Intelligent detection device for encapsulated particles and detection method thereof

Abstract

The invention discloses an intelligent detection device for encapsulated particles and a detection method thereof, and relates to the technical field of microcapsule detection. The device comprises a microscope, an image acquisition module, an external computer and a special glass slide, wherein the glass slide is provided with a composite microgroove structure comprising a hydrophilic coating concentric annular groove, a radial micro-channel, a hydrophobic capillary lock and an annular isolation strip; and a high-resilience sealing rubber ring is arranged in the edge sinking type sealing groove and cooperates with the distributed magnet unit and the soft iron ring of the magnetic conductive cover glass to form a magnetic control flattening mechanism. During detection, a liquid sample is dropped into the circle center and then self-diffused through the micro-channel to fill the circular ring groove, overflow is blocked through the capillary lock, the rubber ring is compressed through magnetic attraction force after the magnetic cover glass is covered, radial sealing and liquid film flattening are achieved, and finally in-situ accurate monitoring of the dynamic performance of encapsulated particles is achieved through microscope observation and computer analysis. The device breaks through the bottleneck of traditional liquid membrane preparation, and solves the problems of uneven liquid membrane, particle aggregation and complex operation.

Description

Technical Field

[0001] The present invention relates to the technical field of microcapsule detection, and in particular to an intelligent detection device for encapsulated particles and a detection method thereof. Background Art

[0002] In oil and gas field development, especially in horizontal and highly deviated well drilling operations, encapsulated lubricants effectively reduce the friction between the drill string and the wellbore, making them crucial for safe and efficient drilling. Therefore, accurate and reliable real-time monitoring of the dynamic properties of encapsulated particles in a liquid environment is crucial for optimizing lubricant performance and evaluating its field effectiveness.

[0003] However, the existing liquid encapsulated particle detection technology based on conventional optical microscopes has technical bottlenecks. When the liquid sample is applied to the slide and covered with a coverslip manually, the liquid film area is not accurately controlled, which easily leads to excessive sample coverage and overflow to the edge of the coverslip. The overflowed liquid will contaminate the microscope stage and optical components. At the same time, due to the lack of effective sealing at the edge of the coverslip, the liquid film will continue to leak due to evaporation or vibration during the observation process, destroying the stability of the observation environment and ultimately interfering with the continuous monitoring and analysis of the dynamic behavior of the particles. To this end, we propose an intelligent detection device and detection method for encapsulated particles. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention provides an intelligent detection device for encapsulated particles and a detection method thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: An intelligent detection device for encapsulated particles comprises a microscope, an image acquisition module and an external computer; it also comprises a glass slide placed on a microscope stage, with a composite microgroove structure provided in the central area; the composite microgroove structure comprises: multiple layers of concentric circular grooves, the bottom of the grooves being covered with a hydrophilic coating; radial microchannels extending outward from the geometric center of the glass slide and connecting the concentric circular grooves of each layer; a capillary lock, which is an annular microslit structure, provided at the outer edge of the outermost concentric circular groove and having a hydrophobic surface treatment; an annular isolation belt surrounding the outer edge of the composite microgroove structure; a sunken sealing groove provided outside the annular isolation belt; an elastic sealing rubber ring fixed in the sunken sealing groove and naturally protruding from the base surface of the glass slide; a distributed magnetic adsorption unit, which is composed of a plurality of independent magnets, the plurality of independent magnets being embedded below the sunken sealing groove and arranged in a ring corresponding to the edge projection of the sunken sealing groove; a magnetic cover glass, the edge of which is embedded with a soft iron ring, the projection of the soft iron ring covering the sunken sealing groove.

[0006] Preferably, the groove wall of the concentric annular groove has an inverted trapezoidal cross section.

[0007] Preferably, the surface of the annular isolation zone is a plane made of hydrophobic material.

[0008] Preferably, the cross section of the soft iron ring is a narrow rectangle.

[0009] Preferably, the radial microchannels extend evenly between adjacent concentric annular grooves, and the ends of the radial microchannels are tangentially connected to the concentric annular grooves.

[0010] Preferably, the elastic sealing rubber ring is made of synthetic rubber with a high compression rebound rate.

[0011] Preferably, the slit width of the capillary lock is smaller than the capillary critical value of the liquid.

[0012] Preferably, the depth of the radial microchannel is the same as the depth of the concentric annular groove.

[0013] Preferably, the magnets of the distributed magnetic adsorption unit are permanent magnets and are arranged with alternating polarities.

[0014] A method for detecting encapsulated particles using an intelligent detection device, comprising: S1, drop the liquid sample into the center of the composite microgroove structure; S2, the sample diffuses through the radial microchannel to fill the concentric ring groove, and the capillary lock blocks the overflow; S3, covering with a magnetic cover glass, the soft iron ring is compressed by the distributed magnetic adsorption unit to form a radial seal and flatten the liquid film; S4. The liquid film is observed by microscope, and the image acquisition module transmits data to the computer to analyze the dynamic performance of the particles.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The device achieves automatic and controllable diffusion of liquid samples through a composite microgroove structure and a hydrophilic / hydrophobic coating design (with radial microchannels). The sample is evenly filled in the concentric grooves through the radial microchannels to form a liquid film with uniform thickness; the hydrophobic microslit structure of the capillary lock accurately blocks liquid overflow, and the annular isolation zone further constrains the liquid film boundary. Combined with the radial seal and uniform pressure formed by the elastic sealing ring compressed by the magnetic cover glass under the action of the distributed magnetic adsorption unit, a highly stable and uniform thickness observation liquid film is finally obtained, eliminating the problems of liquid film unevenness, particle agglomeration or sedimentation caused by traditional manual smearing, laying the foundation for accurate imaging; The concentric circular grooves with an inverted trapezoidal cross-section, combined with a hydrophilic coating on the bottom of the grooves, provide a flow space for the encapsulated particles that resembles a real liquid environment, reducing interference from wall effects. The radial microchannels guide the sample to fill smoothly in a laminar manner, avoiding abnormal particle movement caused by turbulence. This biomimetic flow channel design, combined with a stable liquid film environment, allows the encapsulated particles to display their true dispersion state and dynamic behavior (such as motion trajectory and deformation characteristics) under downhole conditions during observation, ensuring clear and distortion-free images captured by the microscope, thereby supporting accurate analysis of particle morphology, size distribution, and dynamic performance. The device utilizes an integrated "drop-self-diffusion-magnetic sealing" process design. Simply drop the sample into the center of the circle and cover it with a magnetic cover glass. The distributed magnetic adsorption unit automatically achieves uniform compression of the elastic sealing rubber ring and flattening of the liquid film through a soft iron ring, eliminating the need for specialized smearing techniques or complex operations. This fast and reliable packaging method not only simplifies the process and reduces human error, but also enables direct application in oilfield environments, meeting the urgent need for real-time, in-situ monitoring of encapsulated lubricant performance and providing immediate data support for optimizing drilling processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of placing a glass slide according to the present invention; Figure 3 It is a partial cross-sectional schematic diagram of the structure of the glass slide of the present invention; Figure 4 Schematic diagram of separation of a glass slide and a magnetic cover glass according to the present invention; Figure 5 This is a schematic diagram of the bottom structure of the magnetic cover glass of the present invention; Figure 6 Schematic diagram of the composite microgroove structure of the present invention; Figure 7 This is a schematic cross-sectional view of the concentric ring grooves of the present invention; Figure 8 It is a schematic cross-sectional view of the structure of the sunken sealing groove of the present invention.

[0018] Explanation of the figure numbers: 1. Microscope; 2. Image acquisition module; 3. Computer; 4. Glass slide; 5. Composite microgroove structure; 6. Concentric ring grooves; 7. Radial microchannels; 8. Capillary lock; 9. Annular isolation belt; 10. Sunken sealing groove; 11. Elastic sealing rubber ring; 12. Distributed magnetic adsorption unit; 13. Magnetic cover glass; 14. Soft iron ring. DETAILED DESCRIPTION

[0019] The present invention will be described in further detail below with reference to the accompanying drawings.

[0020] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are for illustrative purposes only, and those skilled in the art will readily appreciate other obvious variations. The basic principles of the present invention defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0021] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "transverse", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate directions or positions are based on the directions or positional relationships shown in the accompanying drawings, which are merely simplified descriptions for the convenience of describing the present invention, and do not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the above terms should not be understood as limiting the present invention.

[0022] It is understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the elements may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0023] Example 1:

[0024] See also Figures 1-8 An intelligent detection device for encapsulated particles includes a microscope 1, an image acquisition module 2, and an external computer 3. The device also includes a glass slide 4 placed on a stage of the microscope 1, with a composite microgroove structure 5 disposed in the center. The composite microgroove structure 5 includes multiple layers of concentric annular grooves 6, the bottoms of which are covered with a hydrophilic coating. The multiple layers of concentric annular grooves 6 and the hydrophilic bottoms of the grooves create a gradient wetting field, which not only guides the uniform spreading of the liquid film, but also simulates the annular liquid storage area in the downhole annulus flow channel, causing the encapsulated particles to exhibit multi-radius curvature motion. Radial microfluidic channels 7 extend outward from the geometric center of the glass slide 4 and connect the concentric annular grooves 6. This design simultaneously achieves sample flow diversion and microscale eddy suppression, preventing distortion of the initial velocity of particles upon collision. Specifically, even at slow liquid flow rates, in traditional open smears or unstructured flow channels, sudden localized resistance fluctuations (e.g., contact angle hysteresis or wall roughness) can occur when the liquid edge contacts the glass slide 4. This resistance differential causes the liquid front to split into multiple streams, forming tiny vortices at their intersections (similar to the vortexes formed when water encounters a stone). These vortices can cause particles to rotate or accelerate, altering their natural motion. In this device, radial channels 7 extend uniformly from the center of the annular groove 6, evenly distributing the liquid from the center outward, thus preventing eddies caused by uneven forces on the liquid front. Furthermore, the micrometer-scale depth of the radial channels 7 maintains an ultra-low Reynolds number laminar flow regime (dominated by viscous forces), where inertial forces are negligible, naturally suppressing eddies. Furthermore, in traditional manual smears, eddies created during liquid spreading can impart additional rotation or instantaneous acceleration to particles, causing the observed particle trajectory under the microscope to deviate from its true state (e.g., particles should be moving at a constant speed, but are briefly accelerated by eddies). However, the laminar flow of radial flow channels 7 allows particles to be pulled only by the viscous forces of the liquid, resulting in an initial velocity closer to their true behavior in the encapsulated lubricant.

[0025] The capillary lock 8 is an annular micro-slit structure, which is provided on the outer edge of the outermost concentric ring groove 6 and has a hydrophobic surface treatment. While blocking overflow, it uses gas permeability to maintain the pressure balance of the microenvironment in the groove; The annular isolation zone 9 surrounds the outer edge of the composite micro-groove structure 5; the sunken sealing groove 10 is arranged outside the annular isolation zone 9; the two form a double-stage overflow prevention dam; The elastic sealing rubber ring 11 is fixed in the sunken sealing groove 10, and naturally protrudes from the base surface of the slide 4. When magnetically compressed, it produces radial creep, which not only seals but also eliminates the assembly tolerance of the magnetic cover glass 13; The distributed magnetic adsorption unit 12 is composed of multiple independent magnets, which are embedded under the sunken sealing groove 10 and arranged in a ring corresponding to the edge projection of the sunken sealing groove 10; the magnetic cover glass 13 has a soft iron ring 14 embedded on the edge, and the projection of the soft iron ring 14 covers the sunken sealing groove 10; the distributed magnetic adsorption unit 12 is coupled with the soft iron ring 14 of the magnetic cover glass 13 to convert discrete magnetic force into continuous surface pressure, thereby simultaneously realizing liquid film flattening and seismic buffering, such as vibration of oil field equipment.

[0026] Among them, the groove wall of the concentric ring groove 6 has an inverted trapezoidal cross-section. On the basis of expanding the hydrophilic contact area: the inclined surface guides the particles to spiral up along the wall, offsetting the gravitational sedimentation trend; the sharp-angled edge cuts the liquid boundary layer, inhibiting the centripetal migration of particles caused by the Weissenberg effect; the flat area at the bottom of the groove provides a zero-distortion observation window for the microscope 1, avoiding distortion of curved surface refraction imaging.

[0027] At the same time, the surface of the annular isolation belt 9 is a plane made of hydrophobic material, with capillary locks 8 and sunken sealing grooves 10 on both sides respectively. Its surface is flush with the surface of the glass slide 4. The hydrophobic material is used to construct a micron-level rough structure to achieve an increase in the super-liquid-repellent threshold and resist high-pressure seepage; at the same time, the annular isolation belt 9 can physically block the thermal expansion of the liquid film from overflowing into the sunken sealing groove 10; optionally, conductive particles can be doped into the hydrophobic material to electrostatically shield the influence of external electromagnetic interference on the movement of particles.

[0028] In this technical solution, the cross-section of the soft iron ring 14 is a narrow rectangle. The soft iron ring 14 with a narrow rectangular cross-section can achieve a magnetic flux concentration effect and enhance the edge magnet strength. At the same time, since the long side of the rectangle is parallel to the base surface of the glass slide 4, a parallel plate-like flow field can be formed when under pressure to avoid shear thinning of the liquid film. Furthermore, the low coercive force characteristics of the soft iron material can eliminate the liquid film disturbance caused by residual magnetic adsorption when the cover is removed.

[0029] In this technical solution, the radial microchannels 7 are evenly distributed and extend between adjacent concentric annular grooves 6, with a fast filling speed. Moreover, since the ends of the radial microchannels 7 are tangentially connected to the concentric annular grooves 6, the liquid is induced to form steady-state Taylor vortices, thereby enhancing the stability of particle suspension. At the same time, the equal-angle distribution of the radial microchannels 7 can form an optical diffraction grating to assist in the focal plane calibration of the microscope 1.

[0030] In addition, the depth of the radial microchannel 7 is the same as the depth of the concentric annular groove 6. The equal-depth design of the radial microchannel 7 and the concentric annular groove 6 can eliminate local pressure fluctuations caused by sudden changes in the channel cross-section, ensure continuous and smooth filling of the liquid, and avoid bubble mixing or uneven particle distribution; at the same time, the equal-depth channel can reduce the Reynolds number and maintain the Stokes flow state; in addition, the coplanarity of the groove bottom can reduce the optical thickness difference of the liquid film and meet the interference measurement accuracy.

[0031] It is worth noting that the elastic sealing ring 11 is made of synthetic rubber with a high compression rebound rate. The polymer chain entanglement structure of the synthetic rubber generates isotropic restoring force when under pressure to compensate for temperature deformation; at the same time, its oil-resistant molecular skeleton can resist lubricant swelling and ensure service life.

[0032] In this technical solution, the slit width of the capillary lock 8 is smaller than the capillary critical value of the liquid, and the hydrophobic coating can control the energy barrier of the liquid-gas interface to prevent leakage; at the same time, the micro-slit constitutes a Laplace pressure valve, which automatically increases pressure and locks when the liquid film expands; in addition, the nanoporous hydrophobic inner wall of the capillary lock 8 can adsorb gas molecules, forming an air film lubrication layer to reduce the adhesion of particles to the wall.

[0033] The operating process of the device is as follows: The first step is sample loading and initial diffusion. A suspension of encapsulated particles to be tested is dropped onto the starting point of the composite microgroove structure 5 at the center of the glass slide 4. When the droplet contacts the bottom of the concentric circular grooves 6 of the hydrophilic coating, the solid-liquid interfacial energy drops sharply, triggering capillary wetting. The liquid diffuses radially along the radial microchannels 7, forming a symmetrical flow front due to the uniform distribution of the channels. The inverted trapezoidal groove walls guide the liquid upward, preventing filling stagnation caused by contact angle hysteresis. The coordinated design of the channel depth stabilizes the initial thickness.

[0034] Step 2: Annular Groove Filling and Boundary Locking. Allow the device to rest for 5-10 seconds to allow the liquid to fill autonomously. Liquid flows through radial microchannels 7 into the multi-layered concentric grooves 6. The hydrophilic coating on the groove bottom continues to spread. The hydrophobic microslits of capillary locks 8 generate Laplace negative pressure, preventing liquid from overflowing. The hydrophobic surface of annular isolation zone 9 forms a second overflow barrier. The liquid front is confined within the outermost concentric grooves 6, forming an observation area with a constant diameter.

[0035] Step 3: Pre-position the magnetic cover glass 13. Horizontally place the magnetic cover glass 13 over the composite microgrooved area of ​​the slide 4. Initially align the narrow rectangular soft iron ring 14 at the edge of the magnetic cover glass 13 with the sunken sealing groove 10. The elastic sealing rubber ring 11 lightly contacts the soft iron ring 14, providing initial positioning friction. Maintaining a certain air gap before compression prevents premature deformation of the liquid film. The polarity distribution of the soft iron ring 14 and the magnet unit generates a weak guiding magnetic field, preventing the magnetic cover glass 13 from shifting.

[0036] Step 4: Magnetic Seal Flattens the Liquid Film. Lightly press the center of the magnetic cover glass 13 to trigger magnetic attraction. The magnets in the distributed magnetic attraction unit 12 generate a uniform magnetic field, which pulls the soft iron ring 14 downward. The soft iron ring 14 compresses the elastic sealing rubber ring 11, causing it to expand radially and fill the sunken sealing groove 10. The restoring force of the rubber ring is converted into vertical pressure, evenly flattening the liquid film beneath the magnetic cover glass 13.

[0037] Step 5: Establishing a Steady Microenvironment. The device is left to rest for 30 seconds to allow the system to equilibrate. The nano-air film layer of the capillary lock 8 regulates the micro-air pressure within the chamber, suppressing evaporation. The isobath flow channel and the tangential connection maintain Taylor-Couette flow, allowing the sample to reach a stable state.

[0038] Step 6: Dynamic Observation and Data Analysis. Activate microscope 1 and image acquisition module 2. The inverted trapezoidal walls of the concentric annular grooves 6 provide an observation window; the evenly distributed radial microchannels 7 form a diffraction grating, assisting in autofocus; and the magnetic sealing system provides shock absorption and cushioning.

[0039] After that, the data processing flow is as follows: First, a high-speed camera captures the particle motion; then computer 3 reconstructs the 3D trajectory and quantifies parameters (such as particle deformation index and dispersion uniformity); then computer 3 outputs a report on the dynamic performance evaluation of the lubricant (such as the predicted friction coefficient). Example 2:

[0040] This embodiment supplements the embodiment 1. Specifically, the magnet of the distributed magnet adsorption unit 12 is a permanent magnet with staggered polarity. The alternating NS pole arrangement of the permanent magnet can produce a Halbach array effect, thereby improving the uniformity of the magnetic field in the center of the magnetic cover glass 13; at the same time, it offsets the edge flux leakage and avoids the chain agglomeration of the magnetized encapsulated particles; further, the alternating magnetic field can induce the soft iron ring 14 to produce a slight vibration, thereby preventing the particles from settling.

[0041] Those skilled in the art will appreciate that the embodiments of the present invention described above and shown in the accompanying drawings are intended only as examples and are not intended to limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and illustrated in the embodiments. Any variations or modifications may be made to the embodiments of the present invention without departing from the principles herein.

Claims

1. An intelligent detection device for encapsulated particles, comprising a microscope (1), an image acquisition module (2) and an external computer (3); It is characterized by: It also includes a glass slide (4) placed on the placement table of the microscope (1), and a composite microgroove structure (5) is provided in the central area; the composite microgroove structure (5) includes: Multiple layers of concentric annular grooves (6), the bottom of the grooves being covered with a hydrophilic coating; Radial microfluidic channels (7) extending outward from the geometric center of the glass slide (4) and connecting the concentric annular grooves (6) of each layer; The capillary lock (8) is an annular micro-slit structure, which is provided on the outer edge of the concentric annular groove (6) in the outermost circle and has a hydrophobic surface treatment; An annular isolation zone (9) surrounding the outer edge of the composite microgroove structure (5); A sunken sealing groove (10) is provided outside the annular isolation zone (9); An elastic sealing rubber ring (11) is fixed in the sunken sealing groove (10) and naturally protrudes from the base surface of the slide glass (4); A distributed magnetic adsorption unit (12) is composed of a plurality of independent magnets, wherein the plurality of independent magnets are embedded below the sunken sealing groove (10) and arranged in a circular manner corresponding to the edge projection of the sunken sealing groove (10); A magnetic cover glass (13) has a soft iron ring (14) embedded in its edge, and the projection of the soft iron ring (14) covers the sunken sealing groove (10).

2. The intelligent detection device for encapsulated particles according to claim 1, characterized in that: The groove wall of the concentric annular groove (6) has an inverted trapezoidal cross section.

3. The intelligent detection device for encapsulated particles according to claim 1, characterized in that: The surface of the annular isolation zone (9) is a plane made of hydrophobic material.

4. The intelligent detection device for encapsulated particles according to claim 1, characterized in that: The cross section of the soft iron ring (14) is a narrow rectangle.

5. The intelligent detection device for encapsulated particles according to claim 1, characterized in that: The radial microchannels (7) are uniformly distributed and extend between adjacent concentric annular grooves (6), and the ends of the radial microchannels (7) are tangentially connected to the concentric annular grooves (6).

6. The intelligent detection device for encapsulated particles according to claim 1, characterized in that: The elastic sealing rubber ring (11) is made of synthetic rubber with a high compression rebound rate.

7. The intelligent detection device for encapsulated particles according to claim 1, characterized in that: The slit width of the capillary lock (8) is smaller than the capillary critical value of the liquid.

8. The intelligent detection device for encapsulated particles according to claim 1, characterized in that: The depth of the radial microchannel (7) is the same as the depth of the concentric annular groove (6).

9. The intelligent detection device for encapsulated particles according to claim 1, characterized in that: The magnets of the distributed magnetic adsorption unit (12) are permanent magnets and are arranged with alternating polarities.

10. A detection method based on the device according to any one of claims 1 to 9, characterized in that: include: S1, dropping the liquid sample into the center of the composite microgroove structure (5); S2, the sample diffuses through the radial microchannel (7) to fill the concentric annular groove (6), and the capillary lock (8) blocks overflow; S3, covering the magnetic cover glass (13), the soft iron ring (14) is acted upon by the distributed magnetic adsorption unit (12) to compress the elastic sealing rubber ring (11), thereby forming a radial seal and flattening the liquid film; S4, the microscope (1) observes the liquid film, and the image acquisition module (2) transmits data to the computer (3) to analyze the dynamic performance of the particles.

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