Carbon dioxide sealing system and method for underwater abandoned well

Abstract

The invention provides a carbon dioxide sealing system and method for an underwater abandoned well, and relates to the technical field of carbon capture and sealing. The carbon dioxide sealing and storing system comprises a floating platform and a carbon dioxide sealing and storing device, the floating platform is used for floating on the water surface, the carbon dioxide sealing and storing device is arranged on the floating platform and comprises a gas storage tank, a gas conveying pipe and a butt joint which are sequentially communicated, and the gas storage tank can store captured carbon dioxide; the butt joint can be in butt joint with a wellhead of an underwater abandoned well, and the gas conveying pipe can convey carbon dioxide in the gas storage tank into the abandoned well for sealing after the butt joint is in butt joint with the wellhead. On the basis, organic combination of the underwater abandoned well and carbon dioxide sequestration is achieved, integration of offshore oil exploration and carbon dioxide sequestration is achieved, emission of carbon dioxide can be reduced, development of the environmental protection cause can be promoted, the utilization rate of the underwater abandoned well can be increased, and the environmental burden of the offshore oil industry can be relieved.

Description

Technical Field

[0001] The present application relates to the technical field of carbon capture and storage, and in particular to a carbon dioxide storage system and method for abandoned underwater wells. Background Art

[0002] In recent years, with the depletion of offshore oil resources around the world, almost every country with offshore oil exploration capabilities has been actively conducting offshore oil exploration. In the relevant technology, when conducting offshore oil exploration, it is necessary to drill several exploration wells on the seabed of a certain exploration location to detect whether there is offshore oil at this exploration location through these exploration wells. If it is finally found that there is no offshore oil at this exploration location, then the drilled exploration wells will be abandoned and thus become abandoned wells. These abandoned wells cannot be effectively utilized, thereby increasing the environmental burden of the offshore oil industry. Summary of the invention

[0003] The present application provides a carbon dioxide storage system and method for underwater abandoned wells, aiming to solve the problem in the related art that abandoned wells left over from offshore oil exploration cannot be effectively utilized.

[0004] In order to solve the above-mentioned drawbacks existing in the related art, the first aspect of the present application provides a carbon dioxide storage system for underwater abandoned wells, including a floating platform and a carbon dioxide storage device, the floating platform is used to float on the water surface, the carbon dioxide storage device is arranged on the floating platform, the carbon dioxide storage device includes a gas storage tank, a gas pipeline and a docking joint with a receiving cavity, the docking joint also has a relative connection end and a receiving end, the receiving end is provided with a receiving port connected to the receiving cavity, the connection end is provided with a socket connected to the receiving cavity, the gas pipeline has a relative air inlet end and an exhaust end, the air inlet end is connected to the gas storage tank, and the exhaust end is inserted into the receiving cavity through the socket. Among them, the gas storage tank is used to store the carbon dioxide to be sealed; the docking joint is used to receive the wellhead of the underwater abandoned well through the receiving port when docking, and the receiving end is abutted against the ground around the wellhead; the air inlet end is used to lead out the carbon dioxide to be sealed in the gas storage tank; the exhaust end is used to insert the abandoned well through the wellhead after the docking joint is docked with the wellhead, so as to introduce the carbon dioxide to be sealed into the abandoned well.

[0005] In some implementation schemes, the carbon dioxide storage device also includes a nozzle, which is arranged on the exhaust end and connected to the gas pipe. The nozzle is used to inject the carbon dioxide to be sealed transported by the gas pipe into the abandoned well after the exhaust end is inserted into the abandoned well through the wellhead.

[0006] In some implementation schemes, the carbon dioxide storage device also includes a water pumping pipe, a water tank and a water pump all arranged on the floating platform, one end of the water pumping pipe is connected to the gas pipe, and the other end opposite is connected to the water tank through the water pump; the water pump is used to pump the water in the accommodating cavity into the water tank through the nozzle, the gas pipe and the water pumping pipe after the docking joint is docked with the wellhead, so that a pressure difference is formed inside and outside the docking joint, so as to utilize the pressure difference to press the docking joint tightly against the ground around the wellhead.

[0007] In some implementation schemes, the accommodating chamber includes an upper accommodating chamber, a middle accommodating chamber and a lower accommodating chamber. The upper accommodating chamber, the middle accommodating chamber and the lower accommodating chamber are arranged in sequence and spaced from each other along the direction from the connecting end to the receiving end. The socket is connected to the upper accommodating chamber, the exhaust end is inserted in the upper accommodating chamber through the socket, the middle accommodating chamber is connected to the upper accommodating chamber through the upper through hole, the middle accommodating chamber is connected to the lower accommodating chamber through the lower through hole, and the receiving port is connected to the lower accommodating chamber; the docking head is specifically used to accommodate the wellhead in the lower accommodating chamber through the receiving port when docking with the wellhead, and to align the wellhead with the lower through hole. Furthermore, the nozzle is a self-propelled nozzle, and the carbon dioxide storage device also includes a buffer guide, which has a through hole extending from one end to the other opposite end. The buffer guide is arranged in the middle accommodating chamber, and one end of the buffer guide abuts against the inner wall of the middle accommodating chamber with an upper through hole, and the other opposite end abuts against the inner wall of the middle accommodating chamber with a lower through hole. The two opposite openings of the through hole are respectively aligned and connected to the upper through hole and the lower through hole, and the through hole is used to connect the upper accommodating chamber with the lower accommodating chamber; the self-propelled nozzle is used to spray the carbon dioxide to be sealed transported by the gas pipe outward after the docking head is docked with the wellhead, so as to utilize the reaction force generated during the spraying to pass through the through hole into the lower accommodating chamber, and insert into the abandoned well through the wellhead, so as to spray the carbon dioxide to be sealed transported by the gas pipe into the abandoned well.

[0008] In some implementation schemes, the buffer guide includes a main body, a connecting column and a plug, one end of the connecting column is arranged on one end of the main body, and the plug is arranged on the other end of the connecting column. The main body is arranged in the middle accommodating cavity, the connecting column is arranged in the upper through hole, and the plug is arranged in the upper accommodating cavity. One end of the main body with the connecting column abuts against the inner wall of the middle accommodating cavity with the upper through hole, and the other end of the main body without the connecting column abuts against the inner wall of the middle accommodating cavity with the lower through hole, the side wall of the connecting column abuts against the hole wall of the upper through hole, and the side of the plug close to the main body abuts against the inner wall of the upper accommodating cavity with the upper through hole, and the two opposite orifices of the through hole are respectively located on the end of the plug away from the main body and on the end of the main body without the connecting column.

[0009] In some implementation schemes, the carbon dioxide storage device further includes a sealing ring, which is located between one end of the main body provided with a connecting column and the inner wall of the middle accommodating cavity provided with an upper through hole, and surrounds the connecting column.

[0010] In some implementation schemes, the carbon dioxide storage device also includes at least one buffer spring, which is located between one end of the main body with a connecting column and the inner wall of the middle accommodating chamber with an upper through hole, and its two ends respectively abut against one end of the main body with a connecting column and the inner wall of the middle accommodating chamber with an upper through hole.

[0011] In some implementation schemes, the thickness of the butt joint gradually decreases along the direction from the receiving end to the connecting end, and the shape of the accommodating cavity matches the shape of the butt joint.

[0012] In some implementations, the floating platform includes a vessel.

[0013] The second aspect of the present application provides a method for storing carbon dioxide in underwater abandoned wells, which is applied to the carbon dioxide storage system mentioned in the first aspect of the present application, including: inserting a docking joint and a gas pipe with one end arranged in the docking joint underwater; docking the docking joint with the wellhead of the underwater abandoned well, so that the wellhead is received in the docking joint through the receiving opening of the docking joint, and the end of the docking joint with the receiving opening is abutted against the ground around the wellhead; inserting one end of the gas pipe located in the docking joint into the abandoned well through the wellhead; and using the gas pipe to transport the carbon dioxide to be stored into the abandoned well.

[0014] The carbon dioxide storage system provided in the present application includes a floating platform for floating on the water surface and a carbon dioxide storage device arranged on the floating platform. The carbon dioxide storage device is composed of a gas pipeline, a gas storage tank for storing carbon dioxide and a docking joint with a receiving chamber. The docking joint has a relative connecting end and a receiving end. The receiving end is provided with a receiving port connected to the receiving chamber, and the connecting end is provided with a socket connected to the receiving chamber. The gas pipeline has a relative air inlet end and an exhaust end. The air inlet end is connected to the gas storage tank, and the exhaust end is inserted into the receiving chamber through the socket. The docking joint is used to receive the wellhead of an underwater abandoned well in the receiving chamber through the receiving port when docking with the wellhead, and to make the receiving end abut against the ground around the wellhead. The air inlet end is used to draw out the carbon dioxide in the gas storage tank. The exhaust end is used to insert into the abandoned well through the wellhead after the docking joint is docked with the wellhead, so as to introduce carbon dioxide into the abandoned well. It can be seen that the present application can transport carbon dioxide to underwater abandoned wells for storage, thus realizing the organic combination of underwater abandoned wells and carbon dioxide storage, and achieving the integration of marine oil exploration and carbon dioxide storage. It can not only reduce carbon dioxide emissions and promote the development of environmental protection, but also improve the utilization rate of underwater abandoned wells and reduce the environmental burden of the marine oil industry.

[0015] The carbon dioxide storage method provided in the present application is applied in the carbon dioxide storage system provided in the present application, that is, it is implemented based on the carbon dioxide storage system provided in the present application, so it has all the advantages of the carbon dioxide storage system provided in the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the related technologies or the embodiments of the present application, the drawings required for use in the description of the related technologies or the embodiments of the present application will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, not all embodiments. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A schematic diagram of the structure of a carbon dioxide storage system provided in an embodiment of the present application;

[0018] Figure 2 A cross-sectional view of a butt joint provided in an embodiment of the present application;

[0019] Figure 3 A schematic flow chart of the carbon dioxide storage method provided in an embodiment of the present application.

[0020] The symbols in the above drawings represent:

[0021] 100-floating platform, 200-carbon dioxide sealing device, 210-gas storage tank, 220-gas transmission pipe, 230-joint, 231-receiving port, 232-socket, 240-nozzle, 250-buffer guide, 251-main body, 252-connecting column, 253-plug, 260-sealing ring. DETAILED DESCRIPTION

[0022] In the related art, when conducting offshore oil exploration, it is necessary to drill several exploration wells on the seabed of a certain exploration location to detect whether there is offshore oil at this exploration location through these exploration wells. If it is finally found that there is no offshore oil at this exploration location, then these exploration wells drilled will be abandoned, thus becoming abandoned wells. These abandoned wells cannot be effectively utilized, thereby increasing the environmental burden of the offshore oil industry. In view of this, the present application proposes a carbon dioxide storage system and a corresponding carbon dioxide storage method for underwater abandoned wells in the following embodiments, which can seal carbon dioxide in underwater abandoned wells, realize the organic combination of underwater abandoned wells and carbon dioxide storage, and achieve the integration of offshore oil exploration and carbon dioxide storage, which can not only reduce carbon dioxide emissions and promote the development of environmental protection, but also improve the utilization rate of underwater abandoned wells and reduce the environmental burden of the offshore oil industry, thereby avoiding the above-mentioned disadvantages existing in the related art.

[0023] In order to make the purpose, technical solutions and advantages of the present application more obvious and easy to understand, the present application will be clearly and completely described below in conjunction with the embodiments of the present application and the corresponding drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. It should be understood that the embodiments of the present application described below are only used to explain the present application and are not used to limit the present application, that is, based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0024] See also Figure 1 , Figure 1 : is a structural schematic diagram of a carbon dioxide storage system. This embodiment provides a carbon dioxide storage system for an underwater abandoned well, which includes a floating platform 100 and a carbon dioxide storage device 200. The floating platform 100 is used to float on the water surface. The carbon dioxide storage device 200 is arranged on the floating platform 100. The carbon dioxide storage device 200 includes a gas storage tank 210, a gas pipeline 220, and a docking head 230 having a receiving cavity (not shown in the figure). The docking head 230 also has a relative connecting end and a receiving end. The receiving end is provided with a receiving port 231 connected to the receiving cavity, and the connecting end is provided with a socket 232 connected to the receiving cavity. The gas pipeline 220 has a relative air inlet end and an exhaust end. The air inlet end is connected to the gas storage tank 210, and the exhaust end is inserted into the receiving cavity through the socket 232 and is confined in the receiving cavity.

[0025] Specifically, the gas tank 210 is used to store the carbon dioxide to be sealed; the docking joint 230 is used to accommodate the wellhead in the accommodating cavity through the receiving port 231 when docking with the wellhead of the underwater abandoned well, and to make its own receiving end abut against the ground (i.e., the seabed) around the wellhead to surround the wellhead; the air inlet end of the gas transmission pipe 220 is used to lead out the carbon dioxide to be sealed in the gas tank 210; the exhaust end of the gas transmission pipe 220 is used to insert the abandoned well through the wellhead after the docking joint 230 is docked with the wellhead, so as to introduce the carbon dioxide to be sealed into the abandoned well. In other words, the gas tank 210 can store the carbon dioxide to be sealed, the docking joint 230 can dock with the wellhead of the underwater abandoned well, and the gas transmission pipe 220 can transport the carbon dioxide to be sealed in the gas tank 210 to the abandoned well for sealing after the docking joint 230 is docked with the wellhead.

[0026] In this embodiment, the floating platform 100 can be a truss structure that is above the water surface and has a horizontal surface (such as a deep-sea floating platform), or a ship (such as a deep-water floating ship). It can be set according to actual needs, and this application does not make a sole limitation on this; however, in order to improve the mobility of the carbon dioxide storage system and facilitate its movement between abandoned wells in different locations, the floating platform 100 is preferably a ship. The carbon dioxide to be stored in the gas tank 210 is not limited to the carbon dioxide captured on land, but also includes carbon dioxide in the exhaust gas discharged by the ship. It can be set according to actual needs, and this application does not make a sole limitation on this. The gas pipe 220 can be either a hose or a hard pipe. The gas pipe 220 can rely on equipment with exhaust functions such as a fan to transport the carbon dioxide to be sealed in the gas tank 210, or it can rely on the gravity of the carbon dioxide to be sealed itself. It can be set according to actual needs, and this application does not make a sole limitation on this. Preferably, when the gas pipeline 220 relies on the gravity of the carbon dioxide to be sealed in the gas storage tank 210, energy can be effectively saved. At this time, the gas storage tank 210 is a low-temperature gas storage tank, and the carbon dioxide to be sealed stored in the gas storage tank 210 is low-temperature supercritical carbon dioxide.

[0027] As can be seen from the above, this embodiment can transport carbon dioxide to underwater abandoned wells for storage, realize the organic combination of underwater abandoned wells and carbon dioxide storage, and achieve the integration of marine oil exploration and carbon dioxide storage, which can not only reduce carbon dioxide emissions and promote the development of environmental protection, but also improve the utilization rate of underwater abandoned wells and reduce the environmental burden of the marine oil industry. Moreover, the entire underwater part of the carbon dioxide storage system (i.e., the gas pipeline 220 and the docking joint 230) does not contain any electrical equipment, is simple to maintain, has good safety, strong applicability, and can also obtain better stability. In addition, it is also very convenient to extract the carbon dioxide sealed in the abandoned well when realizing carbon dioxide-related uses in the future.

[0028] In some embodiments, please combine Figure 2 , Figure 2 It is a cross-sectional view of the docking joint. In addition to the structure given above, the carbon dioxide storage device 200 also includes a nozzle 240. The nozzle 240 is located in the accommodating cavity of the docking joint 230. The nozzle 240 is arranged on the exhaust end of the gas pipeline 220 and is connected to the gas pipeline 220. Specifically, the nozzle 240 is used to inject the carbon dioxide to be stored transported by the gas pipeline 220 into the abandoned well after the exhaust end of the gas pipeline 220 is inserted into the abandoned well through the wellhead. On the one hand, it can ensure the sufficiency and uniformity of carbon dioxide storage, and on the other hand, it can speed up the progress of carbon dioxide storage, thereby improving the carbon dioxide storage efficiency.

[0029] In some embodiments, in addition to the structure given above, the carbon dioxide storage device 200 also includes a water tank (not shown), a water pump (not shown) and a water pump pipe (not shown). The water tank and the water pump are both arranged on the floating platform 100. One end of the water pump pipe is connected to the gas pipe 220, and the other end is connected to the water tank through the water pump. Specifically, the water pump is used to pump the water in the accommodating cavity into the water tank through the nozzle 240, the gas pipe 220 and the water pump pipe after the docking joint 230 is docked with the wellhead, so that a pressure difference is formed inside and outside the docking joint 230, so as to use this pressure difference to press the docking joint 230 against the ground around the wellhead, so as to improve the docking stability between the docking joint 230 and the wellhead of the abandoned well, and also prevent the docking joint 230 from shaking in the water, thereby affecting the delivery pipe 220 to transport the carbon dioxide to be sealed to the abandoned well. It can be understood that the nozzle 240 is used for both spraying the carbon dioxide to be sealed and absorbing the water in the accommodating cavity of the docking head 230 .

[0030] In some embodiments, see Figure 2 The receiving chamber of the docking joint 230 includes an upper receiving chamber, a middle receiving chamber and a lower receiving chamber. The upper receiving chamber, the middle receiving chamber and the lower receiving chamber are arranged in sequence and spaced from each other along the direction from the connecting end of the docking joint 230 to the receiving end. The socket 232 is connected to the upper receiving chamber. The exhaust end of the gas transmission pipe 220 is inserted in the upper receiving chamber through the socket 232. The middle receiving chamber is connected to the upper receiving chamber by opening an upper through hole. The middle receiving chamber is connected to the lower receiving chamber by opening a lower through hole. The receiving port 231 is connected to the lower receiving chamber. When the docking joint 230 is docked with the wellhead, the wellhead is received in the lower receiving chamber through the receiving port 231 and the wellhead is aligned with the lower through hole.

[0031] Furthermore, the nozzle 240 is a self-propelled nozzle. In addition to the structure given above, the carbon dioxide storage device 200 also includes a buffer guide 250. The buffer guide 250 has a through hole that runs from one end to the other end opposite to it. The buffer guide 250 is arranged in the middle accommodating chamber. One end of the buffer guide 250 abuts against the inner wall of the middle accommodating chamber with an upper through hole, and the other end opposite to it abuts against the inner wall of the middle accommodating chamber with a lower through hole. The two opposite openings of the through hole are respectively aligned and connected to the upper through hole and the lower through hole. The through hole is used to connect the upper accommodating chamber with the lower accommodating chamber. Specifically, the self-propelled nozzle is used to spray the carbon dioxide to be sealed transported by the gas pipe 220 outward after the docking joint 230 is docked with the wellhead, so as to use the reaction force generated during the spraying to make itself pass through the through hole of the buffer guide 250 into the lower accommodating chamber, and insert into the abandoned well through the wellhead, so as to spray the carbon dioxide to be sealed transported by the gas pipe 220 into the abandoned well.

[0032] As one embodiment, the self-propelled nozzle includes a nozzle (not shown), a propulsion mechanism (not shown), a connection structure (not shown) and a guide mechanism (not shown). The nozzle is the part where the carbon dioxide is ejected, and is usually designed to have a specific shape and size to control the ejection direction and flow rate of the carbon dioxide. It may be made of wear-resistant and corrosion-resistant materials to adapt to the physical and chemical properties of carbon dioxide and the working environment; the propulsion mechanism generally includes a spiral blade or a similar structure, and its function is to use the reaction force to generate a forward propulsion force when the carbon dioxide is ejected. The angle and shape of the spiral blade are carefully designed to ensure that the carbon dioxide is ejected. An effective propulsion effect can be produced under the action of flow; the connecting structure is used to connect the nozzle with the gas pipe 220 for transporting carbon dioxide to ensure a stable supply of carbon dioxide and fixation of the nozzle, and usually needs to have good sealing and pressure resistance to prevent carbon dioxide leakage; the guide mechanism can help the nozzle 240 maintain the correct direction to prevent it from deviating or shaking during the vertical downward transport of carbon dioxide. It may include some guide wheels, guide rails or other structures to ensure that the nozzle 240 can move stably along a predetermined path. For example, the buffer guide 250 described in this application can be used as a guide mechanism.

[0033] In this embodiment, when carbon dioxide enters the self-propelled nozzle through the gas pipe 220, due to the design of the nozzle, carbon dioxide will be ejected at a high speed, and according to Newton's third law, the ejected carbon dioxide will generate a force in the opposite direction, so in the case of vertically downward delivery of carbon dioxide, this reaction force will push the nozzle 240 to move downward, and eventually the nozzle 240 will pass through the through hole of the buffer guide 250 into the lower accommodating chamber and be inserted into the abandoned well through the wellhead. Specifically, when carbon dioxide is ejected from the nozzle, its high-speed flow will generate a rotating force and forward thrust on the spiral blade or the propulsion mechanism. The design of the spiral blade enables the flow of carbon dioxide to be converted into the forward power of the nozzle 240, and the guide mechanism will ensure that the nozzle 240 moves forward stably in the vertical direction without deviating from the predetermined path. It can be understood that the design of this self-propelled nozzle can realize automatic propulsion in the process of vertically downward delivery of carbon dioxide, improve work efficiency, reduce dependence on external power equipment, and can also more accurately control the delivery position and flow of carbon dioxide.

[0034] As one example, see Figure 2The buffer guide 250 includes a main body 251, a connecting column 252 and a plug 253, one end of the connecting column 252 is arranged on one end of the main body 251, and the plug 253 is arranged on the other end of the connecting column 252. The main body 251 is arranged in the middle accommodating cavity, the connecting column 252 is arranged in the upper through hole, and the plug 253 is arranged in the upper accommodating cavity. One end of the main body 251 provided with the connecting column 252 abuts against the inner wall of the middle accommodating cavity with the upper through hole, and the other end not provided with the connecting column 252 abuts against the inner wall of the middle accommodating cavity with the lower through hole. The side wall of the connecting column 252 abuts against the hole wall of the upper through hole, and the side of the plug 253 close to the main body 251 abuts against the inner wall of the upper accommodating cavity with the upper through hole. The two opposite orifices of the through hole are respectively located on the end of the plug 253 away from the main body 251 and the end of the main body 251 without the connecting column 252. In this embodiment, the main body 251, the connecting column 252 and the plug 253 can all be made of elastic materials commonly used in the art, such as rubber, foamed silicone, polyurethane (PU), etc., which can further improve the sealing between the three accommodating cavities.

[0035] As one example, see Figure 2 In addition to the structure given above, the carbon dioxide storage device 200 also includes a sealing ring 260 and at least one buffer spring (not shown). The sealing ring 260 is located between one end of the main body 251 provided with the connecting column 252 and the inner wall of the middle accommodating chamber provided with the upper through hole, and surrounds the connecting column 252. The buffer spring is located between one end of the main body 251 provided with the connecting column 252 and the inner wall of the middle accommodating chamber provided with the upper through hole. The opposite ends of the buffer spring are respectively abutted against one end of the main body 251 provided with the connecting column 252 and the inner wall of the middle accommodating chamber provided with the upper through hole. It can be understood that in this embodiment, the buffer spring and the sealing ring 260 are arranged between one end of the main body 251 provided with the connecting column 252 and the inner wall of the middle accommodating chamber provided with the upper through hole, which can effectively improve the buffering performance and sealing performance. Preferably, when the buffer spring includes multiple buffer springs, multiple buffer springs are arranged around the connecting column 252.

[0036] In some embodiments, see Figure 2, the butt joint 230 is trumpet-shaped, that is, the thickness of the butt joint 230 gradually decreases along the direction from the receiving end to the connecting end; correspondingly, the receiving cavity of the butt joint 230 is also trumpet-shaped, that is, the shape of the receiving cavity matches the shape of the butt joint 230. It can be understood that, under the premise that the receiving cavity of the butt joint 230 is trumpet-shaped, when the size of the wellhead of the abandoned well is large, after the wellhead is received in the receiving cavity of the butt joint 230, it will be located in the receiving cavity close to the receiving port 231, and when the size of the wellhead of the abandoned well is small, after the wellhead is received in the receiving cavity of the butt joint 230, it will be located in the receiving cavity far away from the receiving port 231, that is, the trumpet-shaped receiving cavity can make the butt joint 230 applicable to the wellheads of abandoned wells of different sizes, and has a wider range of applications.

[0037] See also Figure 3 , Figure 3 It is a flow chart of the carbon dioxide sequestration method. This embodiment provides a carbon dioxide sequestration method for underwater abandoned wells, which is applied to the carbon dioxide sequestration system described above, including the following steps 301 to 304 (abbreviated as S301 to S304), namely: S301, inserting the docking joint and the gas pipe with one end arranged in the docking joint underwater; S302, docking the docking joint with the wellhead of the underwater abandoned well, so that the wellhead is accommodated in the docking joint through the receiving opening of the docking joint, and the end of the docking joint with the receiving opening is abutted against the ground around the wellhead; S303, inserting one end of the gas pipe located in the docking joint through the wellhead into the abandoned well; S304, using the gas pipe to transport the carbon dioxide to be sealed into the abandoned well. It should be noted that for the incomplete description of the carbon dioxide storage method, such as extracting water from the accommodating chamber to form a pressure difference between the inside and outside of the docking joint 230 to press the docking joint 230 against the seabed, and the self-propelled nozzle self-propelling during the process of injecting carbon dioxide and inserting into an abandoned well through the wellhead, etc., please refer to the relevant description of the carbon dioxide storage system in the previous text, and the present application will not repeat them here.

[0038] The above embodiments are only preferred implementations of the present application, and are not the only limitations on the contents related to the carbon dioxide storage system and the carbon dioxide storage method; in this regard, those skilled in the art can flexibly set them according to the actual application scenarios based on the above embodiments. It can be understood that through the implementation of the above embodiments of the present application, the carbon dioxide storage system includes a floating platform 100 for floating on the water surface and a carbon dioxide storage device 200 arranged on the floating platform 100. The carbon dioxide storage device 200 is composed of a gas pipeline 220, a gas storage tank 210 for storing carbon dioxide, and a docking joint 230 with a accommodating chamber. The docking joint 230 has a relative connecting end and a receiving end. The receiving end is provided with a receiving port 231 connected to the accommodating chamber, and the connecting end is provided with a plug connected to the accommodating chamber. The gas pipe 220 has a relative air inlet end and an exhaust end, the air inlet end is connected to the gas storage tank 210, and the exhaust end is inserted into the accommodating cavity through the socket 232; wherein, the docking joint 230 is used to accommodate the wellhead in the accommodating cavity through the receiving port 231 when docking with the wellhead of the underwater abandoned well, and the receiving end is abutted against the ground around the wellhead; the air inlet end is used to lead out the carbon dioxide in the gas storage tank 210; the exhaust end is used to insert the abandoned well through the wellhead after the docking joint 230 is docked with the wellhead to introduce carbon dioxide into the abandoned well. It can be seen that the present application can transport carbon dioxide to the underwater abandoned well for sealing, realize the organic combination of underwater abandoned wells and carbon dioxide sealing, and achieve the integration of marine oil exploration and carbon dioxide sealing, which can not only reduce the emission of carbon dioxide and promote the development of environmental protection, but also improve the utilization rate of underwater abandoned wells and reduce the environmental burden of the marine oil industry. Moreover, the entire underwater part of the carbon dioxide storage system (i.e., the gas transmission pipe 220 and the docking joint 230) does not contain any electrical equipment, is easy to maintain, has good safety, strong applicability, and can also obtain better stability. In addition, it is also very convenient to extract the carbon dioxide stored in the abandoned well when realizing carbon dioxide related uses in the future.

[0039] It should be noted that the several embodiments shown in the present application are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can refer to each other. It should also be noted that in the text description of the present application, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is such an actual relationship or order between these entities or operations. Further, the terms "include", "comprise" or any other corresponding variants are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only these elements, but also other elements that are not explicitly listed, or may also include elements inherent to such process, method, article or equipment; and, in the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0040] In addition, by implementing the several embodiments shown above in the present application, professionals and technicians in this field can implement or use the present application. For the several embodiments shown above in the present application, various modifications will be obvious to professionals and technicians in this field, and the general principles defined in the present application can be implemented in other embodiments not shown without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the several embodiments shown above, but will comply with the widest range consistent with the principles and novel features disclosed in the present application.

Claims

1. A carbon dioxide storage system for an abandoned underwater well, characterized in that: The invention comprises a floating platform and a carbon dioxide storage device, wherein the floating platform is used to float on the water surface, the carbon dioxide storage device is arranged on the floating platform, the carbon dioxide storage device comprises a gas storage tank, a gas transmission pipe and a joint with a receiving cavity, the joint further comprises a connecting end and a receiving end opposite to each other, the receiving end is provided with a receiving port connected to the receiving cavity, the connecting end is provided with a socket connected to the receiving cavity, the gas transmission pipe has an opposite air inlet end and an air outlet end, the air inlet end is connected to the gas storage tank, and the air outlet end is inserted into the receiving cavity through the socket, wherein: The gas storage tank is used to store the carbon dioxide to be sealed; The docking joint is used to accommodate the wellhead of an abandoned well underwater, through the receiving opening, the wellhead is accommodated in the accommodating cavity, and the receiving end is abutted against the ground around the wellhead; The air inlet end is used to lead out the carbon dioxide to be sealed in the gas storage tank; The exhaust end is used to be inserted into the abandoned well through the wellhead after the docking head is docked with the wellhead, so as to introduce the carbon dioxide to be sealed into the abandoned well.

2. The carbon dioxide storage system according to claim 1, characterized in that: The carbon dioxide sealing device also includes a nozzle, which is arranged on the exhaust end and connected to the gas pipe, and is used to inject the carbon dioxide to be sealed transported by the gas pipe into the abandoned well after the exhaust end is inserted into the abandoned well through the wellhead.

3. The carbon dioxide storage system according to claim 2, characterized in that: The carbon dioxide storage device further comprises a water tank, a water pump and a water pumping pipe, wherein the water tank and the water pump are both arranged on the floating platform, one end of the water pumping pipe is connected to the gas transmission pipe, and the other end opposite thereto is connected to the water tank through the water pump; The water pump is used to pump the water in the accommodating chamber into the water tank through the nozzle, the air pipe and the water pumping pipe after the docking joint is docked with the wellhead, so as to form a pressure difference inside and outside the docking joint, so as to use the pressure difference to press the docking joint against the ground around the wellhead.

4. The carbon dioxide storage system according to claim 2, characterized in that: The accommodating chamber comprises an upper accommodating chamber, a middle accommodating chamber and a lower accommodating chamber, the upper accommodating chamber, the middle accommodating chamber and the lower accommodating chamber are sequentially arranged along the direction from the connecting end to the accommodating end and are spaced from each other, the socket is connected to the upper accommodating chamber, the exhaust end is inserted into the upper accommodating chamber through the socket, the middle accommodating chamber is connected to the upper accommodating chamber through an upper through hole, the middle accommodating chamber is connected to the lower accommodating chamber through a lower through hole, and the accommodating port is connected to the lower accommodating chamber; The docking head is specifically used to accommodate the wellhead in the lower accommodating cavity through the receiving opening when docking the wellhead, and to align the wellhead with the lower through hole; The nozzle is a self-propelled nozzle, and the carbon dioxide storage device further includes a buffer guide, the buffer guide has a through hole extending from one end to the other opposite end, the buffer guide is arranged in the middle accommodating chamber, one end of the buffer guide abuts against the inner wall of the middle accommodating chamber with the upper through hole, and the other opposite end abuts against the inner wall of the middle accommodating chamber with the lower through hole, the two opposite orifices of the through hole are respectively aligned and connected to the upper through hole and the lower through hole, and the through hole is used to connect the upper accommodating chamber with the lower accommodating chamber; The self-propelled nozzle is used to spray the carbon dioxide to be sealed transported by the gas pipe outward after the docking joint is docked with the wellhead, so as to utilize the reaction force generated during the spraying to allow itself to pass through the through hole into the lower accommodating chamber, and be inserted into the abandoned well through the wellhead, so as to spray the carbon dioxide to be sealed transported by the gas pipe into the abandoned well.

5. The carbon dioxide storage system according to claim 4, characterized in that: The buffer guide member includes a main body, a connecting column and a plug, one end of the connecting column is arranged on one end of the main body, and the plug is arranged on the other end of the connecting column, the main body is arranged in the middle accommodating cavity, the connecting column is arranged in the upper through hole, and the plug is arranged in the upper accommodating cavity, one end of the main body provided with the connecting column abuts against the inner wall of the middle accommodating cavity with the upper through hole, and the other end of the main body not provided with the connecting column abuts against the inner wall of the middle accommodating cavity with the lower through hole, the side wall of the connecting column abuts against the hole wall of the upper through hole, and the side of the plug close to the main body abuts against the inner wall of the upper accommodating cavity with the upper through hole, and the two opposite orifices of the through hole are respectively located on the end of the plug away from the main body and on the end of the main body without the connecting column.

6. The carbon dioxide storage system according to claim 5, characterized in that: The carbon dioxide storage device further includes a sealing ring, which is located between one end of the main body provided with the connecting column and the inner wall of the middle accommodating cavity provided with the upper through hole, and surrounds the connecting column.

7. The carbon dioxide storage system according to claim 5, characterized in that: The carbon dioxide storage device also includes at least one buffer spring, which is located between one end of the main body provided with the connecting column and the inner wall of the middle accommodating chamber provided with the upper through hole, and the opposite ends of the buffer spring respectively abut against one end of the main body provided with the connecting column and the inner wall of the middle accommodating chamber provided with the upper through hole.

8. The carbon dioxide storage system according to claim 1, characterized in that: The thickness of the butt joint gradually decreases along the direction from the receiving end to the connecting end, and the shape of the accommodating cavity matches the shape of the butt joint.

9. The carbon dioxide storage system according to claim 1, characterized in that: The floating platform comprises a ship.

10. A method for storing carbon dioxide in an abandoned underwater well, characterized in that: The carbon dioxide storage system according to any one of claims 1 to 9 comprises: Inserting the butt joint and a gas pipe with one end disposed in the butt joint underwater; The docking joint is docked with the wellhead of an underwater abandoned well, so that the wellhead is received in the docking joint through the receiving opening of the docking joint, and the end of the docking joint having the receiving opening is abutted against the ground around the wellhead; Inserting one end of the gas pipeline located in the docking joint into the abandoned well through the wellhead; The gas pipeline is used to transport the carbon dioxide to be sealed into the abandoned well.

Images