A temperature-controlled control method based on surface displacement change and a well sliding sleeve

Abstract

The present invention discloses a temperature-controlled control method and a downhole sliding sleeve based on surface displacement change, and the control method comprises: a temperature sensor arranged on the sliding sleeve body collects the initial temperature at the downhole sliding sleeve; a fluid with a set flow rate is pumped into the wellbore, and when the fluid reaches the downhole sliding sleeve for t time, the temperature sensor collects the temperature of the fluid at the downhole sliding sleeve; a control circuit board detects the temperature difference between the initial temperature and the temperature of the fluid at the downhole sliding sleeve; when the temperature difference is within a first temperature difference setting range, the control circuit board of the first downhole sliding sleeve controls the actuator through a controller to start the first downhole sliding sleeve; when the temperature difference is within a second temperature difference setting range, the control circuit board of the first downhole sliding sleeve controls the actuator through a controller to close the first downhole sliding sleeve. The present invention adopts a temperature control method to open or close the downhole sliding sleeve based on the temperature difference before and after the fluid is pumped, and has the advantages of simple operation and high opening success rate.

Description

Technical Field

[0001] The invention belongs to the technical field of downhole tools for oil and gas field exploration and development, and in particular relates to a temperature control method based on surface displacement change and a downhole sliding sleeve. Background Art

[0002] Downhole tools are special tools that assist in oil and gas development and can achieve certain specific functions underground. At present, downhole tools are mainly based on pure mechanical structures, and the control of the movement of downhole tools is also mainly achieved by the mechanical properties of the pipe string itself or the pressure of the wellbore fluid. Moreover, the structure is complex, the control is difficult, and precise control cannot be achieved. With the advancement of technology, downhole tools are gradually developing in the direction of electrification and intelligence, and many remote control methods for downhole tools have also emerged, mainly including cable control, pressure wave control, electromagnetic wave control, and acoustic wave control. Among them, the cable control method is relatively reliable and has stable performance, but because the cable must be connected to the downhole tool and led to the ground, it will have a very large impact on the on-site construction, so its use is limited; although pressure wave control, electromagnetic wave control, acoustic wave control and other methods can realize wireless transmission of control signals, due to the complexity of the wellbore and the interference on site, the signal transmission will be unstable, making it difficult to achieve reliable control of downhole tools. Based on this, the present invention proposes a new multi-level downhole intelligent tool control signal sending method and a downhole sliding sleeve, which can send different instructions to control different downhole tools when multiple intelligent tools exist in the well at the same time. Summary of the invention

[0003] In view of the above problems, the present invention discloses a temperature control method based on ground displacement change, comprising the following steps:

[0004] The temperature sensor arranged on the sleeve body collects the initial temperature of the sleeve in the well;

[0005] Pump fluid at a set flow rate into the wellbore. When the fluid reaches the downhole sleeve t time later, the temperature sensor collects the temperature of the fluid at the downhole sleeve.

[0006] The control circuit board detects the temperature difference between the initial temperature and the temperature of the fluid at the downhole sleeve;

[0007] When the temperature difference is within the first temperature difference setting range, the control circuit board of the first downhole sliding sleeve controls the actuator through the controller to start the first downhole sliding sleeve; when the temperature difference is within the second temperature difference setting range, the control circuit board of the first downhole sliding sleeve controls the actuator through the controller to close the first downhole sliding sleeve.

[0008] Furthermore, after the control circuit board detects the temperature difference between the initial temperature and the temperature of the fluid at the downhole sliding sleeve, the following steps are also included:

[0009] When the temperature difference is within the third temperature difference setting range, the control circuit board of the second downhole sliding sleeve controls the actuator through the controller to start the second downhole sliding sleeve; when the temperature difference is within the fourth temperature difference setting range, the control circuit board of the second downhole sliding sleeve controls the actuator through the controller to close the second downhole sliding sleeve.

[0010] Furthermore, the specific steps of starting the downhole sliding sleeve are as follows:

[0011] The control circuit board sends a start control signal to the controller;

[0012] The controller receives the start control signal and drives the actuator;

[0013] The actuator pushes the piston to move downward, so that the first flow hole on the piston is connected with the second flow hole on the side wall of the sliding sleeve body.

[0014] Furthermore, the specific steps of closing the downhole casing are as follows:

[0015] The control circuit board sends a closing control signal to the controller;

[0016] The controller receives the closing control signal and drives the actuator;

[0017] The actuator drives the piston to move upward, so that the first flow hole on the piston is disconnected from the second flow hole on the side wall of the sliding sleeve body.

[0018] Furthermore, before the temperature sensor disposed on the sleeve body collects the initial temperature of the sleeve in the well, the method further comprises:

[0019] Multiple downhole sliding sleeves are connected in series with pipelines at intervals and dropped into the well at set positions.

[0020] A temperature-controlled downhole sliding sleeve based on surface displacement change, comprising: a sliding sleeve body, a control circuit board, an actuator, a temperature sensor and a controller;

[0021] The sliding sleeve body is provided with a first groove, a second groove and a through hole;

[0022] The control circuit board is arranged in the first groove of the sliding sleeve body;

[0023] The actuator is arranged in the second groove of the sleeve body;

[0024] The temperature sensor is arranged in the through hole of the sleeve body;

[0025] The controller is arranged in the first groove of the sleeve body and is connected to the control circuit board and the actuator.

[0026] Furthermore, the downhole sliding sleeve further comprises: a sealing ring and a housing;

[0027] The housing is arranged outside the sleeve body and is sleeved with the sleeve body, the first groove forms a sleeve test cavity, and the second groove forms a sleeve execution cavity;

[0028] Sealing rings are arranged at the connection points at both ends of the shell and the sliding sleeve body.

[0029] Furthermore, the downhole sliding sleeve further comprises: a battery;

[0030] The battery is arranged in the sleeve test cavity and is respectively connected with the control circuit board, the actuator, the temperature sensor and the controller.

[0031] Furthermore, the downhole sliding sleeve further comprises: a communicating hole;

[0032] The communicating hole is arranged on the sliding sleeve body.

[0033] Furthermore, the downhole sliding sleeve further comprises: a piston and a first flow hole;

[0034] The piston is arranged inside the sliding sleeve body, and a first flow hole is arranged on the side wall of the piston.

[0035] Furthermore, the downhole sliding sleeve further comprises: a second flow hole;

[0036] The second flow hole is arranged on the side wall of the sliding sleeve body.

[0037] Compared with the prior art, the embodiments of the present invention have at least the following advantages:

[0038] 1. The downhole sleeve adopts temperature control to open or close based on the temperature difference before and after fluid injection. It has the advantages of simple structure, easy operation and high opening success rate.

[0039] 2. The present invention can realize the control of downhole tools by only pumping according to the set flow rate. The control method has low cost, simple process, safe and reliable operation;

[0040] 3. Independent control of different downhole tools at different flow rates. When there are multiple intelligent downhole tools in the well at the same time, the fluid is pumped according to the set fluid flow rate, and the fluid temperature is adjusted so that the temperature sensor receives different temperature changes to control different downhole tools in the well. The control is stable, reliable and practical.

[0041] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 It shows a structural schematic diagram of a downhole sliding sleeve in a closed state according to an embodiment of the present invention;

[0044] Figure 2 A structural schematic diagram of an open downhole sleeve according to an embodiment of the present invention is shown.

[0045] Figure numerals: 1. sleeve body; 2. sealing ring; 3. battery; 4. control circuit board; 5. actuator; 6. temperature sensor; 7. housing; 8. controller; 9. connecting hole; 10. first flow hole; 11. piston; 12. second flow hole. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] Figure 1 The structure schematic diagram of the downhole sleeve closing state according to an embodiment of the present invention is shown. Figure 1 As shown, the temperature-controlled downhole sliding sleeve based on surface displacement change proposed by the present invention comprises: a sliding sleeve body 1, a control circuit board 4, an actuator 5, a temperature sensor 6 and a controller 8;

[0048] The sleeve body 1 is provided with a first groove, a second groove and a through hole;

[0049] The control circuit board 4 is arranged in the first groove of the sleeve body 1;

[0050] The actuator 5 is arranged in the second groove of the sleeve body 1;

[0051] The temperature sensor 6 is arranged in the through hole of the sleeve body 1;

[0052] The controller 8 is disposed in the first groove of the sleeve body 1 and is connected to the control circuit board 4 and the actuator 5 .

[0053] Both ends of the sleeve body 1 are provided with threads for connecting the tool pipes in series.

[0054] The control circuit board 4 is used to collect the initial temperature of the downhole sleeve or the temperature of the fluid in the downhole sleeve, calculate the temperature difference between the two, and judge whether it is a control signal for the downhole sleeve according to the temperature difference. It should be noted that the temperature difference setting range of the program setting of the control circuit board 4 in different downhole sleeves is different, so that different control instructions can be implemented to control different downhole sleeves.

[0055] The opening control signal of the first downhole sleeve is that the temperature difference between the initial temperature at the first downhole sleeve and the temperature of the fluid at the first downhole sleeve is in the first temperature difference setting range. The closing control signal of the first downhole sleeve is that the temperature difference between the initial temperature at the first downhole sleeve and the temperature of the fluid at the first downhole sleeve is in the second temperature difference setting range. Exemplarily, the first temperature difference setting range is 0°C < ΔT ≤ 2°C, and the second temperature difference setting range is 2°C < ΔT ≤ 4°C.

[0056] The opening control signal of the second downhole sleeve is that the temperature difference between the initial temperature at the second downhole sleeve and the temperature of the fluid at the second downhole sleeve is in the third temperature difference setting range. The closing control signal of the second downhole sleeve is that the temperature difference between the initial temperature at the second downhole sleeve and the temperature of the fluid at the second downhole sleeve is in the fourth temperature difference setting range. Exemplarily, the third temperature difference setting range is 4°C < ΔT ≤ 6°C, and the fourth temperature difference setting range is 6°C < ΔT ≤ 8°C.

[0057] The above-mentioned first temperature difference setting range, second temperature difference setting range, third temperature difference setting range and fourth temperature difference setting range are all exemplary descriptions, but the present invention is not limited thereto, and other temperature difference setting ranges of the downhole sliding sleeve can be set according to actual conditions.

[0058] The actuator 5 is installed in the sleeve execution chamber and is used to drive the piston 11 to move.

[0059] The temperature sensor 6 is installed in the sleeve test cavity, and is used to detect the initial temperature of the sleeve downhole and the temperature of the fluid in the sleeve downhole, and send them to the control circuit board 4 for identification.

[0060] The controller 8 is installed in the sleeve test cavity, and is used to receive the control signal sent by the control circuit board 4 and drive the actuator 5 to perform an action.

[0061] The downhole sliding sleeve also includes: a sealing ring 2 and a housing 7;

[0062] The housing 7 is arranged outside the sleeve body 1 and is sleeved with the sleeve body 1. The first groove forms a sleeve test cavity, and the second groove forms a sleeve execution cavity.

[0063] The two ends of the housing 7 and the sleeve body 1 are connected with sealing rings 2. The sealing rings 2 are used to ensure the sealing between the housing 7 and the sleeve body 1, and prevent liquid from entering the sleeve test cavity and the sleeve execution cavity. The housing isolates the electrical components in the sleeve test cavity and the sleeve execution cavity from the outside of the downhole sleeve, and ensures the stable operation of the electrical components.

[0064] The downhole sliding sleeve also includes: a battery 3;

[0065] The battery 3 is arranged in the sleeve test cavity and is respectively connected to the control circuit board 4, the actuator 5, the temperature sensor 6 and the controller 8. The battery 3 is used to provide the control circuit board 4, the actuator 5, the temperature sensor 6 and the controller 8 with the required voltage.

[0066] The downhole sliding sleeve also includes: a connecting hole 9;

[0067] The communication hole 9 is arranged on the sleeve body 1. The communication hole 9 is used to connect the inner and outer fluid channels of the downhole sleeve to provide a liquid passage for the liquid.

[0068] The downhole sliding sleeve further includes: a piston 11 and a first flow hole 10;

[0069] The piston 11 is arranged inside the bottom end of the sleeve body 1, and a first flow hole 10 is arranged on the side wall of the piston 11;

[0070] The piston 11 is used to open or close the downhole sliding sleeve.

[0071] The downhole sliding sleeve further includes: a second flow hole 12;

[0072] The second flow hole 12 is disposed on the side wall of the bottom end of the sliding sleeve body 1 .

[0073] like Figure 2 As shown, when the actuator 5 performs the opening action, the piston 11 is pushed downward, so that the first flow hole 10 on the piston 11 is connected with the second flow hole 12 on the side wall of the sleeve body 1, and the downhole sleeve is opened; Figure 1 As shown, when the actuator 5 performs the closing action, the piston 11 is pushed to return upward, so that the first flow hole 10 on the piston 11 is disconnected from the second flow hole 12 on the side wall of the sleeve body 1, thereby closing the sleeve under the well.

[0074] The downhole sliding sleeve adopts temperature control to open or close based on the temperature difference before and after fluid pumping. It has the advantages of simple structure, easy operation and high opening success rate.

[0075] Based on the above-mentioned temperature-controlled downhole sliding sleeve based on surface displacement change, this embodiment proposes a temperature-controlled control method based on surface displacement change, including the following steps:

[0076] The temperature sensor 6 disposed on the sleeve body 1 collects the initial temperature of the sleeve in the well;

[0077] The fluid with a set flow rate is pumped into the wellbore. When the fluid reaches the downhole sleeve t time later, the temperature sensor 6 collects the temperature of the fluid at the downhole sleeve;

[0078] The control circuit board 4 detects the temperature difference between the initial temperature and the temperature of the fluid at the downhole casing;

[0079] When the temperature difference is within the first temperature difference setting range, the control circuit board 4 of the first downhole sliding sleeve controls the actuator 5 through the controller 8 to start the first downhole sliding sleeve; when the temperature difference is within the second temperature difference setting range, the control circuit board 4 of the first downhole sliding sleeve controls the actuator 5 through the controller 8 to close the first downhole sliding sleeve.

[0080] When the temperature difference is within the third temperature difference setting range, the control circuit board 4 of the second downhole sliding sleeve controls the actuator 5 through the controller 8 to start the second downhole sliding sleeve; when the temperature difference is within the fourth temperature difference setting range, the control circuit board 4 of the second downhole sliding sleeve controls the actuator 5 through the controller 8 to close the second downhole sliding sleeve.

[0081] The fluid is downhole working fluid such as water, mud or oil; the initial temperature range of the fluid is 0-60°C.

[0082] In some embodiments, the pumping flow rate of the fluid ranges from 0.1 to 20 m / s. 3 / min.

[0083] In some embodiments, the fluid pumping flow rate of the first downhole casing is controlled to be in the range of 1-2 m 3 / min;

[0084] In some embodiments, the fluid pumping flow rate of the second downhole casing is controlled to be in the range of 2.5-3.5 m / s. 3 / min;

[0085] In some embodiments, the fluid pumping flow rate of the third downhole casing is controlled to be in the range of 4-5 m 3 / min.

[0086] It should be noted that the first downhole sleeve is set at the deepest part of the well bottom, at a distance of L1 from the ground, the second downhole sleeve is set above the first downhole sleeve, at a distance of L2 from the ground, and the third downhole sleeve is set above the second downhole sleeve, at a distance of L3 from the ground. Among them, L1>L2>L3. Other downhole sleeves are also set according to the above method.

[0087] The specific steps of starting the downhole sliding sleeve are as follows:

[0088] The control circuit board 4 sends a start control signal to the controller 8;

[0089] The controller 8 receives the start control signal and drives the actuator 5;

[0090] The actuator 5 pushes the piston 11 to move downward, so that the first flow hole 10 on the piston 11 is connected with the second flow hole 12 on the side wall of the sleeve body 1 .

[0091] The specific steps of closing the downhole casing are as follows:

[0092] The control circuit board 4 sends a closing control signal to the controller 8;

[0093] The controller 8 receives the closing control signal and drives the actuator 5;

[0094] The actuator 5 drives the piston 11 to move upward, so that the first flow hole 10 on the piston 11 is disconnected from the second flow hole 12 on the side wall of the sleeve body 1 .

[0095] Before the temperature sensor 6 disposed on the sleeve body 1 collects the initial temperature of the sleeve in the well, the following steps are also included:

[0096] Multiple downhole sliding sleeves are connected in series with pipelines at intervals and dropped into the well at set positions.

[0097] The temperature-controlled control method based on ground displacement changes of the present invention effectively solves the technical problems in the prior art that it is difficult to achieve reliable control of downhole tools due to complex construction sites and limited use, and ultimately achieves the ability to remotely control the opening or closing of the downhole sleeve on the ground. The control method is easy to operate and has strong practicality, and can control the opening or closing of different downhole sleeves according to the injection of different amounts of fluid.

[0098] During the field operation, firstly, a temperature sensor 6 is installed on each downhole tool (taking the downhole sliding sleeve as an example), and the sliding sleeve body 1 is connected to the tool pipe string through a thread, and the pipe string is lowered from the wellhead to the designed position at the bottom of the well in sequence. When the downhole sliding sleeve is in the initial static state, the piston 11 is not connected to the sliding sleeve body 1, and the downhole sliding sleeve is in a closed state; when the construction operation begins, the downhole fluid temperature is adjusted on the ground by changing the pumping displacement. Since the downhole temperature is higher than the ground, the process of the fluid flowing downward along the wellbore is a process of continuously heating the pumped fluid. Under the conditions of constant ground fluid temperature, wellbore size and formation temperature gradient, the larger the ground pumping displacement, the faster the fluid flows downward in the wellbore, the shorter the fluid heating time, and the lower the temperature when it reaches the downhole sliding sleeve. Assuming that the initial temperature of the downhole sleeve before pumping is T0 (T0 is considered to be the formation temperature), when the pumped fluid reaches the downhole sleeve time t, when the pumped fluid reaches the downhole sleeve at the same downhole position, the temperature of the downhole sleeve becomes T1 (T1 is less than T0), therefore, after a certain time t, the temperature change of the downhole sleeve is ΔT = T0-T1. The value range of time t is any time within 1-600 seconds, and the specific value is determined according to the actual situation such as the pipeline length and the pumping speed. For example, t is 30 seconds.

[0099] In some embodiments, the downhole sleeve is lowered to the designed position at the bottom of the well, and the initial temperature of the first downhole sleeve, the initial temperature of the second downhole sleeve, and the initial temperature of the third downhole sleeve are tested to be 100°C. To control the opening of the first downhole sleeve, water is pumped into the well. The initial temperature of the water is 20°C, and the flow rate of the first pumping is 1m / s. 3 / min, when it is detected that the fluid reaches the downhole sleeve 30 seconds later, the fluid temperature at each downhole sleeve is tested respectively, and the fluid temperature at the first downhole sleeve is 98°C, the fluid temperature at the second downhole sleeve is 97.5°C, and the fluid temperature at the third downhole sleeve is 97°C. The temperature difference is calculated respectively, and the temperature difference at the first downhole sleeve is 2°C, which meets the set range. The control circuit board 4 of the first downhole sleeve sends a start control signal to the controller 8; the controller 8 receives the start control signal and drives the actuator 5; the actuator 5 pushes the piston 11 to move downward, so that the first flow hole 10 on the piston 11 is connected with the second flow hole 12 on the side wall of the sleeve body 1, and the first downhole sleeve is opened.

[0100] In some embodiments, to control the closing of the first downhole casing, water is pumped into the well at a flow rate of 2 m 3 / min.

[0101] In some embodiments, to control the opening of the second downhole sliding sleeve, the flow rate of water pumped into the well is 2.75m 3 / min.

[0102] In some embodiments, to control the closing of the second downhole casing, the flow rate of water pumped into the well is 3.25m 3 / min.

[0103] When it is necessary to control a downhole sleeve, fluid is pumped into the well at a certain displacement. During this period, the control circuit board 4 on the downhole sleeve continuously collects the fluid temperature value at the downhole sleeve position and compares it with the collected initial temperature value to obtain a ΔT value. When there is no pumped fluid, ΔT is close to 0; when it is necessary to control the downhole sleeve, when the pumped fluid passes through the position of the temperature sensor 6 installed on the downhole sleeve, the collected temperature value decreases and the ΔT value increases. When the ΔT value reaches a certain range, the control circuit board 4 determines that this is a control signal for the downhole sleeve, and then the downhole sleeve's own control system is started and the required downhole action is performed.

[0104] Use constant temperature equipment to keep the surface fluid at a constant temperature; set different temperature difference setting ranges for different downhole sleeves; for example, 0℃<ΔT≤2℃ is the first temperature difference setting range for the first downhole sleeve opening action, and 2℃<ΔT≤4℃ is the second temperature difference setting range for the first downhole sleeve closing action. 4℃<ΔT≤6℃ is the third temperature difference setting range for the second downhole sleeve opening action, 6℃<ΔT≤8℃ is the fourth temperature difference setting range for the second downhole sleeve closing action, and so on.

[0105] The temperature sensor 6 detects the real-time temperature of the downhole fluid and sends it to the control circuit board 4 for identification. The control circuit board 4 on the downhole sleeve continuously collects the fluid temperature information at the downhole sleeve and compares it with the collected initial temperature value to obtain a ΔT value. When there is no pumped fluid, ΔT is close to 0; when the pumped fluid passes through the position of the temperature sensor 6 installed on the downhole sleeve, the collected temperature value decreases and the ΔT value increases. When the ΔT value reaches a certain range, the control circuit board 4 determines that this is a control signal for the downhole sleeve. The program in the control circuit board 4 believes that a control signal has been received, and drives the actuator 5 to operate through the controller 8 to realize the opening or closing of the downhole sleeve.

[0106] The present invention proposes a temperature-controlled control method based on surface displacement changes and a downhole sliding sleeve, which can realize the control of downhole tools by pumping according to the set displacement. The control method has low cost, simple process, safe and reliable operation; different displacements can independently control different downhole tools. When there are multiple intelligent downhole tools in the well at the same time, the fluid is pumped according to the set displacement, the fluid temperature is adjusted, and the temperature sensor receives different temperature changes to control different downhole tools in the well. The control is stable and reliable, and the practicability is strong.

[0107] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A temperature control method based on ground displacement change, characterized in that: The following steps are involved: A temperature sensor (6) disposed on the sleeve body (1) collects the initial temperature of the sleeve in the well; A fluid with a set flow rate is pumped into the wellbore. When the fluid reaches the downhole sleeve after t time, a temperature sensor (6) collects the temperature of the fluid at the downhole sleeve; The control circuit board (4) detects the temperature difference between the initial temperature and the temperature of the fluid at the downhole sliding sleeve; When the temperature difference is within a first temperature difference setting range, the control circuit board (4) of the first downhole sliding sleeve controls the actuator (5) via the controller (8) to start the first downhole sliding sleeve; when the temperature difference is within a second temperature difference setting range, the control circuit board (4) of the first downhole sliding sleeve controls the actuator (5) via the controller (8) to close the first downhole sliding sleeve; The pumping velocity range of the fluid is 0.1-20m 3 / min; The initial temperature of the fluid ranges from 0 to 60°C; The downhole sliding sleeve comprises: a sliding sleeve body (1), a control circuit board (4), an actuator (5), a temperature sensor (6) and a controller (8); The sliding sleeve body (1) is provided with a first groove, a second groove and a through hole; The control circuit board (4) is arranged in the first groove of the sliding sleeve body (1); The actuator (5) is arranged in the second groove of the sleeve body (1); The temperature sensor (6) is arranged in the through hole of the sliding sleeve body (1); The controller (8) is arranged in the first groove of the sleeve body (1), and is connected to the control circuit board (4) and the actuator (5).

2. The temperature control method based on ground displacement change according to claim 1 is characterized in that: After the control circuit board (4) detects the temperature difference between the initial temperature and the temperature of the fluid at the downhole casing, the control circuit board (4) further comprises the following steps: When the temperature difference is within a third temperature difference setting range, the control circuit board (4) of the second downhole sliding sleeve controls the actuator (5) via the controller (8) to start the second downhole sliding sleeve; when the temperature difference is within a fourth temperature difference setting range, the control circuit board (4) of the second downhole sliding sleeve controls the actuator (5) via the controller (8) to close the second downhole sliding sleeve.

3. The temperature control method based on ground displacement change according to claim 1 or 2, characterized in that: The specific steps of starting the downhole sliding sleeve are as follows: The control circuit board (4) sends a start control signal to the controller (8); The controller (8) receives the start control signal and drives the actuator (5); The actuator (5) pushes the piston (11) to move downward, so that the first flow hole (10) on the piston (11) is connected to the second flow hole (12) on the side wall of the sleeve body (1); The downhole sliding sleeve further comprises: a communicating hole (9); The communicating hole (9) is arranged on the sliding sleeve body (1); The downhole sliding sleeve further comprises: a piston (11) and a first flow hole (10); The piston (11) is arranged inside the sliding sleeve body (1), and a first flow hole (10) is arranged on the side wall of the piston (11); The downhole sliding sleeve further comprises: a second flow hole (12); The second flow hole (12) is arranged on the side wall of the sliding sleeve body (1).

4. The temperature control method based on ground displacement change according to claim 3 is characterized in that: The specific steps of closing the downhole casing are as follows: The control circuit board (4) sends a closing control signal to the controller (8); The controller (8) receives the closing control signal and drives the actuator (5); The actuator (5) drives the piston (11) to move upward, so that the first flow hole (10) on the piston (11) is disconnected from the second flow hole (12) on the side wall of the sleeve body (1).

5. The temperature control method based on ground displacement change according to claim 1 is characterized in that: Before the temperature sensor (6) disposed on the sleeve body (1) collects the initial temperature of the sleeve in the well, the method further comprises: Multiple downhole sliding sleeves are connected in series with pipelines at intervals and dropped into the well at set positions.

6. The temperature control method based on ground displacement change according to claim 1 is characterized in that: The downhole sliding sleeve further comprises: a sealing ring (2) and an outer shell (7); The housing (7) is arranged outside the sleeve body (1) and is sleeved with the sleeve body (1); the first groove forms a sleeve test cavity, and the second groove forms a sleeve execution cavity; Sealing rings (2) are provided at the connection points between the outer shell (7) and the sliding sleeve body (1) at both ends.

7. The temperature control method based on ground displacement change according to claim 6 is characterized in that: The downhole sliding sleeve further comprises: a battery (3); The battery (3) is arranged in the sleeve test cavity and is respectively connected to the control circuit board (4), the actuator (5), the temperature sensor (6) and the controller (8).

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