A particle drag coefficient measurement system and method

Abstract

The application discloses a kind of granule resistance coefficient measurement system and measurement method, it is related to petroleum and natural gas technical field, measurement system includes: main structure includes cylinder, U-shaped pipe, peristaltic pump and flow sensor, cylinder is vertically arranged, the top end opening of cylinder, bottom end is closed, U-shaped pipe both ends are communicated with cylinder, peristaltic pump and flow sensor are arranged on U-shaped pipe;Fixed structure includes support frame, push-pull force meter and stem, push-pull force meter is arranged on support frame, push-pull force meter is located directly above cylinder, the detection end of push-pull force meter is connected with vertically arranged stem, the bottom end of stem extends into cylinder and is located between the both ends of U-shaped pipe, the bottom end of stem is connected spherical particle;Controller is electrically connected with peristaltic pump, for controlling the opening and closing of peristaltic pump, controller is electrically connected with push-pull force meter, flow sensor the advantage of the application lies in, can more accurately simulate the real working condition when wall surface constraint effect, improve measurement accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and natural gas, and in particular to a particle resistance coefficient measurement system and a measurement method. Background Art

[0002] During oil and gas drilling, drilling operations often must be temporarily halted due to operational constraints (such as changing drill bits or splicing) or unexpected circumstances, temporarily interrupting drilling fluid circulation within the annulus. Cuttings previously transported to the wellhead by the drilling fluid circulation begin to settle and deposit at the bottom of the well, causing wellbore cleaning issues. Settling velocity can be used to estimate the formation depth of drilled cuttings. Analysis of cuttings can reveal important formation information such as lithology, porosity, permeability, and pore pressure. Cutting settling velocity can typically be calculated using a particle settling resistance coefficient prediction model, and all cuttings transport models derived from physical laws require this resistance coefficient. In oil and gas development, accurate measurement of the particle settling resistance coefficient is a key technical foundation for evaluating cuttings transport efficiency and optimizing proppant transport and recirculation behavior. This parameter directly impacts wellbore cleaning during drilling, as well as the conductivity and production enhancement of the fracturing operation, ultimately impacting drilling safety and the efficiency of fracturing development.

[0003] In confined space flow problems involving cuttings transport in the wellbore annulus or proppant placement in fractures, the interference between particles and the wall significantly affects their motion. To study the wall effect, existing technologies often use glass plates with a fixed gap to simulate the wall effects in the drilling annulus and hydraulic fracturing fracture environments. This is used to measure the settling resistance of particles that take into account the wall effect. The specific measurement method is: fluid is poured between two glass plates with a fixed gap, and the test particles are dropped into the fluid using the ball dropping method. The particles are allowed to settle freely in the test fluid. The settling process of the particles is recorded by a high-speed camera to determine the terminal settling velocity of the particles. The measured velocity is then used to calculate the particle resistance coefficient. Although the above method is simple to operate, it cannot simulate the actual working conditions of particle settling. When the particle size is large (high Reynolds number) and the falling velocity is large enough, the inertial force of the surrounding fluid exceeds the viscous force, causing the laminar flow to transition to turbulent flow. The formation of turbulence will cause the free sedimentation path of particles to deviate. At the same time, when the measured particles are large, the gap between them and the wall of the glass plate is small, and the particles may also stick to the wall of the glass plate, resulting in low measurement accuracy and the inability to accurately restore the movement patterns of particles constrained by the wall in a confined space.

[0004] In summary, a method for measuring the particle drag coefficient that can more accurately simulate the wall confinement effect is needed. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a particle drag coefficient measurement system and measurement method, which can more accurately simulate the actual working conditions when the wall constraint effect occurs and improve measurement accuracy.

[0006] The present invention provides a particle drag coefficient measurement system, comprising:

[0007] The main structure includes a cylinder, a U-shaped tube, a peristaltic pump, and a flow sensor. The cylinder is vertically arranged with an open top and a closed bottom. Both ends of the U-shaped tube are connected to the cylinder. The peristaltic pump and the flow sensor are both arranged on the U-shaped tube. The peristaltic pump is used to deliver fluid into the cylinder.

[0008] A fixing structure for fixing spherical particles, the fixing structure comprising a support frame, a push-pull force gauge and a rod body, the push-pull force gauge being arranged on the support frame and being located directly above the cylinder body, the detection end of the push-pull force gauge being connected to the vertically arranged rod body, the bottom end of the rod body extending into the cylinder body and being located between the two ends of the U-shaped tube, the bottom end of the rod body being used to connect to the spherical particles, and the diameter of the rod body being smaller than the diameter of the spherical particles;

[0009] A controller is electrically connected to the peristaltic pump and is used to control the opening and closing of the peristaltic pump. The controller is electrically connected to the push-pull force meter and the flow sensor and is used to receive data detected by the push-pull force meter and the flow sensor in real time, and determine the resistance coefficient of the spherical particles based on the data detected by the push-pull force meter and the flow sensor, the cross-sectional area of ​​the cylinder, the diameter of the spherical particles and the density of the fluid.

[0010] Preferably, a flow sensor is provided on the U-shaped tube, the flow sensor is communicated with the output end of the peristaltic pump, and the flow sensor is electrically connected to the controller.

[0011] Preferably, the cylinder is a double-layer structure, both ends of the U-shaped tube are connected to the inner layer of the cylinder, and the bottom end of the rod is located in the inner layer of the cylinder.

[0012] Preferably, the inner diameter of the inner layer of the cylinder and the diameter of the spherical particles meet the requirement of 0.05< <1, where is the inner diameter of the inner layer of the cylinder, in m, is the diameter of the spherical particles, in m.

[0013] Preferably, the diameter of the rod and the diameter of the spherical particles satisfy 0.01 < <0.05, where is the diameter of the spherical particles, in m, a is the diameter of the rod, in m.

[0014] Preferably, further comprising: a temperature control structure for regulating the temperature of the fluid in the barrel, the temperature control structure comprising:

[0015] a water bath heating assembly, comprising a water tank, a temperature sensor, a water pump and a heating element, the water tank being used to hold a heat exchange medium, the temperature sensor, the water pump and the heating element being arranged in the water tank, the controller being electrically connected with the temperature sensor, the water pump and the heating element;

[0016] a water inlet pipe, one end of which is in communication with the water tank and the other end of which is in communication with the outer layer of the barrel;

[0017] a water outlet pipe, one end of which is in communication with the water tank and the other end of which is in communication with the outer layer of the barrel, the water inlet pipe being close to the bottom end of the barrel and the water outlet pipe being close to the top end of the barrel.

[0018] Preferably, the water inlet pipe and the water outlet pipe are detachably connected with the barrel and the detachable connection structures are the same, the detachable connection structure of the water inlet pipe and the barrel comprising:

[0019] a connecting head arranged on the sidewall of the barrel, the connecting head being in communication with the outer layer of the barrel, and the end of the water inlet pipe being threadedly connected with the connecting head.

[0020] A method for measuring the drag coefficient of particles, using a particle drag coefficient measuring system, comprising the following steps:

[0021] Pouring the fluid from the top of the barrel to ensure that the fluid submerges both ends of the U-shaped tube;

[0022] Fixing the spherical particles at the bottom end of the rod, then inserting the rod into the barrel, and setting zero when the value of the push-pull force gauge is constant;

[0023] Starting the peristaltic pump to make the fluid flow in the barrel from the bottom end to the top end of the barrel;

[0024] Making the flow sensor work, and recording the data detected by the push-pull force gauge and the flow sensor when the value detected by the flow sensor is constant;

[0025] Determining the particle drag coefficient based on the data detected by the push-pull force gauge and the flow sensor, the cross-sectional area of the inner layer of the barrel, the diameter of the spherical particles and the density of the fluid.

[0026] Preferably, the method for calculating the drag coefficient comprises the following steps:

[0027] (11)

[0028] wherein in formula (11), Q is the flow rate of the fluid detected by the flow sensor, in m 3 / s; A is the cross-sectional area of the inner layer of the cylinder, in m 2 ; V is the flow velocity of the fluid, in m / s;

[0029] (12)

[0030] wherein in formula (12), C is the drag coefficient; F is the force exerted on the spherical particle by the fluid detected by the push-pull gauge, in N; p is the density of the fluid, in kg / m 3 ; V 1 is the velocity of the fluid flowing in the cylinder, in m / s; D is the diameter of the spherical particle, in m, V is the velocity of the spherical particle, V is 0 m / s.

[0031] Compared with the prior art, the particle drag coefficient measurement system and measurement method have the beneficial effects that:

[0032] The system is different from the existing measurement system in the way of putting the spherical particles into the fluid. The device fixes the spherical particles by connecting the rod to the spherical particles. By making the fluid continuously flow between the cylinder and the U-shaped tube, the actual sinking scene of the spherical particles is simulated. The fixed spherical particles can limit the lateral freedom of the spherical particles. When the fluid flows through the spherical particles, the spherical particles will remain stable and will not swing, thereby avoiding the spherical particles deviating from the center line or adhering to the inner wall of the cylinder, affecting the measurement accuracy. The fluid flows from bottom to top in the cylinder, so that the push-pull gauge records the drag force on the simulated spherical particles during the falling process of the spherical particles, avoiding the influence of the rod on the detection accuracy. In summary, the system can simulate the actual working condition of the spherical particle settling, avoid the situation of the spherical particles deviating from the center line or adhering to the wall, and improve the measurement accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0034] Figure 1 It is a structural schematic diagram of the present invention;

[0035] Figure 2 It is a structural schematic diagram of the cylinder of the present invention;

[0036] Figure 3 For the present invention Figure 2 Schematic cross-section of the BB.

[0037] Reference numerals:

[0038] 1—support frame, 2—force gauge, 3—rod, 4—cylinder, 5—water tank, 6—flow sensor, 7—peristaltic pump, 8—U-shaped tube, 9—water inlet pipe, 10—spherical particles. DETAILED DESCRIPTION

[0039] A specific embodiment of the present invention is described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiment.

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the technical solution of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0041] In the description of the present invention, it should be noted that, unless otherwise specified or limited, the term "connection" should be understood in a broad sense. For example, it can mean a fixed connection, a detachable connection, or an integral connection; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean internal communication between two components. For those skilled in the art, the specific meanings of the above terms in this application can be understood by those skilled in the art in specific circumstances.

[0042] Additionally, in the description of the present invention, "plurality" refers to two or more than two. The terms "first" and "second" are used for descriptive purposes only and should not be understood to imply or suggest relative importance or implicitly indicate the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0043] Example 1

[0044] The embodiment of the present invention provides a particle drag coefficient measurement system such as Figure 1As shown, it includes: a main structure, a fixed structure, and a temperature control structure. The main structure includes a barrel 4, a U-shaped tube 8, a peristaltic pump 7, a flow sensor 6, and a controller. The barrel 4 is vertically arranged, and the top opening of the barrel 4 is convenient for fluid entry. The two ends of the U-shaped tube 8 are respectively connected to the barrel 4, and the fluid can enter the U-shaped tube 8 for circulation. The peristaltic pump 7 and the flow sensor 6 are both arranged on the U-shaped tube 8. By arranging the peristaltic pump 7, the fluid can circulate between the U-shaped tube 8 and the barrel 4. The peristaltic pump 7 consists of a driver, a pump head, and a hose. The fluid is isolated and operates in the U-shaped tube 8. The flow rate can be adjusted by adjusting the operating frequency of the peristaltic pump 7 (the flow rate range is 1m 3 / h~50m 3 / h), the flow sensor 6 is connected to the output end of the peristaltic pump 7, and the flow sensor 6 can detect the speed of the fluid passing through. The flow sensor 6 is a clamp-type flow sensor. The flow sensor 6 is installed at the outlet of the peristaltic pump 7. After installation, it is in a non-liquid-contact state and will not affect the flow of the fluid. The controller is electrically connected to the flow sensor 6 and the peristaltic pump 7. The barrel 4 is used to pass the fluid. The type of fluid is selected according to the needs of the experiment, including Newtonian fluid, non-Newtonian fluid (such as power-law fluid, Bingham plastic fluid and Herbach fluid) and fiber-containing drilling fluid, fracturing fluid, or other types of fluid. The fluid is circulated between the barrel 4 and the U-shaped tube 8 through the peristaltic pump 7. The flow sensor 6 can detect the flow rate of the fluid passing through and send the flow rate to the controller. In addition, the flow sensor 6 can also be set Inside the cylinder 4, it only needs to detect the flow rate of the fluid. The controller controls the operating frequency of the peristaltic pump 7 so that the flow rate of the fluid flowing between the cylinder 4 and the U-shaped tube 8 is stable (the flow rate required for the experiment can be set); the fixed structure is used to fix the spherical particles 10. The fixed structure includes a support frame 1, a push-pull force gauge 2 and a rod body 3. The push-pull force gauge 2 is set on the support frame 1 and is located directly above the cylinder 4. The push-pull force gauge 2 can be digitally displayed to facilitate readings during the experiment. The force range of the push-pull force gauge 2 is 0.001N~100N (resolution 0.001N). At the same time, the push-pull force gauge 2 can also be electrically connected to the controller to directly feed back the numerical value to the controller. The detection end of the push-pull force gauge 2 is connected to a vertically arranged rod body 3. The rod body 3 is a rigid thin rod and can be made of 316L stainless steel with a diameter of ≤0.5 mm to ensure that the spherical particles 10 have no lateral swing or rotation during fluid flow, thereby achieving precise measurement of micro-newton-level force, such as Figure 2 、 Figure 3As shown, the bottom end of the rod body 3 extends into the cylinder 4 and is located between the two ends of the U-shaped tube 8. The bottom end of the rod body 3 is used to connect the spherical particle 10. The diameter of the rod body 3 is smaller than the diameter of the spherical particle 10 and the diameter of the rod body 3 should be as small as possible. The rod body 3 is made of a rigid material and can fix the spherical particle 10, that is, the spherical particle 10 extends into the cylinder 4 and is located between the two ends of the U-shaped tube 8 (here, it refers to the height position of the spherical particle 10 in the cylinder 4 between the height positions of the two ends of the U-shaped tube 8). Fluid flows in the cylinder 4, and the rod body 3 connected to the spherical particle 10 can limit the lateral freedom of the spherical particle 10, so that the spherical particle 10 remains as stable as possible during fluid flow, thereby improving measurement accuracy; the temperature control structure is used to regulate the temperature of the fluid in the cylinder 4. The temperature control structure is electrically connected to the controller. The controller controls the temperature control structure to adjust the temperature so that the temperature of the fluid in the cylinder 4 is uniformly stable to avoid temperature differences affecting the measurement accuracy. In specific experiments, the temperature is usually controlled between 15°C and 30°C and kept at room temperature as much as possible.

[0045] This system is different from the existing measurement system that drops spherical particles 10 into the fluid. This device uses a rod 3 to connect the spherical particles 10 to fix the spherical particles 10. By allowing the fluid to continuously circulate between the cylinder 4 and the U-shaped tube 8, the actual sinking scene of the spherical particles 10 is simulated. Fixing the spherical particles 10 can limit the lateral freedom of the spherical particles 10. When the fluid flows through the spherical particles 10, the spherical particles 10 will remain stable and not swing, thereby preventing the spherical particles 10 from deviating from the center line or adhering to the inner wall of the cylinder 4, affecting the measurement accuracy. The fluid flows from bottom to top in the cylinder 4, so that the push-pull dynamometer 2 records the drag force exerted on the spherical particles 10 during the falling process of the simulated spherical particles 10, avoiding the influence of the rod 3 and causing inaccurate detection. In summary, this system can simulate the actual working conditions of the spherical particles 10 settling, avoid the situation where the spherical particles 10 deviate from the center line or adhere to the wall, and improve the measurement accuracy. In addition, the system is also provided with a temperature control structure, which can regulate the temperature of the fluid in the cylinder 4 to be consistent and stable, avoid the influence of temperature differences on the accuracy of measurement, and avoid the problem of inaccurate detection caused by various influences during detection. At the same time, even if the density of some spherical particles 10 is too low to realize the free sedimentation test of the particles in the fluid, the test can be realized in this device, which has extremely strong versatility and engineering applicability. It can also record the dynamic fluctuations of the force on the particles in the fiber-containing fluid in real time, extract the mean and variance of the resistance coefficient, and guide the optimization of the fiber type and concentration. It breaks through the traditional optical tracking method for fluid transparency, is not limited by the huge time-consuming experiment due to the low density of the particles, can be used for experimental testing with a variety of different types of particles, and is easy to operate, which significantly improves the universality of the experimental test.

[0046] This system, based on the principle of measuring particle forces driven by fluid circulation, connects a spherical particle 10 to a highly sensitive force-measuring element (a push-pull dynamometer 2), enabling real-time measurement of the drag force acting on the spherical particle 10 and automatic calculation of the drag coefficient. Compared to traditional ball-casting methods that rely on high-speed photography and image recognition, this device offers higher measurement accuracy and stronger anti-interference capabilities, avoiding systematic errors caused by factors such as eccentric particle settling and image resolution errors. Furthermore, the system can continuously adjust the flow rate, enabling simultaneous measurements under multiple Reynolds number conditions, significantly improving experimental efficiency and data density. It is suitable for drag coefficient testing scenarios involving particles of varying particle size, density, and fluid viscosity, as well as those that consider the influence of wall effects.

[0047] Furthermore, the cylinder 4 has a double-layer structure, having an inner layer and an outer layer, and the top and bottom ends between the inner layer and the outer layer are closed to form a closed interlayer. The two ends of the U-shaped tube 8 are connected to the inner layer of the cylinder 4, and the bottom end of the rod body 3 is located in the inner layer of the cylinder 4. The inner layer of the cylinder 4 is used to pass fluid.

[0048] Furthermore, the inner diameter of the inner layer of the cylinder 4 and the diameter of the spherical particles 10 satisfy 0.05< <1, where is the inner diameter of the inner layer of the cylinder 4, in m, is the diameter of the spherical particle 10, in m. The diameter of the spherical particle 10 can be changed within 5 mm to 98 mm, that is, 0.005 m to 0.098 m. This embodiment is to study the particle resistance coefficient when the influence of the particle wall effect is considered. Therefore, it is necessary to use large-sized particles of various sizes and densities for testing. Large-sized and high-density spherical particles 10 are installed to accelerate sedimentation and highlight the wall resistance. The diameter of the selected spherical particle 10 and the inner diameter of the inner layer of the cylinder 4 need to meet the above range. When conducting actual experiments, the particle resistance coefficient when the influence of the particle wall effect is not considered can also be studied as a control experiment. At this time, the diameter of the spherical particle 10 and the inner diameter of the inner layer of the cylinder 4 need to meet <0.05, that is, spherical particles with smaller particle size 10 (in this case, it can be considered that there is no wall effect). Setting a control group can analyze the influence of the wall effect on the particle resistance coefficient.

[0049] Furthermore, the diameter of the rod 3 and the diameter of the spherical particle 10 satisfy 0.01 < <0.05, where is the diameter of the spherical particle 10, in m, ais the diameter of the rod 3, in meters. This means that the selected diameter of the rod 3 and the diameter of the spherical particles 10 must fall within the aforementioned range. If the diameter is greater than this range, the rod 3 is too thick, which could affect fluid flow and the experimental results. If the diameter is less than this range, the rod 3 is too thin, which could cause the lateral oscillation of the spherical particles 10 to be unstable and introduce friction errors. Therefore, the diameter of the thin rod should be minimized without affecting the lateral oscillation of the spherical particles 10. The material used for the rod 3 can also be considered during actual experiments. If the rod 3 is made of a more rigid material, the diameter of the rod 3 can be even smaller. The aforementioned ranges given in this embodiment assume that the rod 3 is made of steel.

[0050] Example 2

[0051] As a further improvement on Example 1, this embodiment provides a specific method of temperature control structure, such as Figure 1 As shown, the temperature control structure further includes: a water bath heating component, a water inlet pipe 9, and a drain pipe. The water bath heating component includes a water tank 5, a temperature sensor, a water pump, and a heating element. The water tank 5 is used to hold a heat exchange medium (which can be a hot medium or a cold medium). In this embodiment, the water tank 5 holds water. The temperature sensor, water pump, and heating element are all arranged in the water tank 5. A cooling element can also be arranged in the water tank 5. The temperature of the water in the water tank 5 is regulated by controlling the operation of the heating and cooling elements. The controller is electrically connected to the temperature sensor, water pump, and heating element. One end of the water inlet pipe 9 is connected to the water tank 5, and the other end is connected to the outer layer of the cylinder 4. One end of the drain pipe is connected to the water tank 5, and the other end is connected to the outer layer of the cylinder 4. The water inlet pipe 9 is close to the bottom end of the cylinder 4, and the drain pipe is close to the top end of the cylinder 4. The operating principle of the temperature control structure in this embodiment is as follows: a temperature sensor detects the temperature of the water in the water tank 5 and feeds it back to the controller. The controller controls the operation of the heating or cooling element based on the measured temperature to adjust the temperature of the water in the water tank 5 to the desired temperature. The controller then activates the water pump to pump the water in the water tank 5 to the outer layer of the cylinder 4 for heat exchange, thereby regulating the temperature of the fluid in the inner layer of the cylinder 4 and stabilizing the fluid temperature. The heat-exchanged water flows radially downward along the cylinder 4 through the drain pipe and is then re-introduced into the water tank 5 for repeated use. The water inlet pipe 9 is located at the bottom end of the cylinder 4, and the drain pipe is located at the top end of the cylinder 4 (the drain pipe is located above the liquid level of the fluid in the cylinder 4). This is to ensure that the heat exchange medium flows from the bottom end of the cylinder 4 to the top end of the cylinder 4, allowing for better heat exchange with the fluid in the inner layer of the cylinder 4 and allowing the heat exchange medium to pass through the entire outer layer of the cylinder 4. Among them, the temperature control structure can adjust the temperature range from 0℃ to 80℃, with both heating and cooling effects. The set temperature and displayed temperature are clearly displayed, eliminating the influence of temperature on experimental results and improving test accuracy.

[0052] Furthermore, the water inlet pipe 9 and the drain pipe are both detachably connected to the cylinder 4, and the detachable connection structure is the same. This embodiment provides a specific method of a detachable connection structure. The detachable connection structure of the water inlet pipe 9 and the cylinder 4 includes: a connecting head is arranged on the side wall of the cylinder 4, the connecting head is connected to the outer layer of the cylinder 4, and the end of the water inlet pipe 9 is threadedly connected to the connecting head, that is, the water inlet pipe 9 and the drain pipe are both threadedly connected to the side wall of the cylinder 4 through the connecting head and are connected to the cylinder 4.

[0053] Among them, the other structures of this embodiment are consistent with those of Example 1, and are just optimizations made to Example 1.

[0054] Example 3

[0055] The embodiment of the present invention provides a method for measuring a particle drag coefficient, which is performed using the particle drag coefficient measurement system of embodiment 1 and embodiment 2, and includes the following steps:

[0056] Step 1: Pour the fluid into the cylinder 4 from the top, ensuring that the fluid submerges both ends of the U-shaped tube 8 and fills the U-shaped tube 8 and the cylinder 4 to simulate the fluid environment;

[0057] Step 2: Thread the water inlet pipe 9 and the drain pipe onto the side wall of the cylinder 4 through the connector, and start the water pump to introduce the heat exchange medium (water) in the water tank 5 into the outer layer of the cylinder 4, and continue to allow the heat exchange medium to circulate between the outer layer of the cylinder 4 and the water tank 5;

[0058] Step 3: Fix the push-pull force gauge 2 on the support frame 1, and fix the spherical particle 10 to the bottom end of the rod body 3 (the end of the rod body 3 away from the push-pull force gauge 2). The fixing method can be selected according to the material of the spherical particle 10 and the rod body 3. Then extend the rod body 3 into the cylinder body 4 so that the spherical particle 10 is located below the top of the U-shaped tube 8. After the value of the push-pull force gauge 2 remains unchanged, it is reset to zero. When the spherical particle 10 is inserted into the fluid in the cylinder body 4, the value detected by the push-pull force gauge 2 is the difference between the gravity of the spherical particle 10 and the rod body 3 and the buoyancy of the spherical particle 10 in the fluid. After the value is reset to zero, the value detected when the fluid flows is the resistance of the fluid to the spherical particle 10.

[0059] Step 4: Start the peristaltic pump 7 to allow the fluid to flow from the bottom end of the cylinder 4 to the top end of the cylinder 4 to conduct the experiment;

[0060] Step 5: Start the flow sensor 6. After the value detected by the flow sensor 6 remains unchanged, that is, after the flow rate stabilizes, record the data detected by the push-pull force meter 2 and the flow sensor 6, as well as the temperature of the outer layer of the cylinder 4 (experimental temperature).

[0061] Step 6: Obtain the density of the fluid and the diameter of the spherical particle 10, and determine the particle resistance coefficient and Reynolds number based on the data detected by the push-pull dynamometer 2 and the flow sensor 6, the cross-sectional area of ​​the inner layer of the cylinder 4, the diameter of the spherical particle 10 and the density of the fluid.

[0062] Furthermore, the calculation method of the drag coefficient includes the following steps:

[0063] Step 1: Calculate the fluid flow rate;

[0064]

[0065] The above formula is a standard formula. The following formula is obtained by converting the values ​​required by this embodiment:

[0066] (11)

[0067] In the above formula (11), Q The flow rate of the fluid passing through the flow sensor 6, that is, the value after the flow rate stabilizes when the fluid is flowing, in units of m 3 / s; The cross-sectional area of ​​the inner layer of the cylinder 4 (the area of ​​the inner circle, that is, calculated by the inner diameter of the cylinder 4), can be calculated according to the diameter of the U-shaped tube 8 selected, and the unit is m 2 ; is the flow velocity of the fluid, in m / s. The flow velocity of the fluid can be calculated by substituting specific values ​​into the above formula;

[0068] Step 2: Calculate the drag coefficient (the above obtained Substitute into the following formula to calculate);

[0069]

[0070] The above formula is a standard formula. The following formula is obtained by converting the values ​​required by this embodiment:

[0071] (12)

[0072] In the above formula (12), The force exerted by the fluid on the spherical particle 10 when the fluid flows between the cylinder 4 and the U-shaped tube 8 is the core parameter describing the momentum and energy transfer between the fluid and the spherical particle 10. It is one of the key characteristic parameters of the interaction between the fluid and the spherical particle 10, that is, the drag force of the fluid on the spherical particle 10, that is, the value displayed on the push-pull force meter 2 recorded above, in N; is the density of the fluid in kg / m 3 ; Vs is the velocity of the spherical particle 10, in m / s. Since this embodiment uses the particle resistance coefficient measurement system in Embodiment 1 and Embodiment 2, the spherical particle 10 is stationary. V s 0m / s; V 1 is the velocity of the fluid flowing in the inner layer of the cylinder, which is the value calculated in the first step, in m / s; is the diameter of the spherical particle 10, in m; is the resistance coefficient, which can be calculated based on the above formula and the numerical value recorded in the method .

[0073] Furthermore, the calculation method of the Reynolds number includes the following steps:

[0074] Particles settling in Newtonian fluids, particle Reynolds number The expression is as follows:

[0075] (13)

[0076] In formula (13), μ is the viscosity of the Newtonian fluid, in Pa.s; is the density of the fluid in kg / m 3 ; V 1 is the velocity of the fluid flowing in the inner layer of the cylinder 4, which is calculated according to the above formula (11) and the unit is m / s; is the diameter of the spherical particle 10, in m.

[0077] For a power-law fluid, the particle Reynolds number The calculation formula is as follows:

[0078] (14)

[0079] In formula (14), n is the fluid flow index, which is dimensionless; K is the power law fluid viscosity coefficient, the unit is Pa.s; is the density of the fluid in kg / m 3 ; V 1 is the velocity of the fluid flowing in the inner layer of the cylinder 4, which is calculated according to the above formula (11) and the unit is m / s; is the diameter of the spherical particle 10, in m.

[0080] For a Herbach fluid, the particle Reynolds number The calculation formula is as follows:

[0081] (15)

[0082] In formula (15), τ 0 is the fluid yield value, in Pa; K is the fluid viscosity coefficient, Pa.s; n is the fluid flow index, dimensionless; V s is the velocity of the spherical particle 10 in m / s; V 1 is the velocity of the fluid flowing in the inner layer of the cylinder 4, in m / s; is the density of the fluid in kg / m 3 ; is the diameter of the spherical particle 10, in m.

[0083] For different types of fluids, the particle Reynolds number can be obtained by substituting it into the above formula.

[0084] In addition, in this embodiment, the data detected by the push-pull force meter 2 and the flow sensor 6 can be directly fed back to the controller during calculation. The controller can calculate and process the feedback data and substitute it into the above formula to obtain the measured particle resistance coefficient without manual calculation.

[0085] The core measurement method for calculating the particle drag coefficient, using "fixed particles + active pumping of fluid," changes the traditional sedimentation test method. It fully considers the effects of the fluid, spherical particles 10, temperature, and the wall effect of cylinder 4. Spherical particles 10 are connected via a push-pull force gauge 2, which keeps them stable and motionless. The forces applied to them are measured in cylinder 4, while a peristaltic pump 7 is used to control the fluid flow rate. The data is recorded to determine the Reynolds number and drag coefficient. By using the steady-state forces applied to spherical particles 10 in the flowing fluid (rather than the traditional free sedimentation trajectory), this sedimentation test measurement method does not require particle detection, and fluid visibility is no longer a limiting condition for the experiment. This simplifies experimental operations and eliminates the need for reliance on high-cost optical equipment. The experimental applicability is expanded to 100% non-transparent working conditions, enabling high-precision measurements of non-transparent and highly viscous fluids. The time required for a single test is greatly shortened, and automatic calculation and output are possible, significantly improving data output efficiency. At the same time, by actively pumping fluid to generate relative motion, particles with density differences as low as 0.1g / cm³ (such as resin proppants) can be measured, resolving the time-consuming measurement issues associated with traditional free sedimentation methods, which hinder rapid particle settling due to insufficient gravity. By accurately measuring multiple drilling fluid rheological parameters, the resulting drag coefficient and critical settling velocity are more accurate, ensuring the drilling fluid's circulation efficiency, rock-carrying capacity, and the normal operation of downhole operations. This significantly reduces the incidence of stuck pipe, high friction, and well control accidents, thereby lowering downhole operational risks. Based on accurate particle settling test data, this invention provides clear guidance for drilling fluid performance optimization and wellbore cleaning design, helping engineers make more scientific decisions and improving the overall quality and safety of drilling projects. Pumping parameters are optimized based on dynamic proppant drag coefficient data, improving sand bank distribution and proppant placement effectiveness. The fiber-proppant coupling drag coefficient is quantified to guide the extension of the proppant far-field placement distance.

[0086] The advantage of the present invention is that this system is different from the existing measurement system in that it drops spherical particles into the fluid. This device uses a rod to connect the spherical particles to fix the spherical particles. By allowing the fluid to continue to circulate between the cylinder and the U-shaped tube, it simulates the actual scene of the spherical particles sinking. Fixing the spherical particles can limit the lateral freedom of the spherical particles. When the fluid flows through the spherical particles, the spherical particles will remain stable and not swing, thereby avoiding the spherical particles from deviating from the center line or sticking to the inner wall of the cylinder, affecting the measurement accuracy. The fluid flows from bottom to top in the cylinder, so that the push-pull dynamometer records the drag force on the spherical particles during the simulated spherical particle falling process, avoiding the influence of the rod body causing inaccurate detection. In summary, this system can simulate the actual working conditions of spherical particle sedimentation, avoid the situation where spherical particles deviate from the center line or stick to the wall, and improve the measurement accuracy.

[0087] The above disclosures are only a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. A particle drag coefficient measurement system, characterized in that: include: The main structure comprises a cylinder (4), a U-shaped tube (8), a peristaltic pump (7) and a flow sensor (6); the cylinder (4) is arranged vertically, the top end of the cylinder (4) is open and the bottom end is closed, the two ends of the U-shaped tube (8) are respectively connected to the cylinder (4), the peristaltic pump (7) and the flow sensor (6) are both arranged on the U-shaped tube (8), and the peristaltic pump (7) is used to deliver the fluid into the cylinder (4); A fixed structure for fixing spherical particles (10), the fixed structure comprising a support frame (1), a push-pull force gauge (2) and a rod body (3), the push-pull force gauge (2) being arranged on the support frame (1), the push-pull force gauge (2) being located directly above the cylinder (4), the detection end of the push-pull force gauge (2) being connected to the vertically arranged rod body (3), the bottom end of the rod body (3) extending into the cylinder (4) and being located between the two ends of the U-shaped tube (8), the bottom end of the rod body (3) being used for connecting the spherical particles (10), and the diameter of the rod body (3) being smaller than the diameter of the spherical particles (10); a controller electrically connected to the peristaltic pump (7) for controlling the opening and closing of the peristaltic pump (7); the controller electrically connected to the push-pull force meter (2) and the flow sensor (6) for receiving data detected by the push-pull force meter (2) and the flow sensor (6) in real time, and determining the resistance coefficient of the spherical particle (10) based on the data detected by the push-pull force meter (2) and the flow sensor (6) and the cross-sectional area of ​​the cylinder (4), the diameter of the spherical particle (10) and the density of the fluid; The cylinder (4) has a double-layer structure, both ends of the U-shaped tube (8) are connected to the inner layer of the cylinder (4), and the bottom end of the rod (3) is located in the inner layer of the cylinder (4); The inner diameter of the inner layer of the cylinder (4) and the diameter of the spherical particles (10) satisfy 0.05 < <1, where is the inner diameter of the inner layer of the cylinder (4), in m, is the diameter of the spherical particle (10), in m; The diameter of the rod (3) and the diameter of the spherical particle (10) satisfy 0.01 < <0.05, where is the diameter of the spherical particle (10), in m, a is the diameter of the rod (3), in m.

2. A particle drag coefficient measurement system according to claim 1, characterized in that: Also includes: A temperature control structure is used to control the temperature of the fluid in the cylinder (4), and the temperature control structure includes: A water bath heating assembly comprises a water tank (5), a temperature sensor, a water pump and a heating element, wherein the water tank (5) is used to contain a heat exchange medium, the temperature sensor, the water pump and the heating element are all arranged in the water tank (5), and the controller is electrically connected to the temperature sensor, the water pump and the heating element; a water inlet pipe (9), one end of which is connected to the water tank (5) and the other end of which is connected to the outer layer of the cylinder (4); A drainage pipe, one end of which is connected to the water tank (5) and the other end of which is connected to the outer layer of the cylinder (4); the water inlet pipe (9) is close to the bottom end of the cylinder (4), and the drainage pipe is close to the top end of the cylinder (4).

3. A particle drag coefficient measurement system according to claim 2, characterized in that: The water inlet pipe (9) and the drain pipe are both detachably connected to the cylinder (4), and the detachable connection structure is the same. The detachable connection structure of the water inlet pipe (9) and the cylinder (4) includes: A connector is provided on the side wall of the cylinder (4), the connector is in communication with the outer layer of the cylinder (4), and the end of the water inlet pipe (9) is threadedly connected to the connector.

4. A method for measuring a particle drag coefficient, using the particle drag coefficient measurement system according to any one of claims 1 to 3, characterized in that: The following steps are involved: Pour the fluid into the cylinder (4) from the top, ensuring that the fluid submerges both ends of the U-shaped tube (8); Fix the spherical particle (10) at the bottom end of the rod (3), then extend the rod (3) into the cylinder (4), and reset the value of the push-pull dynamometer (2) to zero after it remains unchanged; Starting the peristaltic pump (7) so that the fluid flows in the barrel (4) from the bottom end of the barrel (4) to the top end of the barrel (4); The flow sensor (6) is operated, and after the value detected by the flow sensor (6) remains unchanged, the data detected by the push-pull force meter (2) and the flow sensor (6) are recorded; Determining the particle resistance coefficient based on the data detected by the push-pull force meter (2) and the flow sensor (6), the cross-sectional area of ​​the inner layer of the cylinder (4), the diameter of the spherical particle (10) and the density of the fluid; The calculation method of the drag coefficient includes the following steps: （11） In formula (11), The flow rate of the fluid detected by the flow sensor (6), in m 3 / s; is the cross-sectional area of ​​the inner layer of the cylinder (4), in m 2 ; is the flow velocity of the fluid, in m / s; （12） In formula (12), is the drag coefficient; is the force exerted by the fluid on the spherical particle (10) detected by the push-pull dynamometer (2), in N; is the density of the fluid in kg / m 3 ; is the diameter of the spherical particle (10), in m; is the velocity of the spherical particle (10), is 0m / s.

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