Intelligent cementing plug and positioning method

Abstract

This invention provides an intelligent cementing plug and its positioning method. The plug includes a plug body with a stroke detection device and a striking device to transmit the detected stroke data to the surface via striking. The intelligent cementing plug is inserted downhole, and the stroke detection device detects its stroke, transmitting the data to a control device. After a preset time, the control device activates the striking device, converting the data into a striking signal. A receiving device on the surface receives the striking signal and reconstructs it into data. Through these steps, the intelligent cementing plug is positioned downhole. A receiving device is located near the surface on the casing to receive the striking data and is connected to a computer. This method allows for precise positioning of the intelligent cementing plug at depths below 5000 meters, ensuring cementing quality.

Description

Technical Field

[0001] This invention relates to the field of oil drilling and cementing technology, specifically to a cementing plug positioning system and its positioning method. Background Technology

[0002] Cementing is a crucial component of oil and gas drilling operations. During cementing, rubber plugs are used to isolate cement slurry from drilling fluid, preventing cement slurry from seeping into the drilling fluid and affecting cementing quality. For a long time, determining the position of the rubber plug within the casing during cementing operations has relied on calculations based on the cement slurry discharge rate of the mud pump and the casing's inner diameter and volume parameters; alternatively, pre-set retaining rings are punched in the casing, and the plug's position is estimated by monitoring pressure changes. While these methods provide a general indication of the plug's location, they are insufficient for the precise precision required for cementing operations.

[0003] Currently, patented technologies such as Southwest Petroleum University's CN104975847A "Monitoring Device and Detection Method for Rubber Plug Position in Oil and Gas Cementing" and China Petroleum & Chemical Corporation's CN108825214A "Cementing Plug Positioning System and Positioning Method" utilize fiber optic transmission and sonar for information transmission. These technologies involve setting up corresponding sensors, receiving devices, and information processing equipment to monitor pressure and acoustic changes. The pressure wave transmission time difference measured by the wellhead pressure transmitter determines the well depth position of the rubber plug. While these technologies can accurately locate the rubber plug, they involve numerous devices, complex control, and high technical requirements. During cementing operations, if the fiber optic cable or sonar is damaged, information transmission ceases, and the entire system fails. Furthermore, in many horizontal wells, sonar-based methods are insufficient for rubber plug positioning. During cementing operations, if the cementing plug is damaged, the seal with the plug-in seat may be inadequate, resulting in no significant pressure increase after the plug is in place, posing a risk of dead filling. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an intelligent cementing plug and a positioning method, which can transmit its position in the well to the surface, thereby achieving precise positioning of the intelligent cementing plug.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: an intelligent cementing plug, including a plug body, and a stroke detection device is provided on the plug body; The rubber stopper is also equipped with a tapping device, which transmits the detected travel data to the ground by tapping.

[0006] In a preferred embodiment, a receiving device is provided at a position near the ground on the sleeve. The receiving device is used to receive the striking data and is connected to a computer.

[0007] In a preferred embodiment, the receiving device is a MEMS microphone.

[0008] In the preferred embodiment, the rubber stopper is connected to the protective cylinder, and a storage battery is installed inside the protective cylinder. A control device is also provided, which is electrically connected to the stroke detection device and the striking device.

[0009] In the preferred embodiment, the structure of the stroke detection device is as follows: the protective cylinder is provided with multiple swing rods, the ends of the swing rods are provided with rollers, and the swing rods are also connected to the protective cylinder through tension springs so that the rollers are pressed against the inner wall of the sleeve; The outer wall of the roller is provided with a friction layer; The roller is equipped with multiple permanent magnets or iron blocks, and the swing arm is equipped with a magnetic sensor or Hall sensor to detect the rotation angle of the roller. The magnetic sensor or Hall sensor is electrically connected to the control device. Alternatively, the roller is equipped with multiple permanent magnets, and a shaft is provided at the end of the swing arm. Multiple coils are provided on the shaft. The permanent magnets and coils form a generator structure. The rotation of the roller is used to charge the battery. At the same time, the alternating current generated by the coil is used for counting to calculate the rotation angle of the roller. Based on the diameter of the roller, the rotation angle is converted into stroke data of the stroke detection device.

[0010] In a preferred embodiment, the striking device is structured as follows: a motor is installed inside the protective cylinder, the motor is connected to a cam, a striking rod pointing towards the inner wall of the sleeve is provided in the protective cylinder, a first spring is provided between the striking rod and the protective cylinder, the striking rod contacts the cam, and the cam drives the striking rod to strike the sleeve.

[0011] In a preferred embodiment, the striking device is structured such that a T-shaped vibrating rod is supported inside a protective cylinder by a first support and a second support, one end of the T-shaped vibrating rod extends out of the protective cylinder and points towards the inner wall of the sleeve, and the other end of the T-shaped vibrating rod is provided with a suction part, and an electromagnet is provided on at least one side of the suction part, and the electromagnet is electrically connected to the control device.

[0012] In the preferred embodiment, an elastic ring is provided between the second support and the T-shaped vibration rod.

[0013] A positioning method using the above-mentioned intelligent cementing plug includes the following steps: sending the intelligent cementing plug downhole, a stroke detection device detecting the stroke of the intelligent cementing plug, and transmitting the stroke data to a control device; After a preset period of time, the control device activates the striking device, converting the data into striking signals in an encoded manner; The ground-based receiving device receives the impact signal and converts it back into data. Through these steps, the downhole positioning of the intelligent cementing plug is achieved.

[0014] A positioning method using the above-mentioned intelligent cementing plug includes the following steps: the intelligent cementing plug is sent downhole, the roller contacts the inner wall of the casing, and the rotation angle data is sent to a magnetic sensor or a Hall sensor. The magnetic sensor or Hall sensor sends the rotation angle data to a control device. The control device calculates the roller's stroke data, i.e., the intelligent cementing plug's stroke data, by combining the rotation angle signal and the roller diameter. When the data of each roller is inconsistent, the angle data is divided into multiple segments, and the angle signal with the largest value in each segment is selected as the angle signal for calculating the stroke. After a preset period of time, the control device encodes the stroke data into a tapping signal with different time intervals, and the control device drives the tapping device to tap according to the tapping signal. The natural frequency of the casing is detected, the striking frequency is set to a frequency close to the natural frequency of the casing, and the data signal is superimposed on the striking frequency of the striking device. The ground-based receiving device receives the impact signal and converts it back into data. Through these steps, the downhole positioning of the intelligent cementing plug is achieved.

[0015] This invention provides an intelligent cementing plug and a positioning method. By adopting the above-mentioned solution, the intelligent cementing plug can be accurately positioned at a depth of 5,000 meters or more in the well, thereby solving the technical problem of accurately locating the downhole plug and ensuring cementing quality in the prior art. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall structure of the product of the present invention.

[0017] Figure 2 This is a perspective view of the product of the present invention.

[0018] Figure 3 This is a schematic diagram of the structure of the driving striking rod of the present invention.

[0019] Figure 4 This is a schematic diagram of another preferred structure of the product of the present invention.

[0020] Figure 5 This is a schematic diagram of the working structure of the T-shaped vibration rod of the present invention.

[0021] Figure 6 This is a schematic diagram of the encoding of the present invention.

[0022] In the diagram: 1. Rubber stopper; 2. Sealing ring; 3. Protective cylinder; 4. Roller; 41. Friction layer; 42. Permanent magnet; 43. Magnetic sensor; 5. Swing rod; 6. Tension spring; 7. Insulation layer; 8. Control device; 9. Battery; 10. Motor; 11. Cam; 12. Striking rod; 13. First spring; 14. Receiving device; 15. Computer; 16. Sleeve; 17. Electromagnet; 18. Attracting part; 19. Second support; 20. First support; 21. T-shaped vibration rod; 22. Second spring; 23. Sealing ring; 24. Elastic ring. Detailed Implementation

[0023] Example 1: like Figure 1 , 2 4. An intelligent cementing plug, comprising a plug body 1, wherein the plug body 1 is provided with a stroke detection device; The rubber stopper 1 is also equipped with a striking device, which transmits the detected travel data to the ground by striking it. This solution uses the self-detection of travel data by the rubber stopper 1, encodes the travel data, and transmits it over a long distance to the ground by striking it.

[0024] Preferred solutions include Figure 1 In the middle, a receiving device 14 is provided at the position of the sleeve 16 near the ground. The receiving device 14 is used to receive the knocking data and is connected to the computer 15.

[0025] In a preferred embodiment, the receiving device 14 is a MEMS microphone or a MEMS vibration sensor.

[0026] Preferred solutions include Figure 4 In this embodiment, the rubber stopper 1 is connected to the protective cylinder 3. A storage battery 9 is housed inside the protective cylinder 3, as well as a control device 8. The control device 8 is electrically connected to the stroke detection device and the striking device. In this example, the storage battery 9 includes one or more combinations of nickel-metal hydride batteries, lead-acid batteries, alkaline batteries, and supercapacitors.

[0027] In the preferred embodiment, the structure of the stroke detection device is as follows: the protective cylinder 3 is provided with multiple swing rods 5, the end of the swing rod 5 is provided with a roller 4, and the swing rod 5 is also connected to the protective cylinder 3 through a tension spring 6 so that the roller 4 is pressed against the inner wall of the sleeve 16; The outer wall of the roller 4 is provided with a friction layer 41; The roller 4 is equipped with multiple permanent magnets 42 or iron blocks, and the swing arm 5 is equipped with a magnetic sensor 43 or a Hall sensor to detect the rotation angle of the roller 4. The magnetic sensor 43 or the Hall sensor is electrically connected to the control device 8.

[0028] Preferred solutions include Figure 4In the middle, the roller 4 is equipped with multiple permanent magnets 42, and the end of the swing rod 5 is equipped with a shaft with multiple coils. The permanent magnets 42 and the coils form a generator structure. The rotation of the roller 4 is used to charge the storage battery 9. At the same time, the alternating current generated by the coil is used for counting to calculate the rotation angle of the roller 4. Based on the diameter of the roller 4, the rotation angle is converted into the stroke data of the stroke detection device.

[0029] Preferred solutions include Figure 3 The striking device is structured as follows: a motor 10 is installed inside the protective cylinder 3, and the motor 10 is connected to a cam 11. A striking rod 12 pointing to the inner wall of the sleeve 16 is provided in the protective cylinder 3. A first spring 13 is provided between the striking rod 12 and the protective cylinder 3. The striking rod 12 contacts the cam 11, and the cam 11 drives the striking rod 12 to strike the sleeve 16. This structure is relatively simple and the frequency output is relatively accurate.

[0030] Preferred solutions include Figure 5 In the structure of the striking device, a T-shaped vibrating rod 21 is supported in the protective cylinder 3 by a first support 20 and a second support 19. One end of the T-shaped vibrating rod 21 extends out of the protective cylinder 3 and points to the inner wall of the sleeve 16. The other end of the T-shaped vibrating rod 21 is provided with a suction part 18. An electromagnet 17 is provided on at least one side of the suction part 18. The electromagnet 17 is electrically connected to the control device 8.

[0031] Preferred solutions include Figure 5 In this configuration, an elastic ring 24 is provided between the second support 19 and the T-shaped vibrating rod 21. With this structure, a vibration frequency output of 1Hz to 60Hz or higher can be achieved. Preferably, it can output a striking frequency of 35Hz to 55Hz.

[0032] Example 2: A positioning method using the above-mentioned intelligent cementing plug includes the following steps: sending the intelligent cementing plug downhole, a stroke detection device detecting the stroke of the intelligent cementing plug, and transmitting the stroke data to the control device 8; After a preset period of time, such as the time required to walk to a distance close to the target, the control device 8 activates the striking device, converting the data into a striking signal in an encoded manner. The receiving device 14 located on the ground receives the knocking signal and restores the knocking signal into data. Through the above steps, the downhole positioning of the intelligent cementing plug is realized.

[0033] Example 3: A positioning method using the above-mentioned intelligent cementing plug includes the following steps: the intelligent cementing plug is sent downhole, the roller 4 contacts the inner wall of the casing 16, and the rotation angle data is sent to the magnetic sensor 43 or the Hall sensor. The magnetic sensor 43 or the Hall sensor sends the rotation angle data to the control device 8. The control device 8 calculates the stroke data of the roller 4, i.e. the stroke data of the intelligent cementing plug, by combining the rotation angle signal and the diameter of the roller 4. In the preferred embodiment, when the data of each roller 4 is inconsistent, the rotation angle data is divided into multiple segments, and the rotation angle signal with the largest value in each segment is selected as the rotation angle signal for calculating the stroke. This embodiment overcomes the problem of roller 4 losing stroke data due to vibration or relative slippage.

[0034] After a preset period of time, for example, when the device travels to a position approximately 5000 meters from the target location underground, the control device 8 encodes the travel data into striking signals with different time intervals. The control device 8 then drives the striking device to strike according to the striking signals. In a preferred embodiment, the natural frequency of the sleeve 16 is detected, and the striking frequency is set to a frequency close to the natural frequency of the sleeve 16. For example, if the natural frequency of the sleeve 16 is detected to be 43Hz, then the striking frequency is set to 43Hz. At least until the striking device starts and maintains a stable output striking frequency of 43Hz, this is identified as a pulse signal, and the data signal is superimposed on the striking frequency of the striking device. Figure 6 As shown in the diagram, the vertical lines represent the simplified tapping frequency, and T0~T n The intervals between the various striking frequencies constitute the data encoding, and this scheme has the advantage of strong anti-interference capability. In a further optimized scheme, these intervals are divided into two groups representing binary signals, directly realizing the transmission of binary encoding. Using encoding signals with more bases can improve transmission efficiency, but the corresponding anti-interference capability is reduced.

[0035] The receiving device 14 located on the ground receives the knocking signal and restores the knocking signal into data. Through the above steps, the downhole positioning of the intelligent cementing plug is realized.

[0036] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The embodiments and features described in these embodiments can be arbitrarily combined without conflict. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A smart cementing plug, comprising a plug body (1), characterized in that: The rubber stopper (1) is equipped with a stroke detection device; The rubber stopper (1) is also equipped with a striking device, which is used to transmit the detected travel data to the ground by striking. The rubber stopper (1) is connected to the protective cylinder (3). A storage battery (9) is provided inside the protective cylinder (3), and a control device (8) is also provided. The control device (8) is electrically connected to the stroke detection device and the striking device. The structure of the stroke detection device is as follows: multiple swing rods (5) are provided on the protective cylinder (3), and rollers (4) are provided at the ends of the swing rods (5). The swing rods (5) are also connected to the protective cylinder (3) through tension springs (6) so that the rollers (4) are pressed against the inner wall of the sleeve (16). The outer wall of the roller (4) is provided with a friction layer (41); The roller (4) is provided with multiple permanent magnets (42) or iron blocks, and the swing arm (5) is provided with a magnetic sensor (43) or Hall sensor to detect the rotation angle of the roller (4). The magnetic sensor (43) or Hall sensor is electrically connected to the control device (8); or, the roller (4) is provided with multiple permanent magnets (42), and a shaft is provided at the end of the swing arm (5). Multiple coils are provided on the shaft. The permanent magnets (42) and the coils form a generator structure. The rotation of the roller (4) is used to charge the storage battery (9). At the same time, the alternating current generated by the coil is used for counting to calculate the rotation angle of the roller (4), and the rotation angle is converted into the stroke data of the stroke detection device according to the diameter of the roller (4). The structure of the striking device is as follows: a motor (10) is provided inside the protective cylinder (3), the motor (10) is connected to the cam (11), a striking rod (12) pointing to the inner wall of the sleeve (16) is provided in the protective cylinder (3), a first spring (13) is provided between the striking rod (12) and the protective cylinder (3), the striking rod (12) contacts the cam (11), and the cam (11) drives the striking rod (12) to strike the sleeve (16); Alternatively, the structure of the striking device is as follows: a T-shaped vibrating rod (21) is supported in the protective cylinder (3) by a first support (20) and a second support (19). One end of the T-shaped vibrating rod (21) extends out of the protective cylinder (3) and points to the inner wall of the sleeve (16). The other end of the T-shaped vibrating rod (21) is provided with a suction part (18). An electromagnet (17) is provided on at least one side of the suction part (18). The electromagnet (17) is electrically connected to the control device (8).

2. The intelligent cementing plug according to claim 1, characterized in that: A receiving device (14) is provided near the ground on the sleeve (16). The receiving device (14) is used to receive the tapping data and is connected to the computer (15).

3. The intelligent cementing plug according to claim 2, characterized in that: The receiving device (14) is a MEMS microphone.

4. The intelligent cementing plug according to claim 1, characterized in that: An elastic ring (24) is provided between the second support (19) and the T-shaped vibrating rod (21).

5. A positioning method using the intelligent cementing plug as described in any one of claims 1 to 4, characterized in that: Includes the following steps: The intelligent cementing plug is sent downhole, the stroke detection device detects the stroke of the intelligent cementing plug, and the stroke data is transmitted to the control device (8). After a preset period of time, the control device (8) activates the striking device and converts the data into a striking signal in an encoded manner; The receiving device (14) located on the ground receives the knocking signal and restores the knocking signal into data. Through the above steps, the downhole positioning of the intelligent cementing plug is realized.

6. A positioning method using the intelligent cementing plug as described in claim 1 or 4, characterized in that: Includes the following steps: The intelligent cementing plug is sent downhole, the roller (4) contacts the inner wall of the casing (16), and sends the rotation angle data to the magnetic sensor (43) or Hall sensor. The magnetic sensor (43) or Hall sensor sends the rotation angle data to the control device (8). The control device (8) calculates the stroke data of the roller (4) by combining the rotation angle signal and the diameter of the roller (4), which is the stroke data of the intelligent cementing plug. When the data of each roller (4) are inconsistent, the angle data is divided into multiple segments, and the angle signal with the largest value in each segment is selected as the angle signal for calculating the stroke. After a preset period of time, the control device (8) encodes the travel data into a striking signal with different time intervals, and the control device (8) drives the striking device to strike according to the striking signal. The natural frequency of the detection sleeve (16) is set to a frequency close to the natural frequency of the sleeve (16), and the data signal is superimposed on the striking frequency of the striking device. The receiving device (14) located on the ground receives the knocking signal and restores the knocking signal into data. Through the above steps, the downhole positioning of the intelligent cementing plug is realized.

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