A device and experimental method for studying the surface characteristics of rock after acidizing modification

Abstract

This invention discloses an apparatus and experimental method for studying the surface characteristics of rocks after acidizing, belonging to the field of shale oil reservoir acidizing stimulation. The apparatus includes a reaction experiment module for fixing and positioning core samples; an image acquisition module for acquiring image data of the core samples; a 3D scanning module for acquiring stereoscopic images of the core samples; a temperature control module for heating the reaction vessel to provide a high-temperature environment for the acidizing reaction; a movable water injection module for precisely injecting experimental liquid onto the surface of the core samples; a temperature control and acid gas injection module for generating acid gas to acidize the core samples; and also includes a mechanical lifting module and an information calculation module. This invention can analyze different types of rocks and different types of gaseous acids, analyze the characteristics of rocks after acidizing under various combinations, thereby analyzing the mechanism and differences of gaseous acidizing, and providing theoretical support for the continued development of gaseous acidizing.

Description

Technical Field

[0001] This invention relates to the field of shale oil reservoir acidizing stimulation technology, and in particular to an apparatus and experimental method for studying the surface characteristics of rocks after acidizing stimulation. Background Technology

[0002] Currently, shale oil development primarily relies on large-scale volumetric fracturing in horizontal wells and surfactant infiltration. The connection between artificial and natural fractures significantly increases the surface area for surfactant infiltration, enhancing the matrix-fracture flow mechanism in shale oil. However, shale oil reservoirs have poor permeability, high clay mineral content, and poor acid injection capacity. Under acid treatment, clay particles are stripped, migrated, and accumulate in the throat, blocking the flow channels. Simple liquid acidification cannot achieve the goal of reservoir stimulation. Based on these issues, a method using gas-based acid fracturing to stimulate reservoirs is proposed. This method utilizes the ultra-low viscosity of gas to enter the pore throat for acid fracturing.

[0003] The descriptions of rock characteristics after conventional acidizing are relatively complete, but the mechanism of gas acidizing is still unclear, and the proposed evaluation of rock surface characteristics after gas acidizing is still lacking.

[0004] Changes in the roughness and wettability of rock surfaces after acidification can significantly affect the flowability in reservoir pores. The morphological description of rocks after acidification is quite complex. Current conventional description methods are relatively simple and require a lot of time and effort, and lack strict evaluation indicators. Summary of the Invention

[0005] The purpose of this invention is to provide an apparatus and experimental method for studying the surface characteristics of rocks after acidification, thereby solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides an apparatus for studying the surface characteristics of rocks after acidification, including a reaction experiment module for fixing and precisely locating core samples; The image acquisition module is used to acquire high-resolution images, ranging data, and grayscale images of core samples after acid treatment. The 3D scanning module is used to acquire stereoscopic images of core samples after acid treatment. The mechanical lifting module is used to adjust the position of the image acquisition module and the 3D scanning module; The temperature control module is used to heat and control the temperature of the reaction vessel to provide a high-temperature environment for the acidification reaction; A movable water injection module is used to precisely inject experimental liquids into the surface of core samples; The temperature control and acid gas injection module is used to generate acid gas and inject it into the reaction vessel to acidify the core sample. The information computing system is used to collect and analyze high-definition images, ranging data, grayscale images, and stereo images, as well as to control the image acquisition module, 3D scanning module, mechanical lifting module, temperature control module, movable water injection module, and temperature control and acid gas injection module. The image acquisition module includes an image acquisition controller, which is equipped with a level and a detachable lens module. The lens module includes a laser rangefinder, a high-definition camera, and a grayscale tester.

[0007] Preferably, the reaction experiment module includes a reaction vessel with an exhaust valve. Inside the reaction vessel is a flat base with several fixtures evenly distributed on the top of the flat base. One end of the fixture is slidably connected to the flat base via a slide rail, and the other end of the fixture is provided with a screw. By rotating the screw, the core sample is fixed between the fixture and the flat base.

[0008] Preferably, the temperature control module includes a heating cover one fixed to the outside of the reaction vessel. The heating cover one is a transparent heating cover. The heating cover one is connected to the reaction vessel by screw two. A temperature sensor for monitoring the temperature is provided on the heating cover one. An opening is provided on the heating cover one for the image acquisition module to acquire core sample image data.

[0009] Preferably, the movable water injection module includes a movable water injection pipe. The reaction container has an opening for the movable water injection pipe to extend into, and a sealing ring is provided at the opening. The movable water injection pipe is slidably and sealed to the opening of the reaction container through the sealing ring. The end of the movable water injection pipe away from the reaction container is connected to the outlet of an intermediate container for storing experimental liquid through a control container. The intermediate container is connected to a constant pressure and constant speed pump. The inlet and outlet of the control container are respectively provided with an electrically controlled inlet valve and an electrically controlled outlet valve. The control container is used to quantitatively output experimental liquid through the movable water injection pipe. A water level sensor is provided inside the control container to monitor the liquid level inside the control container in real time. An alarm is provided on the control container. When the amount of experimental liquid injected into the control container reaches the target value, the alarm automatically sounds.

[0010] Preferably, the temperature control and acid gas injection module includes an acid-resistant container for holding acid liquid, and a heating cover second is provided on the outside of the acid-resistant container. The heating cover second is used to provide heat to the acid liquid to accelerate the evaporation of acid liquid to form acid gas. The acid-resistant container is connected to the inside of the reaction vessel through a pipe, and an air inlet valve is provided on the pipe. A temperature sensor is provided on the heating cover second.

[0011] Preferably, the mechanical lifting module includes a lifting frame with lifting function, and two independent lifting bases with lifting function are provided on the lifting frame. The two lifting bases are respectively connected to the image acquisition controller and the 3D scanning module. The lifting bases are equipped with displacement sensors for recording the lifting height.

[0012] Preferably, the 3D scanning module includes a 3D scanner, which is mounted on a trolley. The trolley is slidably positioned on a sliding track, which is connected to a lifting base.

[0013] Preferably, the information computing system includes computer and instrument circuitry, with the computer connected to the image acquisition module, 3D scanning module, mechanical lifting module, temperature control module, movable water injection module, and temperature control and acid gas injection module via the instrument circuitry.

[0014] Preferably, it also includes a desktop with a base for supporting the reaction experiment module, the mechanical lifting module, the movable water injection module, and the temperature control and acid gas injection module.

[0015] This invention also provides an experimental method for studying the surface characteristics of rocks after acidification, comprising the following steps: Step S1: Take a natural stratum core, grind the core surface to keep it horizontal, dry it, and form a core sample for later use; Step S2: Clamp the core sample onto the flat plate base. Adjust the position of the retainer via the slide rail to stabilize the core sample and align it with the center of the flat plate base. Adjust the tightness of the screws to fix the core sample. Step S3: Turn on the computer, open the test software, analyze the initial image, and adjust the position of the image acquisition controller through the lifting frame and lifting base to achieve the optimal test position. Step S4: Fill the acid-resistant container with acid solution and close the air inlet valve; Step S5: Manually move the movable water injection pipe, align the water injection port of the movable water injection pipe with the center of the core sample, set the water injection volume of the control container and the injection speed of the constant pressure and constant speed pump, turn on the constant pressure and constant speed pump after preparation, stop the constant pressure and constant speed pump when the alarm sounds, and move the movable water injection pipe out of the field of view of the lens module. In step S6, the heating hood 1 and heating hood 2 are set to the temperature and heated respectively. The air inlet valve is opened, and the acid liquid enters the reaction vessel in gas form, gradually reacting with the water droplets on the surface of the rock sample in step S5. Step S7: Simultaneously with the reaction in step S6, image data is acquired from the surface of the core sample via an image acquisition controller. The acquired image data is transmitted to a computer for testing, and high-definition images, ranging results, and grayscale test results are obtained and stored. The computer records the mechanical parameters and test results of the current test. Step S8: Turn off laser ranging and grayscale testing, turn on the 3D scanner, and with the help of a high-definition camera, obtain a three-dimensional rock scan of the core sample, which is then recorded by the computer. Step S9: The experimenter uses a computer to retrieve the generated image files, analyzes the reports and logs, then shuts down all modules, removes the core sample, pours the remaining acid into the waste liquid bucket, and opens the exhaust valve to release the acid gas from the reaction vessel. Step S10: Clean all containers. The experiment is now complete.

[0016] Therefore, the present invention employs the above-mentioned apparatus and experimental method for studying the surface characteristics of rocks after acid treatment, which has the following beneficial effects: 1. In this invention, laser ranging, grayscale testing, high-definition image capture, and 3D rock scanning are performed simultaneously to achieve complex rock feature analysis and ensure the correspondence of image samples, which facilitates better analysis. The high integration of this invention also avoids improper operation and differences in operation by experimental personnel, and achieves simple, fast and efficient rock feature analysis. 2. This invention analyzes the surface characteristics of acid-treated rock cores, obtains various analytical images, analyzes the characteristic changes of rocks after acid treatment, analyzes the action mechanism of gaseous acid, compares it with conventional acid treatment, and reconstructs an evaluation method for the effect of gaseous acid treatment. 3. The apparatus and method in this invention can analyze different types of rocks and different types of gaseous acids, analyze the characteristics of rocks after acidification under various combinations, and thus analyze the mechanism and differences of gas acidification, providing theoretical support for the continued development of gas acidification.

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the device for studying the surface characteristics of rocks after acidification according to the present invention; Figure 2 This is a top view of the desktop in an embodiment of the present invention; Figure 3 This is a top view of the reaction vessel according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the sliding connection between the trolley and the sliding track according to an embodiment of the present invention; Figure 5 This is a surface contour undulation diagram of a core sample according to an embodiment of the present invention; Figure 6 This is a high-resolution image of the original surface of the core sample according to an embodiment of the present invention; Figure 7 This is a grayscale image of the surface of a core sample according to an embodiment of the present invention. Figure 8 This is a microscopic morphology diagram of the surface of a core sample according to an embodiment of the present invention; Figure 9These are microscopic elevation contour lines on the surface of a core sample according to an embodiment of the present invention.

[0019] Figure label: 1. Computer; 2. Desktop; 3. Instrument circuitry; 4. Equipment base; 5. Lifting frame; 6. Lifting knob; 7. Image acquisition controller; 8. Level; 9. Lens module; 10. Lifting base; 11. Trolley; 12. Sliding rail; 13. 3D scanner; 14. Acid-resistant container; 15. Heating cover II; 16. Air inlet valve; 17. Heating cover I; 18. Fixing device; 19. Flat base; 20. Core sample; 21. Screw I; 22. Exhaust valve; 23. Reaction vessel; 24. Movable water injection pipe; 25. Screw II; 26. Sealing ring; 27. Control container; 28. Alarm; 29. ​​Intermediate container; 30. Constant pressure and constant speed pump; 31. Fixing hole. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the embodiments of the present invention and are not intended to limit the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.

[0021] It should be noted that the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products, or devices.

[0022] Similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0024] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] Example: like Figure 1 As shown, the device for studying the surface characteristics of rocks after acid treatment according to the present invention includes a reaction experiment module, an image acquisition module, a 3D scanning module, a mechanical lifting module, a temperature control module, a movable water injection module, a temperature control and acid gas injection module, and a desktop 2. A device base 4 is provided on the desktop 2 to support the reaction experiment module, the mechanical lifting module, the movable water injection module, and the temperature control and acid gas injection module. Figure 2 As shown, the main function of the equipment base 4 is to support the various modules and connect the desktop 2. The equipment base 4 is provided with multiple fixing holes 31, the main function of which is to fix the various modules with bolts to prevent theft and knocking.

[0026] like Figure 3 As shown, the reaction experiment module is used for the fixation and precise positioning of the core sample 20. The reaction experiment module includes a reaction container 23, on which an exhaust valve 22 is installed. A flat base 19 is installed inside the reaction container 23. A retainer 18 is mounted diagonally on the surface of the flat base 19. One end of the retainer 18 is slidably connected to the flat base 19 via a slide rail, and the other end of the retainer 18 is fitted with a screw 21. There is a gap between the end of the retainer 18 with the screw 21 and the flat base 19. In use, the edge of the core sample 20 is placed in the gap, and the core sample 20 is fixed between the retainer 18 and the flat base 19 by rotating the screw 21. The position of the retainer 18 can be adjusted according to the diameter of the core sample 20 via the slide rail, and the tightness of the screw 21 can be adjusted to control the fixation of the core sample 20 and ensure that the center of the core sample 20 overlaps with the flat base 19 for accurate subsequent image acquisition. The reaction vessel 23 can be made of quartz glass (which has good transparency), which can ensure the effect of image acquisition and keep the reaction at a high temperature.

[0027] A temperature control module is used to heat and control the reaction vessel 23 to provide a high-temperature environment for the acidification reaction. The module includes a heating cover 17 fixed to the outside of the reaction vessel 23, which is connected to the vessel 23 via screws 25. The heating cover 17 has an opening for the image acquisition module to collect image data from the core sample 20, without affecting image acquisition. A required experimental temperature is set on the heating cover 17 to ensure the acidification reaction proceeds at a high temperature, allowing the acid gas entering the reaction vessel 23 to remain in a gaseous state and react with the experimental liquid (water in this embodiment). A temperature sensor is installed on the heating cover 17 to monitor the temperature; it will automatically adjust the temperature rise if a temperature drop is detected. The heating cover 17 is a transparent heating cover, such as an ITO / silver nanowire / graphene transparent conductive heating film, which can achieve uniform heating through resistance heating while maintaining a visible light transmittance of over 85%. By using optical optimization techniques such as selecting a low-haze substrate, applying a double-sided anti-reflection coating, and optimizing the curved surface structure of the cover, interference from light refraction, reflection, and scattering can be effectively eliminated, without causing substantial impact on structured light / laser 3D scanning. In addition, by arranging non-transparent modules such as electrodes, support structures, and pipelines of the heating cover in the edge area of ​​the scanning optical path, the problem of other modules obstructing the scanning field of view can be avoided.

[0028] A movable water injection module is used to precisely inject experimental liquid into the surface of core sample 20. The movable water injection module includes a movable water injection pipe 24, and an opening on the reaction container 23 for the movable water injection pipe 24 to extend into. A sealing ring 26 is provided at the opening, and the movable water injection pipe 24 is slidably sealed to the opening of the reaction container 23 through the sealing ring 26. One end of the movable water injection pipe 24 with the water inlet is inserted into the interior of the reaction container 23 through the opening, and the other end of the movable water injection pipe 24 away from the reaction container 23 is connected to the outlet of an intermediate container 29 for storing experimental liquid through a control container 27. The intermediate container 29 is connected to a constant pressure and constant speed pump 30. The constant pressure and constant speed pump 30 provides power to the intermediate container 29, driving the formation water in the intermediate container 29 to the control container 27. The movable water injection pipe 24 can move back and forth for injection and observation, and the sealing ring 26 mainly ensures that acidic gases inside the reaction container 23 do not leak out. The movable water injection tube 24 is made of alloy material, which ensures that its shape will not change arbitrarily when it is moved, and will not react with other liquids when they need to be injected, thus increasing the accuracy of the experiment.

[0029] The control container 27 is equipped with an electrically controlled inlet valve and an electrically controlled outlet valve at its inlet and outlet ends, respectively. The electrically controlled inlet valve can be installed on the pipeline between the intermediate container 29 and the control container 27, close to the inlet of the control container 27, to control the entry of experimental liquid. The electrically controlled outlet valve is installed on the pipeline between the control container 27 and the movable water injection pipe 24, close to the outlet of the control container 27, to control the quantitative output of experimental liquid. A water level sensor is installed inside the control container 27, which can be placed at the bottom for pressure measurement or at the top center for non-contact measurement, to monitor the liquid level in real time for quantitative measurement. An alarm 28 is installed on the control container 27; when the amount of experimental liquid injected into the control container 27 reaches the target value, the alarm 28 automatically sounds. The constant pressure and constant speed pump 30 is used as a power source to send the experimental liquid from the intermediate container 29 into the control container 27. After the quantitative measurement is completed, the electric control water inlet valve is closed. A small water pump can be installed at the water outlet of the control container 27 to directly provide power to the movable water injection pipe 24. Without relying on gravity or air pressure, the quantitative experimental liquid can be stably and reliably delivered to the surface of the core sample 20.

[0030] The temperature control and acid gas injection module is used to generate acid gas and inject it into the reaction vessel 23 to acidify the core sample 20. The module includes an acid-resistant container 14 for holding the acid solution. A heating shroud 15 is installed around the outside of the acid-resistant container 14 to provide heat to the acid solution, accelerating its evaporation and the formation of acid gas. The acid-resistant container 14 is connected to the inside of the reaction vessel 23 via a pipe equipped with an inlet valve 16. The heating shroud 15 completely encloses the acid-resistant container 14, providing heat to the acid solution and accelerating its evaporation to form acid gas, thus allowing the gaseous acid to enter the reaction vessel 23 more quickly. The acid-resistant container 14 can be made of Hastelloy alloy to prevent the acid solution from reacting with the container while ensuring good heat transfer, thereby increasing the evaporation rate of the acid solution. A temperature sensor is also installed on the heating shroud 15 to monitor and control the heating temperature.

[0031] The image acquisition module is used to acquire high-resolution images, ranging data, and grayscale images of core sample 20 after acid treatment. The 3D scanning module is used to acquire stereoscopic images of core sample 20 after acid treatment. The mechanical lifting module is used to adjust the positions of the image acquisition module and the 3D scanning module.

[0032] The image acquisition module includes an image acquisition controller 7, which is equipped with a level 8 and a detachable lens module 9. The lens module 9 includes a laser rangefinder, a high-definition camera, and a grayscale tester. The mechanical lifting module includes a lifting frame 5 with lifting function, and two independent lifting bases 10 with lifting function on the lifting frame 5. The two lifting bases 10 are connected to the image acquisition controller 7 and the 3D scanning module, respectively. Both the lifting frame 5 and the lifting bases 10 have two lifting modes: manual and automatic. Both the lifting frame 5 and the lifting bases 10 are equipped with lifting knobs 6, which can achieve transmission through a gear and a toothed rod. In manual lifting mode, rotating the lifting knob 6 drives the gear to rotate, and the gear, through meshing, drives the toothed rod to lift, thus lifting the lifting frame 5 and the lifting bases 10. In automatic lifting mode, the lifting frame 5 and the lifting bases 10 are lifted and lowered by hydraulic control (using a hydraulic cylinder) via computer 1. Because the gear can rotate on the toothed rod, hydraulic lifting is not hindered by manual lifting.

[0033] The lifting base 10 is equipped with a displacement sensor for recording the lifting height. Initially, the displacement sensor measures the height (initial position) from the platform (referring to the equipment base 4). After rising or falling, the distance from the platform is obtained from the displacement sensor, and the lifting height is obtained by subtracting the two (which can determine the position of the lens at this moment).

[0034] The various lenses in lens module 9 are replaceable. The high-definition camera, laser rangefinder, and grayscale tester all have a ranging accuracy of 1 micrometer and are connected to the upper lifting base 10 by threads for easy replacement.

[0035] The 3D scanning module includes a 3D scanner 13, which is mounted on a trolley 11. The trolley 11 is slidably mounted on a sliding rail 12, which is connected to a lifting base 10. Figure 4 As shown, a gear is provided on the trolley 11, and a rack adapted to the gear is provided on the sliding track 12. The gear and the rack are meshed together. A fixed shaft is provided in the middle of the gear, which extends to the outside of the trolley 11 and is connected to a manual knob. By turning the manual knob, the gear is rotated, the gear moves on the rack, and the trolley 11 slides on the sliding track 12, so as to realize the manual adjustment of the position.

[0036] The information computing system is used to collect and analyze high-definition images, ranging data, grayscale images, and stereo images, as well as to control the image acquisition module, 3D scanning module, mechanical lifting module, temperature control module, movable water injection module, and temperature control and acid gas injection module. The information computing system consists of a computer 1 and instrument circuit 3. The computer 1 is connected to the image acquisition module, 3D scanning module, mechanical lifting module, temperature control module, movable water injection module, and temperature control and acid gas injection module via instrument circuit 3. The connection between the computer 1 and each module via instrument circuit 3 uses existing electrical connection methods.

[0037] The present invention provides an experimental method for studying the surface characteristics of rocks after acid treatment, comprising the following steps: Step S1: Take a natural stratum core, grind the core surface to keep it horizontal, and dry it to form a core sample 20 for later use; Step S2: Clamp the core sample 20 on the flat base 19. Adjust the position of the fixer 18 through the slide rail to make the core sample 20 stable and coincide with the center of the flat base 19. Adjust the tightness of the screw 21 to fix the core sample 20. Step S3: Turn on computer 1, open test software (such as Image), analyze the initial image, and adjust the position of image acquisition controller 7 through lifting frame 5 and lifting base 10 to achieve the best test position; Step S4: Fill the acid-resistant container 14 with acid and close the air inlet valve 16. Step S5: Manually move the movable water injection pipe 24, align the water injection port of the movable water injection pipe 24 with the center position of the core sample 20, set the water injection volume of the control container 27 and the injection speed of the constant pressure and constant speed pump 30, and turn on the constant pressure and constant speed pump 30 when the control container 27 makes a sound. Then, move the movable water injection pipe 24 out of the field of view of the lens module 9. In step S6, the heating cover 17 and heating cover 2 15 are set to the temperature and heated respectively. The air inlet valve 16 is opened, and the acid liquid enters the reaction vessel 23 in gas form, and gradually reacts with the water droplets on the surface of the rock sample in step S5. In step S7, while reacting in step S6, image data is acquired on the surface of the core sample 20 through the image acquisition controller 7. The acquired image data is transmitted to the computer 1 for testing, and high-definition samples, distance measurement results and grayscale test results are obtained and stored. Step S8: Turn off laser ranging and grayscale testing, turn on 3D scanner 13, and with the help of a high-definition camera, obtain a three-dimensional rock scan of core sample 20, which is then recorded by computer 1. Step S9: The experimenter uses computer 1 to retrieve the acquired image files, analyze the reports and logs, then closes all modules, takes out the core sample 20, pours the remaining acid into the waste liquid bucket, opens the exhaust valve 22, and releases the acid gas from the reaction container 23. Step S10: Clean all containers. The experiment is now complete.

[0038] The implementation method is the same for cores of different sizes. After adjusting the focus by fixing device 18 and lifting frame 5 and lifting base 10, repeat the above steps.

[0039] By observing and comparing the obtained images, including microscopic contour lines, grayscale images, and high-resolution original images, the pitting on the rock surface can be analyzed. Surface roughness can then be calculated using mathematical methods, and the results displayed on a computer. Similarly, the contact angle method can be used to determine the wettability of the rock surface.

[0040] The surface roughness quantification method uses the centerline average roughness method: ; in, It is the sampling length. Is The distance of the contour offset at a given position is integrated by taking the absolute value of that distance as the sum of the distances over the entire sampling length, such as... Figure 5 As shown.

[0041] From the rough surface of the processed core sample 20, a measurement length is cut out. Using the centerline of the protrusions and depressions within this length as the X-axis and the perpendicular line to the centerline as the Y-axis, the roughness curve can be obtained using... This is represented by the following method: Using the centerline as a reference, the lower curve is folded back. The area covered by the entire curve above the centerline after the fold is then calculated, and divided by the measurement length. The resulting value, expressed in micrometers, is the average surface roughness value of the centerline within the measurement length range of the machined surface.

[0042] This invention overcomes the limitations of conventional, complex rock feature analysis. Previous tests often involved inconsistent core samples, testing times, and testing conditions, leading to inconsistent results that didn't accurately reflect the actual rock composition due to operator errors. This invention allows for simultaneous laser ranging, grayscale testing, high-definition image capture, and 3D rock scanning, ensuring consistent image quality for better analysis. Its high level of integration also avoids operator errors and discrepancies, enabling simple, fast, and efficient rock feature analysis.

[0043] This invention can achieve complex rock feature analysis, including but not limited to surface roughness analysis, high-definition image capture, surface grayscale testing, and 3D stereoscopic detection.

[0044] Taking a carbonate rock core as an example, the core surface is polished and then dried. The dried core is placed on a flat base 19, the movable fixing device 18 is moved, and screw 21 is tightened to secure the core. Computer 1 is turned on, the testing software is opened, the initial image is analyzed, and the mechanical lifting module is adjusted for focusing to achieve the optimal testing position. A drop of water is dripped onto the core surface through a movable water injection pipe 24. Subsequently, acidic gases evaporate in a high-temperature environment, causing an acidification reaction on the rock surface in the reaction vessel 23. Simultaneously, computer 1 tests the core surface, obtaining high-definition samples. The ranging and grayscale test results are stored. Laser ranging and grayscale testing are turned off, and 3D scanning is initiated to obtain a three-dimensional rock scan. Computer 1 retrieves useful parameters, generates image files, and produces analysis reports and logs.

[0045] By changing laser rangefinders and high-definition cameras of varying precision, images of different regions of the rock core with varying precision can be observed, allowing for step-by-step analysis from macroscopic to microscopic levels.

[0046] like Figure 6 , Figure 7 , Figure 8 , Figure 9 As shown, computer 1 can be used to analyze rock images at various levels, obtaining original high-resolution images, grayscale test images, reverse highlight images, microscopic morphology maps, microscopic elevation contour lines, and 3D stereoscopic images. By retrieving different locations on the image, the undulation map of the distance measurement results at any line or surface location can be analyzed.

[0047] The main purpose of this invention is to analyze the surface characteristics of acid-treated rock cores, obtain various analytical images, analyze the characteristic changes of rocks after acid treatment, analyze the action mechanism of gaseous acid, compare it with acid treatment with conventional acid solutions, and reconstruct an evaluation method for the effect of gaseous acid treatment.

[0048] The acidification effect varies for different types of rocks and different types of gaseous acids. The experimental methods and equipment provided by this invention can be used to analyze the characteristics of rocks after acidification under various combinations, thereby analyzing the mechanism and differences of gas acidification and providing theoretical support for the continued development of gas acidification.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An apparatus for studying the surface characteristics of rocks after acid treatment, characterized in that: It includes a reaction experiment module for fixing and precisely positioning core samples; The image acquisition module is used to acquire high-resolution images, ranging data, and grayscale images of core samples after acid treatment. The 3D scanning module is used to acquire stereoscopic images of core samples after acid treatment. The mechanical lifting module is used to adjust the position of the image acquisition module and the 3D scanning module; The temperature control module is used to heat and control the temperature of the reaction vessel to provide a high-temperature environment for the acidification reaction; A movable water injection module is used to precisely inject experimental liquids into the surface of core samples; The temperature control and acid gas injection module is used to generate acid gas and inject it into the reaction vessel to acidify the core sample. The information computing system is used to collect and analyze high-definition images, ranging data, grayscale images, and stereo images, as well as to control the image acquisition module, 3D scanning module, mechanical lifting module, temperature control module, movable water injection module, and temperature control and acid gas injection module. The image acquisition module includes an image acquisition controller, which is equipped with a level and a detachable lens module. The lens module includes a laser rangefinder, a high-definition camera, and a grayscale tester.

2. The apparatus for studying the surface characteristics of acid-treated rocks according to claim 1, characterized in that: The reaction experiment module includes a reaction vessel with an exhaust valve. Inside the reaction vessel is a flat base with several fixtures evenly distributed on the top of the flat base. One end of each fixture is slidably connected to the flat base via a slide rail, and the other end of each fixture is fitted with a screw. By rotating the screw, the core sample is fixed between the fixture and the flat base.

3. The apparatus for studying the surface characteristics of acid-treated rocks according to claim 2, characterized in that: The temperature control module includes a heating cover 1 fixed to the outside of the reaction vessel. The heating cover 1 is a transparent heating cover. The heating cover 1 is connected to the reaction vessel by screw 2. A temperature sensor for monitoring the temperature is provided on the heating cover 1. An opening is provided on the heating cover 1 for the image acquisition module to acquire core sample image data.

4. The apparatus for studying the surface characteristics of acid-treated rocks according to claim 3, characterized in that: The movable water injection module includes a movable water injection pipe. An opening for the movable water injection pipe to extend into is provided on the reaction container, and a sealing ring is installed at the opening. The movable water injection pipe is slidably and sealed to the opening of the reaction container through the sealing ring. One end of the movable water injection pipe with a water inlet is inserted into the interior of the reaction container through the opening. The other end of the movable water injection pipe, away from the reaction container, is connected to the outlet of an intermediate container used to store experimental liquids via a control container. The intermediate container is connected to a constant pressure and constant speed pump. The inlet and outlet of the control container are respectively equipped with an electrically controlled inlet valve and an electrically controlled outlet valve. The control container is used to quantitatively output experimental liquids through the movable water injection pipe. A water level sensor is installed inside the control container to monitor the liquid level inside the control container in real time. An alarm is installed on the control container; when the amount of experimental liquid injected into the control container reaches the target value, the alarm automatically sounds.

5. The apparatus for studying the surface characteristics of acid-treated rocks according to claim 4, characterized in that: The temperature control and acid gas injection module includes an acid-resistant container for holding acid liquid. A heating cover is installed on the outside of the acid-resistant container. The heating cover is used to provide heat to the acid liquid to accelerate the evaporation of acid liquid and form acid gas. The acid-resistant container is connected to the inside of the reaction vessel through a pipe. An air inlet valve is installed on the pipe. A temperature sensor is installed on the heating cover.

6. The apparatus for studying the surface characteristics of acid-treated rocks according to claim 5, characterized in that: The mechanical lifting module includes a lifting frame with lifting function, and two independent lifting bases with lifting function are installed on the lifting frame. The two lifting bases are respectively connected to the image acquisition controller and the 3D scanning module. The lifting bases are equipped with displacement sensors for recording the lifting height.

7. The apparatus for studying the surface characteristics of acid-treated rocks according to claim 6, characterized in that: The 3D scanning module includes a 3D scanner, which is mounted on a trolley. The trolley is slidably set on a sliding track, which is connected to a lifting base.

8. The apparatus for studying the surface characteristics of acid-treated rocks according to claim 7, characterized in that: The information computing system includes a computer and instrument circuitry. The computer is connected to the image acquisition module, 3D scanning module, mechanical lifting module, temperature control module, movable water injection module, and temperature control and acid gas injection module via the instrument circuitry.

9. The apparatus for studying the surface characteristics of acid-treated rocks according to claim 1, characterized in that: It also includes a desktop with a base for supporting the reaction experiment module, mechanical lifting module, movable water injection module, and temperature control and acid gas injection module.

10. An experimental method for studying the surface characteristics of rocks after acidification, characterized in that: The apparatus for studying the surface characteristics of acid-treated rocks as described in claim 8 comprises the following steps: Step S1: Take a natural stratum core, grind the core surface to keep it horizontal, dry it, and form a core sample for later use; Step S2: Clamp the core sample onto the flat plate base. Adjust the position of the retainer via the slide rail to stabilize the core sample and align it with the center of the flat plate base. Adjust the tightness of the screws to fix the core sample. Step S3: Turn on the computer, open the test software, analyze the initial image, and adjust the position of the image acquisition controller through the lifting frame and lifting base to achieve the optimal test position. Step S4: Fill the acid-resistant container with acid solution and close the air inlet valve; Step S5: Manually move the movable water injection pipe, align the water injection port of the movable water injection pipe with the center of the core sample, set the water injection volume of the control container and the injection speed of the constant pressure and constant speed pump, turn on the constant pressure and constant speed pump after preparation, stop the constant pressure and constant speed pump when the alarm sounds, and move the movable water injection pipe out of the field of view of the lens module. In step S6, the heating hood 1 and heating hood 2 are set to the temperature and heated respectively. The air inlet valve is opened, and the acid liquid is converted into gas and enters the reaction vessel, where it gradually reacts with the experimental liquid droplets on the surface of the rock sample in step S5. Step S7: Simultaneously with the reaction in step S6, image data is acquired from the surface of the core sample via an image acquisition controller. The acquired image data is transmitted to a computer for testing, and high-definition images, ranging results, and grayscale test results are obtained and stored. Step S8: Turn off laser ranging and grayscale testing, turn on the 3D scanner, and with the help of a high-definition camera, obtain a three-dimensional rock scan of the core sample, which is then recorded by the computer. In step S9, the experimenter uses a computer to retrieve the acquired image files, analyzes the reports and logs, then shuts down all modules, removes the core sample, pours the remaining acid into the waste liquid tank, and opens the exhaust valve to release the acid gas from the reaction vessel. Step S10: Clean all containers. The experiment is now complete.

Images