A method for judging and handling abnormal opening of a full-bore sliding sleeve

Abstract

The present invention discloses a method for determining and handling abnormal opening of a full-bore sleeve, comprising the following steps: S1. Confirming the number of the full-bore sleeve to be opened, selecting the corresponding cartridge and soluble fracturing ball, and inserting them into the fracturing wellhead; S2. Calculating the volume of the full-bore sleeve to be opened to the wellhead, using 1.15 times the calculated volume as the standard volume; S3. Opening the well, pumping at a displacement of 3-4 m³ / min, and recording the fluid volume and pressure during the pumping process; S4. If the pressure value recorded in S3 rises significantly and then falls back rapidly, executing S6; otherwise, executing S5; S5. Analyzing the fluid volume and pressure obtained during the pumping process to determine the type of resistance encountered, and implementing the corresponding treatment method; S6. Conducting fracturing operations. The present invention has the advantages of reducing costs and improving the efficiency of handling abnormal opening of full-bore sleeves.

Description

Technical Field

[0001] The present invention relates to the field of oil and gas field exploration and development, and in particular to a method for judging and processing abnormal opening of a full-bore sliding sleeve. Background Art

[0002] Shale gas development often utilizes horizontal well pumping bridge plug staged fracturing. In wells with complex structures and trajectories, pumping bridge plug tool strings can easily become stuck, and after fracturing, the oil-sweeping plugs can easily self-lock. Consequently, full-bore sliding sleeve staged fracturing is gaining increasing attention.

[0003] The full-bore sliding sleeve is lowered into the wellbore together with the completion casing. During fracturing construction, soluble fracturing balls and chucks corresponding to the sliding sleeve are put in. By pumping the soluble fracturing balls and chucks to the corresponding sliding sleeve positions and opening the sliding sleeve, the sliding sleeve exposes the pre-set holes, and then fracturing construction can be carried out. However, at present, the full-bore sliding sleeve is prone to abnormal opening.

[0004] Patent CN201511032382.7 discloses a method for opening a damaged fracturing sleeve. The damaged fracturing sleeve is installed on a fracturing string. The method includes the following steps: Step 1: After the fracturing ball is seated on the ball seat of the damaged fracturing sleeve, the throttling pressure difference within the fracturing string is determined; Step 2: Based on the throttling pressure difference, the displacement of the ball pusher within the fracturing string is increased to a predetermined value, thereby increasing the throttling pressure difference to open the damaged fracturing sleeve. The method for opening a damaged fracturing sleeve in this invention solves the problem of damaged fracturing sleeves being difficult to open in the prior art. However, this patent does not address the problems of wellhead obstruction, wellbore obstruction, and over-provision of the cartridge pump.

[0005] Patent CN202111518901.6 discloses a toe-end sleeve and a sleeve opening control method, relating to the field of oil and gas production technology. The toe-end sleeve comprises: an upper joint, a connector, and a lower joint connected in sequence to form a hollow pipe structure; a liquid outlet is provided on the side wall of the upper joint, a connection port is provided on the inner wall of the connector, and a pressure-conducting channel is provided in the side wall of the connector, connecting the lower end of the connector and the connection port; a valve channel is provided in the side wall of the lower joint, one end of the valve channel is connected to the pressure-conducting channel, and the other end extends to the inner wall of the lower joint to form a port; a control valve is provided in the valve channel, and a soluble plug is provided at the port; a battery and an electronic control module are provided in the side wall of the lower joint, and a pressure sensor connected to the electronic control module is provided on the inner wall of the lower joint; a sleeve, the upper end of which is sleeved inside the upper joint to block the liquid outlet, and the lower end of which is sleeved inside the connector to block the connection port. The toe end sliding sleeve solves the problem of the current toe end sliding sleeve being unable to open normally or being opened by erroneous operation, but the patent cannot solve the problems of wellhead obstruction, wellbore obstruction and over-position of the cartridge pump.

[0006] Patent CN202111078758.3 discloses a cementing sleeve system and its use method, cementing sleeve assembly method and maintenance method. The use method includes the following steps: (1) the cementing sleeve is lowered into the wellbore to the designed depth according to the operation requirements; (2) after the cementing is completed, the toe sleeve is opened and fracturing is performed; (3) after the fracturing is completed, the first layer of cementing sleeve soluble bridge plug is placed. When the soluble bridge plug reaches the position of the first layer of cementing sleeve, it is lowered 20 to 40 meters more. If there is an over-lift reaction, Then, when the over-lifting is within 0.5T of the suspended weight, stop over-lifting and correct the depth; (4) After confirming the depth is correct in step 3, ignite the soluble bridge plug and remove the sealing tool and cable; (5) Start the pump to pressurize to the opening pressure of the cementing sleeve and observe the change in pump pressure. At the moment the sleeve opens, if there is a momentary pressure drop in the pump pressure, the fracturing operation of this layer can be started; perforating operations are avoided, the fracturing steps are reduced, the service life of the casing is increased, the casing deformation or even rupture is prevented, the parts are avoided from being damaged, and maintenance is facilitated. However, this patent cannot solve the problems of wellhead obstruction, wellbore obstruction, and over-position of the cartridge pump. Summary of the Invention

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a method for judging and handling abnormal opening of a full-bore sliding sleeve that is reusable and highly operable.

[0008] The object of the present invention is achieved through the following technical solutions:

[0009] A method for judging and handling abnormal opening of a full-bore sliding sleeve comprises the following steps:

[0010] S1. Confirm the number of the full-bore sliding sleeve to be opened, select the corresponding chuck and soluble fracturing ball, and put them into the fracturing wellhead;

[0011] S2. Calculate the volume from the full-bore sleeve to be opened to the wellhead, and use 1.15 times the calculated volume as the standard volume;

[0012] S3. Open the well and pump at a rate of 3-4 m³ / min, recording the liquid volume and pressure during the pumping process;

[0013] S4. If the pressure value recorded in S3 rises sharply and then falls back quickly, execute S6; otherwise, execute S5.

[0014] S5. Analyze the liquid volume and pressure obtained during the pumping process to determine the type of resistance encountered and implement corresponding treatment methods;

[0015] S6. Perform fracturing construction.

[0016] Furthermore, the analysis and determination of the type of obstruction in S5 includes the following steps:

[0017] S51. When the pumped liquid volume recorded in S3 exceeds the standard volume recorded in S2, and the pressure recorded in S3 does not change significantly, it is determined that the chuck in the full-bore sleeve opening abnormality is blocked or the chuck is replaced, and the next step of judgment is executed;

[0018] S52. When the pressure recorded in S3 increases significantly and does not decrease within 5 minutes, it is determined that the sleeve does not open after the chuck is in place in the full-bore sleeve opening abnormality, and corresponding measures are implemented.

[0019] Furthermore, the S51 specifically includes the following steps:

[0020] S511: Increase the pumping capacity to 5-6 m³ / min and pump 0.7 standard volumes of liquid. Reduce the capacity to 3-4 m³ / min and pump 0.3 standard volumes of liquid. During this process, if the pumping pressure meets the requirements of S4 or S52, execute the corresponding step and determine that the abnormality is caused by the cartridge being blocked. Otherwise, execute S512.

[0021] S512, using rapid pressure relief to perform agitation and unblocking by re-pressurizing. After each agitation and unblocking, use a displacement of 5-6 m³ / min to pump the first 0.7 standard volumes of liquid, and use a displacement of 3-4 m³ / min to pump the last 0.3 standard volumes of liquid. This step can be performed multiple times. If the pumping pressure during this process meets the requirements of S4 or S52, execute the corresponding step and determine that the abnormality is a cartridge obstruction. Otherwise, execute S513.

[0022] S513: Place a soluble fracturing ball into the wellbore and pump 0.7 standard volumes of liquid at a rate of 5-6 m³ / min for the first 0.7 standard volumes of liquid and 3-4 m³ / min for the last 0.3 standard volumes of liquid. If the pumping pressure during this process meets the requirements of S4 or S52, execute the corresponding step and determine that the abnormality is caused by the cartridge being blocked. Otherwise, execute S514.

[0023] S514: Place a soluble fracturing ball into the wellbore and pump a standard volume of fluid at a rate of 5-6 m³ / min. If the pumping pressure meets the requirements of S4 or S52, execute the corresponding step and determine that the abnormality is caused by a cartridge blockage. Otherwise, execute S515.

[0024] S515. Use continuous tubing with mill shoes to detect the depth of the chuck and soluble fracturing balls, and perform corresponding treatment methods according to different locations.

[0025] Furthermore, the step S52 specifically includes the following steps:

[0026] S521: Use pressure holding or rapid pressure relief within 10 minutes to release the jam by re-pressurizing. If the pressure drops significantly, proceed to S6. Otherwise, use coiled tubing to patch the hole in this section before proceeding to S6.

[0027] Furthermore, the S515 includes the following steps:

[0028] (1) The detection location of the cartridge and the soluble fracturing ball encountering resistance is within the fracturing wellhead, and it is determined that the wellhead encounters resistance in the cartridge;

[0029] The treatment method is to pump 15% KCl or 15% HCl to dissolve the fracturing ball for 24 hours, and re-pump KCl or HCl every 4 hours. After 24 hours, use the coiled tubing with a straightening tool to straighten the chuck. After confirming that the chuck has entered the wellbore, drop a soluble fracturing ball and pump it. Then, perform S4, S51, or S52 according to the actual situation.

[0030] (2) The detection location where the cartridge and soluble fracturing ball encounter resistance is below the fracturing wellhead and above the corresponding sliding sleeve location, which is considered to be the wellbore resistance in the cartridge resistance.

[0031] The solution is to use coiled tubing to push the chuck and soluble fracturing ball downward. If the coiled tubing can push the chuck and soluble ball past the resistance point, execute S4, S51, or S52 according to the actual situation. At the same time, the fracturing mode of the wellbore from the next sliding sleeve position to the resistance point needs to be changed to the bridge plug and perforation staged mode. If the coiled tubing cannot push the chuck and soluble ball past the resistance point, drill and grind the soluble fracturing ball. At the same time, the fracturing mode of the wellbore from the sliding sleeve position to the resistance point needs to be changed to the bridge plug and perforation staged mode.

[0032] (3) The detection position of the chuck and the soluble fracturing ball is below the corresponding sliding sleeve position, and it is judged that the chuck is pumped too far;

[0033] The treatment method is: use coiled tubing to plug the hole in the fracturing section and then execute S6.

[0034] Beneficial effects of the present invention:

[0035] The present invention proposes a method for judging and handling abnormal opening of a full-bore sleeve, which judges the type of abnormal opening of the full-bore sleeve and executes corresponding handling measures, thus saving repeated construction, reducing costs, and effectively improving the efficiency of handling abnormal opening of the full-bore sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a flow chart of the processing method of the present invention;

[0037] Figure 2 is the pressure displacement curve corresponding to Example 1;

[0038] Figure 3 This is the pressure-displacement curve corresponding to Example 2. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] Example 1: In this embodiment, Figures 1 to 2 As shown, a method for judging and handling abnormal opening of a full-bore sliding sleeve includes the following steps:

[0041] S1. Confirm the number of the full-bore sliding sleeve to be opened, select the corresponding chuck and soluble fracturing ball, and put them into the fracturing wellhead;

[0042] S2. The volume from the full-bore sleeve to the wellhead is calculated to be 48.4 m³, and the standard volume is 55.7 m³.

[0043] S3. Open the well and pump at a rate of 3.5 m³ / min. Record the liquid volume and pressure during the pumping process.

[0044] S4. When the liquid volume reached 82.3 m³, the recorded pressure did not show a significant rapid rise and fall. This indicated that the full-bore sleeve was opening abnormally and the chuck was blocked or replaced.

[0045] S5. Increase the pumping capacity to 5 m³ / min, pumping 39 m³ of liquid. Reduce the pumping capacity to 3.8 m³ / min, pumping 25 m³ of liquid. There is no significant increase in the recorded pressure.

[0046] S6: Rapid pressure relief was used to release the jam by re-pressurizing the pump. After restarting the pump, 42 m³ of liquid was pumped at a displacement of 5 m³ / min and 40 m³ was pumped at a displacement of 3.8 m³ / min. No significant change in the recorded pressure was observed.

[0047] S7. Rapid pressure relief was used again to release the jam by re-pressurizing the pump. After restarting the pump, 40 m³ of liquid was pumped at a displacement of 5 m³ / min and 20 m³ of liquid was pumped at a displacement of 3.5-4 m³ / min. No significant change in the recorded pressure was observed.

[0048] S8. Rapid pressure relief was used again to release the jam by re-pressurizing the pump. After restarting the pump, 42 m³ of liquid was pumped at a displacement of 5 m³ / min and 32 m³ was pumped at a displacement of 4 m³ / min. There was no significant change in the recorded pressure.

[0049] S9: One soluble fracturing ball was placed into the wellbore, and 37 m³ of fluid was pumped at a rate of 5 m³ / min. 29 m³ of fluid was pumped at a rate of 3.4-3.7 m³ / min. No significant change in the recorded pressure was observed.

[0050] S10: Another soluble fracturing ball is injected into the wellbore, and 57 m³ of fluid is pumped at a rate of 5 m³ / min. A significant pressure rise and rapid drop are recorded, and the full-bore sleeve opens. This abnormal opening is determined to be due to a cartridge blockage.

[0051] S11. Perform fracturing construction.

[0052] This embodiment is further configured such that the analysis and determination of the type of obstruction in S5 includes the following steps:

[0053] S51. When the pumped liquid volume recorded in S3 exceeds the standard volume recorded in S2, and the pressure recorded in S3 does not change significantly, it is determined that the chuck in the full-bore sleeve opening abnormality is blocked or the chuck is replaced, and the next step of judgment is executed;

[0054] S52. When the pressure recorded in S3 increases significantly and does not decrease within 5 minutes, it is determined that the sleeve does not open after the chuck is in place in the full-bore sleeve opening abnormality, and corresponding measures are implemented.

[0055] This embodiment is further configured as follows: S51 specifically includes the following steps:

[0056] S511: Increase the pumping capacity to 5-6 m³ / min and pump 0.7 standard volumes of liquid. Reduce the capacity to 3-4 m³ / min and pump 0.3 standard volumes of liquid. During this process, if the pumping pressure meets the requirements of S4 or S52, execute the corresponding step and determine that the abnormality is caused by the cartridge being blocked. Otherwise, execute S512.

[0057] S512, using rapid pressure relief to perform agitation and unblocking by re-pressurizing. After each agitation and unblocking, use a displacement of 5-6 m³ / min to pump the first 0.7 standard volumes of liquid, and use a displacement of 3-4 m³ / min to pump the last 0.3 standard volumes of liquid. This step can be performed multiple times. If the pumping pressure during this process meets the requirements of S4 or S52, execute the corresponding step and determine that the abnormality is a cartridge obstruction. Otherwise, execute S513.

[0058] S513: Place a soluble fracturing ball into the wellbore and pump 0.7 standard volumes of liquid at a rate of 5-6 m³ / min for the first 0.7 standard volumes of liquid and 3-4 m³ / min for the last 0.3 standard volumes of liquid. If the pumping pressure during this process meets the requirements of S4 or S52, execute the corresponding step and determine that the abnormality is caused by the cartridge being blocked. Otherwise, execute S514.

[0059] S514: Place a soluble fracturing ball into the wellbore and pump a standard volume of fluid at a rate of 5-6 m³ / min. If the pumping pressure meets the requirements of S4 or S52, execute the corresponding step and determine that the abnormality is caused by a cartridge blockage. Otherwise, execute S515.

[0060] S515. Use continuous tubing with mill shoes to detect the depth of the chuck and soluble fracturing balls, and perform corresponding treatment methods according to different locations.

[0061] This embodiment is further configured as follows: S52 specifically includes the following steps:

[0062] S521: Use pressure holding or rapid pressure relief within 10 minutes to release the jam by re-pressurizing. If the pressure drops significantly, proceed to S6. Otherwise, use coiled tubing to patch the hole in this section before proceeding to S6.

[0063] This embodiment is further configured as follows: S515 includes the following steps:

[0064] (1) The detection location of the cartridge and the soluble fracturing ball encountering resistance is within the fracturing wellhead, and it is determined that the wellhead encounters resistance in the cartridge;

[0065] The treatment method is to pump 15% KCl or 15% HCl to dissolve the fracturing ball for 24 hours, and re-pump KCl or HCl every 4 hours. After 24 hours, use the coiled tubing with a straightening tool to straighten the chuck. After confirming that the chuck has entered the wellbore, drop a soluble fracturing ball and pump it. Then, perform S4, S51, or S52 according to the actual situation.

[0066] (2) The detection location where the cartridge and soluble fracturing ball encounter resistance is below the fracturing wellhead and above the corresponding sliding sleeve location, which is considered to be the wellbore resistance in the cartridge resistance.

[0067] The solution is to use coiled tubing to push the chuck and soluble fracturing ball downward. If the coiled tubing can push the chuck and soluble ball past the resistance point, execute S4, S51, or S52 according to the actual situation. At the same time, the fracturing mode of the wellbore from the next sliding sleeve position to the resistance point needs to be changed to the bridge plug and perforation staged mode. If the coiled tubing cannot push the chuck and soluble ball past the resistance point, drill and grind the soluble fracturing ball. At the same time, the fracturing mode of the wellbore from the sliding sleeve position to the resistance point needs to be changed to the bridge plug and perforation staged mode.

[0068] (3) The detection position of the chuck and the soluble fracturing ball is below the corresponding sliding sleeve position, and it is judged that the chuck is pumped too far;

[0069] The treatment method is: use coiled tubing to plug the hole in the fracturing section and then execute S6.

[0070] Example 2: The difference between this example and Example 1 is that:

[0071] A method for judging and handling abnormal opening of a full-bore sleeve includes the following steps: Figure 3 As shown:

[0072] (1) Confirm the number of the full-bore sliding sleeve to be opened, select the corresponding clamp and soluble fracturing ball, and put them into the fracturing wellhead;

[0073] (2) Calculate the volume from the full-bore sleeve to the wellhead to be opened. The wellhead volume is 50.2 m³ and the standard volume is 57.8 m³.

[0074] (3) Open the well and pump at a rate of 3.5 m³ / min, recording the liquid volume and pressure during the pumping process;

[0075] (4) When the liquid volume reached 52.6 m³, the recorded pressure increased significantly but did not decrease. This was because the sleeve did not open after the chuck was in place.

[0076] (5) Execute the pressure holding treatment measures, which are achieved by stopping pumping without performing pressure relief treatment and maintaining the pressure in the wellbore at the state before stopping the pump. After holding the pressure for 2 minutes, the pressure drops rapidly, and it is judged that the full-bore sliding sleeve is open;

[0077] (6) Carry out fracturing construction.

[0078] In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," "outer," "left," "right," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is typically placed when in use, or are the orientations or positional relationships commonly understood by those skilled in the art. These terms are intended solely to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first," "second," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, terms such as "disposed" and "connected" should be understood broadly. For example, "connected" can mean a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection, an indirect connection through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

Claims

1. A method for judging and handling abnormal opening of a full-bore sliding sleeve, characterized in that: The following steps are involved: S1. Confirm the number of the full-bore sliding sleeve to be opened, select the corresponding chuck and soluble fracturing ball, and put them into the fracturing wellhead; S2. Calculate the volume from the full-bore sleeve to be opened to the wellhead, and use 1.15 times the calculated volume as the standard volume; S3. Open the well and pump at a rate of 3-4 m³ / min, recording the liquid volume and pressure during the pumping process; S4. If the pressure value recorded in S3 rises sharply and then falls back quickly, execute S6; otherwise, execute S5. S5. Analyze the liquid volume and pressure obtained during the pumping process to determine the type of resistance encountered and implement corresponding treatment methods; Analyzing and determining the type of obstruction and implementing the corresponding treatment method specifically includes the following steps: S51. When the pumped liquid volume recorded in S3 exceeds the standard volume in S2, and the pressure recorded in S3 does not change significantly, it is determined that the chuck in the full-bore sleeve opening abnormality is blocked or the chuck is replaced, and the next step is executed: S511: Increase the pumping capacity to 5-6 m³ / min and pump 0.7 standard volumes of liquid. Reduce the pumping capacity to 3-4 m³ / min and pump 0.3 standard volumes of liquid. During this process, if the pumping pressure meets the requirements of S4 or S52, execute the corresponding step and determine that the abnormality is caused by the chuck being blocked. Otherwise, execute S512. S512, perform agitation unblocking by using a method of rapid pressure relief and re-pressurization. After each agitation unblocking, use a displacement of 5-6 m³ / min to pump the first 0.7 standard volumes of liquid, and use a displacement of 3-4 m³ / min to pump the last 0.3 standard volumes of liquid. This step can be performed multiple times. During this process, if the pumping pressure meets the requirements of S4 or S52, execute the corresponding step and determine that the abnormality is the chuck encountering obstruction. Otherwise, execute S513. S513: Place a soluble fracturing ball into the wellbore and pump 0.7 standard volumes of liquid at a rate of 5-6 m³ / min. Pump 0.3 standard volumes of liquid at a rate of 3-4 m³ / min. If the pumping pressure during this process meets the requirements of S4 or S52, execute the corresponding step and determine that the abnormality is caused by the cartridge being blocked. Otherwise, execute S514. S514: Place a soluble fracturing ball into the wellbore and pump a standard volume of fluid at a rate of 5-6 m³ / min. If the pumping pressure meets the requirements of S4 or S52, execute the corresponding step and determine that the abnormality is caused by a cartridge blockage. Otherwise, execute S515. S515. Use coiled tubing with a mill shoe to detect the depth of the chuck and soluble fracturing ball, and perform corresponding treatment methods according to different locations: (1) The detection location of the cartridge and the soluble fracturing ball encountering resistance is within the fracturing wellhead, and it is determined that the wellhead encounters resistance in the cartridge; The treatment method is to pump 15% KCl or 15% HCl to dissolve the fracturing ball for 24 hours, and re-pump KCl or HCl every 4 hours. After 24 hours, use the coiled tubing with a straightening tool to straighten the chuck. After confirming that the chuck has entered the wellbore, drop a soluble fracturing ball and pump it. Then, perform S4, S51, or S52 according to the actual situation. (2) The detection location where the cartridge and soluble fracturing ball encounter resistance is below the fracturing wellhead and above the corresponding sliding sleeve location, which is considered to be the wellbore resistance in the cartridge resistance. The solution is to use coiled tubing to push the chuck and soluble fracturing ball downward. If the coiled tubing can push the chuck and soluble ball past the resistance point, execute S4, S51, or S52 according to the actual situation. At the same time, the fracturing mode of the wellbore from the next sliding sleeve position to the resistance point needs to be changed to the bridge plug and perforation staged mode. If the coiled tubing cannot push the chuck and soluble ball past the resistance point, drill and grind the soluble fracturing ball. At the same time, the fracturing mode of the wellbore from the sliding sleeve position to the resistance point needs to be changed to the bridge plug and perforation staged mode. (3) The detection position of the chuck and the soluble fracturing ball is below the corresponding sliding sleeve position, and it is judged that the chuck is pumped too far; The treatment method is: use coiled tubing to plug the hole in the fracturing section and then execute S6; S52: When the pressure recorded in S3 increases significantly and does not decrease within 5 minutes, it is determined that the sleeve does not open after the chuck is in place in the full-bore sleeve opening abnormality, and corresponding measures are implemented: S521: Unblock the jam by holding the pressure for less than 10 minutes or by quickly releasing the pressure or re-pressurizing the section. If the pressure drops significantly, proceed to S6. Otherwise, use coiled tubing to patch the hole in the section before proceeding to S6. S6. Perform fracturing construction.

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