Integrated drainage and gas production pipe column and gas production method

Abstract

The pipe column comprises an oil pipe and a sleeve arranged on the outer side of the oil pipe in a sleeving mode, the lower end of the oil pipe is connected with a check valve, the bottom of the check valve is connected with a tail pipe, and the check valve and the tail pipe are both located on the inner side of the sleeve; a packer is arranged at the annulus position of the oil pipe and the casing pipe in a setting mode, and a jet pump working barrel is arranged on the upper portion of the packer and connected with the oil pipe. The method comprises the following steps: firstly, assembling to form an integrated drainage and gas production pipe column; then the integrated water drainage and gas production pipe column is tripped into a well, and when the formation liquid production capacity is high, a jet pump core is tripped into an oil pipe to conduct water drainage and gas production operation of the jet pump; and when the formation liquid production capacity is low, the jet pump core is backwashed out, the jet pump isolation sleeve and the plunger device are sequentially put into the oil pipe, and plunger gas lift drainage gas recovery operation is carried out. The method solves the problems that in the prior art, a single drainage process measure is high in cost, and the full-life-cycle continuous drainage production of the medium-high water content gas reservoir gas well cannot be met.

Description

Technical Field

[0001] This invention belongs to the field of natural gas development technology, specifically relating to an integrated drainage and gas production string, and also to an integrated drainage and gas production method. Background Technology

[0002] Gas fields, influenced by regional faults and reservoir properties, typically develop into two types of gas reservoirs: low-water and medium-high water-cut. The gas-water distribution in medium-high water-cut gas reservoirs is mainly controlled by factors such as hydrocarbon generation intensity, regional structure, and reservoir heterogeneity. These reservoirs have poor preservation conditions, low pressure coefficients, generally high water cuts in wells, and low gas saturation. However, medium-high water-cut gas reservoirs have large remaining exploitable reserves and are the main replacement areas for profitable production in gas fields. Their efficient development is crucial for increasing and stabilizing gas field production. Furthermore, with the number of wells deployed for production increasing annually, there is an urgent need to develop new, economically applicable technologies.

[0003] Due to the deep burial of medium-to-high water-cut gas reservoirs and low formation pressure coefficients, post-compression fluid drainage is difficult and costly, resulting in overall low gas well production. Initially, the average daily production per well was 1.1 × 10⁻⁶. 4 m 3 / d, currently the average daily production per well is 0.6×10 4 m 3 / d, the average cumulative production per well is only 1084×10 4 m 3 With an average water-to-gas ratio of 1.2 cubic meters per 10,000 cubic meters per day, production efficiency is poor. In the low-production stage of gas wells, plunger gas lift drainage and gas production technology is widely used. The plunger acts as a mechanical interface within the wellbore, utilizing the pressure difference above and below the plunger during well opening to lift the liquid to the surface. During the lift process, the plunger provides a certain degree of sealing, preventing gas cross-flow and reducing liquid slippage, thus improving lift efficiency. However, in high-production gas wells, most of the natural liquid-carrying period is missing, and the effectiveness of main technical measures such as plungers, bubble drainage, and velocity tubing is less than 50% (78% for low-water-cut gas reservoirs), failing to meet the demand for continuous large-volume liquid drainage.

[0004] Through field tests and research on jet pump and other strong drainage gas production technologies, the jet pump technology has been shown to have no back pressure on the producing formation, no moving parts downhole, minimal impact from solid particles, good stability, long pump maintenance cycle, and a wide drainage range, meeting the drainage needs of gas wells in medium-to-high water-cut gas reservoirs, and is easy to manage. However, due to the high cost of surface-mounted components for jet pumps, it cannot meet the drainage needs throughout the entire life cycle of gas wells. Summary of the Invention

[0005] The purpose of this invention is to provide an integrated drainage and gas production string, which solves the problem that the cost of single drainage and production processes in the prior art is high and cannot meet the problem of continuous drainage production throughout the entire life cycle of gas wells in medium and high water-cut gas reservoirs.

[0006] The first technical solution adopted in this invention is an integrated drainage and gas production tubing string, including an oil pipe and a casing sleeved outside the oil pipe. A check valve is connected to the lower end of the oil pipe, and a tail pipe is connected to the bottom of the check valve. Both the check valve and the tail pipe are located inside the casing.

[0007] A packer is set at the annulus position of the tubing and casing. A jet pump working cylinder is installed on the upper part of the packer. The jet pump working cylinder is connected to the tubing and is used to cooperate with the jet pump core for jet pump drainage and gas extraction, as well as to cooperate with the jet pump isolation sleeve and plunger for plunger gas lift drainage and gas extraction.

[0008] The first technical solution of the present invention is further characterized in that,

[0009] The working cylinder of the jet pump includes an upper oil pipe connector, which is connected to the oil pipe. The lower end of the upper oil pipe connector is connected to the cylinder body. The end of the cylinder body away from the upper oil pipe connector is connected to a lower oil pipe connector, which is connected to the oil pipe. A liquid outlet hole is opened on the side wall of the lower oil pipe connector at a relatively opposite position. A sliding sleeve is movably connected to the inner side of the lower oil pipe connector. When the sliding sleeve moves relative to the lower oil pipe connector, it forms an opening and closing mechanism for the liquid outlet hole.

[0010] The driving pressure range of the sliding sleeve is 5MPa~50MPa, the outer diameter of the working cylinder of the jet pump is 30mm~178mm, the inner diameter is 38mm~100mm, the working pressure range is 70MPa~150MPa, and the working temperature range is 100℃~200℃.

[0011] A plunger limiter is provided at the end of the oil pipe joint away from the cylinder for limiting the plunger position.

[0012] The end of the oil pipe connector near the cylinder is an insertion sealing section for sealing connection with the jet pump isolation sleeve.

[0013] A valve is installed inside the lower connector of the oil pipe, and the valve is located below the outlet hole.

[0014] The packer can be any one of the following: self-sealing packer, compression packer, and expansion packer. The working pressure range of the packer is 7MPa to 100MPa, the working temperature range is 55℃ to 370℃, the outer diameter range is 90mm to 215mm, and the nominal diameter range is 38mm to 100mm.

[0015] The second technical solution adopted in this invention is an integrated drainage and gas extraction method, which specifically includes the following steps:

[0016] Step 1: Connect the oil pipe, jet pump working cylinder, packer, check valve and tailpipe in sequence and then lower them into the casing to form an integrated drainage and gas production tubing string;

[0017] Step 2: Lower the integrated drainage and gas production tubing into the well. When the formation fluid production is 10 to 400 cubic meters per day, insert the jet pump core into the tubing, open the sliding sleeve, and carry out the jet pump drainage and gas production operation.

[0018] Step 3: When the formation fluid production is 0 to 10 cubic meters per day, inject high-pressure dynamic fluid of 5 MPa to 50 MPa into the casing. The fluid flows into the working cylinder of the jet pump through the outlet hole to backwash the pump core of the jet pump to the wellhead.

[0019] Step 4: Insert the jet pump isolation sleeve and plunger into the oil pipe in sequence to carry out plunger gas lift drainage and gas extraction operation.

[0020] The second technical solution of the present invention is further characterized in that,

[0021] In step 2, opening the sliding sleeve involves pressurizing the oil pipe to 5MPa to 50MPa. Under pressure, the sliding sleeve moves downward relative to the working cylinder of the jet pump, and the liquid outlet opens.

[0022] The beneficial effects of this invention are:

[0023] (1) The integrated drainage and gas production method of the present invention achieves the following after fracturing: the installation of an integrated drainage and gas production tubing string, which includes a packer and a jet pump working cylinder. After all the procedures are completed, the jet pump core is first put into the tubing for large-volume drainage. After the formation fluid production is reduced to a certain level, the jet pump core is backwashed out. Then, the jet pump isolation sleeve is put into the tubing to seal the liquid outlet of the jet pump working cylinder. At the same time, the tubing plunger is limited. Then, the plunger is put into the tubing for plunger gas lift. This effectively saves well workover operation costs, reduces the cost of measures, improves drainage and production efficiency, and achieves orderly succession of measures.

[0024] (2) The integrated drainage and gas production method of the present invention combines the characteristics of plunger gas lift and jet pump technology to realize the application of different stages in one wellbore operation, meet the drainage needs of the gas well throughout its entire life cycle, improve the drainage efficiency and stable production rate of the gas well, and give full play to the production capacity of the gas well. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the integrated drainage and gas extraction tubing of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the jet pump core inserted into the integrated drainage and gas extraction tubing of the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of the jet pump isolation sleeve inserted in the integrated drainage and gas extraction tubing of the present invention;

[0028] Figure 4 This is a schematic diagram of the working cylinder of the jet pump in the integrated drainage and gas extraction tubing of the present invention;

[0029] Figure 5 This is a schematic diagram of the jet pump core in the integrated drainage and gas extraction method of the present invention;

[0030] Figure 6 This is a schematic diagram of the jet pump isolation sleeve in the integrated drainage and gas extraction method of the present invention;

[0031] Figure 7 This is a schematic diagram of the connection between the jet pump working cylinder and the jet pump isolation sleeve of the present invention.

[0032] In the diagram, 1. Sleeve, 2. Jet pump working cylinder, 3. Packer, 4. Check valve, 5. Oil pipe, 6. Tailpipe, 7. Jet pump core, 8. Plunger, 9. Jet pump isolation sleeve, 10. Sliding sleeve, 11. Plunger limiter, 12. Liquid outlet, 13. Insert sealing stub, 14. Cylinder, 15. Upper oil pipe connector, 16. Lower oil pipe connector, 17. Valve, 18. Locking device, 19. Flow channel, 20. Packer stub, 21. Nozzle, 22. Mixing chamber, 23. Throat, 24. Diffusion tube. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] This invention relates to an integrated drainage and gas extraction tubing, such as... Figure 1 As shown, it includes an oil pipe 5 and a casing 1 sleeved outside the oil pipe 5. A check valve 4 is connected to the lower end of the oil pipe 5, and a tail pipe 6 is connected to the bottom of the check valve 4. Both the check valve 4 and the tail pipe 6 are located inside the casing 1.

[0036] A packer 3 is set at the annular position of the tubing 5 and the casing 1. A jet pump working cylinder 2 is set on the upper part of the packer 3. The jet pump working cylinder 2 is connected to the tubing 5 and is used to cooperate with the jet pump core 7 to perform jet pump drainage and gas collection, and to cooperate with the jet pump isolation sleeve 9 and the plunger 8 to perform plunger gas lift drainage and gas collection.

[0037] like Figure 2 As shown, when the liquid production is large, the jet pump core 7 is lowered into the oil pipe 5. The jet pump core 7 is connected and cooperates with the jet pump working cylinder 2 to realize the drainage and gas extraction of large liquid volume jet pump. Figure 3 As shown, when the production rate is low, the jet pump isolation sleeve 9 is lowered into the jet pump working cylinder 2 to achieve full-bore wellbore. The plunger limiter 11 on the jet pump working cylinder 2 achieves plunger wellbore limit production, and the plunger device 8 is put into operation for plunger gas lift drainage and gas production.

[0038] Furthermore, such as Figure 4As shown, the working cylinder 2 of the jet pump includes an upper oil pipe connector 15, which is connected to the oil pipe 5. The lower end of the upper oil pipe connector 15 is connected to a cylinder body 14. The end of the cylinder body 14 away from the upper oil pipe connector 15 is connected to a lower oil pipe connector 16, which is connected to the oil pipe 5. A liquid outlet hole 12 is opened on the side wall of the lower oil pipe connector 16 at a relatively opposite position. A sliding sleeve 10 is movably connected to the inner side of the lower oil pipe connector 16. When the sliding sleeve 10 moves relative to the lower oil pipe connector 16, it forms an opening and closing mechanism for the liquid outlet hole 12.

[0039] Furthermore, the driving pressure range of the sliding sleeve 10 is 5MPa to 50MPa. By pressurizing the oil pipe 5, the sliding sleeve 10 moves relative to the lower connector 16 of the oil pipe. The inner wall of the lower connector 16 of the oil pipe has a groove along the moving position of the sliding sleeve 10. A slider is fixed to the sliding sleeve 10 relative to the groove, and the slider is located in the groove. A spring is also provided inside the groove relative to the bottom of the slider. One end of the spring abuts against the lower connector 16 of the oil pipe, and the other end abuts against the slider. When the pressure in the oil pipe 5 is greater than the spring's bearing capacity, the spring is compressed, thereby realizing the sliding of the sliding sleeve 10 and opening the liquid outlet 12. After the liquid outlet 12 is opened, the oil pipe 5 and the sleeve 1 are connected. The outer diameter of the jet pump working cylinder 2 is 30mm to 178mm, the inner diameter is 38mm to 100mm, the working pressure range is 70MPa to 150MPa, and the working temperature range is 100℃ to 200℃.

[0040] The end of the oil pipe connector 15 away from the cylinder 14 is provided with a plunger limiter 11 for limiting the plunger 8.

[0041] The end of the oil pipe connector 15 near the cylinder 14 is an insertion sealing section 13 for sealing connection with the jet pump isolation sleeve 9.

[0042] A valve 17 is installed inside the lower connector 16 of the oil pipe. The valve 17 is located below the outlet hole 12. When the jet pump isolation sleeve 9 is put into the jet pump working cylinder 2, the fluid passing through the valve 17 directly enters the interior of the jet pump isolation sleeve 9.

[0043] Furthermore, the outer diameter of sleeve 1 ranges from 88.9 mm to 508 mm, and the wall thickness ranges from 5.21 mm to 22.22 mm.

[0044] Furthermore, the outer diameter of the oil pipe 5 ranges from 26.67 mm to 473.08 mm, and the wall thickness ranges from 2.87 mm to 22.22 mm.

[0045] Furthermore, the outer diameter of the tailpipe 6 ranges from 26.67 mm to 473.08 mm.

[0046] Furthermore, the one-way pressure of the flow valve 4 is 10MPa to 50MPa.

[0047] Furthermore, the packer 3 is any one of a self-sealing packer, a compression packer, and an expansion packer. The working pressure range of the packer 3 is 7MPa to 100MPa, the working temperature range is 55℃ to 370℃, the outer diameter range is 90mm to 215mm, and the nominal diameter range is 38mm to 100mm.

[0048] Example 2

[0049] The integrated drainage and gas extraction method of the present invention uses the integrated drainage and gas extraction tubing as described in Example 1, and specifically includes the following steps:

[0050] Step 1: Connect the oil pipe 5, jet pump working cylinder 2, packer 3, check valve 4 and tail pipe 6 in sequence and then lower them into the casing 1 to form an integrated drainage and gas production tubing string;

[0051] Step 2: Lower the integrated drainage and gas production tubing into the well. When the formation fluid production is 10 to 400 cubic meters per day, insert the jet pump core 7 into the tubing 5. The jet pump core 7 and the jet pump working cylinder 2 form an insertion seal. Open the sliding sleeve 10 to carry out the jet pump drainage and gas production operation.

[0052] Furthermore, opening the sliding sleeve 10 specifically involves pressurizing the oil pipe 5 to 5MPa~50MPa. Under the pressure, the sliding sleeve 10 moves downward relative to the working cylinder 2 of the jet pump, and the liquid outlet 12 opens.

[0053] The jet pump drainage and gas production operation specifically involves injecting a 5-50 MPa high-pressure dynamic fluid into the tubing 5. The high-pressure dynamic fluid is mixed with the formation produced fluid via the jet pump core 7. Under the action of the jet pump core 7, the mixed fluid is lifted to the ground through the casing 1 via the connection of the sliding sleeve 10, thus realizing the jet pump drainage and gas production process.

[0054] Step 3: When the formation fluid production is 0 to 10 cubic meters per day, inject high-pressure dynamic fluid of 5 MPa to 50 MPa into the casing 1. The fluid flows into the working cylinder 2 of the jet pump through the outlet hole 12 to backwash the pump core 7 to the wellhead.

[0055] Step 4: Remove the jet pump core 7, insert the jet pump isolation sleeve 9 into the oil pipe 5, the jet pump isolation sleeve 9 seals the sliding sleeve 10 on the jet pump working cylinder 2, completing the sealing of the liquid outlet 12, and then insert the plunger 8 to carry out the plunger gas lift drainage gas extraction operation.

[0056] The high-pressure kinetic fluid in step 2 and the high-pressure kinetic liquid in step 3 are either gas or liquid.

[0057] Example 3

[0058] Based on Example 2, such as Figure 5As shown, the jet pump core 7 used in the integrated drainage and gas production method of this invention includes a nozzle 21, an inlet, a throat 23, and a diffuser 24. When the liquid production rate is high, it is lowered into the oil pipe 5, forming an insertion seal with the jet pump working cylinder 2. High-pressure kinetic fluid is injected from the ground into the oil pipe 5 and ejected at high speed through the nozzle 21. At the outlet of the nozzle 21, due to the turbulent diffusion effect of the jet boundary layer, it exchanges momentum with the surrounding formation fluid drawn in from the inlet in the mixing chamber 22. The two are fully mixed in the throat 23, and the velocity of the mixed fluid gradually becomes consistent at the outlet of the throat 23. The potential energy of the mixed fluid gradually increases in the throat 23, and the kinetic energy is further converted into potential energy through the action of the diffuser 24, thereby lifting the mixed fluid to the ground and realizing large-volume jet pump drainage and gas production.

[0059] The jet pump core 7 can achieve positive circulation injection and reverse circulation injection in the jet pump working cylinder 2. Positive circulation injection means that it works with the jet pump working cylinder 2 to carry out jet pump drainage and gas extraction operations. Reverse circulation injection means that high pressure fluid is injected into the sleeve 1 and the jet pump core is backwashed out of the jet pump working cylinder 2 through the liquid outlet 12.

[0060] The outer diameter of the jet pump core 7 ranges from 20 to 178 mm, the length ranges from 500 to 1500 mm, the maximum working pressure ranges from 70 to 150 MPa, and the maximum working temperature ranges from 100 to 200℃. A pressure gauge is installed at the bottom, along with a pressure gauge support with a shock-absorbing device. The support contains a shock-absorbing spring to prevent the pressure gauge from being damaged by impacts during the jet pump core's descent into the well, ensuring normal pressure reading, storage, and operation. The pressure gauge is a storage type and can meet the operating requirements for 90 to 180 days.

[0061] Furthermore, such as Figure 6 As shown, the jet pump isolation sleeve 9 used in the integrated drainage and gas extraction method of the present invention includes three parts: a locking device 18, a flow channel 19, and a sealing stub 20. Figure 7 As shown, after the jet pump isolation sleeve 9 is lowered into the jet pump working cylinder 2, the locking device 18 cooperates with the insertion sealing short section 13 on the jet pump working cylinder 2 to achieve a seal, while the sealing short section 20 blocks the liquid outlet hole 12; the lower end of the jet pump isolation sleeve 9 is connected to the end of the valve 17, and the gas and liquid through the valve 17 enter the flow channel 19 inside the jet pump isolation sleeve 9 and are transmitted to the ground. The maximum working pressure range of the jet pump isolation sleeve 9 is 70-150 MPa, and the maximum working temperature range is 100-200℃.

[0062] Furthermore, the plunger 8 used in the integrated drainage and gas extraction method of the present invention has an outer diameter range of 20mm to 178mm, a maximum working pressure range of 70MPa to 150MPa, and a maximum working temperature range of 150℃ to 200℃.

[0063] Example 4

[0064] Taking a certain natural gas production well as an example, in the above-mentioned integrated drainage and gas production tubing, casing 1 is made of casing with an outer diameter of 114.3 mm and a wall thickness of mm, and is laid down to a depth of m;

[0065] Oil pipe 5 is an oil pipe with an outer diameter of 88.9 mm and a wall thickness of mm, and is laid to a depth of m; tailpipe 6 is an 88.9 mm tailpipe;

[0066] One-way valve 4 is used; the MPa one-way valve can be opened to allow fluid to pass through.

[0067] Packer 3 is a compression packer (model Y441-115) with a maximum working pressure of 20MPa, a maximum working temperature of 180℃, a maximum outer diameter of 115mm, and a bore range of 48mm.

[0068] When the jet pump working cylinder 2 is lowered into the well, the outlet hole 12 is closed. The sliding sleeve 10 is opened by pressurizing. The opening pressure range of the sliding sleeve 10 is 25MPa, which can connect the tubing 5 and the casing 1. The outer diameter range of the jet pump working cylinder 2 is 108mm, the inner diameter range is 55mm, the maximum working pressure range is 100MPa, and the maximum working temperature range is 150℃.

[0069] Using the integrated drainage and gas production method of this invention, the tailpipe 6, check valve 4, packer 3, jet pump working cylinder 2, and tubing 5 are first sequentially installed from bottom to top inside the casing 1 to form an integrated drainage and gas production string. When the formation liquid production is 60 cubic meters / day, the jet pump core 7 is installed, and the jet pump core 7 and the jet pump working cylinder 2 form an insertion seal.

[0070] Then, pressurize the tubing 5 to 25 MPa, open the sliding sleeve 10, and connect the tubing 5 and the casing 1. Inject 30 MPa high-pressure dynamic fluid (clean water) into the tubing 5. The high-pressure dynamic fluid is mixed with the formation produced fluid through the jet pump core 7. Under the action of the jet pump core 7, the mixture is lifted to the ground through the outlet hole 12 from the casing 1, realizing the jet pump drainage and gas production process.

[0071] When the formation fluid production is 5 cubic meters per day, 20 MPa high-pressure dynamic fluid is injected into casing 1 and flows into the jet pump working cylinder 2 through the outlet hole 12 to backwash the jet pump core 7 to the wellhead. After removing the jet pump core 7, the jet pump isolation sleeve 9 is inserted into the tubing to seal the outlet hole 12 inside the jet pump working cylinder 2, forming a full-bore tubing. The plunger 8 is lowered into the plunger limiter 11 at the top of the jet pump working cylinder 2 to realize the plunger gas lift drainage gas production process.

[0072] The jet pump isolation sleeve 9 is installed after the jet pump discharges, sealing the outlet hole 12. The maximum working pressure is 100MPa and the maximum working temperature is 150℃. The outer diameter of the jet pump core 7 is 68mm and the length is 1231mm. The maximum working pressure is 100MPa and the maximum working temperature is 150℃. The outer diameter of the plunger 8 is 68mm, and the maximum working pressure range is 100MPa and the maximum working temperature range is 150℃.

[0073] This invention utilizes an integrated drainage and gas production string, combining the characteristics of plunger gas lift and jet pump processes, to achieve simultaneous wellbore operations and transitions between different stages, thereby improving gas well drainage efficiency and stable production rate, and fully maximizing gas well productivity. This integrated drainage and gas production method can be applied indoors to simulate gas well drainage and gas production under dynamic conditions. Dynamic experiments are conducted using relevant parameters optimized through indoor experiments. By comparing the experimental results, the current status of production technology for drainage and gas production in medium- and high-yield water-bearing gas wells can be understood, and the influence of jet pump high-pressure power medium injection pressure, process transition timing, and plunger operating regime on the drainage and gas production effect can be obtained. Compared to single drainage and gas production processes, this process has significant advantages in terms of investment cost, subsequent maintenance, operability, operational stability, and safety and environmental protection.

Claims

1. An integrated drain gas production string, characterized by, The oil pipe (5) is connected with a one-way valve (4) at the lower end, and the one-way valve (4) is connected with a tail pipe (6) at the bottom, and the one-way valve (4) and the tail pipe (6) are located inside the casing pipe (1); The annular position of the oil pipe (5) and the casing pipe (1) is set with a packer (3), and the upper part of the packer (3) is provided with a jet pump working cylinder (2), which is connected with the oil pipe (5) and used for cooperating with the jet pump pump core (7) to carry out jet pump drainage gas recovery and cooperating with the jet pump isolation sleeve (9) and the plunger device (8) to carry out plunger gas lift drainage gas recovery.

2. The integrated drain gas recovery string of claim 1, wherein, The jet pump working cylinder (2) comprises an oil pipe upper joint (15) connected with the oil pipe (5), a cylinder body (14) connected with the oil pipe upper joint (15), an oil pipe lower joint (16) connected with the cylinder body (14) away from the oil pipe upper joint (15), and a sliding sleeve (10) movably connected with the inside of the oil pipe lower joint (16).

3. The integrated drain gas recovery string of claim 2, wherein, The driving pressure range of the sliding sleeve (10) is 5MPa-50MPa, the outer diameter of the jet pump working cylinder (2) is 30mm-178mm, the inner diameter is 38mm-100mm, the working pressure range is 70MPa-150MPa, and the working temperature range is 100℃-200℃.

4. The integrated drain gas recovery string of claim 2, wherein, The oil pipe upper joint (15) is provided with a plunger limiter (11) for limiting the plunger device (8) at the end away from the cylinder body (14); The oil pipe upper joint (15) is provided with an insertion sealing nipple (13) for sealing connection with the jet pump isolation sleeve (9) at the end close to the cylinder body (14).

5. The integrated drain gas recovery string of claim 2, wherein, The oil pipe lower joint (16) is provided with a valve (17) below the liquid outlet hole (12).

6. The integrated drain gas recovery string of claim 1, wherein, The packer (3) is any one of a self-sealing packer, a compression packer and a dilatation packer, the working pressure range of the packer (3) is 7MPa-100MPa, the working temperature range is 55℃-370℃, the outer diameter range is 90mm-215mm, and the diameter range is 38mm-100mm.

7. The method of integrated drainage gas recovery characterized by, The integrated drainage gas recovery pipe string is used, and the specific steps are as follows: Step 1, sequentially connecting the oil pipe (5), the jet pump working cylinder (2), the packer (3), the one-way valve (4) and the tail pipe (6) and then lowering into the casing pipe (1) to form an integrated drainage gas recovery pipe string; Step 2, lowering the integrated drainage gas recovery pipe string into the well, when the formation liquid production is 10-400m3 / d, lowering the jet pump pump core (7) into the oil pipe (5), opening the sliding sleeve (10), and carrying out jet pump drainage gas recovery operation; Step 3, when the formation fluid production is 0-10 cubic meters per day, high pressure power fluid with a pressure of 5-50 MPa is injected into the casing (1) and flows into the jet pump working cylinder (2) through the outlet hole (12) to backwash the jet pump core (7) to the wellhead; Step 4, the jet pump isolation sleeve (9) and the plunger device (8) are sequentially lowered into the oil pipe (5) to perform plunger gas lift drainage gas recovery operation.

8. The integrated drainage gas recovery method of claim 1, wherein, The step 2 of opening the sliding sleeve (10) specifically comprises pressing to 5-50 MPa in the oil pipe (5), and the sliding sleeve (10) moves downward relative to the jet pump working cylinder (2) under the action of pressure, and the outlet hole (12) is opened.

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