Compressed air energy storage straight-inclined shaft high-frequency injection and production pipe column and well completion method

Abstract

The application is a compressed air energy storage straight and inclined well high-frequency injection and production pipe column and well completion method, the injection and production pipe column is connected with downhole combined sealing device, downhole annular flow limiting device and downhole safety valve from bottom to top through tubing, the downhole combined sealing device is inserted and connected by prepositioning working cylinder and sealing working cylinder, the sealing insert cylinder seals the sealing insert cylinder sealing cavity of prepositioning lower outer cylinder, the sealing assembly seals the sealing part sealing cavity of prepositioning lower outer cylinder, the downhole annular flow limiting device is provided with a skin bowl and a center tube, the flow limiting plate of the staggered collection flow channel is fixed in the flow limiting plate mounting groove in the wall of the center tube, and the seat sealing hole and the seat sealing boost hole are arranged in the wall without the flow limiting plate mounting groove. The injection and production pipe column provided by the application has the function of backwashing well, the scaling and waxing in the tubing are cleaned by backwashing the well washing fluid with the cleaning function, the maintenance is realized without moving the pipe column, the conventional operation cost and time are reduced, and the working efficiency of the gas storage is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas storage construction in oil field development of the petroleum industry and the field of carbon dioxide injection technology, in particular to a compressed air energy storage straight and deviated well high-frequency injection and production string and completion method. BACKGROUND

[0002] Compared with traditional ground storage facilities, underground gas storage has the characteristics of large storage capacity, strong mobility, wide peak regulation range, long service life and high safety factor. The gas storage built in the world today is mainly divided into four types according to the characteristics of the underground gas reservoir, namely depleted oil and gas reservoir gas storage, aquifer gas storage, salt cavern gas storage and abandoned mine gas storage. Among them, the stored gas is mainly natural gas, and the functions of air energy storage gas storage and natural gas storage are basically the same, both of which play the role of temporary storage of energy and peak regulation of supply and demand, but because of the difference in storage energy, the injection and production capacity requirements of the injection and production wells in the storage area are completely different.

[0003] The supply and demand peak of natural gas storage is usually in the cold winter and spring, so in the higher temperature summer and autumn, the injection and production wells are mainly injected, and in the winter and spring, they are mainly produced. The injection and production string works in one working state for a long period of time, and the stress alternation frequency is low, so the working requirements of the packer in the string are relatively low. The conventional gas-tight packer can meet its working needs, such as the following patent technologies:

[0004] The injection and production string and the completion method using the same disclosed in the authorized announcement No. CN112647857B and the oil and gas reservoir type gas storage injection and production well completion string disclosed in the authorized announcement No. CN206205797U both use packer anchoring and sealing.

[0005] At the same time, because the natural gas in the reservoir of the natural gas storage does not need to be converted for the second time, and the injection and production are both natural gas, the requirements for the displacement and flow rate of the gas in the injection and production string are also low.

[0006] The energy stored in the air energy storage gas storage is electric energy, and the peak period of electric energy use is during the day, and the valley period is at night, so it needs to be stored and retrieved once a day to play the peak regulation function, and the injection and production frequency is high. At the same time, the air in the existing gas storage is only a transmission medium in the energy conversion and storage process, and the air energy storage gas storage needs to be converted for the second time by a turbine, so there are high requirements for the purity, flow rate and displacement of the gas in the injection and production string.

[0007] The reservoirs of the air gas storage built in China so far are all of the salt cavern type, and the underground reservoir is relatively clean, without formation sand, so there is no need to consider the problem of formation sand production, and only the problems of scaling and corrosion of the injection and production string need to be considered.

[0008] If the compressed air type gas storage established by the depleted oil and gas reservoir is adopted, the reservoir contains not only air, water vapor and the like, but also sand, and if the injection and production string used in the salt cavern type gas storage is used for production, the sand prevention problem of the injection and production well in the storage cannot be met.

[0009] If the injection and production string used in the conventional natural gas storage depleted oil and gas reservoir is used in the compressed air storage, the practical demand of long life work of the injection and production well in the storage under the condition of high frequency stress alternation cannot be met, as described in the articles such as 'Dynamic characteristics of flow-induced vibration and buckling of injection and production string of gas storage' and 'Buckling behavior of gas storage tubing under multi-cycle injection and production conditions'.

[0010] Therefore, a new type of injection and production string is urgently needed to solve the above problems. SUMMARY

[0011] To solve the above problems, the present application provides a compressed air energy storage straight and inclined well high frequency injection and production string and completion method, mainly solves the problem that the injection and production string used in the existing salt cavern type and depleted type gas storage cannot meet the current demand of the injection and production string used in the compressed air storage established by the depleted oil reservoir, and provides an injection and production string suitable for the compressed air storage with high injection and production frequency. The production efficiency of the compressed air storage is improved, and the injection and production benefit is improved.

[0012] The technical solution of the present application is: a compressed air energy storage straight and inclined shaft high-frequency injection and production pipe column is provided with a tubing and a downhole safety valve, wherein: the injection and production pipe column is sequentially connected with a downhole combined sealing device, a downhole annular flow limiting device and the downhole safety valve through the tubing from bottom to top, the downhole combined sealing device is formed by inserting a preset working barrel and a sealing working barrel; in the preset working barrel, a preset locking ring provided with a dog tooth is installed between a preset upper outer barrel and a preset lower outer barrel, the preset upper outer barrel is connected with the preset lower outer barrel, and the preset working barrel is advanced to a preset position in the well with a well completion pipe column; the sealing working barrel comprises a sealing part mainly composed of a sealing insert barrel and a sealing assembly and an inner barrel; the inner barrel is provided with a backwashing hole and a backwashing control hole, and an outer circle of a limiting step three in the inner barrel is processed with a dog tooth; the sealing working barrel is connected to the lower end of the injection and production pipe column and inserted into the preset working barrel, the inner barrel is connected with the dog tooth in the preset locking ring, the sealing insert barrel seals a sealing insert barrel sealing cavity of the preset lower outer barrel, and the sealing assembly seals a sealing part sealing cavity of the preset lower outer barrel; the downhole annular flow limiting device is provided with a cup and a central tube, flow limiting plates of the staggered collection flow channel are fixed in flow limiting plate installation grooves in the wall of the central tube, and seat sealing holes and seat sealing boost holes are arranged in the wall without the flow limiting plate installation grooves; above a pushing barrel limiting step of the central tube, a flow limiting device sliding barrel, the cup and an upper pushing barrel are sequentially installed from top to bottom; the flow limiting device limiting ring installed with a locking ring is arranged in the flow limiting device limiting ring sliding barrel above the cup, and the locking ring is installed in a locking ring groove in the outer circle of the central tube; the upper pushing barrel is matched with the flow limiting device locking ring in the locking ring installation groove of the central tube through the dog tooth.

[0013] Preferably, the sealing working barrel is further provided with an upper locking ring, a working barrel sliding barrel, a working barrel spring, a disc spring, a middle locking ring and a sealing compression ring, the upper locking ring, the working barrel sliding barrel and the working barrel spring are sequentially installed above the limiting step three from top to bottom; the disc spring, the sealing insert barrel, the middle locking ring, the sealing assembly, the sealing compression ring are sequentially installed below the limiting step three from top to bottom.

[0014] Preferably, the top of the ring body of the preset locking ring is provided with a locking ring torque transmission spline, the lower inner circle of the preset locking ring is provided with a dog tooth, and the preset locking ring is an open ring with straight or inclined through grooves opened axially; the preset upper outer barrel is a non-equal-diameter cylindrical body, the upper inner cavity of the preset upper outer barrel is provided with an internal thread connected with the well completion pipe column, the lower part is a threaded inner cavity, the middle inner cavity is provided with a locking ring limiting step, and the inner circle of the locking ring limiting step is provided with an upper outer barrel torque transmission spline; the upper outer barrel torque transmission spline can be matched with the locking ring torque transmission spline at the top of the ring body of the preset locking ring, and the matched preset locking ring is located in the locking ring installation cavity between the locking ring limiting step and the threaded inner cavity of the lower part.

[0015] Preferably, the preset lower outer cylinder is a non-equal diameter cylindrical body, both ends of the preset lower outer cylinder are provided with external threads and can be respectively connected with the internal threads in the threaded inner cavity of the lower part of the preset upper outer cylinder and the lower casing thread in the completion string; the upper inner cavity of the preset lower outer cylinder is a sealing insert sealing cavity, and the lower inner cavity is a sealing element sealing cavity; the sealing insert sealing cavity is a conical cavity.

[0016] Preferably, the sealing insert can be made of rubber or high polymer material, soft metal or memory alloy material, the lower outer circle of the sealing insert is a conical outer circle which cooperates with the sealing insert sealing cavity of the preset lower outer cylinder; a disc spring top ring is further arranged between the disc spring and the sealing insert.

[0017] Preferably, the inner cylinder is a non-equal diameter cylindrical body, the upper and lower ends of the inner cylinder are respectively provided with injection-production string connecting threads and spare part connecting threads; the outer circle of the inner cylinder is sequentially provided with limiting steps one, two, three, four and five from top to bottom, and the outer circles of the limiting steps one, two, three, four and five are all precisely processed outer surfaces.

[0018] Preferably, the backwashing hole and the backwashing control hole are arranged in the limiting step one, the backwashing hole is arranged in the outer circle below the injection-production string connecting threads and sealing ring grooves one and a mounting sealing ring are arranged on both sides of the backwashing hole; the backwashing control hole is arranged at the root of the limiting step one and at least one sealing ring groove two is arranged on the top outer circle of the limiting step two; the limiting step three has the largest outer diameter and a zigzag buckle is processed on the outer circle, a middle locking ring connecting thread is arranged at the lower end of the outer circle of the limiting step four; a spare part connecting thread is processed on the lower part of the limiting step five.

[0019] Preferably, the middle locking ring is provided with a central hole and an inner thread, and the inner thread of the middle locking ring is threadedly connected with the middle locking ring connecting thread after the middle locking ring is sleeved on the outer surface of the inner cylinder; the sealing assembly is a combined sealing element which at least includes a sealing ring and a polytetrafluoroethylene made backup ring which is respectively arranged on both sides of the sealing ring, the outer diameter of the sealing ring is greater than the inner diameter of the sealing element sealing cavity in the preset lower outer cylinder; the sealing compression ring is connected with the spare part connecting thread of the lower part of the limiting step five and a lower compression ring and a dissolvable plug are further connected below the sealing compression ring.

[0020] Preferably, the inner circle of the working cylinder sliding cylinder is processed with two sections of inner diameters which are small at the top and large at the bottom, and the small inner diameter section is arranged on the outer surface of the limiting step one of the inner cylinder and the large inner diameter section is arranged on the outer surface of the limiting step two; the two sections of inner diameters of the inner circle of the working cylinder sliding cylinder are both precisely processed surfaces; in the normal working state, the small inner diameter section of the working cylinder sliding cylinder blocks the backwashing hole and the large inner diameter section communicates with the backwashing control hole.

[0021] Preferably, the skin bowl is installed in the flow limiting device sliding cylinder and the lower part is located between the flow limiting device sliding cylinder and the upper pushing cylinder, and the sealing surface of the outer circle of the center tube is equipped with a sealing element; the staggered collection flow channel is composed of a main channel groove processed in the center of the flow limiting plate and an auxiliary channel groove connected with the main channel groove; the limiting plate installation groove provided on the outer wall of the center tube and the flow limiting plate are provided in more than one set, and the flow limiting plate is welded in the limiting plate installation groove.

[0022] Preferably, the main channel groove is a straight groove passing through both ends of the flow limiting plate body; the auxiliary channel groove is arranged on both sides of the main channel groove and has an arc-shaped and downward inclined shape; the auxiliary channel grooves on both sides are staggered and connected head to tail in the main channel groove.

[0023] Preferably, the lock ring and the flow limiting device locking ring are both broken rings provided with axial notches, the axial notch is an oblique notch with an angle of 1-89 degrees or a vertical notch; the inner diameter of the lock ring in the natural state is smaller than the outer diameter of the center tube segment; the outer circle of the flow limiting device locking ring is processed with a dog tooth and can be matched with the dog tooth processed in the inner circle of the upper pushing cylinder.

[0024] Preferably, the upper pushing cylinder is a non-equal-diameter cylindrical body provided with an upper cylinder body and a retreat-stop thread provided in a lower cylinder body, the inner diameter of the upper cylinder body is smaller than that of the lower cylinder body, at least one auxiliary sealing liquid passage is provided on the outer wall of the upper cylinder body, and the auxiliary sealing liquid passage penetrates through the top of the upper cylinder body; the inner circle of the lower cylinder body of the upper pushing cylinder is provided with a retreat-stop thread, and the retreat-stop thread is a dog tooth type thread and can be matched with the dog tooth thread of the outer circle of the flow limiting device locking ring.

[0025] Preferably, the outer circle of the center tube below the upper pushing cylinder limiting step is processed with a continuation thread, and the continuation thread can be connected with the auxiliary sealing liquid passage of the auxiliary sealing and anti-spraying mechanism through the thread.

[0026] Preferably, the auxiliary sealing and anti-spraying mechanism is provided with a flow limiting device upper outer cylinder, a flow limiting device lower outer cylinder, a lower pushing cylinder, a flow limiting device spring and a limiting cylinder, the two ends of the flow limiting device upper outer cylinder are respectively connected with the continuation thread in the center tube and the flow limiting device lower outer cylinder, the lower pushing cylinder and the flow limiting device spring are installed in the flow limiting device lower outer cylinder, and the limiting cylinder is installed below the flow limiting device spring and connected with the flow limiting device lower outer cylinder through threads; at least one auxiliary sealing and anti-spraying liquid passage is provided in the limiting cylinder.

[0027] Preferably, the inner circle of the flow limiting device lower outer cylinder is a non-equal-diameter inner circle, and the inner threads at both ends are respectively connected with the flow limiting device upper outer cylinder and the limiting cylinder through threads; an inner taper matching surface is provided between the two non-equal-diameter inner circles of the flow limiting device lower outer cylinder, and the inner taper matching surface is a downward inclined surface.

[0028] Preferably, the lower pushing cylinder is a non-equal diameter cylindrical body, the upper outer wall of the lower pushing cylinder is an outer taper matching surface, the outer taper matching surface is an upper inclined surface and can be matched with an inner taper matching surface in the lower outer cylinder of the flow limiting device, and at least one sealing ring groove is formed in the outer taper matching surface; the spring of the flow limiting device is installed in the inner cavity below the spring limiting step in the lower pushing cylinder.

[0029] Preferably, the upper outer circle of the limiting cylinder is provided with external threads and can be threadedly connected with the lower outer cylinder of the flow limiting device; the washing and anti-spraying liquid passing groove provided in the outer wall of the limiting cylinder is a through groove and at least one groove is provided; the upper outer cylinder of the flow limiting device is a non-equal diameter cylindrical body, and the inner and outer threads in the cylinder bodies at the upper and lower ends can be connected with the continuation threads of the central pipe and the threads of the lower outer cylinder of the flow limiting device, respectively; the lower inner cavity of the upper outer cylinder of the flow limiting device after being connected with the central pipe is in communication with the limiting plate mounting groove.

[0030] Preferably, the centralizer is connected in the high-frequency injection and production pipe string of the straight well section on the upper and lower sides of the downhole annulus flow limiting device, and the flow joint is connected in the high-frequency injection and production pipe string of the straight well section on the upper and lower sides of the downhole safety valve; the tubing includes a small-diameter tubing and a large-diameter tubing, the centralizer and the downhole annulus flow limiting device are connected in series in the small-diameter tubing, and the downhole safety valve and the flow joint are connected in series in the large-diameter tubing.

[0031] The well completion method applied to the compressed air energy storage straight and inclined well high-frequency injection and production pipe string includes the following steps: A, the preset working cylinder in the downhole combined sealing device is connected in series at a predetermined position in the well completion pipe string and is lowered into the well for well completion; B, the sealing working cylinder is connected at the lower end of the injection and production pipe string and is lowered into the well, the sealing working cylinder is pressed down through the injection and production pipe string to anchor and seal the injection and production pipe string and the well completion pipe string; C, the downhole annulus flow limiting device is positively pressure tested and sealed, and whether the injection and production pipe string leaks is tested; D, if the injection and production pipe string does not leak after the pressure test, the downhole annulus flow limiting device is started; E, after the downhole annulus flow limiting device is started, the reverse well flushing is continuously carried out, and whether the downhole combined sealing device works normally is verified; F, after the downhole combined sealing device is verified to work normally, the casing protection liquid is injected; G, the well flushing pipeline is switched to the positive well flushing process, the ground pressure is applied after a period of time, the soluble plug in the downhole combined sealing device is broken, and the well completion of the straight and inclined well high-frequency injection and production pipe string is realized.

[0032] Compared with the prior art, the present application has the following advantages: (1) the injection and production pipe string provided by the present application can realize efficient anchoring of the injection and production pipe string through the downhole combined sealing device, and solve the problem that the slips in the packer are prone to loosen and fail under the condition of high-frequency injection and production stress alternation; and the injection and production pipe string provided by the present application can also be used in a well for injecting carbon dioxide.

[0033] (2) The injection and production pipe column provided by the application has the reverse well washing function, can clean the scale and wax in the oil pipe by reverse circulation of the well washing fluid with the cleaning function after the normal injection and production cycle ends, realizes the maintenance without moving the pipe column, reduces the normal operation cost and time, prolongs the service life of the injection and production pipe column, and improves the working efficiency of the gas storage.

[0034] (3) The inner cylinder of the sealing working cylinder in the application has the reverse well washing function, is easier to carry out the well killing by the reverse circulation when the blowout occurs, effectively reduces the well killing difficulty when the blowout occurs, and improves the safety factor of the injection and production well from the process principle.

[0035] (4) Compared with the packer used in the existing pipe column, the downhole combined sealing device in the application has the simple and reliable working principle, improves the anchoring and sealing capacity, enhances the safety of the whole pipe column and tool, the reverse well washing process channel greatly reduces the downhole accident probability caused by the water scale blockage or wax blockage in the pipe column after the injection and production well is put into production.

[0036] (5) The injection and production pipe column provided by the application realizes the requirement of the oil jacket annulus blowout prevention under the premise of ensuring the smoothness of the reverse washing channel of the injection and production pipe column, and improves the safety of the whole injection and production pipe column.

[0037] (6) The unlimited injection and replacement of the casing protection fluid are possible through the reverse well washing process channel, the corrosion in the oil jacket annulus in the well can be well prevented, the requirement for the casing material is reduced, and the completion cost is greatly saved.

[0038] (7) The completion method provided by the application can check the reliability of the injection and production pipe column in each step in the completion process, and prevents the injection and production pipe column with hidden dangers from being put into the well.

[0039] In summary, the application improves the safety of the whole pipe column, provides the reverse well washing process channel, greatly reduces the downhole accident probability caused by the water scale blockage in the oil pipe and the requirement for the casing material, prolongs the service life of the injection and production pipe column, and improves the working efficiency of the gas storage. The application has good economic and social benefits, and has great popularization space. BRIEF DESCRIPTION OF DRAWINGS

[0040] The accompanying drawings are used to provide further understanding of the application, and constitute a part of the specification, together with the embodiments of the application, to explain the application, and do not constitute the limitation to the application. In the drawings: Figure 1 is the overall structure schematic diagram of the injection and production pipe column in the application.

[0041] Figure 2 is the structure schematic diagram of the preset working cylinder in the application.

[0042] Figure 3 is Figure 2 Structure diagram of the upper outer cylinder.

[0043] Figure 4 is Figure 2 Structure diagram of the locking ring.

[0044] Figure 5 Structure diagram of the sealing working cylinder.

[0045] Figure 6 is Figure 5 Structure diagram of the inner cylinder.

[0046] Figure 7 is Figure 1 Structure diagram of the annulus flow-restricting device.

[0047] Figure 8 is Figure 7 Structure diagram of the central tube.

[0048] Figure 9 is Figure 7 Structure diagram of the upper pushing cylinder.

[0049] Figure 10 is Figure 7 Structure diagram of the flow-restricting plate.

[0050] Figure 11 is Figure 7 Structure diagram of the lower outer cylinder.

[0051] Figure 12 is Figure 7 Structure diagram of the lower pushing cylinder.

[0052] Figure 13 is Figure 7 Structure diagram of the limiting cylinder.

[0053] In the figure: preset working cylinder 1, sealing working cylinder 2, small-diameter oil pipe 3, downhole annulus flow-restricting device 4, large-diameter oil pipe 5, downhole safety valve 6, flow joint 7, centralizer 8; preset working cylinder 1: preset upper outer cylinder 1-1, upper outer cylinder torque transmission spline 1-11; preset locking ring 1-2, locking ring torque transmission spline 1-21; preset lower outer cylinder 1-3.

[0054] Sealing working barrel 2: inner barrel 2-1, backwashing hole 2-101, sealing ring groove one 2-102, limiting step one 2-103, backwashing control hole 2-104, sealing ring groove two 2-105, limiting step two 2-106, limiting step three 2-107, limiting step four 2-108, middle locking ring connecting thread 2-109, limiting step five 2-110; upper locking ring 2-2, working barrel sliding barrel 2-3, working barrel spring 2-4, disc spring 2-5, disc spring top ring 2-6, sealing plug 2-7, middle locking ring 2-8, working barrel limiting ring 2-9, sealing assembly 2-10, sealing compression ring 2-11, lower compression ring 2-12; downhole annular flow limiting device 4, upper joint 4-1, central tube 4-2, limiting plate mounting groove 4-2-1, seat sealing hole 4-2-2, locking ring groove 4-2-3, seat sealing boost hole 4-2-4, locking ring mounting groove 4-2-5, upper push barrel limiting step 4-2-6, continuation thread 4-2-7, flow limiting device sliding barrel 4-3, locking ring 4-4, flow limiting device limiting ring 4-5, leather cup 4-6, upper push barrel 4-7, retreat stop thread 4-7-1, upper barrel body 4-7-2, flow limiting device locking ring 4-8, flow limiting device upper outer barrel 4-9, flow limiting plate 4-10, main channel groove 4-10-1, auxiliary channel groove 4-10-2, flow limiting device lower outer barrel 4-11, inner taper matching surface 4-11-1, lower push barrel 4-12, outer taper matching surface 4-12-1, flow limiting device spring 4-13, limiting barrel 4-14, backwashing and blowout prevention flow passage 4-14-1. DETAILED DESCRIPTION

[0055] The accompanying drawings are only used for reference and illustration, and are not used to limit the protection scope of the present application. The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0056] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application will be further described in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0057] In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, in the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0058] Referring to Figures 1-13 A compressed air energy storage straight-inclined well high-frequency injection and production pipe string is provided with a tubing and a downhole safety valve 6, wherein: the injection and production pipe string is connected with a downhole combined sealing device, a downhole annular flow limiting device 4 and the downhole safety valve 6 in sequence from bottom to top through the tubing, the downhole combined sealing device is inserted and connected by a preset working barrel 1 and a sealing working barrel 2; in the preset working barrel 1, a preset locking ring 1-2 with a dog tooth is installed between a preset upper outer barrel 1-1 and a preset lower outer barrel 1-3, the preset upper outer barrel 1-1 is connected with the preset lower outer barrel 1-3, and the preset working barrel 1 is advanced to a preset position in the well with a completion pipe string; the sealing working barrel 2 includes a sealing part mainly composed of a sealing insertion barrel 2-7 and a sealing assembly 2-10, and an inner barrel 2-1; the inner barrel 2-1 is provided with a backwashing hole 2-101 and a backwashing control hole 2-104, and the outer circle of a limiting step three 2-107 in the inner barrel 2-1 is processed with a dog tooth; the sealing working barrel 2 is connected at the lower end of the injection and production pipe string and inserted into the preset working barrel 1, the inner barrel 2-1 is matched with the dog tooth in the preset locking ring 1-2, the sealing insertion barrel 2-7 seals a sealing insertion barrel sealing cavity of the preset lower outer barrel 1-3, and the sealing assembly 2-10 seals a sealing piece sealing cavity of the preset lower outer barrel 1-3; the downhole annular flow limiting device 4 is provided with a cup 4-6 and a central pipe 4-2, a flow limiting plate 4-10 of a staggered converging flow channel is fixed in a flow limiting plate mounting groove 4-2-1 in the wall of the central pipe 4-2 and is provided with a seat sealing hole 4-2-2 and a seat sealing boost hole 4-2-4 in the wall without the flow limiting plate mounting groove 4-2-1; above a top pushing barrel limiting step 4-2-6 of the central pipe 4-2, a flow limiting device sliding barrel 4-3, the cup 4-6 and an upper top pushing barrel 4-7 are installed in sequence from top to bottom; the flow limiting device limiting ring 4-5 with a locking ring 4-4 installed in the flow limiting device limiting ring 4-5 is installed in the flow limiting device sliding barrel 4-3 above the cup 4-6, and the locking ring 4-4 is installed in a locking ring groove 4-2-3 of the outer circle of the central pipe 4-2; the upper top pushing barrel 4-7 is matched with the flow limiting device locking ring 4-8 installed in the locking ring mounting groove 4-2-5 of the central pipe 4-2 through the dog tooth.

[0059] The downhole combined sealing device in the application is composed of two parts, pre-setting working barrel 1 and sealing working barrel 2, and is used in cooperation. The inner wall of pre-setting locking ring 1-2 in pre-setting working barrel 1 is processed with a ratchet, and the upper end is processed with locking ring torque transmission spline 1-21 matched with upper outer barrel torque transmission spline 1-11 in pre-setting upper outer barrel 1-1. The two are matched through spline to realize torque transmission function. The ratchet of the inner wall of pre-setting locking ring 1-2 is matched with the ratchet in inner barrel 2-1 to realize axial one-way locking function.

[0060] According to the process requirement, when the cup 4-6 is seated in the downhole annular flow-restricting device 4, the liquid flow enters the gap between the sliding cylinder 4-3 and the limiting ring 4-5 of the flow-restricting device through the seating hole 4-2-2 in the tubing, pushes the sliding cylinder 4-3 to move upward, and then the cup 4-6 is released from the sliding cylinder 4-3. With the liquid entering through the seating assisting hole 4-2-4, the upper pushing cylinder 4-7 moves upward and pushes the cup 4-6 to death in the annulus of the oil jacket, thereby realizing the isolation between the sliding cylinder 4-3 and the casing. At this time, the reverse well washing operation can be carried out through the staggered collection flow channel in the flow-restricting plate 4-10.

[0061] When the well bottom pressure rises and blowout occurs, the well fluid is blocked from flowing upward through the staggered collection flow channel in the flow-restricting plate 4-10, effectively slows down the flow speed of the well fluid and weakens the intensity of the blowout, thereby gaining valuable time for the blowout control work on the ground.

[0062] The flow-restricting plate 4-10 in the device is provided with a staggered collection flow channel and is fixed in the flow-restricting plate mounting groove 4-2-1 in the wall of the central pipe 4-2. The seating hole 4-2-2 and the seating assisting hole 4-2-4 are arranged in the wall of the central pipe 4-2 without the flow-restricting plate mounting groove 4-2-1.

[0063] The cup 4-6 is installed in the sliding cylinder 4-3 and is located between the sliding cylinder 4-3 and the upper pushing cylinder 4-7. The limiting ring 4-5 of the flow-restricting device is installed in the sliding cylinder 4-3 above the cup 4-6. The locking ring 4-4 installed in the locking ring groove 4-2-3 of the outer circle of the central pipe 4-2 locks the limiting ring 4-5 of the flow-restricting device at the inner top end of the sliding cylinder 4-3 outside the central pipe 4-2. The flow-restricting device locking ring 4-8 is installed in the locking ring mounting groove 4-2-5 of the central pipe 4-2 and is matched with the upper pushing cylinder 4-7 through the ratchet. The flow-restricting device locking ring 4-8 is fixed in the locking ring mounting groove 4-2-5 and cannot move axially. The upper pushing cylinder 4-7 can move upward along the flow-restricting device locking ring 4-8, expand the cup 4-6, and seal the annulus between the sliding cylinder 4-3 and the casing.

[0064] The downhole annular flow limiting device 4 can not only backwash the well while sealing the oil sleeve annulus by using the leather cup 4-6, but also can throttle and limit the upwelling well fluid through the flow limiting plate 4-10.

[0065] The downhole annular flow limiting device 4 can control blowout of the gas storage injection-production well, increase a safety guarantee, avoid adverse consequences caused by blowout, improve economic benefits and has remarkable use effect.

[0066] On the basis of the above-mentioned embodiment one, the application further has the following embodiments: a preferred embodiment: the sealing working barrel 2 is further provided with an upper locking ring 2-2, a working barrel sliding barrel 2-3, a working barrel spring 2-4, a disc spring 2-5, a middle locking ring 2-8 and a sealing compression ring 2-11, the upper locking ring 2-2, the working barrel sliding barrel 2-3 and the working barrel spring 2-4 are sequentially installed above the upper limiting step three 2-107 from top to bottom; the disc spring 2-5, the sealing insert barrel 2-7, the middle locking ring 2-8, the sealing assembly 2-10 and the sealing compression ring 2-11 are sequentially installed below the limiting step three 2-107 from top to bottom. The sealing working barrel 2 connected with the preset working barrel 1 is below the limiting step three 2-107 tightly connected with the dog tooth buckle, and is further provided with the disc spring 2-5 and the disc spring top ring 2-6, the disc spring top ring 2-6 can effectively transmit axial pressure, compress the disc spring 2-5 and store a certain tonnage of pressure when the injection-production pipe string is pressed down, and prevent the dog tooth buckle between the preset working barrel 1 and the sealing working barrel 2 from creeping within a pitch range, and the middle locking ring 2-8 threadedly connected with the inner barrel 2-1 is further arranged below the sealing insert barrel 2-7 to limit and tightly press the sealing insert barrel 2-7.

[0067] A preferred embodiment: the ring body top of the preset locking ring 1-2 is provided with a locking ring torque transmission spline 1-21, the lower inner circle of the preset locking ring 1-2 is provided with a dog tooth buckle, and the preset locking ring 1-2 is an open ring with straight or inclined through grooves opened axially; the preset upper outer barrel 1-1 is a non-equal-diameter cylindrical body, the upper inner cavity of the preset upper outer barrel 1-1 is provided with an inner thread connected with the well completion pipe string, the lower inner cavity is a threaded inner cavity, the middle inner cavity is provided with a locking ring limiting step, and the inner circle of the locking ring limiting step is provided with an upper outer barrel torque transmission spline 1-11; the upper outer barrel torque transmission spline 1-11 can cooperate with the locking ring torque transmission spline 1-21 at the ring body top of the preset locking ring 1-2, and the preset locking ring 1-2 after cooperation is just located in the locking ring mounting cavity between the locking ring limiting step and the threaded inner cavity of the lower part.

[0068] A preferred embodiment: the preset lower outer cylinder 1-3 is a non-equal diameter cylindrical body, both ends of the preset lower outer cylinder 1-3 are provided with external threads and can be respectively connected with the internal threads in the threaded inner cavity of the lower part of the preset upper outer cylinder 1-1 and the lower casing thread in the completion string; the upper inner cavity of the preset lower outer cylinder 1-3 is a sealing sleeve sealing cavity, and the lower inner cavity is a sealing element sealing cavity; the sealing sleeve sealing cavity is a conical cavity.

[0069] A preferred embodiment: the sealing sleeve 2-7 can be made of rubber or high polymer material, soft metal or memory alloy material, the lower outer circle of the sealing sleeve 2-7 is a conical outer circle which cooperates with the sealing sleeve sealing cavity of the preset lower outer cylinder 1-3; a disc spring top ring 2-6 is further arranged between the disc spring 2-5 and the sealing sleeve 2-7. The high polymer material includes engineering resin and engineering plastic, and the soft metal includes copper and lead. The disc spring top ring 2-6 can protect the top end of the sealing sleeve 2-7 and provide a tightening force to prevent the loosening of the cog when working, thereby improving and strengthening the tightening effect of the disc spring 2-5 on the sealing sleeve 2-7 and further improving the sealing effect.

[0070] A preferred embodiment: the inner cylinder 2-1 is a non-equal diameter cylindrical body, the upper and lower ends of the inner cylinder 2-1 are respectively provided with injection-production string connecting threads and spare part connecting threads; the outer circle of the inner cylinder 2-1 is sequentially provided with a limiting step one 2-103, a limiting step two 2-106, a limiting step three 2-107, a limiting step four 2-108 and a limiting step five 2-110 from top to bottom, and the outer circles of the limiting step one 2-103, the limiting step two 2-106, the limiting step three 2-107, the limiting step four 2-108 and the limiting step five 2-110 are all precisely processed outer circle surfaces.

[0071] A preferred embodiment: the backwashing hole 2-101 and the backwashing control hole 2-104 are arranged in the limiting step one 2-103, the backwashing hole 2-101 is arranged in the outer circle below the injection-production string connecting threads and sealing rings are arranged on both sides of the backwashing hole 2-101; the backwashing control hole 2-104 is arranged at the root of the limiting step one 2-103 and at least one sealing ring groove two 2-105 is arranged on the top outer circle of the limiting step two 2-106; the limiting step three 2-107 has the largest outer diameter and has a cog processed on the outer circle, the middle locking ring connecting threads 2-109 are arranged on the lower end of the outer circle of the limiting step four 2-108; the spare part connecting threads are processed on the lower part of the limiting step five 2-110.

[0072] A preferred embodiment: the center lock ring 2-8 is provided with a center hole and the inner circle is provided with threads, and after the center lock ring 2-8 is sleeved on the outside of the inner cylinder 2-1, the internal threads of the inner circle are threadedly connected with the center lock ring connecting threads 2-109, thereby providing support for the sealing plug 2-7; the sealing assembly 2-10 is a combined seal, which at least includes a sealing ring and a polytetrafluoroethylene-made protective ring installed on both sides of the sealing ring, respectively, and the outer diameter of the sealing ring is greater than the inner diameter of the sealing cavity of the preset lower outer cylinder 1-3; the sealing compression ring 2-11 is threadedly connected with the spare part connecting threads of the lower part of the limiting step five 2-110, and the lower compression ring 2-12 and the dissolvable plug are further connected below the sealing compression ring 2-11, thereby further providing compression and locking force for the sealing assembly 2-10 and the sealing compression ring 2-11 and preventing the sealing compression ring 2-11 from loosening.

[0073] A preferred embodiment: the inner circle of the working cylinder sliding cylinder 2-3 is processed into two sections of inner diameters with the small section being on the outside of the limiting step one 2-103 of the inner cylinder 2-1 and the large section being on the outside of the limiting step two 2-106; both sections of the inner circle of the working cylinder sliding cylinder 2-3 are precision finished surfaces; in the normal working state, the small section of the working cylinder sliding cylinder 2-3 blocks the backwashing hole 2-101, and the large section is in communication with the backwashing control hole 2-104. In the process of backwashing, pumping casing protection fluid into the annulus between the oil jacket and the casing, and reverse circulation well killing, under the action of pressure difference, the working cylinder sliding cylinder 2-3 moves downward to expose the backwashing hole 2-101, forming a backwashing channel; the backwashing control hole 2-104 discharges the liquid in the inner cavity of the working cylinder sliding cylinder 2-3 to the inside of the oil pipe, preventing the formation of a dead space and hindering the downward movement of the working cylinder sliding cylinder 2-3 when it moves downward. After the backwashing operation is completed, under the pushing force of the working cylinder spring 2-4, the working cylinder sliding cylinder 2-3 moves upward and closes the backwashing hole 2-101, sealing the oil jacket communication channel.

[0074] In addition to the sealing plug 2-7 being able to realize sealing between the preset working cylinder 1 and the sealing working cylinder 2, the sealing assembly 2-10 is further provided below the sealing plug 2-7, which at least includes a sealing ring and two protective rings, thereby further providing a sealing barrier for the device, ensuring the sealing effect of the device, prolonging the service life of the sealing tool and the injection-production pipe column, and reducing production costs.

[0075] The working principle of the downhole combined sealing device is to first fix the preset working cylinder 1 in the well and then connect the sealing working cylinder 2 to the lowermost end of the injection-production pipe column, and then lower the injection-production pipe column into the well.

[0076] When the sealing working barrel 2 is inserted into the pre-working barrel 1, the sealing insert barrel 2-7 and the sealing assembly 2-10 cooperate with the corresponding sealing surface in the pre-working barrel 1 to achieve the sealing of the oil jacket annulus; at the same time, the external wall of the limiting step three 2-107 of the inner barrel 2-1 of the sealing working barrel 2 cooperates with the pre-locking ring 1-2 in the pre-working barrel 1 to achieve axial locking; in addition, a part of the injection and production string is pressed down, and the tonnage is transmitted to the disc spring 2-5 through the sealing insert barrel 2-7, the disc spring 2-5 is compressed and stores a certain tonnage of pressure, preventing the ratchet from creeping within one pitch.

[0077] The disc spring 2-5 can always ensure the tension of the ratchet in the pre-working barrel 1 and the sealing working barrel 2, and reduce the damage of the sealing assembly 2-10 caused by the creep of the injection and production string. The sliding sleeve 2-3 is in a closed state during normal operation, and when the injection and production string needs to be backwashed, pumped into the casing protection fluid or encounters a well blowout accident, the well washing fluid or the kill fluid can be pumped into the oil jacket annulus, providing a process channel for the cleaning or well killing operation of the injection and production string.

[0078] A preferred embodiment is shown in Figure 7 , Figure 8 and Figure 10 The skin bowl 4-6 is installed in the flow limiting device sliding barrel 4-3 and the lower part is located between the flow limiting device sliding barrel 4-3 and the upper pushing barrel 4-7, and the sealing surface of the outer circle of the center pipe 4-2 is installed with a sealing element; the staggered collection flow channel is composed of the main channel groove 4-10-1 processed in the center of the flow limiting plate 4-10 and the auxiliary channel groove 4-10-2 connected with the main channel groove 4-10-1; the limiting plate installation groove 4-2-1 and the flow limiting plate 4-10 provided on the outer wall of the center pipe 4-2 are set in more than one set, and the flow limiting plate 4-10 is welded in the limiting plate installation groove 4-2-1.

[0079] A preferred embodiment is shown in Figure 7 , Figure 8 and Figure 10 The main channel groove 4-10-1 is a straight groove passing through both ends of the flow limiting plate 4-10; the auxiliary channel groove 4-10-2 is arranged on both sides of the main channel groove 4-10-1 and has an arc-shaped downward inclined shape, and the auxiliary channel grooves 4-10-2 on both sides are connected in a staggered manner in the main channel groove 4-10-1. The staggered collection flow channel in the flow limiting plate 4-10 can also have other forms and structures, and in principle, the liquid flow from above the invention should flow smoothly, and the liquid flow from below the invention should be difficult to return upward.

[0080] In a preferred embodiment: both the locking ring 4-4 ​​and the flow-limiting device locking ring 4-8 are broken rings with axial cuts. The axial cuts are either oblique cuts or vertical cuts with an angle between 1 degree and 89 degrees. The inner diameter of the locking ring 4-4 ​​in its natural state is smaller than the outer diameter of the central pipe 4-2 section it is in. This is mainly to take into account installation issues. The inner diameter of the locking ring 4-4 ​​is slightly smaller than the outer diameter of the upper part of the central pipe 4-2. After installation and restoration, it can still be locked in the locking ring groove 4-2-3. The outer circle of the flow-limiting device locking ring 4-8 is machined with toothed threads and can cooperate with the toothed threads machined on the inner circle of the upper push cylinder 4-7.

[0081] In a preferred embodiment: the upper push cylinder 4-7 is a non-uniform diameter cylindrical body, having an upper cylinder 4-7-2 and a backstop thread 4-7-1 disposed in the lower cylinder. The inner diameter of the upper cylinder 4-7-2 is smaller than the inner diameter of the lower cylinder. At least one sealing liquid passage groove 4-7-3 is provided on the outer wall of the upper cylinder 4-7-2, and the sealing liquid passage groove 4-7-3 communicates with the top of the upper cylinder 4-7-2. The inner circle of the lower cylinder of the upper push cylinder 4-7 is provided with a backstop thread 4-7-1, which is a toothed thread and can engage with the toothed thread on the outer circle of the locking ring 4-8 of the flow limiting device.

[0082] In a preferred embodiment, the outer circle of the central tube 4-2 below the upper push cylinder limiting step 4-2-6 is machined with a continuing thread 4-2-7, which can be threadedly connected to the washing and anti-spray mechanism.

[0083] A preferred embodiment: See Figure 12 The anti-spray mechanism includes an upper outer cylinder 4-9 of the flow limiting device, a lower outer cylinder 4-11 of the flow limiting device, a lower push cylinder 4-12, a spring 4-13 of the flow limiting device, and a limiting cylinder 4-14. The two ends of the upper outer cylinder 4-9 of the flow limiting device are respectively threaded to the continuation thread 4-2-7 in the central tube 4-2 and the lower outer cylinder 4-11 of the flow limiting device. The lower push cylinder 4-12 and the spring 4-13 of the flow limiting device are installed inside the lower outer cylinder 4-11 of the flow limiting device. The limiting cylinder 4-14 is installed below the spring 4-13 of the flow limiting device and is threaded to the lower outer cylinder 4-11 of the flow limiting device. The limiting cylinder 4-14 is provided with at least one anti-spray liquid passage groove 4-14-1. This prevents incoming water and liquid from below the annular flow restrictor from entering the upper part of the annular flow restrictor through the lower push cylinder 4-12, while allowing incoming water and liquid from above the annular flow restrictor to enter the lower part of the annular flow restrictor by pushing open the lower push cylinder 4-12 held in place by the spring 4-13 of the flow restrictor.

[0084] A preferred embodiment: See Figure 11, the inner circle of the lower outer cylinder 4-11 of the flow limiting device is a non-equal-diameter inner circle, and the internal threads at both ends are respectively threadedly connected with the upper outer cylinder 4-9 and the limiting cylinder 4-14 of the flow limiting device; the inner tapered matching surface 4-11-1 is arranged between the two outer non-equal-diameter inner circles of the lower outer cylinder 4-11 of the flow limiting device, and the inner tapered matching surface 4-11-1 is a lower inclined surface.

[0085] A preferred embodiment is shown in the following table: Figure 12 , the lower pushing cylinder 4-12 is a non-equal-diameter cylindrical body, the upper outer wall of the lower pushing cylinder 4-12 is an outer tapered matching surface 4-12-1, the outer tapered matching surface 4-12-1 is an upper inclined surface and can be matched with the inner tapered matching surface 4-11-1 in the lower outer cylinder 4-11 of the flow limiting device, and at least one sealing ring groove is processed in the outer tapered matching surface 4-12-1; the spring 4-13 of the flow limiting device is installed in the inner cavity below the spring limiting step 4-12-2 in the lower pushing cylinder 4-12.

[0086] A preferred embodiment is shown in the following table: Figure 13 , the upper outer circle of the limiting cylinder 4-14 is provided with external threads and can be threadedly connected with the lower outer cylinder 4-11 of the flow limiting device; the washing and anti-spray liquid passing groove 4-14-1 arranged in the outer wall of the limiting cylinder 4-14 is a through groove from top to bottom and at least one groove is arranged; the upper outer cylinder 4-9 of the flow limiting device is a non-equal-diameter cylindrical body, and the internal and external threads in the cylindrical bodies at the upper and lower ends can be respectively threadedly connected with the continuation threads 4-2-7 of the central pipe 4-2 and the lower outer cylinder 4-11 of the flow limiting device, and the lower inner cavity of the upper outer cylinder 4-9 of the flow limiting device after being connected with the central pipe 4-2 is in communication with the limiting plate mounting groove 4-2-1. In the annular flow limiting device, sealing elements are arranged in the sealing matching surfaces between the components.

[0087] The washing and anti-spray mechanism connected with the lower part of the central pipe 4-2 adds another protection for the blowout prevention and the jet flow limiting during the blowout. The water from the reverse well washing above the device can increase the pump pressure, push away the lower pushing cylinder 4-12, and spray from the washing and anti-spray liquid passing groove 4-14-1 to the oil casing annulus to perform reverse circulation well washing.

[0088] When the downhole pressure increases and blowout occurs, due to the sealing of the skin bowl 4-6 and the inner and outer tapered matching surfaces in the lower outer cylinder 4-11 and the lower pushing cylinder 4-12 of the flow limiting device, the water and liquid cannot return from the washing and anti-spray liquid passing groove 4-14-1 of the limiting cylinder 4-14; if the washing and anti-spray mechanism fails, the inner and outer tapered matching surfaces in the lower outer cylinder 4-11 and the lower pushing cylinder 4-12 of the flow limiting device cannot be sealed and cannot realize the one-way flow control function, and the liquid flow can only pass through the staggered collection flow channels in the flow limiting plate 4-10, and when the liquid passes through the staggered collection flow channels, due to the mutual impact of the liquid flow directions in the main channel groove 4-10-1 and the auxiliary channel groove 4-10-2, the upwelling flow and pressure are greatly reduced, which gives more time for the ground staff to prevent blowout.

[0089] One preferred embodiment: the high-frequency injection and production string is connected with centralizer 8 on both sides of the straight well section above and below the downhole annulus flow-restricting device 4, and flow sub 7 on both sides of the straight well section above and below the downhole safety valve 6; the tubing includes small-diameter tubing 3 and large-diameter tubing 5, the centralizer 8 and the downhole annulus flow-restricting device 4 are connected in series in the small-diameter tubing 3, and the downhole safety valve 6 and the flow sub 7 are connected in series in the large-diameter tubing 5. The flow sub 7 is installed at both ends of the downhole safety valve 6 to ensure the stability of the fluid flow in the tubing. The centralizer 8 is installed at both ends of the downhole annulus flow-restricting device 4 to improve the centralization of the device and ensure the normal operation of the device. The tubing is divided into two diameters, the small-diameter tubing 3 is connected to the lower part of the string, and the large-diameter tubing 5 is connected to the upper part of the string, the pressure is adjusted by changing the flow area of the fluid, and the formation of scale is slowed down.

[0090] The completion method applied to the high-frequency injection and production string of the compressed air energy storage straight and inclined well includes the following steps: A, the preset working barrel 1 in the downhole combined sealing device is connected in series at a predetermined position in the completion string and is lowered into the well for completion; B, the sealing working barrel 2 is connected to the lower end of the injection and production string and is lowered into the well, the sealing working barrel 2 is pressed down through the injection and production string to anchor and seal the injection and production string and the completion string; C, the downhole annulus flow-restricting device is positively pressurized and sealed, and whether the injection and production string leaks is tested; during this process, if the leakage is positive, the injection and production string is pulled out and replaced.

[0091] D, if the injection and production string does not leak after being tested by pressurization, the downhole annulus flow-restricting device 4 is started; during this process, the casing valve pipeline is pressurized from the oil-casing annulus to start the downhole annulus flow-restricting device 4, and if the pressure suddenly drops, it proves that the starting is successful.

[0092] E, after the downhole annulus flow-restricting device 4 is started, the reverse well flushing is continued to verify whether the downhole combined sealing device is working normally; during this process, if there is return fluid in the wellhead tubing, it proves that the reverse flushing channel in the downhole combined sealing device is normally opened; then the well flushing pipeline is switched to the positive flushing process for pressurization, and if the pressure does not decrease to the predetermined value, it proves that the reverse flushing channel in the downhole combined sealing device is normally closed.

[0093] F, after the downhole combined sealing device is verified to be working normally, the casing protection fluid is injected; during this process, the well flushing pipeline is switched to the reverse flushing process, and the quantitative casing protection fluid is injected into the oil-casing annulus.

[0094] G, the well flushing pipeline is switched to the positive flushing process, the ground is pressurized after a period of time, the soluble plug in the downhole combined sealing device is broken, and the completion of the high-frequency injection and production string of the straight and inclined well is realized. If there is any abnormal situation in the above process steps, the injection and production string needs to be pulled out and replaced.

[0095] The working principle of the injection-production pipe string is that after a normal injection-production cycle, the inside of the injection-production pipe string is cleaned by backwashing with a scale, rust and wax removing liquid to prevent a large amount of scale from blocking the channel of the injection-production pipe string due to high air intensity and high frequency, and the annular casing is protected by a liquid to reduce the cost and time of replacing the injection-production pipe string, prolong the service life of the injection-production pipe string and improve the use efficiency of the gas storage.

[0096] The above-described embodiments are merely typical embodiments, but the present application is not limited to these embodiments, and those skilled in the art can make modifications without departing from the spirit and disclosure of the present application. Although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art can modify the technical solutions recorded in the foregoing embodiments or make equivalent replacements for some technical features. Any modification, equivalent replacement, improvement, etc. within the spirit and concept of the present application shall be included in the protection scope of the present application. Therefore, the protection scope is not limited to the above description.

Claims

1. A compressed air energy storage straight-inclined well high-frequency injection-production string, provided with a tubing and a downhole safety valve (6), characterized in that, The injection-production string is connected with the downhole combined sealing device, the downhole annular flow-restricting device (4) and the downhole safety valve (6) from bottom to top through the tubing, and the downhole combined sealing device is formed by inserting the preset working barrel (1) and the sealing working barrel (2); in the preset working barrel (1), the preset locking ring (1-2) provided with the dog tooth is installed between the preset upper outer barrel (1-1) and the preset lower outer barrel (1-3), the preset upper outer barrel (1-1) is connected with the preset lower outer barrel (1-3), and the preset working barrel (1) is lowered into the preset position in the well in advance with the completion string; the sealing working barrel (2) comprises a sealing part mainly composed of the sealing insertion barrel (2-7) and the sealing assembly (2-10) and the inner barrel (2-1); the inner barrel (2-1) is provided with the backwashing hole (2-101) and the backwashing control hole (2-104), and the outer circle of the limiting step three (2-107) in the inner barrel (2-1) is processed with the dog tooth; the sealing working barrel (2) is connected at the lower end of the injection-production string and lowered into the preset working barrel (1), the inner barrel (2-1) is connected with the dog tooth in the preset locking ring (1-2), the sealing insertion barrel (2-7) seals the sealing insertion barrel sealing cavity of the preset lower outer barrel (1-3), and the sealing assembly (2-10) seals the sealing part sealing cavity of the preset lower outer barrel (1-3); the downhole annular flow-restricting device (4) is provided with the cup (4-6) and the central pipe (4-2), the flow-restricting plate (4-10) of the staggered collection flow channel is fixed in the flow-restricting plate mounting groove (4-2-1) in the pipe wall of the central pipe (4-2) and is provided with the seat sealing hole (4-2-2) and the seat sealing boost hole (4-2-4) in the pipe wall without the flow-restricting plate mounting groove (4-2-1); above the upper pushing barrel limiting step (4-2-6) of the central pipe (4-2), the flow-restricting device sliding barrel (4-3), the cup (4-6) and the upper pushing barrel (4-7) are sequentially installed from top to bottom; the flow-restricting device limiting ring (4-5) provided with the locking ring (4-4) is arranged in the flow-restricting device sliding barrel (4-3) above the cup (4-6), and the locking ring (4-4) is installed in the locking ring groove (4-2-3) of the outer circle of the central pipe (4-2); the upper pushing barrel (4-7) is matched with the flow-restricting device locking ring (4-8) installed in the locking ring mounting groove (4-2-5) of the central pipe (4-2) through the dog tooth.

2. The compressed air energy storage straight-inclined shaft high-frequency injection and production string according to claim 1, characterized in that, The sealing working barrel (2) is further provided with the upper locking ring (2-2), the working barrel sliding barrel (2-3), the working barrel spring (2-4), the disc spring (2-5), the middle locking ring (2-8) and the sealing compression ring (2-11), the upper locking ring (2-2), the working barrel sliding barrel (2-3) and the working barrel spring (2-4) are sequentially installed above the limiting step three (2-107) from top to bottom; the disc spring (2-5), the sealing insertion barrel (2-7), the middle locking ring (2-8), the sealing assembly (2-10), the sealing compression ring (2-11) are sequentially installed below the limiting step three (2-107) from top to bottom.

3. The compressed air energy storage straight-inclined shaft high-frequency injection-production string according to claim 2, characterized in that, The top of the ring body of the preset locking ring (1-2) is provided with a locking ring torque transmission spline (1-21), the lower inner circle of the preset locking ring (1-2) is provided with a zigzag buckle, and the preset locking ring (1-2) is an open ring with straight or inclined through grooves opened in the axial direction; the preset upper outer cylinder (1-1) is a non-equal-diameter cylindrical body, the upper inner cavity of the preset upper outer cylinder (1-1) is provided with an internal thread connected with a well completion string, the lower part is a threaded inner cavity, the middle inner cavity is provided with a locking ring limiting step, and the inner circle of the locking ring limiting step is provided with an upper outer cylinder torque transmission spline (1-11); the upper outer cylinder torque transmission spline (1-11) can cooperate with the locking ring torque transmission spline (1-21) at the top of the ring body of the preset locking ring (1-2), and the preset locking ring (1-2) after cooperation is located in the locking ring installation cavity between the locking ring limiting step and the threaded inner cavity of the lower part.

4. The compressed air energy storage straight-inclined shaft high-frequency injection-production string according to claim 3, characterized in that, The preset lower outer cylinder (1-3) is a non-equal-diameter cylindrical body, the outer circles of the two ends of the preset lower outer cylinder (1-3) are provided with external threads and can be connected with the internal threads in the threaded inner cavities of the lower part of the preset upper outer cylinder (1-1) and the lower casing thread in the well completion string respectively; the upper inner cavity of the preset lower outer cylinder (1-3) is a sealing insert cylinder sealing cavity, and the lower inner cavity is a sealing element sealing cavity; the sealing insert cylinder sealing cavity is a conical cavity.

5. The compressed air energy storage straight-inclined shaft high-frequency injection-production string according to claim 2, characterized in that, The sealing insert cylinder (2-7) can be made of high polymer material, soft metal or memory alloy material, the lower outer circle of the sealing insert cylinder (2-7) is a conical outer circle which cooperates with the sealing insert cylinder sealing cavity of the preset lower outer cylinder (1-3); a disc spring top ring (2-6) is further arranged between the disc spring (2-5) and the sealing insert cylinder (2-7).

6. The compressed air energy storage straight-inclined shaft high-frequency injection-production string according to claim 5, characterized in that, The inner cylinder (2-1) is a non-equal-diameter cylindrical body, the upper and lower ends of the inner cylinder (2-1) are respectively provided with injection-production string connection threads and spare part connection threads; the outer circles of the inner cylinder (2-1) are sequentially provided with a limiting step one (2-103), a limiting step two (2-106), a limiting step three (2-107), a limiting step four (2-108) and a limiting step five (2-110) from top to bottom, and the outer circles of the limiting step one (2-103), the limiting step two (2-106), the limiting step three (2-107), the limiting step four (2-108) and the limiting step five (2-110) are all precisely processed outer circle faces.

7. The compressed air energy storage straight-inclined shaft high-frequency injection-production string according to claim 6, characterized in that, The backwashing hole (2-101) and the backwashing control hole (2-104) are arranged in the limiting step one (2-103), the backwashing hole (2-101) is arranged in the outer circle below the injection-production pipe column connecting thread and sealing ring grooves one and sealing rings are arranged on the upper and lower sides of the backwashing hole (2-101); the backwashing control hole (2-104) is arranged at the root of the limiting step one (2-103) and at least one sealing ring groove two (2-105) is arranged at the top outer circle of the limiting step two (2-106); the limiting step three (2-107) has the maximum outer diameter, the outer circle is processed with the dog-tooth buckle, the middle locking ring connecting thread (2-109) is arranged at the lower end of the outer circle of the limiting step four (2-108); the standby part connecting thread is processed at the lower part of the limiting step five (2-110).

8. The compressed air energy storage straight-inclined shaft high-frequency injection-production string according to claim 7, characterized in that, The middle locking ring (2-8) is provided with a central hole and the inner circle is provided with a thread, the middle locking ring (2-8) is sleeved on the outside of the inner cylinder (2-1), the inner thread of the inner circle is threadedly connected with the middle locking ring connecting thread (2-109); the sealing assembly (2-10) is a combined sealing element, at least including a sealing ring and the polytetrafluoroethylene-made backup ring respectively installed on the two sides of the sealing ring, the outer diameter of the sealing ring is greater than the inner diameter of the sealing cavity of the preset lower outer cylinder (1-3); the sealing compression ring (2-11) is connected with the standby part connecting thread of the lower part of the limiting step five (2-110) and the lower compression ring (2-12) and the soluble plug are further connected below the sealing compression ring (2-11).

9. The compressed air energy storage straight-inclined shaft high-frequency injection-production string according to claim 8, characterized in that, The inner circle of the working cylinder sliding cylinder (2-3) is processed with two sections of inner diameters with small upper and large lower and the small inner diameter section is installed on the outside of the limiting step one (103) of the inner cylinder (2-1) and the large inner diameter section is installed on the outside of the limiting step two (106); the two sections of inner diameters of the inner circle of the working cylinder sliding cylinder (2-3) are both precision processing surfaces; in the normal working state, the small inner diameter section of the working cylinder sliding cylinder (2-3) blocks the backwashing hole (2-101) and the large inner diameter section is communicated with the backwashing control hole (2-104).

10. The compressed air energy storage straight-inclined shaft high-frequency injection and production string according to claim 1, characterized in that, The skin bowl (4-6) is installed in the flow limiting device sliding cylinder (4-3) and the lower part is located between the flow limiting device sliding cylinder (4-3) and the upper pushing cylinder (4-7), the sealing surface of the outer circle of the central pipe (4-2) is provided with the sealing element; the staggered collection flow channel is composed of the main channel groove (4-10-1) processed in the center of the flow limiting plate (4-10) and the auxiliary channel groove (4-10-2) communicated with the main channel groove (4-10-1); the limiting plate installation groove (4-2-1) provided on the outer wall of the central pipe (4-2) and the flow limiting plate (4-10) are arranged in more than one set, the flow limiting plate (4-10) is welded in the limiting plate installation groove (4-2-1).

11. The compressed air energy storage straight-inclined shaft high-frequency injection-production string according to claim 10, characterized in that, The main channel groove (4-10-1) is a straight groove passing through both ends of the flow limiting plate (4-10) plate body; the auxiliary channel groove (4-10-2) is arranged on both sides of the main channel groove (4-10-1) and the flow channel shape is arc-shaped and downward inclined, the auxiliary channel grooves (4-10-2) on both sides are staggered and connected head to tail in the main channel groove (4-10-1).

12. The compressed air energy storage straight-inclined well high-frequency injection-production string according to claim 11, characterized in that, The lock ring (4-4) and the flow limiting device locking ring (4-8) are both broken rings provided with axial cuts, the axial cuts are oblique cuts with an angle of 1-89 degrees or vertical cuts; the inner diameter of the lock ring (4-4) in the natural state is smaller than the outer diameter of the pipe section of the center pipe (4-2); the outer circle of the flow limiting device locking ring (4-8) is provided with a dog tooth and can be matched with the dog tooth of the inner circle of the upper pushing cylinder (4-7).

13. The compressed air energy storage straight-inclined shaft high-frequency injection-production string according to claim 12, characterized in that, The upper pushing cylinder (4-7) is a non-equal-diameter cylindrical body, provided with an upper cylinder body (4-7-2) and a retreat-stop thread (4-7-1) arranged in the lower cylinder body, the inner diameter of the upper cylinder body (4-7-2) is smaller than the inner diameter of the lower cylinder body, at least one auxiliary fluid passage (4-7-3) is arranged on the outer wall of the upper cylinder body (4-7-2), and the auxiliary fluid passage (4-7-3) penetrates the top of the upper cylinder body (4-7-2); the inner circle of the lower cylinder body of the upper pushing cylinder (4-7) is provided with a retreat-stop thread (4-7-1), and the retreat-stop thread (4-7-1) is a dog tooth type thread and can be matched with the dog tooth thread of the outer circle of the flow limiting device locking ring (4-8).

14. The compressed air energy storage straight-inclined shaft high-frequency injection-production string according to claim 13, characterized in that, The outer circle of the center pipe (4-2) below the upper pushing cylinder limiting step (4-2-6) is provided with a continuation thread (4-2-7), and the continuation thread (4-2-7) can be threadedly connected with the auxiliary washing and blowout prevention mechanism.

15. The compressed air energy storage straight-inclined shaft high-frequency injection-production string according to claim 14, characterized in that, The auxiliary washing and blowout prevention mechanism is provided with a flow limiting device upper outer cylinder (4-9), a flow limiting device lower outer cylinder (4-11), a lower pushing cylinder (4-12), a flow limiting device spring (4-13) and a limiting cylinder (4-14), the two ends of the flow limiting device upper outer cylinder (4-9) are respectively threadedly connected with the continuation thread (4-2-7) in the center pipe (4-2) and the flow limiting device lower outer cylinder (4-11), the lower pushing cylinder (4-12) and the flow limiting device spring (4-13) are installed in the flow limiting device lower outer cylinder (4-11), the limiting cylinder (4-14) is installed below the flow limiting device spring (4-13) and is threadedly connected with the flow limiting device lower outer cylinder (4-11); at least one auxiliary washing and blowout prevention fluid passage (4-14-1) is arranged in the limiting cylinder (4-14).

16. The compressed air energy storage straight-inclined well high-frequency injection-production string according to claim 15, characterized in that, The inner circle of the flow limiting device lower outer cylinder (4-11) is a non-equal-diameter inner circle, and the inner threads at the two ends are respectively threadedly connected with the flow limiting device upper outer cylinder (4-9) and the limiting cylinder (4-14); an inner taper matching surface (4-11-1) is arranged between the two non-equal-diameter inner circles of the flow limiting device lower outer cylinder (4-11), and the inner taper matching surface (4-11-1) is a lower inclined surface.

17. The compressed air energy storage straight-inclined well high-frequency injection-production string according to claim 16, characterized in that, The lower pushing cylinder (4-12) is a non-equal-diameter cylindrical body, the upper outer wall of the lower pushing cylinder (4-12) is an outer taper matching surface (4-12-1), the outer taper matching surface (4-12-1) is an upper inclined surface and can be matched with the inner taper matching surface (4-11-1) in the flow limiting device lower outer cylinder (4-11), and at least one sealing ring groove is arranged in the outer taper matching surface (4-12-1); the flow limiting device spring (4-13) is installed in the inner cavity below the spring limiting step (4-12-2) in the lower pushing cylinder (4-12).

18. The compressed air energy storage straight-inclined well high-frequency injection-production string according to claim 17, characterized in that, The upper outer circle of the limiting cylinder (4-14) is provided with external threads and can be threadedly connected with the flow limiting device lower outer cylinder (4-11); the washing and anti-spraying liquid tank (4-14-1) provided in the outer wall of the limiting cylinder (4-14) is a through tank and at least one is provided; the flow limiting device upper outer cylinder (4-9) is a non-equal-diameter cylindrical body, and the inner and outer threads in the upper and lower ends of the cylindrical body can be respectively threadedly connected with the continuation threads (4-2-7) of the central pipe (4-2) and the flow limiting device lower outer cylinder (4-11), and the lower inner cavity of the flow limiting device upper outer cylinder (4-9) connected with the central pipe (4-2) is in communication with the limiting plate installation groove (4-2-1).

19. The compressed air energy storage straight-inclined well high-frequency injection-production string according to claim 18, characterized in that, in The straight well section on the upper and lower sides of the downhole annulus flow limiting device (4) is connected with the centralizer (8) in the high-frequency injection and production pipe string, and the straight well section on the upper and lower sides of the downhole safety valve (6) is connected with the flow joint (7) in the high-frequency injection and production pipe string; the oil pipe includes a small-diameter oil pipe (3) and a large-diameter oil pipe (5), the centralizer (8) and the downhole annulus flow limiting device (4) are connected in series in the small-diameter oil pipe (3), and the downhole safety valve (6) and the flow joint (7) are connected in series in the large-diameter oil pipe (5).

20. The method according to any one of claims 1-19, wherein the method is applied to the completion of the compressed air energy storage straight-inclined shaft high-frequency injection-production string. The method comprises the following steps: A, the preset working cylinder (1) in the downhole combined sealing device is connected in series in the completion pipe string at a predetermined position and is lowered into the well for completion; B, the sealing working cylinder (2) is connected to the lower end of the injection and production pipe string, is lowered into the well, and the sealing working cylinder (2) is pressed down through the injection and production pipe string to anchor and seal the injection and production pipe string and the completion pipe string; C, the downhole annulus flow limiting device (4) is positively pressure tested, and whether the injection and production pipe string leaks is tested; D, if the injection and production pipe string does not leak after pressure testing, the downhole annulus flow limiting device (4) is started; E, after the downhole annulus flow limiting device (4) is started, reverse flushing is continued to verify whether the downhole combined sealing device works normally; F, after the downhole combined sealing device is verified to work normally, casing protection fluid is injected; G, the flushing pipeline is switched to the positive flushing process, the ground pressure is pressed after a period of time, the soluble plug in the downhole combined sealing device is broken, and the completion of the high-frequency injection and production pipe string in the straight and inclined well is realized.

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