Gas well under-pressure induced flow blocking removal and liquid drainage method

Abstract

The invention discloses a gas well under-pressure induced flow plug removal and liquid drainage method, and belongs to the technical field of gas well gas recovery. The method comprises the steps that accumulated liquid in a gas well is pumped out through pressurized swabbing operation till the liquid level descends to the depth position of an oil well pump; after swabbing operation is completed, a packer is adopted immediately for setting operation; after seat sealing is completed, underground well closing is conducted, and then pressure suppression operation is conducted; after the pressure suppression operation is completed, the packer is unblocked, then induced flow unblocking operation is carried out, induced flow unblocking is carried out on an oil well blocked in a near passing zone through an underground well shut-in pressure measurement process, the well pressure measurement time is prolonged to 15-20 days from conventional 7 days, high pressure of an oil layer gathered when the packer is unblocked is released instantly, induced flow unblocking is carried out on the oil layer, and the oil layer is blocked. The method is mainly suitable for oil wells with high gas-oil ratio oil reservoirs, high formation pressure, large injection-production ratio and severely polluted near wellbore areas, and is particularly suitable for shielding temporary plugging in the drilling process or oil wells which are blocked severely due to the fact that oil layers are pressed when a weighted hydraulic well is used for treating blowout.

Description

Technical Field

[0001] This invention belongs to the field of gas well production technology and relates to a method for unblocking and draining fluid from a gas well under pressure. Background Technology

[0002] During gas production, the accumulation of fluid in the well can cause water flooding and blockage of the gas formation, leading to a gradual decrease in production capacity and even intermittent or complete shutdown, severely impacting well output. This fluid may originate from formation water, condensate, or other fluids. As it accumulates in the wellbore, if it is not drained effectively and promptly, it can trigger a series of serious consequences. First, the accumulated fluid floods the previously unobstructed gas flow, blocking or narrowing the gas flow channels. This significantly reduces gas permeability, further decreasing the well's production capacity. As the amount of fluid increases, the flooding worsens. When the gas formation is heavily occupied by water, the effective gas flow space is further compressed, potentially preventing effective gas extraction. At this point, the well's production will plummet, possibly leading to intermittent or complete shutdown. This not only significantly reduces the well's economic efficiency but also negatively impacts the overall development progress and production capacity planning of the gas field. More seriously, the accumulated fluid can also corrode and damage the well's equipment and facilities. The various chemicals and impurities contained in the accumulated fluid can react with the wellbore and wellhead equipment, leading to decreased equipment performance and shortened lifespan. This not only increases the cost of maintenance and equipment replacement but may also cause safety accidents, posing a threat to personnel and the environment. Currently, commonly used methods for fluid drainage in gas wells, including production induction and post-pressurization unblocking, primarily involve coiled tubing and gas lift drainage. These methods are time-consuming, expensive, and sometimes ineffective. Implementing pressurized pumping and induction drainage through the production tubing is the most economical and effective method for gas wells.

[0003] Currently, pumping and drainage technology is limited to processes such as inducing blowouts in oil and water wells or enhancing oil production. Although pump dampers and hydraulically controlled blowout preventers have been developed for safe pumping technology in gas wells, the operation of wellhead blowout preventers and related technologies is relatively simple, limiting it to drainage operations in low-pressure, low-yield, and inefficient gas wells with accumulated liquid, where the wellhead is relatively unpressurized and the formation pressure is relatively low. Currently, the wellhead gas pressure blowout prevention control capabilities and technologies are insufficient to meet the requirements for emergency well control when wellhead pressure suddenly rises after pumping and drainage. Loss of wellhead control will inevitably lead to serious consequences. Conventional unblocking measures, such as fracturing and acidizing, while common to some extent, often have long operation cycles and relatively slow results. These measures not only require significant time and resource investment but are also expensive. Furthermore, they can easily cause secondary damage to the oil-bearing layer, affecting subsequent oil and gas production.

[0004] In summary, current conventional methods of induced spraying to unblock and drain fluid have long operation cycles, slow results, and require a significant investment of time and resources. Summary of the Invention

[0005] The purpose of this invention is to provide a method for unblocking and draining fluid from gas wells under pressure to solve the technical problems of long operation cycles, slow results, and high costs of existing unblocking measures.

[0006] To achieve the above objectives, the present invention employs the following technical solution: This invention provides a method for unblocking and draining fluid from a gas well under pressure, comprising the following steps: The accumulated liquid in the gas well is pumped out through pressurized pumping operations until the liquid level drops to the depth of the oil pump. Immediately after the pumping operation is completed, a packer should be used for sealing. After the well is sealed, the well is shut in downhole, and then pressure is applied. After the packing operation is completed, the packer is unsealed, and then the induced spraying and unblocking operation is carried out.

[0007] Furthermore, the step of pumping out the accumulated liquid in the gas well through pressurized pumping operation until the liquid level drops to the depth of the pumping pump specifically includes: first, lowering the tubing string structure required for pressurized pumping and drainage into the oil well at a predetermined depth; then, performing pressurized pumping operation, starting the pumping pump to pump out the accumulated liquid in the gas well, and continuously observing the changes in the liquid level in the well; and stopping the pumping operation when the liquid level drops to the depth of the pumping pump.

[0008] Furthermore, the tubing string structure includes a female plug, a working cylinder, a first tubing, a packer, a second tubing, a perforated tubing, a third tubing, a pump connector, and a pumping pump connected in sequence; the pumping pump is connected to the wellhead via a fifth tubing.

[0009] Furthermore, the step of immediately using a packer to perform a sealing operation after the pumping operation is completed specifically includes: immediately using a packer to seal the annular space between the fifth tubing and the oil layer after the pumping operation is completed; and then installing a blowout preventer at the wellhead to seal the annular space between the tubing and the casing.

[0010] Furthermore, the blowout preventer is an SFZ14-21 single-gate blowout preventer.

[0011] Furthermore, the steps of shutting in the well after the well is set and then performing pressure-locking operations specifically include: after the well is set and sealed, the wellhead is sealed, and then pressure-locking operations are started, gradually increasing the pressure inside the well to a preset pressure value and maintaining it for a preset time; and continuously measuring the changes in the hydrostatic level of the annulus during the pressure-locking process.

[0012] Furthermore, the preset time for pressure testing is 15 to 20 days; the measuring tool for detecting changes in the hydrostatic level of the annulus is a pressure gauge.

[0013] Furthermore, after the pressurization operation is completed, the packer is unsealed, and then the blowout unblocking operation is performed. Specifically, this includes: after the pressurization operation is completed, the packer is released from its sealing state, so that the annular space between the tubing and the oil layer is reconnected; then the tubing string is quickly lifted to induce blowout unblocking.

[0014] Furthermore, during the process of inducing flow and unblocking, when the fluid level is less than 500m, oil replacement and well control measures are taken.

[0015] Furthermore, it also includes recording the discharge volume and pressure of the accumulated fluid in the well during the process of induced flow unblocking.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a method for induced blowout unblocking and fluid drainage in gas wells. It utilizes downhole shut-in pressure testing to induce blowout unblocking in near-wellbore areas. When the packer is released, the high pressure accumulated in the oil layer is released instantaneously, inducing blowout unblocking. This method is primarily suitable for oil wells with high gas-to-oil ratios, high formation pressure, large injection-production ratios, and severely contaminated near-wellbore areas. It is particularly suitable for oil wells that have experienced severe blockage due to temporary shielding during drilling or the use of weighted hydraulic wells to treat blowouts that have killed the oil layer. Compared to conventional unblocking measures, this method offers advantages such as shorter operation cycles, faster results, lower costs, and no secondary damage to the oil layer.

[0017] Furthermore, the pressure testing time for shut-in wells in this invention is extended from the conventional 7 days to 15-20 days, which allows the high pressure in the oil layer to accumulate more fully. When the packer is released, the high pressure is released instantly, generating a stronger impact on the oil layer, thereby more effectively clearing blockages in the near-wellbore area, improving the success rate and effect of induced blowout unblocking, and reducing the overall operating cost. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a process flow diagram of the present invention; Figure 2 This is a schematic diagram of the string structure in an embodiment of the present invention.

[0020] Wherein: 1-First oil pipe; 2-Packer; 3-Second oil pipe; 4-Swivel pipe; 5-Third oil pipe; 6-Pump connection stub; 7-Oil pump; 8-Fifth oil pipe. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0023] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0025] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0026] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0027] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 1 This invention discloses a method for unblocking and draining fluid from a gas well under pressurized flow, comprising the following steps: S1, through pressurized pumping operation, the accumulated liquid in the gas well is pumped out until the liquid level drops to the depth of the oil pump; First, all necessary equipment and tools for live pumping and drainage operations must be prepared, including but not limited to pumps, tubing, packers, plugs, working tubes, perforated tubing, and pump connectors, forming a complete tubing string structure. This equipment must undergo rigorous inspection to ensure it is intact and functional. An SFZ14-21 single-gate blowout preventer is installed at the wellhead to seal the annular space between the casing and tubing. Then, through tripping operations, this tubing string structure is lowered into the well at the predetermined depth. During the lowering process, close monitoring of the wellbore is crucial to prevent stuck pipe or falling debris. Once the tubing string structure reaches the designated position, live pumping operations begin, i.e., the pumps are started to extract the fluid from the well through the tubing, reducing the bottomhole pressure. This effectively prevents the fluid from flooding the gas layer. This step rapidly reduces the bottomhole pressure, creating favorable conditions for subsequent unblocking operations, while also reducing corrosion of the wellbore and equipment by the fluid, extending the well's service life.

[0028] S2, immediately after the pumping operation is completed, uses a packer for setting and sealing; this ensures the wellbore's sealing, prevents unnecessary loss of formation fluid in subsequent operations, and also provides the necessary pressure environment for the following pressurization operation.

[0029] During pumping operations, it is necessary to continuously monitor changes in the fluid level within the well. When the fluid level drops to the depth of the pump, pumping operations should be stopped, and a packing operation should be performed immediately. Packing refers to using a packer to seal off the annular space between the tubing and the oil layer to prevent subsequent operations from contaminating or damaging the oil layer. The packer setting operation must be performed strictly in accordance with the operating procedures to ensure that it is accurately and securely set in the predetermined position. After setting, a seal test must be performed to ensure that the packer can effectively seal the annular space.

[0030] S3, after the well is sealed, shut in the well and then perform pressure-locking operations; After the wellhead is sealed, a shut-in operation is performed to close the well, creating a closed well environment. Then, a pressure-increasing operation is initiated, gradually raising the well pressure to a certain level and maintaining it for a period (usually 15-20 days). During this process, continuous monitoring of the annular hydrostatic level is necessary to track changes in well pressure. Increasing the wellbore pressure forces gas and fluid in the formation towards the wellhead, helping to further clear blockages in the wellbore and formation, thus improving the well's permeability. This step not only enhances the induced flow effect but also promotes formation pressure balance, which is beneficial for the long-term stable production of the gas well.

[0031] Measuring the hydrostatic level in the annulus of the oil jacket requires specialized measuring tools and equipment, such as pressure gauges. It is crucial to ensure the accuracy and reliability of the data during measurement for subsequent analysis and judgment.

[0032] S4. After the packing operation is completed, the packer is unsealed, and then the induced spraying and unblocking operation is performed.

[0033] After the packer pressurization operation is completed, the pressure gauge needs to be retrieved to obtain well pressure data. Then, a blowout induction and unblocking operation is performed. First, the packer is released, reconnecting the annular space between the tubing and the oil layer. Then, 3-4 tubing strings are quickly pulled up to generate sufficient impact force to create fractures in the oil layer or enlarge existing fractures, thus achieving the purpose of blowout induction and unblocking. When retrieving the tubing string structure, the fluid level outside the tubing must be accurately recorded. If the fluid level is less than 500m, oil displacement and well control measures are implemented to ensure well control safety.

[0034] During the induced flow process, it is necessary to closely monitor pressure changes at the wellhead and in the tubing, and adjust operating parameters and measures accordingly. Simultaneously, safety precautions must be taken to ensure the safe conduct of the induced flow operation. Due to thorough preparation beforehand, the induced flow unblocking process will be smoother, enabling a rapid restoration of the gas well to normal production and significantly increasing its output. Furthermore, because the entire process is conducted under pressure, the potential safety risks associated with sudden releases of formation pressure are effectively avoided.

[0035] S5. During the induced blowout process, close the wellhead single-gate blowout preventer and tubing stopcock, and open the casing blowout line control gate to carry out the blowout operation. Observe the casing blowout line and record the blowout pressure to complete the induced blowout unblocking process, and record the discharge volume and discharge pressure of the accumulated fluid in the well.

[0036] During the induced blowout process, to prevent wellhead loss of control and environmental pollution, the wellhead single-gate blowout preventer and tubing stop valve need to be closed to cut off the internal and external channels of the tubing. At the same time, the casing venting line control gate is opened to discharge the oil and gas generated by the induced blowout into the designated sewage pool through the venting line.

[0037] During venting operations, it is necessary to closely monitor the venting situation of the casing venting pipeline and record relevant data such as venting volume and venting pressure. Simultaneously, it is also necessary to pay attention to whether the emitted oil and gas causes pollution or harm to the environment and take appropriate measures to treat it.

[0038] This embodiment utilizes downhole shut-in pressure testing technology to induce blowouts and unblock oil wells with blockages in the near-wellbore zone. The shut-in pressure testing time is extended from the conventional 7 days to 15-20 days. When the packer is released, the high pressure accumulated in the oil layer is released instantaneously, inducing blowouts and unblocking the oil layer. It is mainly suitable for oil wells with high gas-oil ratio, high formation pressure, large injection-production ratio, and severely contaminated near-wellbore zones. It is especially suitable for oil wells that have been severely blocked due to temporary shielding during drilling or the use of weighted hydraulic wells to treat blowouts that have crushed the oil layer. Compared with conventional unblocking measures, it has the advantages of short operation cycle, quick results, low cost, and no secondary damage to the oil layer.

[0039] In one feasible embodiment of the present invention, see [link to relevant documentation]. Figure 2 The tubing string structure includes a main plug, working cylinder, first tubing 1, packer 2, second tubing 3, perforated tubing 4, third tubing 5, pump connector 6, and pumping pump 7 connected in sequence; the pumping pump 7 is connected to the wellhead via a fifth tubing 8. This tubing string structure ensures effective control and regulation of well pressure, providing a stable environment for induction blowout operations, thereby significantly improving the success rate and efficiency of induction blowout. It fully considers harsh conditions such as high pressure and high temperature in the well, with tight connections and reliable sealing between components, effectively preventing fluid leakage or blowout accidents and improving the safety of the operation process. This tubing string structure can be flexibly adjusted according to the geological conditions and production needs of different gas wells, such as changing the position of the packer or adjusting the orifice diameter of the perforated tubing, to adapt to the needs of induction blowout, unblocking, and drainage operations under different well conditions. In summary, the tubing string structure of this embodiment shows significant beneficial effects in improving induction blowout efficiency, effectively unblocking, optimizing drainage performance, enhancing operational safety, and adaptability, providing strong technical support for the efficient development of gas wells.

[0040] Example: This embodiment provides the specific application of the gas well pressurized induced flow unblocking and fluid drainage method as follows: The Bai 455 area was fully developed in June 2008. Tectonically, it belongs to the southern part of the Shaanbei Slope of the Ordos Basin, and is generally a gently dipping monocline. The predicted oil-bearing area is 13.0 km². 2 Geological reserves: 612.2 × 104 t, average porosity 10.3%, average permeability 1.7 × 10 -3 um 2 The original formation pressure was 19.21 MPa.

[0041] The main oil-bearing strata in the Bai 455 area are the Triassic Chang 8. The Chang 8 reservoir sand bodies are stable, extending in a near NE-SW direction, with an average width of about 8 km and a maximum width of 9 km. The strata thickness is between 45 and 50 m, with a cumulative sand thickness of about 11 to 25 m, and a maximum thickness of about 25 m. The sand-to-soil ratio is 30% to 54%, and the sand bodies are relatively large in scale. The formation of the traps is related to the lateral pinch-out of the sandstone and the tight lithology, forming a lithologic reservoir controlled by both lithology and structure. The original driving type is elastic dissolution gas drive. The reservoir properties are good, with two oil-bearing layers, Chang 813 and Chang 811, developed overall. The two oil-bearing layers overlap in the south, while Chang 811 is the main oil-bearing layer in the north. It is highly heterogeneous, and the high-permeability layers have relatively good water absorption.

[0042] The Bai 455 block is currently in the early stage of rapid development. It adopts a 500m × 150m diamond-shaped inverted nine-point well pattern for advanced water injection development. Its main characteristics are: good reservoir properties (average sand layer thickness 18.8m, average oil layer thickness 13.4m), low water cut oil production period (11.2%) with sufficient energy, and high oil production rate (recoverable reserves oil production rate 9.18%).

[0043] The downhole shut-in induced flow unblocking technology was applied to three wells in the Bai 455 area of ​​Huaqing Oilfield, namely Well A, Well B, and Well C.

[0044] Example 1: In well A, a blowout-inducing and unblocking process was implemented, with the well shut in and pressure maintained for 15 days. Production increased from 1.66 m³ / day before the process. 3 Daily oil production increased from 1.32 tons to 6.40 tons, with a water content of 5.3%. 3 The effect was poor.

[0045] Example 2: The blowout-inducing and unblocking process was implemented in well B. The well was shut in and pressure was applied for 18 days. The daily oil production was 5.07t, the water cut was 5.7%, and the daily oil increase was 3.75t, which was quite good.

[0046] Example 3: In well C, a blowout induction and unblocking process was implemented, followed by a 20-day downhole shut-in and pressure buildup. Well C is an oil production well in the Bai 455 block of the Huachi operating area. In October 2008, during oil testing, a 200m³ blowout occurred due to plug failure. 3 For pure oil, in order to handle the blowout accident, the emergency response team prepared 300ml of KCL kill fluid on site. 3 Well control was performed, causing contamination and blockage in the near-wellbore area (temporary plugging). The formation compressibility coefficient of this well is 13.2 × 10⁻⁶.-4 The formation porosity is 13.48, and the crude oil viscosity is 1.05 × 10⁻⁶. -3 Pa·s, volume index 1.341, gas-oil ratio 106 m 3 / t. Due to formation blockage, production was low after it was put into operation in February 2008, with a daily liquid production of 0.48m³. 3 The daily oil production is 0.36 tons, with a water cut of 7.2%. After well shut-in and blowout induced unblocking, production is higher, reaching 11.96 cubic meters of fluid per day. 3 The daily oil production is 9.56 tons, with a water content of 6.0%, resulting in a cumulative increase of 3,450 tons of oil production, demonstrating significant effectiveness.

[0047] In well C, a real-time blowout unblocking process was implemented, followed by 20 days of downhole shut-in pressure control. Before the measures were implemented, the well's daily fluid production was 0.48 m³. 3 Daily oil production is 0.36 tons, with a water content of 7.8%; after well shut-in and blowout induced unblocking, daily fluid production is 11.96 cubic meters per second. 3 Daily oil production is 9.56 tons, with a water content of 6%. The cumulative increase in oil production is 3,450 tons, demonstrating the significant effectiveness of the measures.

[0048] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for unblocking and draining fluid from a gas well under pressurized flow, characterized in that, Includes the following steps: The accumulated liquid in the gas well is pumped out through pressurized pumping operations until the liquid level drops to the depth of the oil pump. Immediately after the pumping operation is completed, a packer should be used for sealing. After the well is sealed, the well is shut in downhole, and then pressure is applied. After the packing operation is completed, the packer is unsealed, and then the induced spraying and unblocking operation is carried out.

2. The method for unblocking and draining fluid from a gas well under pressure according to claim 1, characterized in that, The step of pumping out the accumulated liquid in the gas well through pressurized pumping operation until the liquid level drops to the depth of the pumping pump specifically includes: first, lowering the tubing string structure required for pressurized pumping and drainage into the oil well at a predetermined depth; then, carrying out pressurized pumping operation, starting the pumping pump to pump out the accumulated liquid in the gas well, and continuously observing the changes in the liquid level in the well; when the liquid level drops to the depth of the pumping pump, stopping the pumping operation.

3. The method for unblocking and draining fluid from a gas well under pressurized flow as described in claim 2, characterized in that, The tubing string structure includes a mother plug, working cylinder, first tubing (1), packer (2), second tubing (3), perforated tubing (4), third tubing (5), pump connection section (6), and pumping pump (7) connected in sequence; the pumping pump (7) is connected to the wellhead through the fifth tubing (8).

4. The method for unblocking and draining fluid from a gas well under pressurized flow as described in claim 1, characterized in that, The steps of immediately using a packer to seal the well after the pumping operation are completed include: immediately using a packer (2) to seal the annular space between the fifth tubing (8) and the oil layer after the pumping operation is completed; and then installing a blowout preventer at the wellhead to seal the annular space between the tubing and the casing.

5. The method for unblocking and draining fluid from a gas well under pressurized flow as described in claim 4, characterized in that, The blowout preventer is an SFZ14-21 single-gate blowout preventer.

6. The method for unblocking and draining fluid from a gas well under pressurized flow as described in claim 1, characterized in that, The steps of shutting in the well after the well is set and then performing pressure-locking operations include: after the well is set and sealed, the wellhead is sealed and then pressure-locking operations are started, the pressure inside the well is gradually increased to a preset pressure value and maintained for a preset time; and during the pressure-locking process, the changes in the hydrostatic level of the annulus are continuously measured.

7. The method for unblocking and draining fluid from a gas well under pressurized flow as described in claim 6, characterized in that, The preset time for pressure testing is 15 to 20 days; the measuring tool for detecting changes in the hydrostatic level of the annulus is a pressure gauge.

8. The method for unblocking and draining fluid from a gas well under pressure according to claim 1, characterized in that, After the pressurization operation is completed, the packer is unsealed, and then the blowout unblocking operation is performed. Specifically, after the pressurization operation is completed, the packer is unsealed to reconnect the annular space between the tubing and the oil layer; then the tubing string is quickly lifted to perform blowout unblocking.

9. A method for unblocking and draining fluid from a gas well under pressure according to claim 8, characterized in that, During the process of inducing flow and unblocking, when the fluid level is less than 500m, oil replacement and well control measures are taken.

10. A method for unblocking and draining fluid from a gas well under pressure according to claim 8, characterized in that, It also includes recording the discharge volume and pressure of the accumulated fluid in the well during the process of induced flow unblocking.

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