A carbon dioxide sequestration well completion device and method

Abstract

The present invention belongs to the technical field of carbon dioxide capture and storage, and discloses a completion device and method for a carbon dioxide storage well. The completion device for the carbon dioxide storage well includes a casing, a tubing string, a sand control screen pipe, a tubing hanger, a safety valve, a circulation sliding sleeve and a check valve. This completion device for the carbon dioxide storage well can effectively solve the problems of scaling, leakage and sand production faced by the carbon dioxide reinjection storage well. During the injection stop process, the check valve can automatically close to prevent backflow, and the sand control screen pipe can automatically block solid particles from the formation. It can realize the functions of injecting chemical agents for plugging removal in the forward direction and reverse circulation well flushing of the upper pipe string, and can meet the functional requirements of plugging removal, scaling prevention, etc. during the long-term injection process of carbon dioxide reinjection wells in offshore oilfields, further improving the operation safety. The above device is used in the completion method for the carbon dioxide storage well, which can complete carbon dioxide injection, chemical agent plugging removal and well flushing operations, improving the efficiency and safety of the reinjection operation of the carbon dioxide reinjection well.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide capture and storage, and particularly to a completion device and method for a carbon dioxide storage well. Background Art

[0002] Carbon capture, utilization and storage is one of the key technologies to address global warming, and it is a necessary technology for the development of various countries. Currently, it has received great attention from countries around the world and has developed rapidly worldwide in recent years. Carbon capture, utilization and storage technology is one of the effective measures for disposing of carbon dioxide and is also an important option for realizing the low-carbon utilization of fossil energy. The saline aquifer in offshore oilfields is a preferred storage method for carbon dioxide due to its wide distribution area, large thickness, huge storage capacity and high safety.

[0003] Since a large amount of carbon dioxide is produced during the exploitation of offshore oil and gas fields, according to the requirements of safe, environmental protection and efficient development of offshore oilfields, it is necessary to seal and reinject the produced carbon dioxide. During the implementation of offshore oilfield carbon dioxide reinjection projects, there are characteristics such as high equipment integration, high requirements for safety and functionality. Technical risks such as scaling of the completion string, carbon dioxide leakage, and formation sand production exist during the operation. Improving the safety of the reinjection operation of carbon dioxide reinjection wells in offshore oilfields and the long-term effectiveness of the completion string is the first technical problem to be solved in the completion process. Summary of the Invention

[0004] The purpose of the present invention is to provide a completion device and method for a carbon dioxide storage well, which is beneficial to improving the efficiency and safety of the reinjection operation of carbon dioxide reinjection wells.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] In the first aspect, a completion device for a carbon dioxide storage well is provided, including:

[0007] A casing, with a perforated wellbore section provided at the end of the casing;

[0008] A tubing, passing through the casing, and a perforating pipe is correspondingly provided at the end of the tubing. Injection holes are evenly opened on the outer periphery of the perforating pipe;

[0009] A sand control screen pipe, sleeved outside the perforating pipe. One end of the sand control screen pipe is provided with a hanging packer, and the other end is installed with a blind plug. The hanging packer is located at the front end of the perforated wellbore section, anchored and sealed with the casing;

[0010] A tubing hanger, installed in the casing and connected to the head end of the tubing;

[0011] A safety valve, communicated with the tubing and placed below the tubing hanger;

[0012] A circulating sleeve, which is communicated with the tubing and is disposed below the safety valve. A circulation hole is provided on the side wall of the circulating sleeve;

[0013] A check valve, which is communicated with the tubing and is disposed below the circulating sleeve. The check valve is configured to conduct from top to bottom;

[0014] In the injection state, the safety valve is in an open state, the circulation hole is in a closed state, and carbon dioxide or chemical fluid can sequentially pass through the safety valve, the circulating sleeve, the check valve, the perforating pipe, the sand control screen pipe and the perforated wellbore section and enter the formation;

[0015] In the well flushing state, the circulation hole is in a conducting state, and the well flushing fluid flows in through the annular space formed by the casing and the tubing, and can enter the tubing through the circulation hole to clean the inner wall of the tubing.

[0016] Optionally, it further includes a monitoring component. The monitoring component includes a pressure sensing device, and the pressure sensing device is installed on the tubing.

[0017] Optionally, the pressure sensing device includes a pressure gauge barrel and an optical fiber pressure gauge. The pressure gauge barrel is connected to the tubing, and the optical fiber pressure gauges are distributed on the pressure gauge barrel.

[0018] Optionally, it further includes a ground demodulation component, and the ground demodulation component is communicatively connected to the pressure sensing device through an optical cable.

[0019] Optionally, it further includes a production packer, and the production packer is installed in the casing and is disposed at the front end of the hanging packer.

[0020] Optionally, optical cable channels are provided on the production packer, the tubing hanger and the pressure gauge barrel for the optical cable to pass through.

[0021] Optionally, one end of the sand control screen pipe is threadedly connected to the hanging packer, and the other end is threadedly connected to the blind plug.

[0022] In a second aspect, a well completion method for a carbon dioxide sequestration well is provided. The well completion device for a carbon dioxide sequestration well described above is used, and it includes:

[0023] A carbon dioxide injection step: opening the safety valve, closing the circulation hole, injecting carbon dioxide into the tubing. The check valve is opened under pressure. After the carbon dioxide injection is completed, the check valve is closed under the action of the self-resetting spring;

[0024] The chemical agent injection step: Inject a chemical agent fluid into the tubing. The one-way valve is opened under pressure. After the injection of the chemical agent fluid is completed, the one-way valve is closed under the action of the self-resetting spring.

[0025] The well flushing step: Open the circulation hole and inject a well flushing fluid into the annular space formed by the casing and the tubing. The well flushing fluid enters the tubing through the circulation hole to clean the tubing.

[0026] Optionally, it further includes an emergency shutdown step. In this emergency shutdown step, stop injecting carbon dioxide into the tubing and close the safety valve.

[0027] Optionally, in the carbon dioxide injection step, the downhole temperature and downhole pressure data are collected in real time through a monitoring component.

[0028] Advantages of the present invention:

[0029] The carbon dioxide storage well completion device can effectively solve the problems of scaling, leakage, and sand production faced by carbon dioxide reinjection storage wells. During the injection stop process, the one-way valve can be automatically closed to prevent backflow, and the sand control screen pipe can automatically block solid particles from the formation. It can achieve the functions of injecting chemical agents for plugging removal in the forward direction and reverse circulation well flushing of the upper pipe string, and can meet the functional requirements of plugging removal, scaling prevention, sand control, etc. during the long-term injection process of carbon dioxide reinjection wells in offshore oilfields, further improving the operation safety.

[0030] In the carbon dioxide storage well completion method, the above carbon dioxide storage well completion device is used, which can complete carbon dioxide injection, chemical agent plugging removal, and well flushing operations, improving the efficiency and safety of the reinjection operation of carbon dioxide reinjection wells. Description of the drawings

[0031] Figure 1 is a schematic structural diagram of the carbon dioxide storage well completion device described in the embodiment of the present invention;

[0032] Figure 2 is a schematic operation diagram of the carbon dioxide storage well completion device in the injection state;

[0033] Figure 3 is Figure 2 a partial enlarged schematic diagram of part A in

[0034] Figure 4 is a schematic operation diagram of the carbon dioxide storage well completion device in the well flushing state;

[0035] Figure 5 is a schematic operation diagram of the carbon dioxide storage well completion device during emergency shutdown;

[0036] Figure 6 is Figure 5Partial enlarged schematic diagram at B in the [Chinese context].

[0037] In the figure:

[0038] 1. Casing; 11. Perforated wellbore section; 2. Tubing; 21. Drilled pipe; 3. Sand control screen pipe; 31. Hanging packer; 32. Blind plug; 4. Tubing hanger; 5. Safety valve; 6. Circulation sliding sleeve; 61. Circulation hole; 7. Check valve; 8. Monitoring component; 81. Pressure gauge drag barrel; 82. Fiber optic pressure gauge; 9. Ground demodulation component; 91. Optical cable; 10. Production packer. Specific implementation manners

[0039] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar components or components with the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation of the present invention.

[0040] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, a mechanical connection, an electrical connection, a direct connection, or an indirect connection through an intermediate medium. It can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In the description of the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first feature and the second feature, or may include the situation where the first feature and the second feature are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is at a higher horizontal height than the second feature. The first feature being "below", "beneath", and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature is at a lower horizontal height than the second feature.

[0042] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "left", and "right" are based on the orientation or positional relationships shown in the accompanying drawings. It is only for the convenience of description and simplifying the operation, and does not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meanings.

[0043] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and through specific embodiments.

[0044] As Figures 1-4 shown, the present invention provides a completion device for a carbon dioxide sequestration well, which includes a casing 1, a tubing 2, a sand control screen pipe 3, a tubing hanger 4, a safety valve 5, a circulation sleeve 6 and a check valve 7. As Figure 1 shown, a perforated wellbore section 11 is provided at the end of the casing 1, and the perforated wellbore section 11 is formed by perforating the wellbore wall after the casing 1 is cemented. The tubing 2 is disposed inside the casing 1, and a perforated pipe 21 is correspondingly arranged at its end with respect to the perforated wellbore section 11. Injection holes are evenly formed on the outer periphery of the perforated pipe 21, and the injection holes are arranged according to a certain hole density, which is the main channel for injecting carbon dioxide into the formation. The sand control screen pipe 3 is sleeved outside the perforated pipe 21, and the positions of the sand control screen pipe 3 correspond to the perforations on the perforated wellbore section 11 and the injection holes on the outer periphery of the perforated pipe 21. The sand control screen pipe 3 includes a sand control filter screen to prevent formation solid particles from flowing back into the wellbore during the injection stop process. A hanging packer 31 is provided at one end of the sand control screen pipe 3, and a blind plug 32 is installed at the other end. The hanging packer 31 and the blind plug 32 are existing devices in the field. In this embodiment, one end of the sand control screen pipe 3 is preferably threadedly connected to the hanging packer 31, and the other end is preferably threadedly connected to the blind plug 32. The hanging packer 31 is located at the front end of the perforated wellbore section 11 and is anchored and sealed with the casing 1. The tubing hanger 4 is installed inside the casing 1 and is connected to the head end of the tubing 2; the safety valve 5 is communicated with the tubing 2 and is disposed below the tubing hanger 4; the circulation sleeve 6 is communicated with the tubing 2 and is disposed below the safety valve 5. A circulation hole 61 is provided on the side wall of the circulation sleeve 6 for establishing a circulation channel between the tubing 2 and the casing 1; the check valve 7 is communicated with the tubing 2 and is disposed below the circulation sleeve 6, and the check valve 7 is configured to conduct from top to bottom. The tubing hanger 4, the circulation sleeve 6 and the check valve 7 are existing devices in the field, and are tightly connected and sealed through the tubing 2. The opening or closing of the circulation hole 61 on the circulation sleeve 6 is controlled by lowering a special circulation sleeve tool. Opening or closing the circulation sleeve 6 through a special circulation sleeve tool is a mature technology in the field, and the implementation process and principle are not described in this embodiment.

[0045] When the completion device for the carbon dioxide sequestration well is in the injection state, that is, when injecting carbon dioxide through the tubing 2 of the device, as Figure 2 shown, the safety valve 5 is in the open state, the circulation hole 61 is in the closed state, the check valve 7 is opened and conducted under the pressure difference from top to bottom, and the carbon dioxide or chemical fluid can sequentially pass through the safety valve 5, the circulation sleeve 6, the check valve 7, the perforated pipe 21, the sand control screen pipe 3 and the perforated wellbore section 11 and then enter the formation to complete the injection operation. After the injection stops, the check valve 7 is closed and sealed under the action of the self-resetting spring, and the sand control screen pipe 3 blocks the solid particles from the formation from entering the wellbore.

[0046] Similarly, when injecting the chemical fluid, the chemical fluid is also injected from the tubing 2, passes through the safety valve 5, the circulating sliding sleeve 6, the check valve 7, the perforating pipe 21, the sand control screen pipe 3 and the perforated wellbore section 11, and then enters the formation to achieve the purposes of plugging removal and scale removal, etc., and prevent scale formation.

[0047] When the carbon dioxide injection well completion device is in the well flushing state, a special circulating sliding sleeve tool is lowered by wire or other means, and the circulating sliding sleeve 6 is opened to the open position, and the circulation hole 61 is in the conducting state. As Figure 3 shown, the well flushing fluid flows into the annular space formed by the casing 1 and the tubing 2, and can enter the tubing 2 through the circulation hole 61 to clean the inner wall of the tubing 2 and complete the downhole cleaning operation.

[0048] In summary, the carbon dioxide injection well completion device can effectively solve the problems of scale formation, leakage and sand production faced by the carbon dioxide reinjection well. The check valve can automatically close to prevent backflow during the injection stop process, and the sand control screen pipe can automatically block the solid particles from the formation. It can realize the function of injecting chemical agents for plugging removal in the forward direction, can realize the function of reverse circulation well flushing of the upper string, can realize the function of emergency shutdown, and can meet the functional requirements of plugging removal, scale removal, sand control, etc. during the long-term injection process of the carbon dioxide reinjection well in the offshore oilfield, and further improve the operation safety.

[0049] Furthermore, as Figure 1 shown, the carbon dioxide injection well completion device further includes a monitoring component 8. The monitoring component 8 includes a pressure sensing device. The pressure sensing device is installed on the tubing 2 and is used to monitor the downhole temperature and pressure in real time. Specifically, the pressure sensing device includes a pressure gauge cartridge 81 and an optical fiber pressure gauge 82. The pressure gauge cartridge 81 is connected to the tubing 2, and the optical fiber pressure gauges 82 are distributed on the pressure gauge cartridge 81. The optical fiber pressure gauges 82 are common sensing devices in the field and can collect downhole temperature and pressure data in real time to monitor the downhole conditions in real time.

[0050] Furthermore, the carbon dioxide injection well completion device further includes a ground demodulation component 9. The ground demodulation component 9 is communicatively connected to the pressure sensing device through an optical cable 91. The ground demodulation component 9 includes a demodulation device and temperature and pressure demodulation software inside the device. The demodulation device and the temperature and pressure demodulation software are existing technologies in the field. The downhole temperature and pressure data collected by the pressure sensing device are transmitted to the ground demodulation component 9 in real time, and the ground demodulation component 9 analyzes the temperature and pressure distribution data and leakage conditions of the wellbore according to the collected data.

[0051] Furthermore, it further includes a production packer 10. The production packer 10 is installed in the casing 1 and is placed at the front end of the hanging packer 31. Optical cable channels are provided on the production packer 10, the tubing hanger 4 and the pressure gauge cartridge 81 to facilitate the optical cable 91 to pass through.

[0052] In addition, this embodiment also provides a well completion method for a carbon dioxide sequestration well, which uses the above-mentioned well completion device for a carbon dioxide sequestration well, including:

[0053] A carbon dioxide injection step. In this step, when carbon dioxide is normally injected, the safety valve 5 is in the open state, the circulation sleeve 6 is in the closed state, the circulation hole 61 is closed, the injected carbon dioxide flows downward in the tubing 2, the check valve 7 is opened under the pressure difference from top to bottom, the carbon dioxide flows to the perforated pipe 21, enters the formation through the injection holes of the perforated pipe 21, the sand control screen pipe 3 and the perforated holes of the perforated wellbore section 11, and the downhole temperature and pressure data are collected through the downhole optical cable 91 and the fiber optic pressure gauge 82. The information is transmitted by the optical cable 91 to the ground demodulation component 9, and the downhole temperature, pressure profile and leakage condition are analyzed by the temperature and pressure demodulation software. After the carbon dioxide injection is completed and the injection stops, the check valve 7 is closed and sealed under the action of the self-resetting spring, and the sand control screen pipe 3 blocks the solid-phase particles from the formation from entering the wellbore.

[0054] A chemical agent injection step. In this step, in order to prevent scaling of the well completion device for a carbon dioxide sequestration well, a chemical agent fluid needs to be injected into the tubing 2. The chemical agent fluid is a common chemical agent in the field. Similarly, at this time, the check valve 7 is opened under the pressure difference from top to bottom, the chemical agent flows to the perforated pipe 21, and enters the formation through the injection holes of the perforated pipe 21, the sand control screen pipe 3 and the perforated holes of the perforated wellbore section 11 to achieve purposes such as plug removal and scale removal.

[0055] A well flushing step. In this step, when a well flushing operation needs to be carried out, a special circulation sleeve tool is lowered by wire or other means, the circulation sleeve 6 is opened to the open position, the circulation hole 61 is opened, and the well flushing fluid is injected into the annular space formed by the casing 1 and the tubing 2. The well flushing fluid enters the tubing 2 through the circulation hole 61 to clean the tubing 2. After the well flushing operation is completed, a special circulation sleeve tool is lowered by wire or other means to close the circulation hole 61 of the circulation sleeve 6.

[0056] Optionally, in the above steps, an emergency shutdown step is further included. In the emergency shutdown step, when an emergency occurs during the injection operation and the device needs to be shut down, first stop injecting carbon dioxide or chemical agent fluid into the tubing 2, and directly control the closing of the safety valve 5. The internal channel of the safety valve 5 is cut off and closed. As Figure 4 shown, the opening and closing of the safety valve 5 are controlled by the pressure of the hydraulic control pipeline of the safety valve 5. The internal channel of the safety valve 2 is opened under the action of the pressure of the hydraulic control pipeline, and the safety valve 2 is closed when the hydraulic control pipeline is depressurized. Controlling the opening and closing of the safety valve 5 through the pressure of the hydraulic control pipeline is an existing technology in the field, and this embodiment will not be elaborated further.

[0057] Optionally, in the carbon dioxide injection step, it further includes collecting downhole temperature and downhole pressure data in real time through the monitoring component 8 to monitor the downhole temperature and pressure conditions in real time and prevent accidents from occurring.

[0058] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A well completion device for a carbon dioxide sequestration well, characterized in that Comprising: A casing (1), with a perforated wellbore section (11) provided at the end of the casing (1); A tubing string (2), passing through the casing (1), and a perforated pipe (21) is correspondingly provided at the end of the tubing string (2) opposite to the perforated wellbore section (11), and injection holes are evenly formed on the outer circumference of the perforated pipe (21); A sand control screen pipe (3), sleeved outside the perforated pipe (21), with a hanging packer (31) provided at one end of the sand control screen pipe (3) and a blind plug (32) installed at the other end, and the hanging packer (31) is located at the front end of the perforated wellbore section (11), anchored and sealed with the casing (1); A tubing hanger (4), installed in the casing (1) and connected to the head end of the tubing string (2); A safety valve (5), communicating with the tubing string (2) and placed below the tubing hanger (4); A circulation sliding sleeve (6), communicating with the tubing string (2) and placed below the safety valve (5), and a circulation hole (61) is provided on the side wall of the circulation sliding sleeve (6); A check valve (7), communicating with the tubing string (2) and placed below the circulation sliding sleeve (6), and the check valve (7) is configured to conduct from top to bottom; In the injection state, the safety valve (5) is in an open state, the circulation hole (61) is in a closed state, and carbon dioxide or chemical fluid can sequentially pass through the safety valve (5), the circulation sliding sleeve (6), the check valve (7), the perforated pipe (21), the sand control screen pipe (3) and the perforated wellbore section (11) and enter the formation; In the well flushing state, the circulation hole (61) is in a conducting state, and the well flushing fluid flows in through the annular space formed by the casing (1) and the tubing string (2), and can enter the tubing string (2) through the circulation hole (61) to clean the inner wall of the tubing string (2); The carbon dioxide sequestration well completion device further includes a monitoring assembly (8), and the monitoring assembly (8) includes a pressure sensing device, and the pressure sensing device is installed on the tubing string (2); The pressure sensing device includes a pressure gauge cartridge (81) and an optical fiber pressure gauge (82), the pressure gauge cartridge (81) is connected to the tubing string (2), and the optical fiber pressure gauges (82) are distributed on the pressure gauge cartridge (81).

2. The carbon dioxide sequestration well completion device according to claim 1, wherein It further includes a ground demodulation assembly (9), and the ground demodulation assembly (9) is communicatively connected to the pressure sensing device through an optical cable (91).

3. The carbon dioxide sequestration well completion device according to claim 2, characterized in that It further includes a production packer (10), and the production packer (10) is installed in the casing (1) and placed in front of the hanging packer (31).

4. The carbon dioxide sequestration well completion device according to claim 3, characterized in that, The production packer (10), the tubing hanger (4) and the pressure gauge cartridge (81) are provided with optical cable channels for the optical cable (91) to pass through.

5. The carbon dioxide sequestration well completion device according to any one of claims 1-4, characterized in that, One end of the sand control screen pipe (3) is threadedly connected to the hanging packer (31), and the other end is threadedly connected to the blind plug (32).

6. A method for completing a carbon dioxide sequestration well, characterized in that, Using the carbon dioxide sequestration well completion device according to any one of claims 1-5, comprising: Carbon dioxide injection step: Open the safety valve (5), close the circulation hole (61), inject carbon dioxide into the tubing (2), the check valve (7) is opened under pressure, and after the carbon dioxide injection is completed, the check valve (7) is closed under the action of the self-resetting spring; Agent injection step: Inject the agent fluid into the tubing (2), the check valve (7) is opened under pressure, and after the agent fluid injection is completed, the check valve (7) is closed under the action of the self-resetting spring; Well flushing step: Open the circulation hole (61), inject the well flushing fluid into the annular space formed by the casing (1) and the tubing (2), and the well flushing fluid enters the tubing (2) through the circulation hole (61) to clean the tubing (2).

7. The method for completing a carbon dioxide sequestration well according to claim 6, wherein It also includes an emergency shutdown step. In the emergency shutdown step, stop injecting carbon dioxide into the tubing (2) and close the safety valve (5).

8. The method for completing a carbon dioxide sequestration well according to claim 6, wherein, In the carbon dioxide injection step, the downhole temperature and downhole pressure data are collected in real time through the monitoring component (8).

Images