A kind of on-line detection device and method for drilling fluid viscosity based on closed box

Abstract

The application discloses a kind of based on closed box's drilling fluid viscosity on-line detection device and method, the device can include: closed box, the rotor being arranged in closed box, stator in rotor, the first coupling structure of box top, the second coupling structure of box top, rotor rotation speed reaches preset speed and drives stator rotation;Whether the first coupling structure and the second coupling structure are coupled is detected, when not coupled, stator rotation drives the first coupling structure rotation, the target drilling speed when the first coupling structure rotation reaches stability is sent to data processing module, and the drilling fluid viscosity is calculated;When coupled, stator rotation drives the first coupling structure and the second coupling structure rotation simultaneously, and the torque received when stopping rotation is sent to data processing module, and the drilling fluid viscosity is calculated.The application can realize the drilling fluid viscosity detection in drilling, effectively improve the precision of drilling fluid viscosity detection.

Description

Technical Field

[0001] This invention relates to the field of drilling fluid testing technology, and in particular to an online drilling fluid viscosity testing device and method based on a sealed box. Background Technology

[0002] Drilling fluid viscosity refers to the degree of viscosity of the drilling fluid during flow, and is an important performance parameter of drilling fluid. It reflects the internal friction between solid particles, between solid particles and liquid molecules, and between liquid molecules within the drilling fluid. Accurately determining the viscosity of drilling fluid is of great significance for improving drilling operation efficiency.

[0003] Current technologies for drilling fluid viscosity testing typically require an opening at the top of the measuring device to expose the measuring components. However, this method is generally only applicable to ambient temperature and pressure conditions. Since the temperature and pressure inside a drilling well are usually different from the external environment, this method is not suitable for drilling fluid viscosity testing inside a well, resulting in low accuracy.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This specification provides an online drilling fluid viscosity detection device and method based on a sealed enclosure to solve the problem that existing technologies cannot detect drilling fluid viscosity inside the well and have low accuracy in drilling fluid viscosity detection.

[0006] On one hand, this specification provides an online drilling fluid viscosity detection device based on a sealed box. The device includes: a sealed box, a rotor disposed inside the sealed box, a stator disposed inside the rotor, a first coupling structure disposed at the top of the sealed box, and a second coupling structure disposed at the top of the sealed box. The first coupling structure is connected to the stator and the second coupling structure respectively. When the rotation speed of the rotor reaches a preset speed, it drives the stator to rotate.

[0007] The system detects whether the first coupling structure and the second coupling structure are coupled. When the first coupling structure and the second coupling structure are not coupled, the stator rotates to drive the first coupling structure to rotate. The preset rotation speed of the drill and the target drilling speed when the rotation of the first coupling structure reaches a stable state are sent to the data processing module to calculate the drilling fluid viscosity.

[0008] When the first coupling structure is coupled with the second coupling structure, the stator rotation simultaneously drives the first coupling structure and the second coupling structure to rotate. The torque received by the first coupling structure and the second coupling structure when they stop rotating is sent to the data processing module to calculate the drilling fluid viscosity.

[0009] In some embodiments, the online detection device further includes a motor disposed at the bottom of the sealed housing, the motor being connected to the drill bit for driving the drill bit to rotate during startup.

[0010] In some embodiments, the rotor is rotatably connected to the sealed housing, the rotor has a cavity, and the stator is located inside the cavity of the drill.

[0011] In some embodiments, the online detection device further includes a drill speed identification module, which is used to identify whether the rotation speed of the drill has reached a preset drilling speed.

[0012] In some embodiments, the online detection device further includes a detection module, which includes a coupled detection unit and a speed and torque integrated detection unit. The coupled detection unit is connected to the speed and torque integrated detection unit, and the speed and torque integrated detection unit is connected to the data processing module.

[0013] In some embodiments, the coupling detection unit is used to detect whether the first coupling structure and the second coupling structure are coupled, and send the coupling detection result to the speed and torque integrated detection unit. The speed and torque integrated detection unit is used to detect the target drilling speed of the first coupling structure when it receives the coupling detection result that the first coupling structure and the second coupling structure are not coupled, and to detect the torque on the first coupling structure and the second coupling structure when they stop rotating when it receives the coupling detection result that the first coupling structure and the second coupling structure are coupled, and send the target drilling speed and the torque to the data processing module.

[0014] In some embodiments, the online detection device further includes a torque application structure connected to the second coupling structure, the torque application structure being used to apply an external force to the second coupling structure to stop the rotation of the first coupling structure and the second coupling structure.

[0015] In some embodiments, the online detection device further includes a rotating shaft located inside the stator, the first coupling structure being mounted on the rotating shaft, and the stator being rotatably connected to the first coupling structure at the top of the sealed housing via the rotating shaft.

[0016] On the other hand, embodiments of this specification also provide an online drilling fluid viscosity detection method based on a sealed chamber. Based on the aforementioned online detection device, the method includes:

[0017] Detect whether the first coupling structure and the second coupling structure are coupled;

[0018] When the first coupling structure and the second coupling structure are not coupled, the preset drilling speed of the rotor and the target drilling speed when the rotation of the first coupling structure reaches a stable state are obtained. Based on the preset rotation speed of the rotor and the target drilling speed when the rotation of the first coupling structure reaches a stable state, the drilling fluid viscosity is calculated.

[0019] When the first coupling structure is coupled with the second coupling structure, the torque received by the first coupling structure and the second coupling structure when they stop rotating is obtained, and the drilling fluid viscosity is calculated based on the torque received by the first coupling structure and the second coupling structure when they stop rotating.

[0020] In some embodiments, the preset drilling rate is identified in the following manner:

[0021] The vibration signal generated when the motor starts is frequency graded to obtain multiple frequency signals at different levels, and the target frequency signal related to the rotor drilling speed is extracted from the multiple frequency signals at different levels.

[0022] Calculate the envelope information of the target frequency signal, which is used to identify the periodic changes in drilling speed in the target frequency signal;

[0023] Calculate the weighted center frequency of the envelope information;

[0024] Determine the first target frequency signal corresponding to the target weighted center frequency in the weighted center frequency;

[0025] Based on the first target frequency component, the preset drilling speed is identified.

[0026] This specification provides an online drilling fluid viscosity detection device based on a sealed housing, comprising: a sealed housing, a rotor disposed inside the sealed housing, a stator disposed inside the rotor, a first coupling structure disposed at the top of the sealed housing, and a second coupling structure disposed at the top of the sealed housing. The first coupling structure is connected to both the stator and the second coupling structure. When the rotor reaches a preset rotational speed, it drives the stator to rotate. The device detects whether the first and second coupling structures are coupled. When the first and second coupling structures are not coupled, the stator rotation drives the first coupling structure to rotate. The preset rotational speed of the drill and the target drilling speed when the first coupling structure reaches a stable rotation are sent to a data processing module to calculate the drilling fluid viscosity. When the first and second coupling structures are coupled, the stator rotation simultaneously drives both the first and second coupling structures to rotate. The torque experienced by the first and second coupling structures when they stop rotating is sent to the data processing module to calculate the drilling fluid viscosity. In the embodiments described in this specification, the casing of the online drilling fluid viscosity detection device is completely sealed, thereby adapting to changes in temperature and pressure within the drilling well. This enables the detection of drilling fluid viscosity under different temperatures and pressures within the well, overcoming the limitations and low accuracy of existing online drilling fluid viscosity detection devices that have openings and can only be used for drilling fluid viscosity detection at normal temperature and pressure. By detecting whether the first coupling structure and the second coupling structure are coupled, and then specifically detecting the corresponding data, the data is sent to the data processing module to calculate the drilling fluid viscosity under uncoupled or coupled conditions, thus avoiding limitations and improving the accuracy of drilling fluid viscosity detection.

[0027] This specification provides an online drilling fluid viscosity detection method based on a sealed enclosure, comprising: detecting whether a first coupling structure and a second coupling structure are coupled; when the first coupling structure and the second coupling structure are not coupled, acquiring a preset drilling speed of the rotor and a target drilling speed when the first coupling structure reaches a stable rotation speed, and calculating the drilling fluid viscosity based on the preset rotation speed of the rotor and the target drilling speed when the first coupling structure reaches a stable rotation speed; when the first coupling structure and the second coupling structure are coupled, acquiring the torque received by the first coupling structure and the second coupling structure when they stop rotating, and calculating the drilling fluid viscosity based on the torque received by the first coupling structure and the second coupling structure when they stop rotating. In this specification embodiment, by detecting whether the first coupling structure and the second coupling structure are coupled, different data can be detected based on the coupling state, and different drilling fluid viscosity calculation methods can be selected based on the detected data to accurately obtain the drilling fluid viscosity, which is applicable to varying temperature and pressure environments within drilling operations. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0029] Figure 1 This is a schematic diagram of the structure of an online drilling fluid viscosity detection device based on a sealed box, as provided in the embodiments of this specification.

[0030] Figure 2 This is a schematic diagram of the module structure of the detection module and the data processing module provided in the embodiments of this specification;

[0031] Figure 3 This is a schematic flowchart of an online drilling fluid viscosity detection method based on a sealed box, as provided in the embodiments of this specification.

[0032] Explanation of reference numerals in the attached figures:

[0033] 100. Housing; 200. Motor; 300. Rotor; 350. Drill speed identification module; 400. Stator; 500. First coupling structure; 600. Second coupling structure; 700. Rotating shaft; 800. Torque application structure; 900. Detection module; 950. Data processing module. Detailed Implementation

[0034] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0035] See Figure 1 As shown, the above-mentioned online drilling fluid viscosity detection device based on a sealed box may include: a sealed box 100, a rotor 300 disposed inside the sealed box 100, a stator 400 disposed inside the rotor 300, a first coupling structure 500 disposed at the top inside the sealed box 100, and a second coupling structure 600 disposed at the top outside the sealed box 100. The first coupling structure 500 is connected to the stator 400 and the second coupling structure 600 respectively. When the rotation speed of the rotor 300 reaches a preset speed, it drives the stator 400 to rotate.

[0036] The system detects whether the first coupling structure 500 and the second coupling structure 600 are coupled. When the first coupling structure 500 and the second coupling structure 600 are not coupled, the stator 400 rotates to drive the first coupling structure 500 to rotate. The preset rotation speed of the drill 300 and the target drilling speed when the rotation of the first coupling structure 500 reaches a stable state are sent to the data processing module to calculate the drilling fluid viscosity.

[0037] When the first coupling structure 500 is coupled with the second coupling structure 600, the stator 400 rotates and simultaneously drives the first coupling structure 500 and the second coupling structure 600 to rotate. The torque received by the first coupling structure 500 and the second coupling structure 600 when they stop rotating is sent to the data processing module to calculate the drilling fluid viscosity.

[0038] The aforementioned online drilling fluid viscosity detection device has a completely sealed enclosure (sealed enclosure 100), which allows it to adapt to changes in temperature and pressure within the drilling well. This enables the detection of drilling fluid viscosity under different temperatures and pressures within the well, solving the problem that existing online drilling fluid viscosity detection devices have openings and can only be used for drilling fluid viscosity detection at normal temperature and pressure, resulting in significant limitations and low detection accuracy.

[0039] The aforementioned online drilling fluid viscosity detection device has a first coupling structure 500 at the top of its sealed housing 100 and a second coupling structure 600 at its outer top. When the first coupling structure 500 and the second coupling structure 600 are not coupled, the rotation of the stator 400 is transmitted to the first coupling structure 500. At this time, the target drilling speed when the rotation of the first coupling structure 500 reaches stability can be detected outside the sealed housing 100, thus indicating that the stator 400 has reached a stable drilling speed. This detection method effectively ensures the sealing of the housing, achieves accurate detection of drilling fluid viscosity, and is suitable for varying temperature and pressure environments within drilling operations. When the first coupling structure 500 and the second coupling structure 600 are coupled, the rotation of the stator 400 will drive the coupled rotation of the first coupling structure 500 and the second coupling structure 600. At this time, the torque experienced by the first coupling structure 500 and the second coupling structure 600 when they stop rotating can be detected outside the sealed chamber 100. This allows for accurate detection of drilling fluid viscosity within the sealed chamber 100, and is also applicable to varying temperature and pressure environments within drilling operations. By detecting whether the first coupling structure 500 and the second coupling structure 600 are coupled, and then specifically detecting the corresponding data to calculate the drilling fluid viscosity under uncoupled or coupled conditions, limitations can be avoided, and the accuracy of drilling fluid viscosity detection can be improved.

[0040] In some embodiments, the above-mentioned online detection device may further include a motor 200, which is disposed at the bottom of the sealed housing 100 and is connected to the drill 300 for transmission, and can be used to drive the drill to rotate when started.

[0041] By installing a motor 200 on the sealed housing 100, simply starting the motor 200 will drive the drill 300 to rotate, allowing the drill 300 to reach the preset drilling speed, which in turn will drive the stator 400 to rotate.

[0042] In some embodiments, the rotor 300 is rotatably connected to the sealed housing 100, the rotor 300 has a cavity, and the stator 400 is located inside the cavity of the drill 300.

[0043] The outer wall of the rotor 300 cavity and the inner wall of the stator 400 cavity have a target gap, which can be filled with drilling fluid. When the motor 200 starts, the drilling fluid can flow in the target gap. When the rotor 300 reaches the preset drilling speed, the viscous resistance of the drilling fluid generates torque, which can drive the stator 400 to rotate.

[0044] In some embodiments, the above-mentioned online detection device may further include a drill speed identification module 350, which can be used to identify whether the rotation speed of the drill 300 has reached a preset drilling speed.

[0045] Among them, when the drill speed identification module 350 identifies that the rotation speed of the drill 300 reaches the preset drilling speed, it can send the identified preset drilling speed to the data processing module 950 so that the subsequent data processing module 950 can calculate the drilling fluid viscosity based on the preset drilling speed and other data.

[0046] By using the drill speed identification module 350 to identify whether the rotation speed of the drill 300 has reached the preset drilling speed, it can be ensured that the same preset drilling speed is achieved regardless of whether the first coupling structure 500 and the second coupling structure 600 are coupled. Under the premise of the same preset drilling speed, drilling fluid viscosity detection can be carried out, which can effectively improve the detection accuracy of drilling fluid viscosity.

[0047] In some embodiments, see Figure 2 As shown, the above-mentioned online detection device may further include a detection module 900, which may include a coupling detection unit and a speed and torque integrated detection unit. The coupling detection unit is connected to the speed and torque integrated detection unit, and the speed and torque integrated detection unit is connected to the data processing module 950.

[0048] In some embodiments, the coupling detection unit can be used to detect whether the first coupling structure 500 and the second coupling structure 600 are coupled, and send the coupling detection result to the speed and torque integrated detection unit. The speed and torque integrated detection unit can be used to detect the target drilling speed of the first coupling structure 500 when it receives the coupling detection result that the first coupling structure 500 and the second coupling structure 600 are not coupled, and to detect the torque received by the first coupling structure 500 and the second coupling structure 600 when they stop rotating when it receives the coupling detection result that the first coupling structure 500 and the second coupling structure 600 are coupled, and send the target drilling speed and the torque to the data processing module 950.

[0049] The coupling detection unit detects whether the first coupling structure 500 and the second coupling structure 600 are coupled and sends the coupling detection result to the speed and torque integrated detection unit. This allows the speed and torque integrated detection unit to detect the corresponding data in a timely manner based on the coupling detection result and send it to the data processing module 950 for drilling fluid viscosity calculation. For example, when not coupled, the speed and torque integrated detection unit detects the target drilling speed when the first coupling structure 500 reaches a stable rotation. When coupled, the speed and torque integrated detection unit detects the torque applied when the first coupling structure 500 and the second coupling structure 600 stop rotating. Ultimately, the data processing module 950 can calculate the drilling fluid viscosity under different coupling conditions, making it highly applicable.

[0050] The detection module 900 and the drill speed identification module 350 mentioned above are located outside the sealed box 100. They can detect drilling speed, torque and other parameters inside the sealed box 100 from outside the sealed box 100, and are suitable for the changing temperature and pressure environment inside the well.

[0051] In some embodiments, the above-described online detection device may further include a torque application structure 800, which is connected to the second coupling structure 600. The torque application structure 800 can be used to apply an external force to the second coupling structure 600 to stop the rotation of the first coupling structure 500 and the second coupling structure 600.

[0052] The data processing module 950 described above can calculate the drilling fluid viscosity based on data such as the actual torque applied by the torque application structure 800.

[0053] In some embodiments, the online detection device may further include a rotating shaft 700 located inside the stator 400, the first coupling structure 500 being mounted on the rotating shaft 700, and the stator 400 being rotatably connected to the first coupling structure 500 at the top of the sealed housing 100 via the rotating shaft 700.

[0054] By rotatably connecting the stator 400 to the first coupling structure 500 at the top of the sealed housing 100 via the rotating shaft 700, the stator 400 can rotate to drive the first coupling structure 500 to rotate via the rotating shaft 700, or simultaneously drive the first coupling structure 500 and the second coupling structure 600 to rotate. That is, the rotational state of the stator 400 can be transmitted to the coupling structure via the rotating shaft 700.

[0055] It should be noted that when the first coupling structure 500 and the second coupling structure 600 are not coupled, the rotation of the first coupling structure 500 will not affect the state of the second coupling structure 600. However, when the first coupling structure 500 and the second coupling structure 600 are coupled, the rotation state of the first coupling structure 500 can be transmitted to the second coupling structure 600. Similarly, the second coupling structure 600 can also control the state of the first coupling structure 500, the rotating shaft 700, and the stator 400.

[0056] The working process of the above-mentioned online drilling fluid viscosity detection device based on a sealed box is described below:

[0057] When motor 200 starts, it drives drill 300 to rotate. Drill speed identification module 350 identifies whether the rotation speed of drill 300 reaches the preset drilling speed. If the preset drilling speed is reached, it is sent to data processing module 950. Simultaneously, the viscous resistance of the drilling fluid flow in the target gap between drill 300 and stator 400 generates torque, driving stator 400 to rotate. The rotation of stator 400 causes the rotating shaft 700 to twist. The coupling detection unit in detection module 900 can detect whether the first coupling structure 500 and the second coupling structure 600 are coupled, and the detection result is sent to the speed and torque integrated detection unit in the detection module. When the speed and torque integrated detection unit receives a coupling detection result indicating that the first coupling structure 500 and the second coupling structure 600 are not coupled, the speed and torque integrated detection unit detects the target drilling speed when the first coupling structure 500 reaches stability and the time required to reach the target drilling speed. When it receives a coupling detection result indicating that the first coupling structure 500 and the second coupling structure 600 are coupled, the speed and torque integrated detection unit detects the torque applied by the torque application structure 800 when the first coupling structure 500 and the second coupling structure 600 stop rotating (specifically, the torque application structure 800 applies an external force of 600 to the second coupling structure). The unit then sends the target drilling speed, the time required to reach the target drilling speed, and the torque to the data processing module. The data processing module can calculate the drilling fluid viscosity based on the drill's preset rotation speed, the target drilling speed when the first coupling structure reaches stability, and the time required to reach the target drilling speed, or it can calculate the drilling fluid viscosity based on the torque received when the first and second coupling structures stop rotating.

[0058] The complete sealing of the above-mentioned online drilling fluid viscosity detection device allows for the adjustment of pressure and temperature, thereby enabling the calculation of drilling fluid viscosity at various temperatures and pressures.

[0059] See Figure 3 As shown in the embodiments of this specification, an online drilling fluid viscosity detection method based on a sealed chamber is also provided. The method may include:

[0060] S301: Detect whether the first coupling structure 500 and the second coupling structure 600 are coupled;

[0061] S302: When the first coupling structure 500 and the second coupling structure 600 are not coupled, obtain the preset drilling speed of the rotor 300 and the target drilling speed when the first coupling structure 500 reaches a stable rotation speed. Calculate the drilling fluid viscosity based on the preset rotation speed of the rotor 300 and the target drilling speed when the first coupling structure 500 reaches a stable rotation speed.

[0062] S303: When the first coupling structure 500 is coupled with the second coupling structure 600, obtain the torque received by the first coupling structure 500 and the second coupling structure 600 when they stop rotating, and calculate the drilling fluid viscosity based on the torque received by the first coupling structure 500 and the second coupling structure 600 when they stop rotating.

[0063] In some embodiments, in S301 above, the coupling detection unit in the detection module 900 can be used to detect whether the first coupling structure 500 and the second coupling structure 600 are coupled. Based on the coupling state, different data (such as the target drilling speed when the rotation speed of the first coupling structure 500 reaches stability, the time required to reach stability, the torque received by the first coupling structure 500 and the second coupling structure 600 or the torque applied by the torque applying structure 800) can be detected. By combining the detected data, different drilling fluid viscosity calculation methods can be selected to accurately obtain the drilling fluid viscosity, which has high applicability.

[0064] In some embodiments, S302 can obtain the preset drilling speed of the rotor 300, the target drilling speed when the first coupling structure 500 rotates to a stable state, and the time required for the first coupling structure 500 to rotate to a stable state when the first coupling structure 500 and the second coupling structure 600 are not coupled, and calculate the drilling fluid viscosity when the first coupling structure 500 and the second coupling structure 600 are not coupled based on these parameters.

[0065] Specifically, the viscous torque M acting on the cylindrical side of stator 400 can be determined based on the Taylor-Kueit fluid dynamics theory for small gaps. η :

[0066]

[0067] Where η is the drilling fluid viscosity at the target rotational speed; R i The outer diameter of the stator is 400; R a ω is the inner diameter of rotor 300; L is the height of stator 400; out The preset rotational speed of rotor 300 (the preset drilling speed in this application is determined by drilling speed identification, which will be explained separately later).

[0068] After rearranging equation (1), the drilling fluid viscosity η is obtained as follows:

[0069]

[0070] According to the angular momentum theorem:

[0071] M η t=Jω const -Jω0(3)

[0072] Where J is the moment of inertia of stator 400, which can be calculated in advance; ω const ω0 is the target rotational speed after the first coupling structure 500 stabilizes; ω0 is the initial rotational speed of the first coupling structure 500; t is the time elapsed for the first coupling structure 500 to reach the target rotational speed from the initial rotational speed. In this embodiment, the first coupling structure 500 accelerates from rest to the first rotational speed under the influence of drilling fluid within the target gap, therefore ω0 equals 0.

[0073] Substituting equation (3) into equation (2) yields:

[0074]

[0075] According to the preset rotation speed ω out The time t required to reach stability and the target rotational speed ω when the first coupling structure reaches stability after 500 rotations. const This method can calculate the viscosity η of the drilling fluid to be tested. It is applicable to varying temperature and pressure environments within the drilling site, enabling the detection of drilling fluid viscosity under extreme temperature and pressure conditions.

[0076] In some embodiments, when the first coupling structure 500 and the second coupling structure 600 are coupled, the torque received by the first coupling structure 500 and the second coupling structure 600 when they stop rotating can be obtained, and the drilling fluid viscosity can be calculated based on the torque received by the first coupling structure 500 and the second coupling structure 600 when they stop rotating.

[0077] Specifically, after motor 200 starts, drilling fluid fills the target gap between rotor 300 and stator 400. Motor 200 drives rotor 300 to rotate via transmission belt, and rotor 300 drives the drilling fluid to flow within the target gap. The outer side of stator 400 rotates under the action of the viscous resistance torque of the drilling fluid. By measuring the rotation parameters of stator 400 or the output torque of the motor, the viscous resistance torque on stator 400 (which is equivalent to the torque applied by torque-applying structure 800 when the first coupling structure 500 and the second coupling structure 600 stop rotating) is obtained. Then, the viscosity of the drilling fluid is calculated according to the formula. The specific formula is:

[0078]

[0079] In the formula, η is the drilling fluid viscosity, K is a constant coefficient determined by the shape and size of the rotor 300 and the stator 400, M is the motor output torque (i.e. the torque applied by the torque application structure 800) that is equal to the viscous resistance experienced by the stator 400, and ω is the rotational angular velocity of the rotor 300.

[0080] It should be noted that different drilling fluid viscosities correspond to different K and M values ​​depending on the required measurement accuracy. Therefore, the shape and size of the stator 400 need to be adjusted to improve the accuracy of drilling fluid viscosity detection. Torque transmission via a coupling structure allows for a fully sealed overall device.

[0081] In some embodiments, the preset drilling rate in S302 described above can be identified in the following ways:

[0082] The vibration signal generated when the motor starts is frequency graded to obtain multiple frequency signals at different levels, and the target frequency signal related to the rotor drilling speed is extracted from the multiple frequency signals at different levels.

[0083] Calculate the envelope information of the target frequency signal, which is used to identify the periodic changes in drilling speed in the target frequency signal;

[0084] Calculate the weighted center frequency of the envelope information;

[0085] Determine the first target frequency signal corresponding to the target weighted center frequency in the weighted center frequency;

[0086] Based on the first target frequency component, the preset drilling speed is identified.

[0087] The target weighted center frequency is the weighted center frequency that is greater than a preset threshold, i.e., the maximum weighted center frequency. The first target frequency signal, which is the frequency signal corresponding to the maximum weighted center frequency, can be used as a significant frequency component. Ultimately, the preset drilling speed of drill 300 can be accurately identified through the significant frequency component.

[0088] Specifically, a binary tree filtering technique can be used to perform multi-resolution analysis of vibration signals. By decomposing the vibration or acoustic signal into multiple frequency levels, frequency components related to the equipment rotation speed are extracted, providing a foundation for subsequent processing. Hilbert transform is used to calculate the signal envelope information, which is used to identify the drilling speed cycle variation in the target frequency signal, improving the accuracy of feature extraction. The weighted centroid frequency of the envelope information is calculated. This step determines a representative frequency by weighted averaging the signal spectrum, which is directly related to the actual rotation speed of the equipment. The significant frequency components in the weighted centroid frequency are then identified to infer the equipment rotation speed, enabling real-time monitoring of the equipment's operating status. This invention's method achieves accurate identification of equipment rotation speed through multi-level frequency analysis, envelope information extraction, and weighted centroid frequency calculation. This method overcomes the limitations of traditional rotation speed measurement and is applicable to the condition monitoring of various mechanical equipment.

[0089] By identifying the preset drilling speed, it can be ensured that the same preset drilling speed exists regardless of whether the first coupling structure 500 and the second coupling structure 600 are coupled. Under the premise of the same preset drilling speed, drilling fluid viscosity detection can be carried out, which can effectively improve the detection accuracy of drilling fluid viscosity.

[0090] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0091] Although this specification has been described by way of examples, those skilled in the art will recognize that many variations and modifications are possible without departing from the spirit of this specification, and it is intended that the appended claims cover such variations and modifications without departing from the spirit of this specification.

Claims

1. An online drilling fluid viscosity detection device based on a sealed box, characterized in that, include: A sealed housing, a rotor disposed inside the sealed housing, a stator disposed inside the rotor, a first coupling structure disposed at the top of the sealed housing, and a second coupling structure disposed at the top of the sealed housing. The first coupling structure is connected to the stator and the second coupling structure respectively. When the rotational speed of the rotor reaches a preset speed, it drives the stator to rotate. The system detects whether the first coupling structure and the second coupling structure are coupled. When the first coupling structure and the second coupling structure are not coupled, the stator rotates to drive the first coupling structure to rotate. The preset rotation speed of the drill and the target drilling speed when the rotation of the first coupling structure reaches a stable state are sent to the data processing module to calculate the drilling fluid viscosity. When the first coupling structure is coupled with the second coupling structure, the stator rotation simultaneously drives the first coupling structure and the second coupling structure to rotate. The torque received by the first coupling structure and the second coupling structure when they stop rotating is sent to the data processing module to calculate the drilling fluid viscosity.

2. The online detection device according to claim 1, characterized in that, The online detection device also includes a motor, which is located at the bottom of the sealed housing and is connected to the drill bit for driving the drill bit to rotate when started.

3. The online detection device according to claim 1, characterized in that, The rotor is rotatably connected to the sealed housing, the rotor has a cavity, and the stator is located inside the cavity of the drill.

4. The online detection device according to claim 1, characterized in that, The online detection device also includes a drill speed identification module, which is used to identify whether the rotation speed of the drill has reached the preset drilling speed.

5. The online detection device according to claim 1, characterized in that, The online detection device further includes a detection module, which includes a coupled detection unit and a speed and torque integrated detection unit. The coupled detection unit is connected to the speed and torque integrated detection unit, and the speed and torque integrated detection unit is connected to the data processing module.

6. The online detection device according to claim 5, characterized in that, The coupling detection unit is used to detect whether the first coupling structure and the second coupling structure are coupled, and sends the coupling detection result to the speed and torque integrated detection unit. When the speed and torque integrated detection unit receives the coupling detection result that the first coupling structure and the second coupling structure are not coupled, it detects the target drilling speed of the first coupling structure. When the coupling detection result that the first coupling structure and the second coupling structure are coupled is received, it detects the torque that the first coupling structure and the second coupling structure experience when they stop rotating, and sends the target drilling speed and the torque to the data processing module.

7. The online detection device according to claim 1, characterized in that, The online detection device further includes a torque application structure, which is connected to the second coupling structure. The torque application structure is used to apply an external force to the second coupling structure to stop the rotation of the first coupling structure and the second coupling structure.

8. The online detection device according to claim 1, characterized in that, The online detection device also includes a rotating shaft located inside the stator, the first coupling structure being mounted on the rotating shaft, and the stator being rotatably connected to the first coupling structure at the top of the sealed box via the rotating shaft.

9. A method for online detection of drilling fluid viscosity based on a sealed chamber, characterized in that, Based on the online detection device according to any one of claims 1-8, the method includes: Detect whether the first coupling structure and the second coupling structure are coupled; When the first coupling structure and the second coupling structure are not coupled, the preset drilling speed of the rotor and the target drilling speed when the rotation of the first coupling structure reaches a stable state are obtained. Based on the preset rotation speed of the rotor and the target drilling speed when the rotation of the first coupling structure reaches a stable state, the drilling fluid viscosity is calculated. When the first coupling structure is coupled with the second coupling structure, the torque received by the first coupling structure and the second coupling structure when they stop rotating is obtained, and the drilling fluid viscosity is calculated based on the torque received by the first coupling structure and the second coupling structure when they stop rotating.

10. The online detection method according to claim 9, characterized in that, The preset drilling speed is identified in the following way: The vibration signal generated when the motor starts is frequency graded to obtain multiple frequency signals at different levels, and the target frequency signal related to the rotor drilling speed is extracted from the multiple frequency signals at different levels. Calculate the envelope information of the target frequency signal, which is used to identify the drilling rate periodic changes in the target frequency signal; Calculate the weighted center frequency of the envelope information; Determine the first target frequency signal corresponding to the target weighted center frequency in the weighted center frequency; Based on the first target frequency component, the preset drilling speed is identified.

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