located below is connected to the lower end of the lower jet unblocking pipe of the lower jet unit located above;

[0027] Specifically, the lower end of the lower jet unblocking pipe of the lowermost lower jet unit is connected to the check valve.

[0028] Furthermore, the upper jet unblocking pipe and the lower jet unblocking pipe are both jet unblocking pipes;

[0029] Specifically, a jet pipe coupling is arranged at the upper end of the jet unblocking pipe, and at least two jet nozzles are arranged on the wall of the jet unblocking pipe.

[0030] Furthermore, the upper packer and the lower packer have the same structure, both of which are expansion packers;

[0031] Specifically, the expandable packer includes a base pipe, an upper joint of the packer, a pressure transmission hole of the packer, a sealing device, and a lower joint of the packer;

[0032] Specifically, the upper joint of the packer is connected to the upper end of the base pipe, the lower joint of the packer is connected to the lower end of the base pipe, the sealing device is sleeved on the base pipe, a rubber sleeve is arranged in the sealing device, and a packer pressure transmission hole is arranged on the base pipe.

[0033] Furthermore, the upper joint of the upper packer is connected to the outer wall of the lower end of the conversion joint, and the lower joint of the upper packer is connected to the jet pipe coupling of the upper jet unblocking pipe.

[0034] Further, the packer upper joint of the lower packer is connected to the upper sealing joint, and the packer lower joint of the lower packer is connected to the lower sealing joint;

[0035] Specifically, the lower sealing joint is connected to the jet pipe coupling of the lower jet unblocking pipe.

[0036] Compared with the prior art, the utility model has the following beneficial effects:

[0037] 1. In one trip of the string, selective segmented unblocking is carried out from bottom to top, and jet unblocking is carried out section by section. For each section, different displacement, different treatment radius, and different types of unblocking agents are selected for selective jet unblocking, and the construction parameters of formation jet unblocking are selectively optimized.

[0038] 2. There is no need to drag the pipe during the construction process, which is highly safe. The segmentation can be achieved without the use of continuous tubing, and the construction cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a structural schematic diagram of a horizontal well segmented jet plugging removal string of the utility model;

[0040] Figure 2 It is the state of the pipe string when the pipe string for horizontal well segmented jet plugging removal is lowered in the utility model;

[0041] Figure 3 The utility model is a horizontal well segmented jet unblocking pipe string lower layer jet unblocking pipe string state;

[0042] Figure 4 The utility model is a horizontal well segmented jet unblocking pipe string upper layer jet unblocking pipe string state;

[0043] Figure 5 This is a nitrogen return pipe string state of a horizontal well segmented jet plugging removal pipe string of the utility model;

[0044] In the figure: 1. conversion joint; 2. upper joint of packer; 3. pressure transmission hole of packer; 4. rubber cylinder; 5. upper packer; 6. lower joint of packer; 7. jet pipe coupling; 8. unblocking inner pipe; 9. jet unblocking pipe; 10. jet nozzle; 11. layered jet conversion pipe; 12. steel ball; 13. ball seat sleeve; 14. unblocking liquid conversion outlet; 15. pin; 16. reset spring; 17. upper sealing joint; 18. inner pressure transmission hole; 19. lower packer; 20. lower sealing joint; 21. reset spring stop ring; 22. check valve. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0046] It should be noted that the contents of the drawings are not directly spliced ​​from the cut ends. The connection relationship between the two parts in a figure can be seen through the numbers.

[0047] Embodiment 1:

[0048] See also Figure 1 The utility model provides a horizontal well segmented jet unblocking string, and this embodiment provides a situation of being divided into two sections, including an outer string and an inner string; the outer string includes an upper packer 5, an upper jet unblocking pipe, a lower packer 19, a lower jet unblocking pipe, and a check valve 22 connected in sequence from top to bottom; the inner string includes a conversion joint 1, an unblocking inner pipe 8, and a stratified jet conversion assembly connected in sequence from top to bottom; the upper end of the upper packer 5 is connected to the outer wall of the lower end of the conversion joint 1, and the stratified jet conversion assembly is sealed with the upper inner wall and the lower inner wall of the lower packer 19.

[0049] The stratified jet conversion assembly includes a stratified jet conversion tube 11, a ball seat sleeve 13, a return spring 16, and a return spring stop ring 21; the upper end of the stratified jet conversion tube 11 is connected to the lower end of the unblocking inner tube 8, the stratified jet conversion tube 11 is sealed with the upper inner wall and the lower inner wall of the lower packer 19, the lower end of the stratified jet conversion tube 11 is open, the ball seat sleeve 13 is connected to the stratified jet conversion tube 11 through a pin 15, the return spring stop ring 21 is arranged at the lower end of the inner wall of the stratified jet conversion tube 11, and the return spring 16 is arranged between the ball seat sleeve 13 and the return spring stop ring 21 , can push the ball seat sleeve 13 back to the initial position, the stratified jet conversion pipe 11 is provided with a plugging liquid conversion outlet 14 above the upper sealing area of ​​the lower packer 19, and the stratified jet conversion pipe 11 is provided with an internal pressure transmission hole 18 between the upper sealing area and the lower sealing area of ​​the lower packer 19. When the ball seat sleeve 13 is in the initial position, the ball seat sleeve 13 closes the plugging liquid conversion outlet 14, and the internal pressure transmission hole 18 is located below the ball seat sleeve 13; when the ball seat sleeve 13 is at the lowest point, the plugging liquid conversion outlet 14 is connected, and the internal pressure transmission hole 18 is above the ball seat sleeve 13. The annulus between the plugging inner pipe 8 and the upper packer 5 can transmit pressure, and when the plugging liquid conversion outlet 14 is opened, the pressure can be transmitted to the upper packer 5 to seal, and the pressure shrinks after the pump is stopped.

[0050] The upper jet unblocking pipe and the lower jet unblocking pipe are both jet unblocking pipes 9 , a jet pipe coupling 7 is arranged at the upper end of the jet unblocking pipe 9 , and at least two jet nozzles 10 are arranged on the pipe wall of the jet unblocking pipe 9 .

[0051] The upper packer 5 has the same structure as the lower packer 19, both of which are expansion packers, including a base pipe, a packer upper joint 2, a packer pressure transmission hole 3, a sealing device, and a packer lower joint 6; the packer upper joint 2 is connected to the upper end of the base pipe, the packer lower joint 6 is connected to the lower end of the base pipe, the sealing device is sleeved on the base pipe, a rubber sleeve 4 is provided in the sealing device, and a packer pressure transmission hole 3 is provided on the base pipe for transmitting the sealing pressure.

[0052] The packer upper joint 2 of the upper packer 5 is connected to the outer wall of the lower end of the conversion joint 1, and the packer lower joint 6 of the upper packer 5 is connected to the jet pipe coupling 7 of the upper jet unblocking pipe.

[0053] The upper joint of the lower packer 19 is connected to the upper sealing joint 17, the lower joint of the lower packer 19 is connected to the lower sealing joint 20, the upper sealing joint 17 is connected to the upper jet unblocking pipe, the lower sealing joint 20 is connected to the jet pipe coupling of the lower jet unblocking pipe, and the layered jet conversion pipe 11 is sealed with the inner wall of the upper sealing joint 17 and the inner wall of the lower sealing joint 20.

[0054] From bottom to top, jet unblocking is performed section by section. When performing jet unblocking of the lower layer, the unblocking liquid is directly injected, and the pressure reaches the rubber tube through the internal pressure transmission hole 18 and the packer pressure transmission hole of the lower packer 19, causing the rubber tube to swell and seal. The unblocking liquid passes through the unblocking inner tube 8, the layered jet conversion tube 11, and the ball seat sliding sleeve 13 to reach the lower jet unblocking tube, and finally the screen tube and the oil layer are jet unblocked through the jet nozzle of the lower jet unblocking tube.

[0055] When performing upper layer jet unblocking, the steel ball 12 is put in and the pressure is applied. When the pressure reaches 20MPa, the ball seat sleeve 13 shears off the pin 15, and the ball seat sleeve 13 compresses the reset spring 16 and moves downward, leaking out the unblocking liquid conversion outlet 14 and the stratified jet unblocking internal pressure transmission hole 18. At this time, the pressure causes the rubber tube 4 to swell through the pressure transmission hole 3 of the packer; at the same time, the unblocking liquid can enter the jet unblocking pipe 9 and the unblocking inner pipe 8 annulus through the unblocking liquid conversion outlet 14, and finally perform jet unblocking on the screen pipe and the oil layer through the jet nozzle of the upper jet unblocking pipe. After stopping the pump, the ball seat sleeve 13 is reset and closed by the compression reset spring 16 to prepare for the nitrogen backflow after unblocking.

[0056] The check valve 22 is threadedly connected to the lower end of the jet unblocking pipe 9. When the jet is in the forward direction, the check valve 22 is closed. When the reverse nitrogen is mixed and discharged, the check valve 22 is opened to establish a reverse circulation well washing channel.

[0057] The upper end of the conversion joint 1 is connected to the oil pipe, and the upper joint 2 of the packer and the lower joint 6 of the packer are sealed and matched with the unblocking inner pipe 8 by providing a sealing ring.

[0058] The jet unblocking pipe 9 can be replaced with jet nozzles 10 of different sizes and numbers according to the unblocking displacement and treatment radius requirements.

[0059] Embodiment 2:

[0060] See also Figure 2-5 This embodiment provides a method for using the column:

[0061] S1, running tool: connect the upper packer 5 through the oil pipe, connect the upper jet unblocking pipe, connect the lower packer 19, connect the lower jet unblocking pipe, and connect the check valve 22;

[0062] If more than three sections of jet unblocking are required, a connecting packer, a layered jet conversion assembly, and a jet unblocking pipe can be added. The upper and lower jet unblocking pipes 9 are 5 meters long, and the corresponding number is increased according to the length of the oil layer. The jet nozzle 10 can be replaced with different sizes and different numbers of nozzles according to the requirements of different unblocking displacements and different treatment radii. The segmented jet unblocking process pipe string is lowered to the designed position as required. If the wellbore sand is not in place during the construction process, the well can be washed by reverse circulation, and the well can be washed while being lowered to the designed depth;

[0063] S2, lower layer jet unblocking: When performing lower layer jet unblocking construction, the ground is connected to the construction vehicle group in a positive circulation or positive extrusion mode, and different types of unblocking liquid are pumped into the oil pipe according to the difference in oil layers; the unblocking liquid reaches the unblocking inner pipe 8 through the oil pipe, passes through the stratified jet conversion pipe 11, the ball seat sliding sleeve 13, and the lower packer 19. When the unblocking liquid passes through the lower packer 19, the liquid stratified jet unblocking inner pressure transmission hole 18 and the packer pressure transmission hole of the lower packer 19 are used to expand and seal the rubber cylinder of the lower packer 19. The packer expansion and sealing starting pressure is 0.5MPa. The lower packer 19 is expanded and sealed, and the jet pipe and the casing annulus are sealed, so that the unblocking liquid cannot move upward through the lower packer 19, and can only enter the lower layer to jet unblock the lower layer, thus achieving stratification in a true sense;

[0064] The unblocking fluid passes through the lower packer 19 and finally passes through the lower jet unblocking pipe, and reaches the jet nozzle of the lower jet unblocking pipe to jet unblock the lower screen pipe and the lower oil layer. According to the characteristics of the lower oil reservoir, the type of blockage, and the blockage radius, different displacements, different treatment radii, and different types of unblocking agents are selected for selective jet unblocking. The construction displacement is 600L / min-1000L / min, and the pressure is 15MPa-20MPa.

[0065] S3, upper jet unblocking: when performing upper jet unblocking, the ground is connected to the construction vehicle group in a positive circulation or positive extrusion mode, and the steel ball 12 is put in. The oil pipe is pressurized to send the ball. When the steel ball 12 reaches the ball seat sleeve 13, the pressure is increased. When the pressure reaches 20MPa, the ball seat sleeve 13 cuts off the pin 15, and the ball seat sleeve 13 compresses the return spring 16 and moves downward, leaking out the unblocking liquid conversion outlet 14 and the stratified jet unblocking inner pressure transmission hole 18, and the unblocking liquid reaches the unblocking inner pipe 8 through the oil pipe, passes through the stratified jet conversion pipe 11, and most of the unblocking liquid enters the unblocking inner pipe 8 through the unblocking liquid conversion outlet 14, and the jet The unblocking pipe 9 is in the annular space, and finally reaches the packer pressure transmission hole of the upper packer 5, and the rubber cylinder 4 of the upper packer 5 is expanded and sealed. The packer expansion and sealing start pressure is 0.5MPa. The upper packer 5 is expanded and sealed, and the jet pipe and casing annulus are sealed, so that the unblocking fluid cannot move upward through the outer annulus of the upper packer 5. Finally, it passes through the upper jet unblocking pipe and reaches the jet nozzle of the upper jet unblocking pipe to jet unblock the middle layer screen pipe and the middle layer oil layer. According to the characteristics of the middle layer oil reservoir, the type of blockage, and the blockage radius, different displacements, different treatment radii, and different types of unblocking agents are selected for selective jet unblocking. The construction displacement is 600L / min-1000L / min, and the pressure is 15MPa-20MPa.

[0066] A small portion of the unblocking liquid is segmented and passes through the liquid layered jet unblocking internal pressure transmission hole 18 and the packer pressure transmission hole of the lower packer 19, so that the rubber tube of the lower packer 19 is expanded and sealed. The packer expansion and sealing starting pressure is 0.5MPa. The lower packer 19 is expanded and sealed, and the jet tube and the casing annulus are sealed, so that the unblocking liquid cannot move downward through the lower packer 19, and can only enter the middle layer to jet unblock the middle layer. After stopping the pump, the ball seat sleeve 13 is reset and closed by the compression reset spring 16 to close the unblocking liquid conversion outlet 14, and the rubber tubes of the upper and lower packers return to their original shapes.

[0067] S4. Nitrogen return: When nitrogen is returned, the ground is connected to the construction vehicle group according to the reverse circulation. Nitrogen passes from the oil casing annulus through the upper packer 5, the upper jet unblocking pipe, the lower packer 19, the lower jet unblocking pipe and the check valve 22; the start-up pressure of the check valve 22 is low, and the mixed nitrogen and water carry the residual acid, mud and sand of the oil layer reaction and enter the reset spring stop ring 21, the stratified jet conversion pipe 11, the ball seat sliding sleeve 13, the unblocking inner pipe 8 through the check valve 22, and finally enter the oil pipe and return to the ground, completing the staged design of the unblocking agent negative pressure return construction.

[0068] Embodiment 3:

[0069] Based on Example 1, this embodiment provides a method for setting up more than two sections of the tubing string, including an outer tubing string and an inner tubing string, the outer tubing string including an upper packer 5, an upper jet unblocking pipe, at least one lower jet unit, and a check valve 22 connected in sequence from top to bottom; the inner tubing string includes a conversion joint 1, an unblocking inner pipe 8, and at least one stratified jet conversion assembly connected in sequence; the number of the jet conversion assemblies is the same as that of the lower jet units; each stratified jet conversion assembly corresponds to a lower jet unit; the upper end of the upper packer 5 is connected to the outer wall of the lower end of the conversion joint 1.

[0070] The lower jet unit comprises an upper sealing joint 17, a lower packer, a lower sealing joint 20, and a lower jet unblocking pipe which are connected in sequence.

[0071] The stratified jet conversion assembly includes a stratified jet conversion tube 11, a ball seat sleeve 13, a return spring 16, and a return spring stop ring 21; the stratified jet conversion tube 11 is sealed with an upper sealing joint 17 and a lower sealing joint 20; the ball seat sleeve 13 is connected to the stratified jet conversion tube 11 through a pin 15; the return spring stop ring 21 is arranged at the lower end of the inner wall of the stratified jet conversion tube 11; the return spring 16 is arranged between the ball seat sleeve 13 and the return spring stop ring 21; the stratified jet conversion The tube 11 is provided with a deblocking liquid conversion outlet 14 above the sealing area with the upper sealing joint 17; the stratified jet conversion tube 11 is provided with an internal pressure transmission hole between the sealing areas with the upper sealing joint 17 and the lower sealing joint 20; when the ball seat sleeve 13 is located at the initial position, the ball seat sleeve 13 closes the deblocking liquid conversion outlet 14, and the internal pressure transmission hole is located below the ball seat sleeve 13; when the ball seat sleeve 13 is located at the lowest point, the deblocking liquid conversion outlet 14 is connected, and the internal pressure transmission hole is above the ball seat sleeve 13.

[0072] At least two stratified jet conversion assemblies are arranged; the upper end of the stratified jet conversion tube 11 of the topmost stratified jet conversion assembly is connected to the inner wall of the lower end of the conversion joint through the unblocking inner tube 8; the upper end of the stratified jet conversion tube 11 of the stratified jet conversion assembly located below is connected to the lower end of the stratified jet conversion tube 11 of the stratified jet conversion assembly located above; the inner diameter of the ball seat sleeve 13 gradually decreases from top to bottom.

[0073] At least two lower jet units are arranged; the upper sealing joint 17 of the uppermost lower jet unit is connected to the lower end of the upper jet unblocking pipe; the upper sealing joint 17 of the lower jet unit located below is connected to the lower end of the lower jet unblocking pipe of the lower jet unit located above; the lower end of the lower jet unblocking pipe of the lowermost lower jet unit is connected to the check valve.

[0074] When in use, except for the lower jet unit at the bottom layer which can directly carry out the unblocking work, suitable steel balls 12 need to be put in so that the corresponding ball seat sliding sleeve 13 can be pressed down and the corresponding unblocking liquid conversion outlet 14 can be opened before the unblocking work can be carried out. The unblocking is carried out from bottom to top in sequence, and finally nitrogen is discharged back.

[0075] All components and connection methods of components not discussed in this application belong to the known technologies in this technical field and can be directly applied without further explanation.

[0076] In the present invention, the term "plurality" means two or more than two, unless otherwise clearly defined. The terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0077] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the present invention.

[0078] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0079] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A horizontal well segmented jetting unblocking string, comprising an outer string and an inner string, characterized in that: The outer pipe string includes an upper packer, an upper jetting unblocking pipe, at least one lower jetting unit, and a check valve which are sequentially connected from top to bottom; The inner pipe column includes a conversion joint and at least one stratified jet conversion assembly connected in sequence; the number of the jet conversion assemblies is the same as the number of the lower jet units; each stratified jet conversion assembly corresponds to a lower jet unit; The upper end of the upper packer is connected to the outer wall of the lower end of the conversion joint.

2. A horizontal well segmented jetting unblocking string according to claim 1, characterized in that: The lower jet unit comprises an upper sealing joint, a lower packer, a lower sealing joint and a lower jet unblocking pipe which are connected in sequence.

3. A horizontal well segmented jetting unblocking string according to claim 2, characterized in that: The stratified jet conversion assembly includes a stratified jet conversion tube, a ball seat sleeve, a return spring, and a return spring stop ring; The stratified jet conversion tube is sealed with the upper sealing joint and the lower sealing joint; The ball seat sleeve is connected to the stratified jet conversion tube through a pin; the return spring stop ring is arranged at the lower end of the inner wall of the stratified jet conversion tube; the return spring is arranged between the ball seat sleeve and the return spring stop ring; The stratified jet conversion tube is provided with a deblocking liquid conversion outlet above the sealing area with the upper sealing joint; the stratified jet conversion tube is provided with an internal pressure transmission hole between the sealing areas with the upper sealing joint and the lower sealing joint; When the ball seat sleeve is at the initial position, the ball seat sleeve closes the deblocking liquid conversion outlet, and the internal pressure transmission hole is located below the ball seat sleeve; when the ball seat sleeve is at the lowest point, the deblocking liquid conversion outlet is connected, and the internal pressure transmission hole is above the ball seat sleeve.

4. A horizontal well segmented jetting unblocking string according to claim 3, characterized in that: At least two of the stratified jet conversion assemblies are provided; The upper end of the stratified jet conversion pipe of the uppermost stratified jet conversion assembly is connected to the inner wall of the lower end of the conversion joint through the unblocking inner pipe; The upper end of the stratified jet conversion tube of the stratified jet conversion assembly located below is connected to the lower end of the stratified jet conversion tube of the stratified jet conversion assembly located above; The inner diameter of the ball seat sliding sleeve gradually decreases from top to bottom.

5. A horizontal well segmented jetting unblocking string according to claim 3, characterized in that: The upper sealing joint and the lower sealing joint are sealed and matched with the lower jet unblocking pipe by arranging sealing rings.

6. A horizontal well segmented jetting unblocking string according to claim 2, characterized in that: At least two lower jet units are provided; The upper sealing joint of the uppermost lower jet unit is connected to the lower end of the upper jet unblocking pipe; The upper sealing joint of the lower jet unit located below is connected to the lower end of the lower jet unblocking pipe of the lower jet unit located above; The lower end of the lower jet unblocking pipe of the lowermost lower jet unit is connected to the check valve.

7. A horizontal well segmented jetting plugging removal string according to any one of claims 2 to 6, characterized in that: The upper jet unblocking pipe and the lower jet unblocking pipe are both jet unblocking pipes; A jet pipe coupling is arranged at the upper end of the jet unblocking pipe, and at least two jet nozzles are arranged on the wall of the jet unblocking pipe.

8. A horizontal well segmented jetting plugging removal string according to claim 7, characterized in that: The upper packer and the lower packer have the same structure and are both expansion packers; The expandable packer comprises a base pipe, an upper joint of the packer, a pressure transmission hole of the packer, a sealing device, and a lower joint of the packer; The upper joint of the packer is connected to the upper end of the base pipe, the lower joint of the packer is connected to the lower end of the base pipe, the sealing device is sleeved on the base pipe, a rubber sleeve is arranged in the sealing device, and a packer pressure transmission hole is arranged on the base pipe.

9. A horizontal well segmented jetting plugging removal string according to claim 8, characterized in that: The upper joint of the upper packer is connected to the outer wall of the lower end of the conversion joint, and the lower joint of the upper packer is connected to the jet pipe coupling of the upper jet unblocking pipe.

10. A horizontal well segmented jetting plugging removal string according to claim 8, characterized in that: The packer upper joint of the lower packer is connected to the upper sealing joint, and the packer lower joint of the lower packer is connected to the lower sealing joint; The lower sealing joint is connected to the jet pipe coupling of the lower jet unblocking pipe.

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