A miniaturized formation sand grain size rapid detection device and detection method

Abstract

The application provides a small-sized formation sand particle size rapid detection device and a detection method, and belongs to the technical field of oil and gas development engineering. The rapid detection device comprises a box body, a sand adding funnel, a replaceable grading screen plate, a pluggable small partition plate, a screen plate fixing lock buckle, a liftable support, a vibration motor, a motor switch, a collection unit and an elastic telescopic scale strip. The collection unit comprises a collection sand funnel, a formation sand transparent collection tube and a lifting sliding piston. The device has small overall size and light weight, is convenient to carry, can realize step-by-step screening and independent collection of formation sand samples with different particle size ranges, can quickly judge the content of each particle size and quickly form an approximate visual result of the cumulative distribution of formation sand, and can further obtain particle size distribution characteristics such as D10, D50, D60, D90 and uniformity coefficient, so as to improve the efficiency of on-site particle size analysis and sand prevention decision.

Description

Technical Field

[0001] This invention relates to the field of oil and gas development engineering technology, specifically a miniaturized rapid detection device and method for formation sand particle size. Background Technology

[0002] Formation sand grain size analysis refers to obtaining the distribution characteristics and patterns of formation sand grain size through specialized methods, and obtaining parameters such as median grain size and uniformity coefficient. These parameters are the core content of sand production analysis and the most critical basic parameters for sand control design. For example, whether designing the sand-blocking accuracy of sand control screens, determining the gravel particle size of gravel packing, or judging the severity of sand production in oil and gas wells, formation sand grain size distribution data are required.

[0003] Currently, the particle size distribution of formation sand is mainly obtained through laboratory experiments. Commonly used particle size analysis equipment falls into two main categories: one is a vibrating sieve analyzer, which uses a set of standard sieves of varying precision (usually 8-10 sieve grades) to sieve sand samples under vibration, then weighs the mass of sand samples remaining on each sieve and plots the particle size distribution curve. Existing vibrating sieve analyzers typically employ a multi-layered structure of stacked standard sieves. After sieving, it is necessary to disassemble the sieves layer by layer, collect the residual sand samples separately, weigh the mass of each grade of sand sample, and further calculate the cumulative percentage content and plot the particle size distribution curve to obtain the characteristics of the formation sand particle size distribution. This involves numerous post-sieving and data acquisition steps, which is not conducive to quickly obtaining particle size distribution results at the well site. Furthermore, most vibrating sieve analyzers are bulky (usually occupying 1-2 square meters), heavy (tens or even hundreds of kilograms), require external power supplies and specialized vibrators, and the sieving process is time-consuming and cumbersome. The standard sieves are also easily damaged, making them unsuitable for on-site testing in remote well sites. The second type is the laser particle size analyzer, which uses the principle of laser diffraction to measure particle size. It has the advantages of fast detection speed (2-3 minutes), continuous data, and high degree of automation. However, the instrument has extremely high precision and is expensive. It has strict requirements for environmental protection such as dust prevention, shock prevention, constant temperature, and moisture prevention, and requires professional personnel to operate it. Therefore, it cannot be used in well site environments.

[0004] In actual oil and gas field engineering operations, well sites are often located in remote areas such as deserts, Gobi, mountains, offshore platforms, and swamps, with the nearest laboratory potentially hundreds or even thousands of kilometers away. After obtaining formation sand samples (such as produced sand samples, flowback sand samples, core cuttings, and drilling fluid-carried cuttings) on-site, the round-trip time for laboratory testing can be as short as 3-5 days, and as long as more than a week, severely hindering the efficiency of rapid on-site decision-making. Currently, there are almost no portable, rapid, and low-cost formation sand particle size testing devices suitable for well site use. Therefore, developing a miniaturized, portable, easy-to-operate, robust, and durable rapid formation sand particle size testing device and its supporting methods is an extremely urgent practical need.

[0005] In summary, the key issues that still exist in the current work on the analysis and testing of sand grain size in engineering well sites are mainly as follows: (1) Existing vibrating screen analyzers have complicated steps, many post-screening and data acquisition steps, and are large in size, heavy in weight and have many auxiliary parts; laser particle size analyzers are also large in size, have complicated operation steps, are suitable for optical precision parts, and are expensive; neither instrument is suitable for engineering site scenarios in remote well sites.

[0006] (2) Currently, the particle size analysis of sandstone in oil and gas wells is achieved by sending samples for testing over long distances. This method has problems such as long distances, long time consumption, and low efficiency, which restricts the analysis of sand production and rapid decision-making on sand prevention.

[0007] (3) At the oil and gas well engineering site and well site, there is no rapid detection equipment for formation sand particle size that is easy to carry over long distances, easy to operate and suitable for use at the well site, so it is impossible to realize rapid analysis of sand samples on site and support on-site engineering decision-making. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a miniaturized rapid formation sand particle size detection device and method, which is suitable for rapid detection and analysis of particle size distribution characteristics of produced sand samples or sand samples flushed out during operations at oil and gas well production sites, obtaining particle size distribution data to support on-site decision-making. It is also applicable to indoor formation sand particle size analysis and detection scenarios.

[0009] The technical solution of this invention is as follows: A miniaturized rapid detection device for formation sand particle size includes a housing, a sand adding funnel, a replaceable grading screen plate, a pluggable small partition, a screen plate fixing lock, a liftable support, a vibration motor, a motor switch, a collection unit, and an elastic retractable scale strip. The collection unit includes a sand collecting funnel, a transparent formation sand collecting tube, and a lifting sliding piston. The sand-adding funnel is located at the upper part of the starting end of the box and is connected to the grading and screening channel inside the box, used to introduce the sand sample of the formation to be tested into the first-level grading screen area. The replaceable grading screen plate is installed in the screen plate mounting groove on the upper part of the box, arranged along the length of the box, and fixed by the screen plate fixing buckle. The replaceable grading screen plate is provided with multiple continuous grading screen areas, and a partition slot is provided between two adjacent grading screen areas. The pluggable small partition is inserted into the partition slot to prevent the sand sample from entering the next grading screen area in advance during the step-by-step grading process, so that the sand sample can be fully vibrated and sieved in the current grading screen area. The screen plate fixing lock is located on both sides of the upper part of the box or at the edge of the replaceable grading screen plate, and is used to fix the replaceable grading screen plate in the box to prevent the replaceable grading screen plate from loosening during the screening process. The liftable support is located at the bottom of the box and is used to support the device, adjust the height of the device, adjust the horizontal state of the box, and adjust the sieve tilt angle. The vibration motor is located on the side or bottom of the box and is fixedly connected to the box via a mounting bracket. It is used to provide micro-vibration to the box and the replaceable grading screen plate, so that the sand sample is fully loosened, bounced and sieved in each grading screen area. The motor switch is located on the outside of the housing and is used to control the start and stop of the vibration motor; The sand collecting funnel is fixedly installed below each graded screen area and corresponds one-to-one with the corresponding graded screen area; the upper opening of the sand collecting funnel covers the effective screening area of ​​the corresponding graded screen area, so that all the sand particles passing through the screen can fall into the corresponding sand collecting funnel. The formation sand transparent collection pipe is a slender cylindrical transparent tube, the upper end of which is connected to the lower end of the sand collection funnel.

[0010] The lifting sliding piston is located at the bottom of the transparent formation sand collection tube, and can move up and down inside the tube, forming a seal at the bottom. After the test is completed, the operator can push the lifting sliding piston to move the formation sand column inside the transparent formation sand collection tube upwards, so as to read the sand sample height or discharge the sand sample. The elastic, stretchable scale strip is installed on one side of the formation sand transparent collection tube array. Its 0-degree end is fixed to the bottom of the first formation sand transparent collection tube, and its 100-degree end can elastically extend and retract along the direction of the collection tube. The elastic, stretchable scale strip is used to cooperate with the sand sample interface in each formation sand transparent collection tube after being pushed up by the lifting sliding piston, so as to quickly approximate the cumulative distribution of the formation sand sample.

[0011] Preferably, the box body is a small, elongated box structure used to install and fix the sand adding funnel, replaceable grading screen plate, pluggable small partition, liftable support, vibrating motor and sand collecting funnel.

[0012] Preferably, the housing is made of one of stainless steel, aluminum alloy, or high-strength engineering plastic.

[0013] More preferably, when used in a humid, saline, or oily well environment, the housing is made of stainless steel.

[0014] Preferably, to meet the requirements of portable use, the box has a small external size, which can be carried in an engineer's toolbox, equipment bag or backpack.

[0015] Preferably, the sides of the box are equipped with small handles, buckles, protective frames or anti-slip support feet to facilitate well site transportation and rapid on-site deployment.

[0016] Preferably, the sand-adding funnel is made of stainless steel.

[0017] Preferably, the sand-adding funnel is a cone-shaped funnel structure that is larger at the top and smaller at the bottom.

[0018] Furthermore, for ease of storage and carrying, the sand-adding funnel is a detachable structure. When in use, the sand-adding funnel is installed at the sand inlet end of the box, and it can be removed after the test is completed.

[0019] Preferably, to ensure the portability of the device, the replaceable grading screen plate adopts a short-pitch dense grading structure, that is, multiple grading screen areas are arranged within a limited length.

[0020] More preferably, the replaceable grading screen plate is provided with 20 grading screen zones, each grading screen zone corresponding to a particle size level; the length of each grading screen zone is the same or basically the same, and a clear dividing line is set between each grading screen zone; the screen precision is consistent within each grading screen zone, and the precision of different grading screen zones varies sequentially according to a preset particle size range.

[0021] The precision of the grading screen area can be configured according to the particle size characteristics of the sand samples at the well site. For example, it can be set to: 0.020mm, 0.038mm, 0.053mm, 0.075mm, 0.090mm, 0.106mm, 0.125mm, 0.150mm, 0.180mm, 0.212mm, 0.250mm, 0.300mm, 0.355mm, 0.425mm, 0.500mm, 0.600mm, 0.710mm, 0.850mm, 1.180mm, and 1.700mm. In practical applications, different precision combinations of screen plates can be replaced according to the formation sand particle size range to meet the testing needs of fine sand, medium sand, coarse sand, or mixed particle size sand samples.

[0022] More preferably, the replaceable grading screen plate is further provided with a tailings collection area, and a sand collection funnel and a transparent formation sand collection pipe connected to the lower end of the sand collection funnel are provided below the tailings collection area. Formation sand larger than the maximum sieve particle size of the replaceable grading screen plate will fall into the transparent formation sand collection pipe below the tailings collection area.

[0023] Preferably, the replaceable grading screen plate is made of stainless steel or wear-resistant metal.

[0024] Preferably, the pluggable partition is made of stainless steel, aluminum alloy or wear-resistant engineering plastic.

[0025] Preferably, the top of the pluggable partition is provided with a lifting hole, a lifting ring, or a bent handle so that the operator can remove it in sequence during the sieving process.

[0026] For the 20 grading screen areas and 1 tailings collection area, a total of 20 pluggable small partitions are set up to separate adjacent grading screen areas.

[0027] Preferably, the screen plate fixing buckle adopts a small stainless steel buckle, spring buckle, knob clamping part or quick clamp structure.

[0028] Preferably, 4 to 10 screen plate fixing buckles are set along the length of the box to ensure that the screen plate is subjected to uniform force and facilitates quick on-site disassembly, cleaning and maintenance.

[0029] Preferably, the liftable bracket adopts a foldable threaded adjustment foot, telescopic support foot, or anti-slip support foot structure.

[0030] More preferably, the materials of the liftable bracket include stainless steel screws, aluminum alloy supports, and rubber anti-slip bases.

[0031] Preferably, for easy packing and carrying, the height-adjustable support adopts a telescopic, foldable, or detachable structure.

[0032] Preferably, the bottom of the chamber is equipped with four adjustable supports, each with a height adjustment range of 5-50mm. By adjusting the height difference between the starting and ending supports, the chamber can be tilted at an angle of 0°-15° along the direction of sand sample movement. When the vibration motor provides vibration, this tilt angle allows the sand that has not passed through the current grading screen zone to slide more easily into the next grading screen zone after the adjacent pluggable partition is removed, thereby improving the efficiency of step-by-step grading and reducing sand sample loss or cross-grading mixing caused by manual manipulation.

[0033] Preferably, the vibration motor is a small eccentric vibration motor, and the motor housing is made of aluminum alloy or stainless steel protective housing.

[0034] Preferably, to meet the portable power supply requirements, the vibration motor uses 12V or 24V DC power supply, with a power of 5~50W, a vibration frequency of 20~60Hz, and an amplitude of 0.5~2.0mm.

[0035] Preferably, the motor switch can be connected to a speed control module to adjust the vibration intensity according to the sand sample particle size, moisture content, mud content, and agglomeration state. The power supply can be a rechargeable lithium battery, a portable power module, or an external DC power supply.

[0036] Preferably, the lower end of the sand collecting funnel is provided with an external thread, and the upper end of the transparent sand collecting pipe is provided with an internal thread connection port that matches the external thread at the lower end of the sand collecting funnel. The sand collecting funnel and the transparent sand collecting pipe are connected by threads.

[0037] Preferably, the sand collection funnel is made of one of stainless steel, aluminum alloy or transparent PC material, and has a shape that is larger at the top and smaller at the bottom; for 20 graded screen areas and 1 tailings collection area, a total of 21 sand collection funnels are set up to achieve independent collection of sand samples from each grade.

[0038] Preferably, the transparent collection pipe for formation sand is made of transparent PC, transparent acrylic, or transparent borosilicate glass.

[0039] Preferably, the transparent collection pipe for formation sand is made of transparent PC material to meet the impact resistance requirements of the well site.

[0040] Preferably, to meet the requirements for portable storage, the transparent sand collection tube adopts a detachable structure, which is screwed onto the bottom of the corresponding sand collection funnel during testing, and removed for centralized storage after testing is completed.

[0041] Preferably, the outer wall of the transparent formation sand collection pipe is provided with graduation lines to facilitate direct reading of the volume of sand samples at each level on site. A total of 21 transparent formation sand collection pipes are installed for 20 grading screen areas and 1 tailings collection area, ensuring that each grading screen area and tailings collection area corresponds to an independent collection pipe.

[0042] Preferably, the lifting sliding piston includes a piston body, a sealing ring, a push rod, and a push rod handle. The piston body is disposed inside the transparent collecting tube, and a sealing ring is installed on its outer periphery, forming a sliding seal with the inner wall of the collecting tube to prevent fine sand from leaking from around the piston. The upper end of the push rod is fixedly connected to the bottom of the piston body, and the lower end passes through the bottom of the collecting tube and is connected to the push rod handle. When the push rod handle is pushed, the push rod drives the piston body and the sealing ring to move upward along the inner wall of the transparent collecting tube, thereby pushing the sand in the tube upward as a whole; when the push rod handle is pulled downward, the piston body can return to its original position.

[0043] Preferably, a guide hole or guide sleeve is provided at the bottom of the transparent collection tube to limit the displacement of the push rod and ensure that the piston rises and falls smoothly.

[0044] More preferably, the piston body is made of one of the following materials: polytetrafluoroethylene, silicone, nitrile rubber, or stainless steel-coated sealing material, and the push rod is made of stainless steel.

[0045] Preferably, when not in use, the elastic and retractable scale strip can be rolled up and stored by a winding mechanism to reduce the overall space occupied by the device and improve portability.

[0046] Without installing the transparent sand collection tube, the box can be placed directly into a toolbox or backpack. The transparent sand collection tube, sand adding funnel, replaceable grading screen plate, and pluggable small partition can be placed separately in the storage box. When in use, the operator places the box on a flat surface, unfolds or adjusts the height-adjustable support, and installs the transparent sand collection tube, sand adding funnel, replaceable grading screen plate, and pluggable small partition to quickly detect the particle size of the sand. During operation, the sand sample to be tested enters the first-stage grading sieve area through the sand addition funnel and undergoes vibration sieving under the obstruction of the removable small partitions. After the first-stage sieving is completed, the adjacent removable small partitions are removed, and the remaining sand sample slides into the next-stage grading sieve area under the action of vibration and tilt angle, completing 20 stages of grading sieving in sequence. After sieving, sand samples of different particle size ranges fall into the corresponding formation sand transparent collection tubes, forming sand columns of different heights. Operators can obtain formation sand particle size distribution data based on the elastic extensible scale strip on one side of the formation sand transparent collection tube or the weighing results.

[0047] The detection method of the aforementioned miniaturized rapid formation sand particle size detection device includes the following steps: Using a grading screen plate to progressively sieve formation sand of different particle sizes, sand samples of different particle size ranges fall into their corresponding transparent collection tubes; keeping the sand sample interface in the first transparent collection tube unchanged, starting from the second transparent collection tube, push the bottom sliding piston to move the sand sample in the second transparent collection tube upwards until the lower reference position of the sand sample in the second transparent collection tube is connected to or aligned with the top of the sand sample interface in the first transparent collection tube; then push the bottom sliding piston of the third transparent collection tube to connect or align the lower reference position of the sand sample in the third transparent collection tube with the top of the sand sample interface in the second transparent collection tube; and so on, progressively pushing the bottom sliding pistons of subsequent transparent collection tubes to connect the interfaces of each level of sand sample, forming a continuous sand sample interface line. This interface line can approximately characterize the particle size sieving curve of the formation sand sample, thereby enabling rapid reading and judgment of the formation sand particle size distribution under well site conditions.

[0048] Preferably, the specific steps include: (1) Installation and adjustment of the device: Place the device on a flat surface and adjust the adjustable support to create a certain tilt angle along the direction of sand sample movement. Install the replaceable grading screen plate into the sieve plate mounting slot on the upper part of the box and secure it with the sieve plate fixing buckle. Insert the pluggable small partitions into the partition slots between adjacent grading screen areas in sequence. Install the transparent collection pipes for each stratum sand into the lower end of the corresponding sand collection funnel using threaded connections, ensuring that each grading screen area corresponds to one sand collection funnel and one transparent collection pipe for stratum sand.

[0049] (2) Sand sample addition and initial sieve analysis: Take a certain amount of sand sample from the formation to be tested and pour it into the sand adding funnel so that the sand sample enters the first-stage grading screen area. Start the vibration motor so that the sand sample is vibrated and sieved in the first-stage grading screen area. Sand particles smaller than the precision of the first-stage screen fall through the screen into the corresponding sand collection funnel and enter the first formation sand transparent collection tube. Sand particles that do not pass through the first-stage screen continue to remain in the current grading screen area under the obstruction of the pluggable small partition until the first-stage sieve is completed.

[0050] (3) Step-by-step plate selection and sequential sieving: After the first-stage sieving is completed, the pluggable partition between the first-stage and second-stage sieving screen areas is removed, allowing the remaining sand sample that did not pass through the first-stage screen to slide down into the second-stage sieving screen area under the influence of vibration and the tilt of the box. It is then blocked by the pluggable partition after the second stage. Vibration sieving continues, allowing sand particles that meet the second-stage particle size range to pass through the second-stage screen and enter the second formation sand transparent collection tube. In the same manner, the pluggable partitions between adjacent sieving screen areas are removed sequentially, allowing the sand sample to be sieved step by step according to particle size and fall into the corresponding formation sand transparent collection tube, until the sieving of all sieving screen areas is completed.

[0051] (4) Sand sample settling and sand column formation: After all grading and sieving are completed, the vibration motor is turned off, allowing the sand samples in the transparent collection tubes of each stratum to settle naturally. If necessary, the transparent collection tubes can be gently tapped or briefly vibrated to make the sand samples more compacted. At this time, sand columns of different heights will form in each transparent collection tube. Since each transparent collection tube has the same inner diameter and cross-sectional area, and the sand samples of each grade settle under the same or nearly the same compaction conditions, the height of each sand column is approximately related to the volume of the sand sample of the corresponding grain size grade. Each transparent collection tube represents a grain size grade. According to the scale on each transparent collection tube, the height or volume of each grade of sand sample can be read. The height of the sand column in each transparent collection tube can be used as a basis for rapid on-site reading of the sand sample content of that grain size grade.

[0052] (5) Piston progressively rising and interface connection: Using the sand sample interface in the first transparent collection tube corresponding to the smallest grain size classification as the starting reference interface, the sand sample interface in the first transparent collection tube is kept unchanged. Starting from the second transparent collection tube, the bottom sliding piston is pushed to move the sand sample in the second transparent collection tube upwards until the lower reference position of the sand sample in the second transparent collection tube is connected or aligned with the top of the sand sample interface in the first transparent collection tube. Then, the bottom sliding piston of the third transparent collection tube is pushed to make the lower reference position of the sand sample in the third transparent collection tube connected or aligned with the top of the sand sample interface in the second transparent collection tube. And so on, pushing the bottom sliding pistons of the subsequent transparent collection tubes one after another, so that the sand sample interfaces of each level are connected end to end, and finally forming a sand sample interface line that extends continuously from fine grain size to coarse grain size.

[0053] (6) Flexible and retractable scale strip assists in rapid reading: After the sand sample interface line is formed, an elastic and stretchable scale strip is set on one side or the front side of the formation sand transparent collection tube array, with the 0 scale end corresponding to the lower reference position of the first formation sand transparent collection tube, and the 100 scale end can be elastically stretched according to the cumulative interface height of the sand sample in the transparent collection tube. The operator can quickly approximate the cumulative distribution characteristics of the formation sand sample by observing the correspondence between the sand sample interface and the 0~100 scale on the scale strip.

[0054] The elastic and retractable scale strip is used to assist in reading the approximate cumulative percentage content of the formation sand sample. Its function is to establish a visual correspondence between the sand sample interface formed by the piston in the transparent collection tube and the cumulative percentage scale of 0~100, so that the grain size distribution trend of the formation sand can be quickly determined without immediate weighing or drawing.

[0055] (7) Judgment of the trend of approximate particle size sieve analysis: After the sand sample interfaces in the transparent collection tubes of each formation are connected end to end and correspond to the elastically expandable scale strip, all sand sample interfaces together form an approximate cumulative interface line extending from fine to coarse grains. This interface line represents different particle size levels horizontally and the approximate cumulative volume or cumulative relative content of sand samples of the corresponding particle size level vertically. Based on the correspondence between this interface line and the 0-100 scale on the elastically expandable scale strip, the approximate positions of characteristic particle sizes such as D10, D50, D60, and D90 can be quickly obtained. For rapid judgment scenarios at the well site, the continuous sand sample interface line formed after the lifting and sliding piston is pushed up can be directly used in combination with the reading of the elastically expandable scale strip as an approximate cumulative particle size sieving curve. This curve is used for selecting the sand blocking accuracy of sand control screens, making preliminary judgments on gravel filling particle size, and analyzing the severity of sand production.

[0056] The sand sample interface line formed after the lifting sliding piston is pushed up is a visual result for rapid on-site identification and is not the same as the standard cumulative particle size sieve analysis curve. The standard cumulative particle size sieve analysis curve is obtained by calculating the percentage content of each particle size based on the height, volume or mass of the sand sample in each transparent collection tube, and then calculating the cumulative percentage content in order of particle size from small to large.

[0057] Preferably, the above detection method further includes the following steps: (8) Data recording and plotting of standard cumulative particle size sieving curves: Based on the graduations on the transparent collection tubes of each stratum of sand, read the height or volume of each sand sample, and plot the standard cumulative particle size sieve analysis curve in conjunction with the corresponding sieve precision. The specific steps are as follows: Let hi be the height or volume of the sand sample in the i-th transparent collection tube, and H be the sum of the heights or volumes of the sand samples in all transparent collection tubes. Then, the formula for calculating the relative content pi of the i-th particle size fraction is shown in Equation I: (I) By accumulating the content in ascending order of particle size, the cumulative percentage content Pi corresponding to the i-th particle size can be obtained, and the calculation formula is shown in Equation II: (II) By plotting the sieve precision *di* corresponding to each graded sieve zone on the x-axis and the cumulative percentage content *Pi* on the y-axis, and smoothly connecting the points, a standard cumulative particle size sieve analysis curve can be obtained. This curve typically exhibits a smooth upward trend and can be used to determine particle size parameters such as D10, D50, D60, D90, and uniformity coefficient of formation sand samples. This provides a basis for on-site sand output analysis, selection of sand-blocking screen precision, and gravel filling particle size design.

[0058] In a further preferred embodiment, if further quantitative analysis is required in step (8), sand samples of each grade can be pushed out of the transparent collection tube of the formation sand and weighed to calculate the mass fraction of each particle size, thereby obtaining accurate particle size parameters such as D10, D50, D60, D90 and uniformity coefficient.

[0059] Preferably, the above detection method further includes the following steps: (9) Cleaning and resetting: After the test is completed, the formation sand transparent collection pipe, sand collection funnel, pluggable small partition and replaceable grading screen plate are removed in sequence, residual sand samples are removed and cleaned; after cleaning, each part is dried or wiped dry and put back into the storage container such as storage box or storage bag for use in the next well site test.

[0060] Through the above method, this invention not only enables stepwise sieving and independent collection of formation sand samples with different particle size ranges, but also allows for rapid determination of the content of each particle size class and rapid formation of an approximate visual result of the cumulative distribution of formation sand (approximate cumulative particle size sieving curve) using a transparent collection tube, a lifting sliding piston, and an elastic, expandable scale strip. Furthermore, it can obtain particle size distribution characteristics such as D10, D50, D60, D90, and uniformity coefficient, reducing the time consumption in traditional sample delivery and weighing sieving processes, and minimizing steps such as layer-by-layer sieving, transfer, weighing, and manual drawing, thereby improving the efficiency of on-site particle size analysis and sand control decision-making. Simultaneously, when precise analysis is required, the standard cumulative particle size sieving curve can be calculated based on the height, volume, or mass of each sand sample, achieving a combination of rapid identification and quantitative analysis.

[0061] Beneficial effects: (1) This invention provides a novel miniaturized rapid detection device and method for formation sand particle size. This device can not only achieve stepwise sieving and independent collection of formation sand samples with different particle size ranges, but also quickly determine the content of each particle size and quickly form an approximate visual result of the cumulative distribution of formation sand. Furthermore, it can obtain particle size distribution characteristics such as D10, D50, D60, D90 and uniformity coefficient, thereby improving the efficiency of on-site particle size analysis and sand control decision-making. At the same time, when precise analysis is required, the cumulative particle size sieving curve can be calculated based on the height, volume or mass of each level of sand sample, thereby achieving a combination of rapid identification and quantitative analysis.

[0062] (2) The device provided by the present invention is small in size and light in weight, and can be easily put into the toolbox or backpack of the engineer, making it easy to carry to any well site. It does not require an external power supply, is easy to use, and is suitable for rapid detection at engineering well sites. The detection method is simple and short in time, which can reduce the time consumption in the traditional process of sending and weighing and screening. It also reduces the steps of disassembling, transferring, weighing and drawing manually in the process of weighing and screening. Compared with the traditional process of sending and screening, which takes 3 to 5 days or even longer, this device shortens the detection time by hundreds of times, so that the field engineer can obtain particle size data immediately after receiving the sand sample, and timely support the sand production analysis and sand prevention decision.

[0063] (3) The device provided by the present invention has a simple structure, no expensive optical or precision mechanical parts, and the manufacturing cost is far lower than that of existing laser particle size analyzers and professional vibrating sieve analyzers; the initial investment is small, and it is easy to equip and promote its application in large quantities. Attached Figure Description

[0064] Figure 1 Front view of a miniaturized rapid formation sand grain size detection device; Figure 2 Top view of a miniaturized rapid formation sand grain size detection device; Figure 3Structural diagram of the collection unit for a miniaturized rapid detection device for formation sand grain size; Figure 4 Top view of a replaceable grading screen plate with pluggable partitions; Figure 5 Side view of a replaceable grading screen plate with pluggable partitions; Figure 6 The content of formation sand of each particle size in the transparent collection tube and the approximate cumulative particle size sieve analysis curves; Figure 7 The standard cumulative particle size sieve analysis curve; The components include: 1. Box body; 2. Sand adding funnel; 3. Replaceable grading screen plate; 4. Insertable small partition; 5. Screen plate fixing lock; 6. Liftable support; 7. Vibration motor; 8. Motor switch; 9. Sand collecting funnel; 10. Transparent collection pipe for formation sand; 11. Lifting sliding piston; 12. Elastic retractable scale strip; 13. Tailings collection area. Detailed Implementation

[0065] The present invention will now be described in detail with reference to specific embodiments. The description in this section is merely illustrative and explanatory, and should not be construed as limiting the scope of protection of the present invention.

[0066] Example 1: like Figures 1-5 As shown, a miniaturized rapid detection device for formation sand particle size includes a housing 1, a sand adding funnel 2, a replaceable grading screen plate 3, a pluggable small partition 4, a screen plate fixing lock 5, a liftable support 6, a vibration motor 7, a motor switch 8, a collection unit, and an elastic retractable scale strip 12. The collection unit includes a sand collecting funnel 9, a transparent formation sand collecting tube 10, and a lifting sliding piston 11.

[0067] The box 1 is a small, long, rectangular box structure. The box is made of SUS304 stainless steel and has the following external dimensions: length 520mm, width 100mm, and height 200mm.

[0068] The sand-adding funnel 2 is located at the upper part of the starting end of the box 1 and is connected to the grading and screening channel inside the box 1. It is used to introduce the sand sample of the formation to be tested into the first-level grading screen area. The sand-adding funnel 2 is a detachable structure. It is made of SUS304 stainless steel and has a cone-shaped funnel structure that is larger at the top and smaller at the bottom. Its upper diameter is 60mm, its lower diameter is 20mm, and its height is 60mm.

[0069] The replaceable grading screen plate 3 is installed in the screen plate mounting groove on the upper part of the housing 1, arranged along the length of the housing 1, and fixed by the screen plate fixing lock 5. The replaceable grading screen plate 3 is made of 316L stainless steel, with a length of 470mm, a width of 62mm, an effective screening width of 60mm, and a thickness of 0.8mm. The replaceable grading screen plate 3 is provided with 20 grading screen zones and 1 tailings collection zone 13, with each grading screen zone corresponding to a particle size level. To control the length of the device, the length of each grading screen zone is 20mm, the length of the tailings collection zone 13 is 20mm, and the spacing between adjacent grading screen zones is 1.5mm. The precision of the grading screen area is configured according to the particle size characteristics of the sand sample at the well site, specifically set as follows: 0.020mm, 0.038mm, 0.053mm, 0.075mm, 0.090mm, 0.106mm, 0.125mm, 0.150mm, 0.180mm, 0.212mm, 0.250mm, 0.300mm, 0.355mm, 0.425mm, 0.500mm, 0.600mm, 0.710mm, 0.850mm, 1.180mm, and 1.700mm.

[0070] Below the tailings collection area 13, there is a sand collection funnel 9 and a formation sand transparent collection pipe 10 connected to the lower end of the sand collection funnel 9. Formation sand larger than the maximum sieve particle size (1.700mm) of the replaceable grading screen plate will fall into the formation sand transparent collection pipe 10 below the tailings collection area 13.

[0071] A partition slot is provided between two adjacent grading screen zones. The pluggable small partition 4 is inserted into the partition slot to prevent the sand sample from entering the next grading screen zone prematurely during the step-by-step sieving process, so that the sand sample can be fully vibrated and sieved within the current grading screen zone. A total of 20 pluggable small partitions 4 are provided. They are made of stainless steel, with a thickness of 1.0 mm, a height of 30 mm, and a width that matches the effective sieving width of the replaceable grading screen plate 3.

[0072] The screen plate fixing buckle 5 is a small stainless steel buckle, which is set on both sides of the upper part of the box 1. Nine screen plate fixing buckles 5 are set along the length of the box to fix the replaceable grading screen plate 3 inside the box 1 and prevent the replaceable grading screen plate 3 from loosening during the screening process. The bottom of the box 1 is equipped with four liftable supports 6. The liftable supports 6 adopt telescopic support feet, including stainless steel screws, aluminum alloy supports and rubber anti-slip bases. The height adjustment range of a single liftable support 6 is 5~50mm. By adjusting the height difference between the starting end and the end support, the box can form an inclination angle of 0°~15° along the direction of sand sample movement.

[0073] The vibration motor 7 is located on the outside of the housing 1 and is fixedly connected to the housing 1 via a mounting bracket. It is used to provide micro-amplitude vibration to the housing 1 and the replaceable grading screen plate 3, so that the sand sample is fully loosened, agitated, and sieved in each grading screen area. The vibration motor 7 is a small eccentric vibration motor, powered by 12V DC, with a power of 30W, a vibration frequency of 50Hz, and an amplitude of 0.5~2.0mm; the motor housing is made of stainless steel protective casing.

[0074] The motor switch 8 is located on the outside of the housing 1 and is used to control the start and stop of the vibration motor 7. The power supply is a rechargeable lithium battery. The motor switch 8 can also be connected to a speed control module to adjust the vibration intensity according to the particle size, moisture content, mud content, and agglomeration state of the sand sample.

[0075] The sand collecting funnel 9 is provided with an external thread at its lower end, and the transparent sand collecting pipe 10 is provided with an internal thread connection port at its upper end that matches the external thread at the lower end of the sand collecting funnel 9. The sand collecting funnel 9 and the transparent sand collecting pipe 10 are connected by threads.

[0076] The sand collecting funnel 9 is fixedly installed below each grading screen area, corresponding one-to-one with the corresponding grading screen area. The upper opening of the sand collecting funnel 9 covers the effective screening area of ​​the corresponding grading screen area, ensuring that all sand particles passing through that level of screen fall into the corresponding sand collecting funnel 9. The sand collecting funnel 9 is made of stainless steel and has a shape that is wider at the top and narrower at the bottom. The upper opening size corresponds to the shape and size of the grading screen area. The upper opening length of the sand collecting funnel 9 is 20mm, the upper opening width is 60mm, and the lower opening diameter is 10mm. For 20 grading screen areas and 1 tailings collection area, a total of 21 sand collecting funnels 9 are set up to achieve independent collection of sand samples from each grading stage.

[0077] The formation sand transparent collection pipe 10 is a slender cylindrical transparent pipe made of transparent PC material, with an inner diameter of 10mm, an outer diameter of 12mm, and a length of 150mm. Graduation lines are set on the outer wall of the pipe. A total of 21 formation sand transparent collection pipes 10 are installed for the 20 grading screen zones and 1 tailings collection zone, ensuring that each grading screen zone and tailings collection zone corresponds to an independent collection pipe.

[0078] The lifting sliding piston 11 is located at the bottom of the transparent formation sand collection tube 10, and can move up and down within the tube, forming a seal at the bottom. The lifting sliding piston 11 includes a piston body, a sealing ring, a push rod, and a push rod handle. The piston body is made of stainless steel coated with sealing material, and the push rod is also made of stainless steel. After testing, the operator can push the lifting sliding piston to move the formation sand column upwards within the transparent formation sand collection tube, allowing for reading the sand sample height or discharging the sand sample.

[0079] The elastic retractable scale strip 12 is disposed on one side of the array of transparent sand collection tubes 10. Its 0-scale end is fixed to the bottom of the first transparent sand collection tube, and its 100-scale end can elastically extend and retract along the direction of the collection tube. When not in use, the elastic retractable scale strip 12 can be rolled up and stored by a winding mechanism to reduce the overall space occupied by the device and improve portability.

[0080] Example 2: In the well site environment, the device provided in Example 1 was used for rapid detection of formation sand particle size. The detection method is as follows: (1) Installation and adjustment of the device: Place the device on a flat surface and adjust the adjustable support 6 so that the box 1 is tilted at a 10° angle along the direction of sand sample movement. Install the replaceable grading screen plate 3 into the screen plate mounting groove on the upper part of the box 1 and fix it with the screen plate fixing buckle 5. Insert the pluggable small partitions 4 into the partition slots between adjacent grading screen areas in sequence. Install the transparent sand collection pipes 10 of each formation sand to the lower end of the corresponding sand collection funnel 9 by means of threaded connection, so that each grading screen area corresponds to a sand collection funnel 9 and a transparent sand collection pipe 10 of the formation sand.

[0081] (2) Sand sample addition and initial sieve analysis: Take a certain amount of sand sample from the formation to be tested and pour it into the sand adding funnel 2 so that the sand sample enters the first-stage grading screen area; start the vibration motor 7 so that the sand sample is vibrated and screened in the first-stage grading screen area. Sand particles smaller than the precision of the first-stage screen fall through the screen into the corresponding sand collecting funnel 9 and enter the first formation sand transparent collecting tube 10; sand particles that do not pass through the first-stage screen continue to remain in the current grading screen area under the obstruction of the pluggable small partition 4 until the first-stage grading is completed.

[0082] (3) Step-by-step plate selection and sequential sieving: After the first-stage sieving is completed, the pluggable partition 4 between the first-stage and second-stage sieving areas is removed, allowing the remaining sand sample that did not pass through the first-stage sieve to slide down to the second-stage sieving area under the action of vibration and the tilt angle of the box 1. It is then blocked by the pluggable partition 4 after the second stage. Vibration sieving continues, allowing sand particles that meet the second-stage particle size range to pass through the second-stage sieve and enter the second formation sand transparent collection tube 10. In the same manner, the pluggable partition 4 between adjacent sieving areas is removed in sequence, allowing the sand sample to be sieved step by step according to the particle size level and fall into the corresponding formation sand transparent collection tube 10, until the sieving of all sieving areas is completed. Sand samples larger than the maximum sieve particle size fall into the formation sand transparent collection tube 10 below the tailings collection area 13.

[0083] (4) Sand sample settling and sand column formation: After all grading and sieving are completed, the vibration motor 7 is turned off, allowing the sand samples in the transparent collection tubes 10 of each stratum to settle naturally. If necessary, the transparent collection tubes can be gently tapped or vibrated briefly to make the sand samples inside the tubes more compact. At this time, sand columns of different heights are formed in each transparent collection tube. According to the scale on each transparent collection tube, the height or volume of each grade of sand sample can be read. The height of the sand column in each transparent collection tube can be used as a basis for rapid on-site reading of the sand content of that grain size.

[0084] (5) Piston progressively rising and interface connection: Using the sand sample interface in the first transparent collection tube 10 corresponding to the smallest grain size classification as the starting reference interface, the sand sample interface in the first transparent collection tube remains unchanged. Starting from the second transparent collection tube, push the bottom sliding piston 11 to move the sand sample in the second transparent collection tube upward as a whole until the lower reference position of the sand sample in the second transparent collection tube is connected or aligned with the top of the sand sample interface in the first transparent collection tube. Then push the bottom sliding piston 11 of the third transparent collection tube to make the lower reference position of the sand sample in the third transparent collection tube connected or aligned with the top of the sand sample interface in the second transparent collection tube. And so on, push the bottom sliding piston 11 of the subsequent transparent collection tubes one after another to make the sand sample interfaces of each level connect end to end, and finally form a sand sample interface line that extends continuously from fine grain size to coarse grain size.

[0085] (6) Flexible and retractable scale strip assists in rapid reading: After the sand sample interface line is formed, the elastic and stretchable scale strip 12 is set on one side of the formation sand transparent collection tube 10 array, and the 0 scale end corresponds to the lower reference position of the first formation sand transparent collection tube. The 100 scale end can be elastically stretched according to the cumulative interface height of the sand sample in the transparent collection tube. The operator can quickly approximate the cumulative distribution characteristics of the formation sand sample by observing the correspondence between the sand sample interface and the 0~100 scale on the scale strip.

[0086] (7) Judgment of the trend of approximate particle size sieving: like Figure 6As shown, after the sand sample interfaces in the transparent collection tubes of each formation are connected end to end and correspond to the elastically expandable scale strip, all sand sample interfaces together form an approximate cumulative interface line extending from fine to coarse grains. This interface line represents different particle size levels horizontally and the approximate cumulative volume or cumulative relative content of sand samples of the corresponding particle size level vertically. Based on the correspondence between this interface line and the 0~100 scale on the elastically expandable scale strip, the approximate positions of characteristic particle sizes such as D10, D50, D60, and D90 can be quickly obtained. For rapid judgment scenarios at the well site, the continuous sand sample interface line formed after the lifting and sliding piston is pushed up can be directly used in combination with the reading of the elastically expandable scale strip as an approximate cumulative particle size sieving curve for selecting the sand blocking accuracy of the sand control screen pipe, making a preliminary judgment on the gravel filling particle size, and analyzing the severity of sand production.

[0087] (8) Data recording and plotting of standard cumulative particle size sieving curves: Based on the graduations on the transparent collection tubes of each stratum of sand, read the height or volume of each sand sample, and plot the standard cumulative particle size sieve analysis curve in conjunction with the corresponding sieve precision. The specific steps are as follows: Let hi be the height or volume of the sand sample in the i-th transparent collection tube, and H be the sum of the heights or volumes of the sand samples in all transparent collection tubes. Then, the formula for calculating the relative content pi of the i-th particle size fraction is shown in Equation I: (I) By accumulating the content in ascending order of particle size, the cumulative percentage content Pi corresponding to the i-th particle size can be obtained, and the calculation formula is shown in Equation II: (II) Plotting the sieve precision *di* corresponding to each graded sieve zone on the x-axis and the cumulative percentage content *Pi* on the y-axis, and then smoothly connecting the points, yields the standard cumulative particle size sieve analysis curve. The standard cumulative particle size sieve analysis curve is shown below. Figure 7 As shown, the curve is similar to... Figure 6 The approximate cumulative particle size sieve analysis curves shown generally maintain a consistent trend; the curves exhibit a smooth upward shape and can be used to determine particle size parameters such as D10, D50, D60, D90, and uniformity coefficient of formation sand samples, providing a basis for on-site sand output analysis, selection of sand-blocking screen pipe accuracy, and gravel filling particle size design.

[0088] If further quantitative analysis is required, sand samples of each grade can be pushed out of the transparent collection tube of the formation sand and weighed to calculate the mass fraction of each particle size, thereby obtaining accurate particle size parameters such as D10, D50, D60, D90 and uniformity coefficient.

[0089] (9) Cleaning and resetting: After the test is completed, the formation sand transparent collection pipe 10, sand collection funnel 9, pluggable small partition 4 and replaceable grading screen plate 3 are removed in sequence, residual sand samples are removed and cleaned; after cleaning, each component is dried or wiped dry and put back into the storage box or storage bag for use in the next well site test.

[0090] Through the above method, this invention not only enables stepwise sieving and independent collection of formation sand samples with different particle size ranges, but also allows for rapid determination of the content of each particle size class and the rapid formation of an approximate visual result of the cumulative distribution of formation sand using a transparent collection tube, a lifting sliding piston, and an elastic, expandable scale strip. Furthermore, it can obtain particle size distribution characteristics such as D10, D50, D60, D90, and uniformity coefficient, reducing the time consumption in traditional sample delivery and weighing sieving processes, and improving the efficiency of on-site particle size analysis and sand control decision-making. Simultaneously, when precise analysis is required, the cumulative particle size sieving curve can be calculated based on the height, volume, or mass of each sand sample, achieving a combination of rapid identification and quantitative analysis.

Claims

1. A miniaturized rapid detection device for formation sand grain size, characterized in that, It includes a housing, a sand funnel, a replaceable grading screen plate, a pluggable small partition, a screen plate fixing lock, a liftable support, a vibration motor, a motor switch, a collection unit, and an elastic retractable scale strip. The collection unit includes a sand collection funnel, a transparent collection pipe for formation sand, and a lifting sliding piston. The sand-adding funnel is located at the upper part of the starting end of the box and is connected to the grading and screening channel inside the box. The replaceable grading screen plate is installed in the screen plate mounting groove on the upper part of the box, arranged along the length of the box, and fixed by the screen plate fixing buckle. The replaceable grading screen plate is provided with multiple continuous grading screen areas, and a partition slot is provided between two adjacent grading screen areas. The pluggable small partition is inserted into the partition slot. The screen plate fixing buckle is set on both sides of the upper part of the box or at the edge of the replaceable grading screen plate. The liftable bracket is located at the bottom of the box; The vibration motor is located on the side or bottom of the housing and is fixedly connected to the housing via a mounting bracket; The motor switch is located on the outside of the housing; The sand collecting funnel is fixedly installed below each graded screen area and corresponds one-to-one with the corresponding graded screen area; the upper opening of the sand collecting funnel covers the effective screening area of ​​the corresponding graded screen area, so that all the sand particles passing through the screen can fall into the corresponding sand collecting funnel. The formation sand transparent collection pipe is a slender cylindrical transparent pipe, the upper end of which is connected to the lower end of the sand collection funnel; The lifting sliding piston is located at the bottom of the transparent sand collection pipe, and can move up and down inside the transparent sand collection pipe to form a seal at the bottom of the transparent sand collection pipe. The elastic and retractable scale strip is set on one side of the formation sand transparent collection tube array, with its 0 scale end fixed to the bottom of the formation sand transparent collection tube, and its 100 scale end elastically extending and retracting along the direction of the collection tube.

2. The apparatus as claimed in claim 1, characterized in that, The sand-adding funnel is a cone-shaped funnel structure that is larger at the top and smaller at the bottom, and the sand-adding funnel is a detachable structure.

3. The apparatus as described in claim 1, characterized in that, The replaceable grading screen plate is arranged with multiple grading screen areas and a tailings collection area. Each grading screen area corresponds to a particle size level. The screen precision in each grading screen area is consistent, and the precision of different grading screen areas changes sequentially according to the preset particle size range. The screen plate fixing buckle adopts a small stainless steel buckle, spring buckle, knob clamping part or quick clamp structure.

4. The apparatus as claimed in claim 1, characterized in that, Multiple liftable supports are provided, all of which adopt a telescopic, foldable, or detachable structure.

5. The apparatus as claimed in claim 1, characterized in that, The vibration motor is a small eccentric vibration motor, and the power supply can be a rechargeable lithium battery, a portable power module, or an external DC power supply.

6. The apparatus as claimed in claim 1, characterized in that, The lower end of the sand collecting funnel is provided with an external thread, and the upper end of the transparent formation sand collecting pipe is provided with an internal thread connection port that matches the external thread at the lower end of the sand collecting funnel. The sand collecting funnel and the transparent formation sand collecting pipe are connected by threads. The outer wall of the transparent sand collection pipe is marked with graduation lines; The lifting sliding piston includes a piston body, a sealing ring, a push rod, and a push rod handle; the piston body is located inside the transparent collection pipe of the formation sand, and a sealing ring is installed on its outer periphery to form a sliding seal with the inner wall of the collection pipe; the upper end of the push rod is fixedly connected to the bottom of the piston body, and the lower end passes through the bottom of the collection pipe and is connected to the push rod handle.

7. The detection method of the miniaturized rapid formation sand grain size detection device according to claim 1, characterized in that, The process includes the following steps: using a grading sieve plate to sieve formation sand of different particle sizes step by step, so that sand samples of different particle size ranges fall into the corresponding formation sand transparent collection tubes; keeping the sand sample interface in the first transparent collection tube unchanged, starting from the second transparent collection tube, push the bottom sliding piston to move the sand sample in the second transparent collection tube upward as a whole until the lower reference position of the sand sample in the second transparent collection tube is connected to or aligned with the top of the sand sample interface in the first transparent collection tube; Then, push the sliding piston at the bottom of the third transparent collection tube to make the lower reference position of the sand sample in the third transparent collection tube connect or align with the top of the sand sample interface in the second transparent collection tube; and so on, push the sliding piston at the bottom of the subsequent transparent collection tubes one after another to make the sand sample interfaces of each level connect end to end, forming a continuous sand sample interface line.

8. The method as described in claim 7, characterized in that, Specifically, the steps include the following: (1) Installation and adjustment of the device: Place the device on a flat surface and adjust the adjustable support to tilt the box along the direction of sand sample movement. Install the replaceable grading screen plate into the sieve plate mounting slot on the upper part of the box and secure it with the sieve plate fixing buckle. Insert the pluggable small partitions into the partition slots between adjacent grading screen areas in sequence. Install the transparent collection pipes of each formation sand to the lower end of the corresponding sand collection funnel by means of threaded connection, ensuring that each grading screen area corresponds to one sand collection funnel and one transparent collection pipe of formation sand. (2) Sand sample addition and initial sieve analysis: Take a sand sample from the formation to be tested and pour it into the sand addition funnel so that the sand sample enters the first-stage grading sieve area; Start the vibration motor to vibrate and sieve the sand sample in the first-stage grading screen area. Sand particles smaller than the precision of the first-stage screen fall through the screen into the corresponding sand collection funnel and enter the first formation sand transparent collection tube. Sand particles that do not pass through the first-stage screen continue to remain in the current grading screen area under the obstruction of the pluggable small partition until the first-stage sieve is completed. (3) Step-by-step plate selection and sequential sieving: After the first-stage sieving is completed, the pluggable partition between the first-stage and second-stage sieving screen areas is removed, allowing the remaining sand sample that did not pass through the first-stage screen to slide down into the second-stage sieving screen area under the influence of vibration and the tilt of the box. It is then blocked by the pluggable partition after the second stage. Vibration sieving continues, allowing sand particles that meet the second-stage particle size range to pass through the second-stage screen and enter the second formation sand transparent collection tube. In the same manner, the pluggable partitions between adjacent sieving screen areas are removed sequentially, allowing the sand sample to be sieved step by step according to particle size and fall into the corresponding formation sand transparent collection tube, until the sieving of all sieving screen areas is completed. (4) Sand sample settling and sand column formation: After all the grading and sieving are completed, the vibration motor is turned off, allowing the sand samples in the transparent collection tubes of each stratum to settle naturally, forming sand columns of different heights in each transparent collection tube; (5) Piston progressively rising and interface connection: The interface of the first sand sample in the transparent collection tube corresponding to the smallest grain size classification is used as the starting reference interface, and the interface of the first sand sample in the transparent collection tube is kept unchanged. Starting from the second transparent collection tube, push the bottom sliding piston to move the sand sample in the second transparent collection tube upwards until the lower reference position of the sand sample in the second transparent collection tube is connected to or aligned with the top of the interface of the sand sample in the first transparent collection tube. Then push the bottom sliding piston of the third transparent collection tube to make the lower reference position of the sand sample in the third transparent collection tube connect or align with the top of the sand sample interface in the second transparent collection tube; and so on, push the bottom sliding piston of the subsequent transparent collection tubes one by one to make the sand sample interfaces of each level connect end to end, and finally form a sand sample interface line that extends continuously from fine-grained to coarse-grained. (6) Flexible and retractable scale strip assists in rapid reading: After the sand sample interface line is formed, the elastic and stretchable scale strip is set on one side or the front side of the formation sand transparent collection tube array, and the 0 scale end corresponds to the lower reference position of the formation sand transparent collection tube, and the 100 scale end is elastically stretched according to the cumulative interface height of the sand sample in the transparent collection tube. (7) Particle size sieving trend judgment: After the sand sample interfaces in the transparent collection tubes of each stratum are connected end to end and correspond to the elastically expandable scale strip, all sand sample interfaces together form a cumulative interface line extending from fine-grained to coarse-grained. This interface line represents different particle size levels horizontally and the cumulative volume or cumulative relative content of sand samples of the corresponding particle size level vertically. Based on the correspondence between this interface line and the 0~100 scale on the elastically expandable scale strip, the characteristic particle size positions of D10, D50, D60, and D90 can be quickly obtained.

9. The method as described in claim 7, characterized in that, It also includes the following steps: Data recording and standard cumulative particle size sieving curve plotting: Based on the graduations on the transparent collection tubes of each stratum of sand, read the height or volume of each sand sample, and plot the standard cumulative particle size sieve analysis curve in conjunction with the corresponding sieve precision. The specific steps are as follows: Let hi be the height or volume of the sand sample in the i-th transparent collection tube, and H be the sum of the heights or volumes of the sand samples in all transparent collection tubes. Then, the formula for calculating the relative content pi of the i-th particle size fraction is shown in Equation I: （I） The cumulative percentage content Pi corresponding to the i-th particle size is obtained by accumulating the values ​​in ascending order of particle size, as shown in Equation II: (II) Plot the points with the sieve precision di corresponding to each graded sieve zone as the abscissa and the cumulative percentage content Pi as the ordinate, and then smoothly connect them to obtain the standard cumulative particle size sieve analysis curve.

10. The method as described in claim 7, characterized in that, It also includes the following steps: Cleaning and Resetting: After the test is completed, the formation sand transparent collection tube, sand collection funnel, pluggable small partition and replaceable grading screen plate are removed in sequence, residual sand samples are removed and cleaned; after cleaning, each part is air-dried or wiped dry and placed in the storage container.

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