Emergency rescue method for out-of-control blowout of overwater wellhead of offshore platform

Abstract

The invention provides an emergency rescue method for out-of-control blowout of an offshore platform overwater wellhead, which comprises the following steps: based on a shallow water overwater wellhead and a platform, immediately starting rescue well preparation work after out-of-control blowout, and starting rescue well drilling operation at any time according to the actual site condition; the on-site actual situation is divided into blowout non-ignition and blowout ignition; when a well blowout does not catch fire, the following steps are carried out in sequence: step S1, investigating an accident well site; s2, evaluating the damage condition of the platform; s3, cleaning a well mouth; s4, establishing a new wellhead; s5, fluid pumping injection is carried out; step S6, the field accident is controlled; according to the shallow water overwater well control emergency disposal method, a whole set of shallow water overwater well control emergency disposal method including rescue well operation, an overwater well mouth disposal method, oil spill disposal and the like is formulated by combining the structural characteristics and the accident state of a shallow water accident platform, and a perfect overwater well mouth well control emergency disposal process aiming at different working conditions is formed.

Description

Technical Field

[0001] The invention belongs to the field of offshore well control and rescue, and in particular relates to a rescue method after a blowout at an above-water wellhead of an offshore platform goes out of control. Background Art

[0002] The ocean is rich in oil and gas resources. The development of offshore oil and gas has broad prospects, but also faces huge risks and challenges. In view of the potential risks of offshore oil and gas development, a set of well control and rescue methods suitable for domestic marine water wellheads is urgently needed. Invention content

[0003] In view of this, the invention aims to propose a rescue method after a blowout at an offshore platform wellhead is out of control, so as to provide a methodological basis for wellhead control and treatment after the accident, and fill the gap in domestic offshore well control rescue methods and technologies, by taking a series of measures and methods after a blowout accident occurs in the marine oil and gas production process.

[0004] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0005] A rescue method for an offshore platform after a blowout is out of control, based on a shallow water wellhead and platform, characterized in that the rescue well preparation work is immediately started after the blowout is out of control, and the rescue well drilling operation is started at any time according to the actual situation on site; the actual situation on site is divided into a blowout without fire and a blowout with fire; wherein, when a blowout without fire occurs, the following steps are implemented in sequence:

[0006] Step S1, investigation of the accident well site;

[0007] Step S2: Assess the damage to the platform, determine whether to use a rescue platform or a work support vessel, and take fire prevention measures;

[0008] Step S3, wellhead cleaning, using a safe and reliable working platform and tools to clean the accident wellhead; the order of the wellhead cleaning is: deck area clearance, derrick area clearance and Christmas tree deck clearance;

[0009] Step S4, establishing a new wellhead, and establishing a new wellhead to provide a channel for well pressure control;

[0010] Step S5: fluid pumping, implementing fluid pumping to achieve pressure balance in the well and control blowout;

[0011] Step S6: The on-site accident is under control and the handling is completed.

[0012] Furthermore, if any one of the steps S3-S5 fails, the operation directly proceeds to the rescue well drilling operation.

[0013] Furthermore, in step S1, the accident scene investigation method includes using helicopters, ships, drones and personnel on platforms to conduct long-distance and short-distance investigations, and the investigation is conducted according to the principles of safety first, long-distance first and short-distance later, and gradual progress.

[0014] Furthermore, in step S2, taking fire prevention measures includes the following methods:

[0015] Step S2.1, continuously injecting water from the drilling spool, casing spool or tubing spool to the wellhead, effectively reducing the concentration of natural gas mixed with the gushing oil and gas flow, reducing the probability of fire and explosion, and implementing a certain degree of suppression of the gushing oil and gas flow;

[0016] Step S2.2, use the fire-fighting ship water cannon, combined with the platform fire-fighting facilities and the fire-fighting module water cannon, adjust the water flow size, water mist system, water outlet angle, injection point and range, and implement spray protection operations for the emergency operation area, hazard source and the range with safety risks to achieve effective cooling, isolation and protection;

[0017] Step S2.3: If there are hazardous chemicals, pyrotechnic products, flammable and explosive items that need to be removed urgently, firefighting cooling protection should be implemented and the platform should be lifted off for disposal;

[0018] Step S2.4: If there are flammable, explosive, toxic or harmful gases on site, a high-power smoke exhaust fan should be deployed upwind in the fire safety area to reduce the risk of gas accumulation.

[0019] Furthermore, the method for cleaning the wellhead in step S3 includes using professional cleaning equipment and auxiliary tools to remove obstacles around the wellhead of the accident platform, fully expose the wellhead, and clear the rescue passage.

[0020] Furthermore, the method for establishing a new wellhead in step S4 includes selecting a new wellhead device according to the remaining platform structure, the wellhead structure and the condition after cleaning, determining a new wellhead establishment plan, and providing a pumping channel for subsequent well pressure control.

[0021] Furthermore, the method for implementing fluid pumping in step S5 includes evaluating the pressure condition in the accident wellbore, rationally selecting a fluid pumping scheme, making good material preparations, and optimizing the operation procedures.

[0022] Furthermore, when a blowout fire occurs, if the fire can be controlled and the accident platform is available, after fire-fighting and explosion-proofing operations are performed, steps S3 to S6 are implemented; when a blowout fire occurs, if the fire can be controlled but the accident platform is not available, a rescue platform is built or a work support vessel is used, and after fire-fighting and explosion-proofing operations are performed, steps S3 to S6 are implemented.

[0023] Furthermore, if a blowout fire occurs and the fire cannot be controlled, and the accident platform is available, then after fire extinguishing and explosion prevention operations are performed, steps S3 to S6 are implemented; if a blowout fire occurs and the fire cannot be controlled, and the accident platform is not available, it is necessary to build a rescue platform or rely on a work support vessel, and after fire extinguishing and explosion prevention operations are performed, steps S3 to S6 are implemented.

[0024] Furthermore, the fire extinguishing and explosion prevention operation includes the following steps:

[0025] Step A9.1, the fire brigade arrives at the scene, and further assesses the accident risk and firefighting capabilities based on the survey situation; confirms the fire, blowout, wellhead, blowout preventer group, derrick base, derrick and surrounding conditions, and demarcates the safe area based on the on-site wind direction and other information; confirms the status of the platform's firefighting equipment and the firefighting capabilities it has; determines the protection level based on the nature of the accident, and reasonably equips personal protective equipment;

[0026] Step A9.2: Before firefighting operations, organize a fire safety technical briefing meeting to clarify the firefighting objectives, firefighting plans, and entry and evacuation plans;

[0027] Step A9.3, firefighters board the platform and adjust the boarding and firefighting plans in time according to the wind direction, and choose to board the platform upwind of the platform away from the danger point;

[0028] Step A9.4, after the firefighters board the platform, they shall select a location far away from the wellhead and dangerous areas to set up a gathering point, check and confirm the firefighting route, the layout, position and placement of firefighting equipment and tools;

[0029] Step A9.5, continuously inject water into the wellhead from the drilling spool, casing spool or tubing spool to suppress the gushing oil and air flow.

[0030] Step A9.6: Multiple firefighting vessels are in position at the predetermined location and simultaneously activate their own safety protection systems.

[0031] Step A9.7, if conditions permit, the fire fighting module can be deployed on the platform: under the fire fighting cooling protection of the platform / ship, use the platform crane / floating crane to put the portable fire monitor, fire pump and fire meter in place, connect the water supply pipeline of the fire pump group, ensure that the equipment is in good condition and installed reliably, and ensure the safety of the working space and passage;

[0032] Step A9.8, use firefighting ship water cannons, combined with firefighting module water cannons, to adopt dense water flow method to extinguish fire. Large displacement directly shoots flames and fire columns, and suffocates fire by adjusting the water outlet angle of firefighting cannons. The main methods of cutting oil and gas flow are:

[0033] Step A9.9, adopt the method of layered parallel cutting: implement fire extinguishing by spraying water to the root of the blowout, and then move upward 1 to 2 meters every 30 to 60 seconds until the flame is separated from the airflow;

[0034] Step A9.10, extinguish the flame by using multiple layers of water flow, overlapping each other, and lifting upward without colliding with each other;

[0035] Step A9.11, if conditions permit, it is recommended to use the fire extinguishing method of covering the ignition tube with high-pressure dense water flow to cap the fire. Before extinguishing the fire, cover the ignition tube to concentrate and guide the bulk flames vertically upward. After the wellhead and the surrounding area are fully cooled, a large amount of direct water injection is then used to cap the top, instantly cutting the oil and gas flow to achieve suffocation extinguishing.

[0036] Step A9.12, if there are flammable, explosive, toxic or harmful gases on site, high-power smoke exhaust fans should be deployed upwind in the fire safety area to reduce the risk of gas accumulation, and fire cooling protection should be implemented at the wellhead throughout the process;

[0037] Step A9.13: If there are hazardous chemicals, pyrotechnic products, flammable and explosive items that need to be removed urgently, firefighting cooling protection should be implemented and the items should be removed from the platform for disposal.

[0038] Step A9.14, if the fire or explosion cannot be controlled, the fire cannon can be used to suppress the fire and cool it down. According to the fire and wind direction, the flames can be pressed to one side, and a breakthrough point can be selected for rescue. Under the premise of ensuring the safety of the operation, the whole process of fire operation and well closing method can be adopted to achieve the purpose of fire extinguishing. That is, by installing a new wellhead with fire, and then implementing the well closing procedure.

[0039] Compared with the prior art, the rescue method after an out-of-control blowout at the wellhead of an offshore platform created by the present invention has the following advantages:

[0040] The emergency rescue method created by the present invention combines the structural characteristics of the shallow water accident platform and the accident status to formulate a complete set of shallow water well control emergency disposal methods including rescue well operations, surface wellhead disposal methods, oil spill disposal, etc., forming a complete surface wellhead well control emergency disposal process for different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0042] Figure 1 A flowchart of the steps in the case of a blowout without fire as described in Embodiment 1 of the present invention;

[0043] Figure 2The present invention creates a flowchart of the emergency rescue method after a blowout at an above-water wellhead of an offshore platform as described in Example 2 of the present invention. DETAILED DESCRIPTION

[0044] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0045] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0046] like Figure 1 As shown, a rescue method after a blowout at an offshore platform wellhead is out of control. Based on a shallow water wellhead and platform, the rescue well preparation work is immediately started after the blowout is out of control, that is, after an A1 well control accident or an A4 platform blowout is out of control, the A2 rescue well preparation work is immediately carried out; the A3 rescue well drilling operation is started at any time according to the actual situation on site; the actual situation on site is divided into a blowout without fire and a blowout with fire, that is, it is determined whether the A6 well blowout is on fire; wherein, when a blowout without fire occurs, the following steps are performed in sequence:

[0047] Step S1, investigation of the accident well site;

[0048] Step S2: Assess the damage to the platform, determine whether to use a rescue platform or a work support vessel, and take fire prevention measures;

[0049] Step S3, wellhead cleaning, using a safe and reliable working platform and tools to clean the accident wellhead; the order of the wellhead cleaning is: deck area clearance, derrick area clearance and Christmas tree deck clearance;

[0050] Step S4, establishing a new wellhead, and establishing a new wellhead to provide a channel for well pressure control;

[0051] Step S5: fluid pumping, implementing fluid pumping to achieve pressure balance in the well and control blowout;

[0052] Step S6: The on-site accident is under control and the handling is completed.

[0053] Furthermore, if any one of the steps S3-S5 fails, the drilling operation of the A4 rescue well is directly transferred to the drilling operation.

[0054] Furthermore, in step S1, the accident scene investigation method includes using helicopters, ships, drones and personnel on platforms to conduct long-distance and short-distance investigations, and the investigation is conducted according to the principles of safety first, long-distance first and short-distance later, and gradual progress.

[0055] Furthermore, in step S2, taking fire prevention measures includes the following methods:

[0056] Step S2.1, continuously injecting water from the drilling spool, casing spool or tubing spool to the wellhead, effectively reducing the concentration of natural gas mixed with the gushing oil and gas flow, reducing the probability of fire and explosion, and implementing a certain degree of suppression of the gushing oil and gas flow;

[0057] Step S2.2, use the fire-fighting ship water cannon, combined with the platform fire-fighting facilities and the fire-fighting module water cannon, adjust the water flow size, water mist system, water outlet angle, injection point and range, and implement spray protection operations for the emergency operation area, hazard source and the range with safety risks to achieve effective cooling, isolation and protection;

[0058] Step S2.3: If there are hazardous chemicals, pyrotechnic products, flammable and explosive items that need to be removed urgently, firefighting cooling protection should be implemented and the platform should be lifted off for disposal;

[0059] Step S2.4: If there are flammable, explosive, toxic or harmful gases on site, a high-power smoke exhaust fan should be deployed upwind in the fire safety area to reduce the risk of gas accumulation.

[0060] Furthermore, the method for cleaning the wellhead in step S3 includes using professional cleaning equipment and auxiliary tools to remove obstacles around the wellhead of the accident platform, fully expose the wellhead, and clear the rescue passage.

[0061] Furthermore, the method for establishing a new wellhead in step S4 includes selecting a new wellhead device and determining a new wellhead establishment plan based on the remaining platform structure, the wellhead structure and the condition after cleaning, so as to provide a pumping channel for subsequent well pressure control.

[0062] Furthermore, the method for implementing fluid pumping in step S5 includes evaluating the pressure condition in the accident wellbore, rationally selecting a fluid pumping scheme, making good material preparations, and optimizing the operation procedures.

[0063] like Figure 2 As shown, when a blowout fire occurs, that is, when it is judged that A6 well blowout fire is yes; and A7 fire control can be obtained, that is, A7 fire control is judged to be yes; and A8 accident platform is available, that is, A8 accident platform is judged to be available as yes, then after A9 fire extinguishing and explosion prevention operations are performed, steps S3 to S6 are implemented; when a blowout fire occurs, that is, when it is judged that A6 well blowout fire is yes; and fire control can be obtained, that is, A7 fire control is judged to be yes; but A8 accident platform is not available, that is, A8 accident platform is judged to be no, then A10 builds a rescue platform or relies on a work support vessel, and after A9 fire extinguishing and explosion prevention operations are performed, steps S3 to S6 are implemented.

[0064] like Figure 2As shown, if a blowout fire occurs, that is, when it is judged that A6 well blowout fire is yes; and the fire cannot be controlled, that is, it is judged that A7 fire control is no; and the accident platform is available, that is, it is judged that A8 accident platform is available is yes, then after A9 fire extinguishing and explosion prevention operations are performed, steps S3 to S6 are implemented; if a blowout fire occurs, that is, when it is judged that A6 well blowout fire is yes; the fire cannot be controlled, that is, it is judged that A7 fire control is no; and the accident platform is unavailable, that is, it is judged that A8 accident platform is available is no, then it is necessary to build a rescue platform or rely on a work support ship, and after fire extinguishing and explosion prevention operations are performed, steps S3 to S6 are implemented.

[0065] Furthermore, the fire extinguishing and explosion prevention operation includes the following steps:

[0066] Step A9.1, the fire brigade arrives at the scene, and based on the survey, further assesses the accident risk, evaluates the firefighting capabilities, and improves the "Firefighting Operation Procedures"; confirms the fire, blowout, wellhead, blowout preventer group, derrick base, derrick and surrounding conditions, and demarcates the safe area based on the on-site wind direction and other information; confirms the status of the platform's firefighting equipment and the firefighting capabilities it has; determines the protection level based on the nature of the accident, and reasonably equips personal protective equipment;

[0067] Step A9.2: Before firefighting operations, organize a fire safety technical briefing meeting to clarify the firefighting objectives, firefighting plans, and entry and evacuation plans;

[0068] Step A9.3, firefighters board the platform and adjust the boarding and firefighting plans in time according to the wind direction, and choose to board the platform upwind of the platform away from the danger point;

[0069] Step A9.4, after the firefighters board the platform, they shall select a location far away from the wellhead and dangerous areas to set up a gathering point, check and confirm the firefighting route, the layout, position and placement of firefighting equipment and tools;

[0070] Step A9.5, continuously inject water into the wellhead from the drilling spool, casing spool or tubing spool to suppress the gushing oil and air flow.

[0071] Step A9.6: Multiple firefighting vessels are in position at the predetermined location and simultaneously activate their own safety protection systems.

[0072] Step A9.7, if conditions permit, the fire fighting module can be deployed on the platform: under the fire fighting cooling protection of the platform / ship, use the platform crane / floating crane to put the portable fire monitor, fire pump and fire meter in place, connect the water supply pipeline of the fire pump group, ensure that the equipment is in good condition and installed reliably, and ensure the safety of the working space and passage;

[0073] Step A9.8, use firefighting ship water cannons, combined with firefighting module water cannons, to adopt dense water flow method to extinguish fire. Large displacement directly shoots flames and fire columns, and suffocates fire by adjusting the water outlet angle of firefighting cannons. The main methods of cutting oil and gas flow are:

[0074] Step A9.9, adopt the method of layered parallel cutting: implement fire extinguishing by spraying water to the root of the blowout, and then move upward 1 to 2 meters every 30 to 60 seconds until the flame is separated from the airflow;

[0075] Step A9.10, extinguish the flame by using a multi-layer water flow, overlapping layers, and lifting upward without colliding with each other; the specific method is: inject water flow into the wellhead natural gas flow in two steps: first, inject two streams of water into the unignited part of the blowout until the flame is extinguished, and the remaining water flow is synchronously moved from bottom to top as in the first method, moving to the edge of the flame, reducing the height of the flame and reducing the radiant heat;

[0076] Step A9.11, if conditions permit, it is recommended to use the fire extinguishing method of covering the ignition tube with high-pressure dense water flow to cap the fire. Before extinguishing the fire, cover the ignition tube to concentrate and guide the bulk flames vertically upward. After the wellhead and the surrounding area are fully cooled, a large amount of direct water injection is then used to cap the top, instantly cutting the oil and gas flow to achieve suffocation extinguishing.

[0077] Step A9.12, if there are flammable, explosive, toxic or harmful gases on site, high-power smoke exhaust fans should be deployed upwind in the fire safety area to reduce the risk of gas accumulation, and fire cooling protection should be implemented at the wellhead throughout the process;

[0078] Step A9.13: If there are hazardous chemicals, pyrotechnic products, flammable and explosive items that need to be removed urgently, firefighting cooling protection should be implemented and the items should be removed from the platform for disposal.

[0079] Step A9.14, if the fire or explosion cannot be controlled, the fire cannon can be used to suppress the fire and cool it down. According to the fire and wind direction, the flames can be pressed to one side, and a breakthrough point can be selected for rescue. Under the premise of ensuring the safety of the operation, the whole process of fire operation and well closing method can be adopted to achieve the purpose of fire extinguishing. That is, by installing a new wellhead with fire, and then implementing the well closing procedure.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A rescue method for an offshore platform after a blowout at an above-water wellhead is out of control, based on a shallow above-water wellhead and platform, characterized in that: Immediately after a blowout goes out of control, rescue well preparation work is started, and rescue well drilling operations are started at any time according to the actual situation on site; the actual situation on site is divided into blowout without fire and blowout with fire; among them, when a blowout without fire occurs, the following steps are implemented in order: Step S1, investigation of the accident well site; Step S2: Assess the damage to the platform, determine whether to use a rescue platform or a work support vessel, and take fire prevention measures; Step S3, wellhead cleaning, using a safe and reliable working platform and tools to clean the accident wellhead; the order of the wellhead cleaning is: deck area clearance, derrick area clearance and Christmas tree deck clearance; Step S4, establishing a new wellhead, and establishing a new wellhead to provide a channel for well pressure control; Step S5: fluid pumping, implementing fluid pumping to achieve pressure balance in the well and control blowout; Step S6: The on-site accident is under control and the handling is completed.

2. The emergency rescue method after a blowout at an offshore platform wellhead according to claim 1 is characterized in that: If any of the steps S3-S5 fails, the drilling operation of the rescue well is directly started.

3. The method for rescuing an out-of-control blowout at an offshore platform wellhead according to claim 1, characterized in that: In step S1, the accident scene investigation method includes using helicopters, ships, drones and personnel on platforms to conduct long-distance and short-distance investigations, and the investigation is conducted according to the principles of safety first, long-distance first and then short-distance, and gradual progress.

4. The emergency rescue method after a blowout at an offshore platform wellhead according to claim 1 is characterized in that: In step S2, taking fire prevention measures includes the following methods: Step S2.1, continuously injecting water from the drilling spool, casing spool or tubing spool to the wellhead, effectively reducing the concentration of natural gas mixed with the gushing oil and gas flow, reducing the probability of fire and explosion, and implementing a certain degree of suppression of the gushing oil and gas flow; Step S2.2, use the fire-fighting ship water cannon, combined with the platform fire-fighting facilities and the fire-fighting module water cannon, adjust the water flow size, water mist system, water outlet angle, injection point and range, and implement spray protection operations for the emergency operation area, hazard source and the range with safety risks to achieve effective cooling, isolation and protection; Step S2.3: If there are hazardous chemicals, pyrotechnic products, flammable and explosive items that need to be removed urgently, firefighting cooling protection should be implemented and the platform should be lifted off for disposal; Step S2.4: If there are flammable, explosive, toxic or harmful gases on site, a high-power smoke exhaust fan should be deployed upwind in the fire safety area to reduce the risk of gas accumulation.

5. The method for rescuing an offshore platform wellhead blowout after it is out of control according to claim 1, characterized in that: The method for cleaning the wellhead in step S3 includes using professional cleaning equipment and auxiliary tools to remove obstacles around the wellhead of the accident platform, fully expose the wellhead, and clear the rescue passage.

6. The method for rescuing an uncontrolled blowout at an offshore platform wellhead according to claim 1, characterized in that: The method for establishing a new wellhead in step S4 includes selecting a new wellhead device according to the remaining platform structure, the wellhead structure and the condition after cleaning, determining a new wellhead establishment plan, and providing a pumping channel for subsequent well pressure control.

7. The method for rescuing an offshore platform wellhead blowout after it is out of control according to claim 1, characterized in that: The method for implementing fluid pumping in step S5 includes evaluating the pressure condition in the accident wellbore, reasonably selecting a fluid pumping scheme, making good material preparations, and optimizing the operation procedures.

8. The method for rescuing an offshore platform wellhead blowout after it is out of control according to claim 1, characterized in that: When a blowout fire occurs, if the fire can be controlled and the accident platform is available, then after fire-fighting and explosion-proofing operations are performed, steps S3 to S6 are implemented; when a blowout fire occurs, if the fire can be controlled but the accident platform is not available, then a rescue platform is built or a work support vessel is used, and after fire-fighting and explosion-proofing operations are performed, steps S3 to S6 are implemented.

9. The method for rescuing an offshore platform wellhead blowout after it is out of control according to claim 1, characterized in that: If a blowout fire occurs and the fire cannot be controlled, and the accident platform is available, then after fire extinguishing and explosion prevention operations are performed, steps S3 to S6 are implemented; if a blowout fire occurs and the fire cannot be controlled, and the accident platform is not available, it is necessary to build a rescue platform or rely on a work support vessel, and after fire extinguishing and explosion prevention operations are performed, steps S3 to S6 are implemented.

10. The method for rescuing an offshore platform from an uncontrolled blowout at a wellhead according to any one of claims 8 to 9, characterized in that: The fire extinguishing and explosion-proof operation comprises the following steps: Step A9.1, the fire brigade arrives at the scene, and further assesses the accident risk and firefighting capabilities based on the survey situation; confirms the fire, blowout, wellhead, blowout preventer group, derrick base, derrick and surrounding conditions, and demarcates the safe area based on the on-site wind direction and other information; confirms the status of the platform's firefighting equipment and the firefighting capabilities it has; determines the protection level based on the nature of the accident, and reasonably equips personal protective equipment; Step A9.2: Before firefighting operations, organize a fire safety technical briefing meeting to clarify the firefighting objectives, firefighting plans, and entry and evacuation plans; Step A9.3, firefighters board the platform, adjust the boarding and firefighting plans in time according to the wind direction, and choose to board the platform upwind of the platform away from the danger point; Step A9.4, after the firefighters board the platform, they shall select a location far away from the wellhead and dangerous areas to set up a gathering point, check and confirm the firefighting route, the layout, position and placement of firefighting equipment and tools; Step A9.5, continuously injecting water from the drilling spool, casing spool or tubing spool into the wellhead to suppress the gushing oil and air flow; Step A9.6, multiple firefighting vessels are in place at the predetermined locations and simultaneously activate their own safety protection systems; Step A9.7, if conditions permit, the fire fighting module can be deployed on the platform: under the fire fighting cooling protection of the platform / ship, use the platform crane / floating crane to put the portable fire monitor, fire pump and fire meter in place, connect the water supply pipeline of the fire pump group, ensure that the equipment is in good condition and installed reliably, and ensure the safety of the working space and passage; Step A9.8, use firefighting ship water cannons, combined with firefighting module water cannons, to adopt dense water flow method to extinguish fire; large-volume direct flames and fire columns, and suffocate fire by adjusting the water outlet angle of the firefighting cannon; the main methods of cutting oil and gas flow are: Step A9.9, adopt the layered parallel cutting method: implement fire extinguishing by spraying water to the root of the blowout, and then move upward 1 to 2 meters every 30 to 60 seconds until the flame is separated from the airflow; Step A9.10, extinguish the flame by using multiple layers of water flow, overlapping each other, and lifting upward without colliding with each other; Step A9.11: If conditions permit, it is recommended to use the fire extinguishing method of covering the ignition tube with high-pressure dense water flow to extinguish the fire. Before extinguishing the fire, cover the ignition tube to guide the loose flames vertically upward. After the wellhead and the surrounding area are fully cooled, a large amount of direct water injection is then used to cover the top, instantly cutting the oil and gas flow to achieve suffocation extinguishing; Step A9.12, if there are flammable, explosive, toxic or harmful gases on site, high-power smoke exhaust fans should be deployed upwind in the fire safety area to reduce the risk of gas accumulation, and fire cooling protection should be implemented at the wellhead throughout the process; Step A9.13: If there are hazardous chemicals, pyrotechnic products, flammable and explosive items that need to be removed urgently, firefighting cooling protection should be implemented and the platform should be lifted off for disposal; Step A9.14, if the fire or explosion cannot be controlled, the fire cannon can be used to suppress the fire and cool it down. According to the fire and wind direction, the flames can be pressed to one side, and a breakthrough point can be selected for rescue. Under the premise of ensuring the safety of the operation, the whole process of fire operation and well closing method can be adopted to achieve the purpose of fire extinguishing. That is, by installing a new wellhead with fire, and then implementing the well closing procedure.

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