Automatic monitoring and plugging device and plugging method for underground carbon dioxide leakage
By designing an automatic underground carbon dioxide leakage monitoring and occlusion device including packer, occluder, monitoring component and drive component, the carbon dioxide phase transition expansion problem caused by wellbore leakage is solved, real-time monitoring and rapid occlusion of the wellbore is achieved, and the safety and long-term effectiveness of geological storage are ensured.
Patent Information
- Application Number
- CN202510529873.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-25
- Publication Date
- 2025-06-13
AI Technical Summary
During the carbon dioxide geological storage process, wellbore leakage causes carbon dioxide phase transformation and expansion, which may cause a surge in the wellbore pressure, threatening the ground environment, equipment and personal safety. It is difficult for the existing technology to achieve real-time monitoring and automatic sealing.
Design an automatic monitoring and occlusion device for underground carbon dioxide leakage, including packer, occlusion device, monitoring component and drive component. The occluder cooperates with the slide chute to achieve automatic sealing during rotation and slipping; the monitoring component monitors the gas flow rate and carbon dioxide concentration in real time, and the driving component automatically drives the occluder to actively or passively seal according to the set threshold.
Real-time monitoring and rapid sealing of wellbore leakage is achieved, reducing the chance of major accidents, and ensuring the safety and long-term effectiveness of carbon dioxide geological storage.
Smart Images
Figure CN120139708A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of carbon dioxide geological storage, and in particular to an underground carbon dioxide leakage automatic monitoring and plugging device and a plugging method. Background Art
[0002] Carbon dioxide geological storage technology is a technology that captures carbon dioxide and injects it into deep underground geological structures for long-term storage, aiming to reduce greenhouse gases in the atmosphere and mitigate climate change. The wellbore is the core channel and key barrier of the carbon dioxide storage system, and its integrity directly determines the safety and long-term effectiveness of the storage project; in this context, the problem of carbon dioxide leakage along the wellbore during the geological storage period has become a research hotspot. Due to the low dynamic viscosity and high expansion characteristics of carbon dioxide, when the casing or plug is corroded and penetrated, if the carbon dioxide leakage situation cannot be detected in time at the underground plugging position, the carbon dioxide will phase change and expand in the wellbore and accumulate in the upper part of the wellbore. When the instantaneous leakage volume is too large, the wellbore pressure surges, which will cause significant harm to the ground environment, equipment and personal safety. Therefore, there is an urgent need for an underground carbon dioxide leakage automatic monitoring and plugging method at the carbon dioxide geological storage site to monitor carbon dioxide leakage events in real time and achieve automatic plugging in time, reducing the probability of major accidents. Summary of the Invention
[0003] In order to monitor carbon dioxide leakage events in real time and achieve automatic plugging in time, this application provides an underground carbon dioxide leakage automatic monitoring and plugging device and a plugging method.
[0004] An underground carbon dioxide leakage automatic monitoring and plugging device provided by this application adopts the following technical solutions: An underground carbon dioxide leakage automatic monitoring and plugging device, comprising: A packer fixedly arranged in the wellbore, a sliding hole is opened at the bottom of the packer, and the sliding hole is cylindrical; a first communication hole is opened at the top of the packer, one end of the first communication hole communicates with the sliding hole, and the other end communicates with the inside of the wellbore, and the first communication hole and the sliding hole are eccentrically arranged; at least two sliding grooves are opened on the inner side wall of the sliding hole of the packer, and the sliding grooves are inclined from bottom to top; A plugging device, which is cylindrical and slidably arranged in the sliding hole; a second communication hole is penetrated through the plugging device, and the axis of the second communication hole and the axis of the plugging device are not collinear; a plurality of ear racks are fixedly connected to the outside of the plugging device, and the ear racks are slidably arranged in the corresponding sliding grooves; when the ear rack is located at the bottom end of the sliding groove, the first communication hole and the second communication hole are communicated; when the ear rack is located at the top end of the sliding groove, the first communication hole and the second communication hole are not communicated, and the upper end surface of the plugging device abuts against the inner top wall of the sliding hole; A monitoring component for monitoring the gas flow rate and carbon dioxide concentration in the second communication hole; A driving component for driving the plug to rotate.
[0005] When the wellbore is in an unsealed state, the ear bracket is located at the bottom end of the chute, and there is a certain distance between the upper end face of the plug and the inner top wall of the sliding hole. At this time, the first communication hole, the sliding hole, and the second communication hole are all connected, making the inside and outside of the wellbore communicate; the monitoring component can monitor the gas flow rate and carbon dioxide concentration in the second communication hole.
[0006] When an external force drives the plug to rotate or slide vertically, the ear bracket slides along the inclined chute, causing the plug to slide along the sliding hole while rotating. When the ear bracket slides to the top end of the chute, the upper end face of the plug abuts against the inner top wall of the sliding hole. At this time, the first communication hole is not connected to the second communication hole, realizing the sealing of the wellbore.
[0007] The device provided by the present application has two modes: active sealing and passive sealing. Among them, the active sealing mode is applicable to the situation of a small amount of carbon dioxide leakage. At this time, the carbon dioxide concentration is greater than the set threshold, and the gas flow rate is not greater than the set threshold. The driving component drives the plug to rotate and slide upward along the sliding hole to realize the sealing of the wellbore; the passive sealing mode is applicable to the situation of a large amount of carbon dioxide leakage in a short time. At this time, the gas flow rate is greater than the set threshold, and the gas pressure in the wellbore pushes the plug to slide upward and rotate along the sliding hole to realize the sealing of the wellbore.
[0008] The device provided by the present application has a simple structure and fast response, and can realize the real-time disposal of wellbore leakage.
[0009] Further, the chute includes an inclined section and a horizontal section connected to the top end of the inclined section.
[0010] Further, a curved transition connection is adopted between the inclined section and the horizontal section.
[0011] When the plug rotates and the ear bracket slides along the chute to the top end of the inclined section, the upper end face of the plug abuts against the inner top wall of the sliding hole. Continuing to rotate the plug causes the ear bracket to slide to the horizontal section of the chute. At this time, the position of the ear bracket is locked, and the plug will not slide downward along the chute under its own gravity, thus realizing the locking of the plug.
[0012] When the plug slides upward and rotates along the sliding hole under the push of the gas pressure in the wellbore, the ear bracket slides along the chute to the top end of the inclined section. At this time, the rotation speed of the plug is not zero. Under the action of inertia, the plug continues to rotate, causing the ear bracket to slide to the horizontal section of the chute, realizing the locking of the plug; the curved transition connection between the inclined section and the horizontal section helps the ear bracket to slide smoothly from the inclined section to the horizontal section.
[0013] Further, the driving assembly includes a gear rotatably disposed on the packer and a driving member for driving the gear to rotate; a tooth groove engaged with the gear is provided on the outer side wall of the plug.
[0014] Further, the gear is a helical gear.
[0015] Driven by the driving member, the gear rotates, driving the plug to rotate and slide along the sliding hole; the rotation of the helical gear applies a vertical force to the plug, which is beneficial to the vertical movement of the plug.
[0016] Further, the driving assembly is located below the sliding groove.
[0017] The driving assembly is not on the moving path of the ear mount and will not interfere with the movement of the plug.
[0018] Further, the monitoring assembly includes a gas flow rate sensor and a carbon dioxide concentration sensor installed on the inner side wall of the second communication hole.
[0019] Further, the downhole carbon dioxide leakage automatic monitoring and plugging device is respectively arranged at different depth positions in the wellbore.
[0020] When the downhole carbon dioxide leakage automatic monitoring and plugging device at the deepest position in the wellbore is plugged and locked, other downhole carbon dioxide leakage automatic monitoring and plugging devices continuously monitor the carbon dioxide concentration and gas flow rate in the wellbore, and multiple downhole carbon dioxide leakage automatic monitoring and plugging devices can perform step-by-step plugging of the wellbore from bottom to top when carbon dioxide leaks.
[0021] The present application also provides a downhole carbon dioxide leakage automatic monitoring and plugging method, which uses a downhole carbon dioxide leakage automatic monitoring and plugging device. The plugging method includes the following steps: The monitoring assembly monitors the gas flow rate and carbon dioxide concentration in the second communication hole; When the carbon dioxide concentration is greater than the set threshold and the gas flow rate is not greater than the set threshold, the driving assembly drives the plug to rotate and slide upward along the sliding hole until the upper end face of the plug abuts against the inner top wall of the sliding hole. At this time, the first communication hole is not communicated with the second communication hole, and wellbore plugging is achieved; When the gas flow rate is greater than the set threshold, under the push of the gas pressure in the wellbore, the plug slides upward and rotates along the sliding hole until the upper end face of the plug abuts against the inner top wall of the sliding hole. At this time, the first communication hole is not communicated with the second communication hole, and wellbore plugging is achieved.
[0022] Further, it also includes the following steps: arranging a plurality of the downhole carbon dioxide leakage automatic monitoring and plugging devices at intervals along the wellbore depth direction, and performing step-by-step plugging of the wellbore from bottom to top when carbon dioxide leaks.
[0023] In summary, the present application includes the following beneficial technical effects: Through the cooperation of the earrest and the sliding groove, the plugging device can slide along the sliding hole while rotating. When the upper end surface of the plugging device abuts against the inner top wall of the sliding hole, the first communication hole and the second communication hole are not communicated, realizing the plugging of the wellbore. The device provided by the present application has two modes: active plugging and passive plugging. Among them, the active plugging mode is applicable to the situation of a small amount of carbon dioxide leakage, and the plugging device is driven to rotate by the driving component; the passive plugging mode is applicable to the situation of a large amount of carbon dioxide leakage in a short time, and the plugging device is driven to move upward by the gas pressure in the wellbore. The device provided by the present application has a simple structure and a fast response, and can realize the real-time disposal of wellbore leakage. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 is a schematic diagram of the overall structure of an embodiment of the present application, where (a) is the state where the wellbore is not plugged, and (b) is the state where the wellbore is plugged; Figure 2 is a schematic diagram of the unfolded structure of the inner wall surface of the sliding hole mainly used to show the sliding groove structure in an embodiment of the present application; Figure 3 is a schematic top view structure of the plugging device in an embodiment of the present application.
[0025] Reference numerals: 1, wellbore; 2, packer; 21, sliding hole; 22, first communication hole; 23, sliding groove; 231, inclined section; 232, horizontal section; 3, plugging device; 31, second communication hole; 32, earrest; 4, monitoring component; 41, gas flow rate sensor; 42, carbon dioxide concentration sensor; 5, driving component; 51, helical gear; 52, motor. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0026] The following will further describe the present application in detail Figures 1-3 with reference to the accompanying drawings.
[0027] An embodiment of the present application discloses an automatic monitoring and plugging device for underground carbon dioxide leakage. Referring to Figure 1 , the automatic monitoring and plugging device for underground carbon dioxide leakage includes a packer 2, a plugging device 3, a monitoring component 4, and a driving component 5.
[0028] Referring to Figure 1 , the packer 2 is fixedly arranged in the wellbore 1, and the outer side wall of the packer 2 is fixedly connected to the inner side wall of the wellbore 1. A sliding hole 21 is opened at the bottom of the packer 2, and the sliding hole 21 is cylindrical; a first communication hole 22 is opened at the top of the packer 2, one end of the first communication hole 22 communicates with the sliding hole 21, and the other end communicates with the inside of the wellbore 1. The aperture of the first communication hole 22 is smaller than the aperture of the sliding hole 21, and the first communication hole 22 and the sliding hole 21 are eccentrically arranged.
[0029] Reference Figure 2 , at least two sliding grooves 23 are formed on the inner side wall of the slip hole 21 of the packer 2, and the sliding grooves 23 are inclined from bottom to top. The sliding groove 23 includes an inclined section 231 and a horizontal section 232 connected to the top end of the inclined section 231, and a curved transition connection is adopted between the inclined section 231 and the horizontal section 232. In this embodiment, the number of the sliding grooves 23 is four.
[0030] Reference Figure 1 , the plug 3 is cylindrical and is slidably arranged in the slip hole 21. The plug 3 is provided with a second communication hole 31 penetrating therethrough. The aperture of the second communication hole 31 is the same as that of the first communication hole 22, and the axis of the second communication hole 31 is not collinear with the axis of the plug 3.
[0031] Reference Figure 1 and Figure 2 , a plurality of ear brackets 32 are fixedly connected to the outer side of the plug 3. In this embodiment, the number of the ear brackets 32 is four, and the four ear brackets 32 are evenly distributed on the outer peripheral side of the plug 3. Each ear bracket 32 is slidably arranged in the corresponding sliding groove 23.
[0032] Reference Figure 1 , the monitoring component 4 includes a gas flow rate sensor 41 and a carbon dioxide concentration sensor 42 installed on the inner side wall of the second communication hole 31, which are respectively used for monitoring the gas flow rate and carbon dioxide concentration in the second communication hole 31.
[0033] Reference Figure 1 and Figure 2 , the driving component 5 is arranged on the packer 2 and is located below the sliding groove 23 for driving the plug 3 to rotate. The driving component 5 includes a helical gear 51 rotatably arranged on the packer 2 and a driving member for driving the helical gear 51 to rotate. The driving member is a motor 52; a helical tooth groove meshing with the helical gear 51 is arranged on the outer side wall of the plug 3. In order to realize the automatic plugging of the wellbore 1, the motor 52 is controlledly connected to the gas flow rate sensor 41 and the carbon dioxide concentration sensor 42 through a controller.
[0034] When the wellbore 1 is in an unplugged state, as shown in (a) of Figure 1 , the ear bracket 32 is located at the bottom end of the sliding groove 23, and there is a certain distance between the upper end surface of the plug 3 and the inner top wall of the slip hole 21. At this time, the first communication hole 22, the slip hole 21, and the second communication hole 31 are all communicated, so that the inside and outside of the wellbore 1 are communicated; the monitoring component 4 can monitor the gas flow rate and carbon dioxide concentration in the second communication hole 31.
[0035] When the plug 3 is driven to rotate or slide vertically by an external force, the ear bracket 32 slides along the inclined section 231 of the sliding groove 23, so that the plug 3 slides along the slip hole 21 while rotating. When the ear bracket 32 slides to the top end of the inclined section 231 of the sliding groove 23, as shown inFigure 1 As shown in (b) therein, the upper end surface of the plugging device 3 abuts against the inner top wall of the sliding hole 21. At this time, the first communication hole 22 is not communicated with the second communication hole 31. Continuing to rotate the plugging device 3, the ear frame 32 slides to the horizontal section 232 of the sliding groove 23, and the position of the ear frame 32 is locked. The plugging device 3 will not slide down along the sliding groove 23 under its own gravity, thereby realizing the locking of the plugging device 3. During this process, the rotation angle of the plugging device 3 is 180°.
[0036] The device provided by this application has two modes: active plugging and passive plugging. Among them, the active plugging mode uses the driving assembly 5 to drive the plugging device 3 to rotate, which is suitable for the situation of a small amount of carbon dioxide leakage; the passive plugging mode uses the gas pressure in the wellbore 1 to drive the plugging device 3 to slide, which is suitable for the situation of a large amount of carbon dioxide leakage in a short time.
[0037] When the carbon dioxide concentration monitored by the carbon dioxide concentration sensor 42 is greater than the set threshold, and the gas flow rate monitored by the gas flow rate sensor 41 is not greater than the set threshold, the active plugging mode is started, and the controller controls the motor 52 to start. The gear drives the plugging device 3 to rotate and slide upward along the sliding hole 21 to realize the plugging of the wellbore 1.
[0038] In the passive plugging mode, the gas flow rate monitored by the gas flow rate sensor 41 is greater than the set threshold, and the gas pressure in the wellbore 1 can overcome the gravity of the plugging device 3, thereby pushing the plugging device 3 to slide upward and rotate along the sliding hole 21. During this process, the ear frame 32 slides along the sliding groove 23 to the top of the inclined section 231. At this time, the rotation speed of the plugging device 3 is not zero. Under the action of inertia, the plugging device 3 continues to rotate, causing the ear frame 32 to slide to the horizontal section 232 of the sliding groove 23, realizing the plugging of the wellbore 1 and the locking of the plugging device 3.
[0039] In order to reduce the friction between the ear frame 32 and the inclined section 231 of the sliding groove 23, the ear frame 32 is set to be cylindrical, and the inner wall of the inclined section 231 of the sliding groove 23 is smooth. In the passive plugging mode, if the air pressure in the wellbore 1 is too high, resulting in a large rotation speed of the plugging device 3, it is not easy for the ear frame 32 to decelerate in the horizontal section 232 of the sliding groove 23, which is not conducive to the locking of the plugging device 3. Therefore, the inner wall of the horizontal section 232 of the sliding groove 23 is set to be rough, that is, the friction coefficient of the inner wall of the horizontal section 232 is greater than the friction coefficient of the inner wall of the inclined section 231. Under the action of friction, the ear frame 32 is easy to decelerate in the horizontal section 232, so that the plugging device 3 stops rotating and locks its position.
[0040] The device provided by this application has a simple structure and fast response, and can realize the real-time disposal of the leakage of the wellbore 1.
[0041] To improve the reliability of the plugging of wellbore 1, downhole automatic monitoring and plugging devices for carbon dioxide leakage can be respectively arranged at different depth positions in wellbore 1. When the downhole automatic monitoring and plugging device at the deepest position in wellbore 1 is plugged and locked, other downhole automatic monitoring and plugging devices for carbon dioxide leakage continuously monitor the concentration and gas flow rate of carbon dioxide in wellbore 1, and multiple downhole automatic monitoring and plugging devices for carbon dioxide leakage can perform step-by-step plugging of wellbore 1 from bottom to top when carbon dioxide leaks.
[0042] This embodiment also provides a downhole automatic monitoring and plugging method for carbon dioxide leakage. Using the above-mentioned downhole automatic monitoring and plugging device, the plugging method includes the following steps: Step 1: After the well is sealed, reasonably arrange the installation points of the downhole automatic monitoring and plugging devices for carbon dioxide leakage according to the depth of wellbore 1. When necessary, multiple installation points can be arranged at intervals along the depth direction of wellbore 1.
[0043] Step 2: Assemble the packer 2, the plugging device 3, the monitoring component 4 and the driving component 5 into a downhole automatic monitoring and plugging device for carbon dioxide leakage and install it at the installation point in wellbore 1; in the initial state, the ear frame 32 is located at the bottom end of the sliding groove 23.
[0044] Step 3: The gas flow rate sensor 41 and the carbon dioxide concentration sensor 42 respectively perform real-time monitoring on the gas flow rate and carbon dioxide concentration in the second communication hole 31.
[0045] Step 4: According to the gas flow rate monitored by the gas flow rate sensor 41 and the carbon dioxide concentration monitored by the carbon dioxide concentration sensor 42, start the active plugging mode or the passive plugging mode, specifically as follows: Unplugged state: When the carbon dioxide concentration is not greater than the set threshold and the gas flow rate is not greater than the set threshold, the plugging device 3 remains stationary; Active plugging mode: When the carbon dioxide concentration is greater than the set threshold and the gas flow rate is not greater than the set threshold, the driving component 5 drives the plugging device 3 to rotate and slide upward along the sliding hole 21 until the upper end face of the plugging device 3 abuts against the inner top wall of the sliding hole 21. At this time, the first communication hole 22 is not connected to the second communication hole 31, and the plugging of wellbore 1 is realized; Passive plugging mode: When the gas flow rate is greater than the set threshold, under the push of the gas pressure in wellbore 1, the plugging device 3 slides upward and rotates along the sliding hole 21 until the upper end face of the plugging device 3 abuts against the inner top wall of the sliding hole 21. At this time, the first communication hole 22 is not connected to the second communication hole 31, and the plugging of wellbore 1 is realized.
[0046] Step 5: When the downhole carbon dioxide leakage automatic monitoring and plugging device located at the deepest position of the wellbore 1 is plugged and locked, other downhole carbon dioxide leakage automatic monitoring and plugging devices continuously monitor the concentration and gas flow rate of carbon dioxide in the wellbore 1, and multiple downhole carbon dioxide leakage automatic monitoring and plugging devices perform a step-by-step plugging of the wellbore 1 from bottom to top when carbon dioxide leaks.
[0047] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application shall be covered within the protection scope of the present application.
Claims
1. An automatic monitoring and plugging device for underground carbon dioxide leakage, characterized in that: include: The packer is fixedly arranged in the wellbore, and a sliding hole is provided at the bottom of the packer, and the sliding hole is cylindrical; a first connecting hole is provided at the top of the packer, and one end of the first connecting hole is connected to the sliding hole, and the other end is connected to the wellbore, and the first connecting hole and the sliding hole are eccentrically arranged; the packer is provided with at least two sliding grooves on the inner side wall of the sliding hole, and the sliding grooves are inclined from bottom to top; The occluder is cylindrical and slidably arranged in the sliding hole; the occluder is penetrated by a second communicating hole, and the axis of the second communicating hole is not colinear with the axis of the occluder; a plurality of ear frames are fixedly connected to the outer side of the occluder, and the ear frames are slidably arranged in the corresponding sliding grooves; when the ear frames are located at the bottom end of the sliding groove, the first communicating hole is connected with the second communicating hole; when the ear frames are located at the top end of the sliding groove, the first communicating hole is not connected with the second communicating hole, and the upper end surface of the occluder abuts against the inner top wall of the sliding hole; A monitoring component, used for monitoring the gas flow rate and carbon dioxide concentration in the second communicating hole; A driving assembly is used to drive the occluder to rotate.
2. The automatic monitoring and plugging device for underground carbon dioxide leakage according to claim 1 is characterized by: The slide groove comprises an inclined section and a horizontal section connected to the top end of the inclined section.
3. The automatic monitoring and plugging device for underground carbon dioxide leakage according to claim 2 is characterized in that: The inclined section and the horizontal section are connected by a curved transition.
4. The automatic monitoring and plugging device for underground carbon dioxide leakage according to claim 1 is characterized in that: The driving assembly comprises a gear rotatably arranged on the packer and a driving member for driving the gear to rotate; the outer side wall of the packer is provided with a tooth groove meshing with the gear.
5. The automatic monitoring and plugging device for underground carbon dioxide leakage according to claim 4 is characterized in that: The gear is a helical gear.
6. The automatic monitoring and plugging device for underground carbon dioxide leakage according to claim 4 is characterized by: The driving assembly is located below the slide slot.
7. The automatic monitoring and plugging device for underground carbon dioxide leakage according to claim 1 is characterized by: The monitoring component includes a gas flow rate sensor and a carbon dioxide concentration sensor installed on the inner side wall of the second connecting hole.
8. The automatic monitoring and plugging device for underground carbon dioxide leakage according to claim 1 is characterized by: The automatic monitoring and plugging devices for underground carbon dioxide leakage are respectively arranged at different depths in the wellbore.
9. A method for automatically monitoring and plugging underground carbon dioxide leakage, using an automatic monitoring and plugging device for underground carbon dioxide leakage according to any one of claims 1 to 8, characterized in that: The following steps are involved: The monitoring component monitors the gas flow rate and carbon dioxide concentration in the second connecting hole; When the carbon dioxide concentration is greater than the set threshold and the gas flow rate is not greater than the set threshold, the driving component drives the plug to rotate and slide upward along the sliding hole until the upper end surface of the plug abuts against the inner top wall of the sliding hole. At this time, the first connecting hole is not connected to the second connecting hole, and the wellbore is blocked; When the gas flow rate is greater than the set threshold, under the push of the gas pressure in the wellbore, the plugger slides upward and rotates along the sliding hole until the upper end surface of the plugger abuts against the inner top wall of the sliding hole. At this time, the first connecting hole and the second connecting hole are not connected, thereby achieving wellbore plugging.
10. The method for automatically monitoring and plugging underground carbon dioxide leakage according to claim 9, characterized in that: The method also includes the following steps: arranging a plurality of automatic monitoring and plugging devices for downhole carbon dioxide leakage at intervals along the depth direction of the wellbore, and performing step-by-step plugging of the wellbore from bottom to top when carbon dioxide leaks.