Method for testing flow conductivity of multi-particle-size proppant

Abstract

The invention relates to a method for testing the flow conductivity of a multi-particle-size proppant, which comprises the following steps: carrying out sandstone core test on a core to obtain the triaxial mechanical strength, rock mineral components and microstructure of sandstone; preparing a simulated sandstone rock plate according to the obtained rock mechanical strength, rock mineral composition and microstructure; loading the rock plate into a flow guide testing device, and setting corresponding experimental parameters under a steam huff and puff injection-production condition; simulating multi-round steam huff and puff injection and production to obtain closing pressure data, fluid displacement data and flow guide chamber port pressure difference value data under the condition of the multi-stage particle size proppant; according to the closing pressure data, the fluid displacement data and the flow guide chamber port pressure difference data, the flow guide capacity of the proppant is determined through a flow guide capacity formula.

Description

Technical Field

[0001] This document relates to the technical field of proppant conductivity testing, especially a method for testing the conductivity of multi - stage particle size proppants. Background Art

[0002] When steam stimulation is used for exploiting loose sandstone heavy oil reservoirs, the injected steam reduces the viscosity of crude oil, destroys the original asphaltene, resin, and argillaceous cementation, resulting in the loose structure of the sandstone. During the initial stage of production, the high production pressure difference and high flow rate cause sand grain migration and sand production in oil wells. The fracturing multi - stage particle size proppant for loose sandstone heavy oil reservoirs is a well - completion method that can effectively prevent sand and increase production. Therefore, the fracturing multi - stage particle size proppant for loose sandstone heavy oil reservoirs needs to not only effectively prevent sand but also have a certain conductivity. A method for testing the conductivity of the fracturing multi - stage particle size proppant for loose sandstone heavy oil reservoirs suitable for steam stimulation is designed according to the technological characteristics of steam stimulation, so as to improve the steam stimulation effect of loose sandstone heavy oil reservoirs. Summary of the Invention

[0003] The inventors of this application found that:

[0004] Generally, the factors that are considered to affect conductivity mainly include: closure pressure, proppant strength, in - fracture sand concentration, and rock hardness, etc. The conductivity decreases with the increase of closure pressure and increases with the increase of proppant strength and concentration. Usually, the conductivity is evaluated according to the SY / T 6302 - 2019 Method for Testing the Conductivity of Fracturing Proppants. Under the conditions of simulating reservoir pressure and temperature by a conductivity meter, the conductivity performance of proppants and fractures is tested through a wide range of pressured fracturing fluids and flow rates. The conductivity of the fracturing multi - stage particle size proppant for loose sandstone heavy oil reservoirs under steam stimulation needs to consider the influence of reservoir characteristics and technological factors, and the conventional testing methods can no longer accurately evaluate the conductivity.

[0005] This application provides a method for testing the conductivity of multi - stage particle size proppants, comprehensively considering the influence of multi - stage particle size proppants and sand production after multiple rounds of steam stimulation; solving the defects that the conductivity result is inaccurate due to incomplete evaluation factors of the conductivity of the multi - stage particle size proppant in the steam stimulation fracture and the test result of the proppant conductivity after multiple rounds of steam stimulation cannot be obtained.

[0006] In a first aspect, the present application provides a method for testing the diversion capacity of multi - level particle size proppants. The method includes: conducting sandstone core tests on the core to obtain the triaxial mechanical strength, rock mineral composition, and micro - structure of the sandstone; preparing a simulated sandstone slab based on the obtained rock mechanical strength, rock mineral composition, and micro - structure; loading the slab into a diversion test device and setting the corresponding experimental parameters under steam stimulation injection - production conditions; simulating multiple rounds of steam stimulation injection - production to obtain the closure pressure data, fluid displacement data, and diversion chamber port pressure difference data under multi - level particle size proppants; and determining the diversion capacity of the proppant using the diversion capacity formula based on the closure pressure data, the fluid displacement data, and the diversion chamber port pressure difference data.

[0007] Compared with the related art, the present application provides a method for testing the diversion capacity of multi - level particle size proppants. The method includes: conducting sandstone core tests on the core to obtain the triaxial mechanical strength, rock mineral composition, and micro - structure of the sandstone; preparing a simulated sandstone slab based on the obtained rock mechanical strength, rock mineral composition, and micro - structure; loading the slab into a diversion test device and setting the corresponding experimental parameters under steam stimulation injection - production conditions; simulating multiple rounds of steam stimulation injection - production to obtain the closure pressure data, fluid displacement data, and diversion chamber port pressure difference data under multi - level particle size proppants; and determining the diversion capacity of the proppant using the diversion capacity formula based on the closure pressure data, the fluid displacement data, and the diversion chamber port pressure difference data. The present application comprehensively considers the influence of multi - level particle size proppants and sand production after multiple rounds of steam stimulation; and can more accurately judge the diversion capacity of the proppant after multiple rounds of steam stimulation.

[0008] Other features and advantages of the present application will be described in the subsequent specification, and part of them will become obvious from the specification, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained through the solutions described in the specification and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The drawings are used to provide an understanding of the technical solutions of the present application, and constitute a part of the specification. They are used together with the embodiments of the present application to explain the technical solutions of the present application, and do not constitute a limitation to the technical solutions of the present application.

[0010] Figure 1 It is a flowchart of the method for testing the diversion capacity of multi - level particle size proppants according to the embodiment of the present application;

[0011] Figure 2 It is a schematic diagram of the diversion test device in some exemplary embodiments. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0012] This application describes multiple embodiments, but the description is exemplary rather than restrictive, and it will be apparent to those of ordinary skill in the art that there can be more embodiments and implementation solutions within the scope of the embodiments described in this application. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically restricted, any feature or element of any embodiment can be combined with any other feature or element in any other embodiment, or can replace any other feature or element in any other embodiment.

[0013] This application includes and contemplates combinations with features and elements known to those of ordinary skill in the art. The embodiments, features, and elements disclosed in this application can also be combined with any conventional features or elements to form unique inventive solutions defined by the claims. Any feature or element of any embodiment can also be combined with features or elements from other inventive solutions to form another unique inventive solution defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this application can be implemented alone or in any suitable combination. Therefore, the embodiments are not subject to other limitations except those made in accordance with the appended claims and their equivalents. In addition, various modifications and changes can be made within the scope of the appended claims.

[0014] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not depend on the specific sequence of steps described herein, the method or process should not be limited to the specific sequence of steps described. As will be understood by those of ordinary skill in the art, other sequences of steps are possible. Therefore, the specific sequence of steps set forth in the specification should not be construed as a limitation on the claims. In addition, the claims directed to the method and / or process should not be limited to performing their steps in the order written, and those skilled in the art can readily understand that these orders can vary and still remain within the spirit and scope of the embodiments of this application.

[0015] Generally, the factors considered to affect the conductivity are mainly: closure pressure, proppant strength, in - seam sand concentration, and rock hardness, etc. The conductivity decreases with the increase of the closure pressure; and increases with the increase of the proppant strength and concentration. Usually, under the conditions of simulating reservoir pressure and temperature with a conductivity tester, through a wide range of pressured fracturing fluids and flow rates, the conductivity performance of the proppant and the fracture is tested. For the conductivity of the multi - stage particle - size proppant in the steam stimulation - produced unconsolidated sandstone heavy - oil reservoir, the influence of reservoir characteristics and process factors needs to be considered, and the conventional test methods can no longer accurately evaluate the conductivity, such as the following factors:

[0016] 1. The conventional testing method for the conductivity of fracturing proppants can only test the conductivity of a single proppant and cannot conduct the conductivity test for multi-stage proppant filling.

[0017] 2. The conventional testing method for the conductivity of fracturing proppants cannot conduct the conductivity test for multi-stage particle size proppants after multiple rounds of steam stimulation. Multiple rounds of steam stimulation will make the structure of unconsolidated sandstone looser, leading to serious sand production in oil wells. Reverse steam injection can wash away the formation sand blocked in the proppants, thereby improving the conductivity. Therefore, the conductivity of multi-stage proppants will change during the injection-production cycle of steam stimulation.

[0018] In order to obtain the conductivity more accurately, a testing method that takes into account both multi-stage particle size proppants and the influence of sand production caused by steam stimulation on the conductivity of proppants needs to be proposed. This application comprehensively considers multi-stage particle size proppants and the influence of sand production after multiple rounds of steam stimulation, and proposes a more accurate testing method for the conductivity of multi-stage particle size proppants that conforms to production practice. This testing method can solve the defects that the current conductivity results are inaccurate due to incomplete evaluation factors for the conductivity of multi-stage particle size proppants in steam stimulation fractures and the testing results of the conductivity of proppants after multiple rounds of steam stimulation cannot be obtained.

[0019] An embodiment of the present invention provides a testing method for the conductivity of multi-stage particle size proppants, as Figure 1 shown, the method includes steps S100 - S140:

[0020] S100: Conduct sandstone core tests on the core to obtain the triaxial mechanical strength, rock mineral composition, and microscopic structure of the sandstone.

[0021] S110: Prepare a simulated sandstone slab according to the obtained triaxial mechanical strength, rock mineral composition, and microscopic structure.

[0022] S120: Install the slab into the conductivity testing device and set the corresponding experimental parameters under the steam stimulation injection-production conditions.

[0023] S130: Simulate multiple rounds of steam stimulation injection-production to obtain the closure pressure data, fluid displacement data, and conductivity chamber port pressure difference data under multi-stage particle size proppants.

[0024] S140: Determine the conductivity of the proppant using the conductivity formula based on the closure pressure data, the fluid displacement data, and the conductivity chamber port pressure difference data.

[0025] In an exemplary embodiment, conducting sandstone core tests on the core to obtain the triaxial mechanical strength, rock mineral composition, and microscopic structure of the unconsolidated sandstone includes:

[0026] S11. Use a rock triaxial testing machine to conduct triaxial compressive strength tests on the core samples.

[0027] S12. Use an X-ray diffractometer to analyze the rock mineral composition of the core samples.

[0028] S13. Use a nuclear magnetic resonance imaging analyzer to obtain the porosity and density of the core samples.

[0029] In an exemplary embodiment, prepare a simulated sandstone slab according to the obtained rock mechanical strength, rock mineral components, and microstructure, including:

[0030] Select core samples, clean, dry, grind, and sieve them to prepare rock powder with a particle size of about 10 μm.

[0031] Use the rock powder to prepare a simulated loose sandstone slab. In this embodiment, use the simulated loose sandstone to process the slab. The slab is 17.70 cm - 17.78 cm long, 3.7 - 3.81 cm wide, and has a thickness greater than 0.90 cm. The two ends of the slab are ground into a round shape to match the experimental device, and the parallelism is maintained within 0.008 cm.

[0032] In an exemplary embodiment, as Figure 2 shown, the diversion test device includes: a diversion chamber, a laminar flow pump, a steam generator, a gas booster pump, a production valve, an injection valve, a production outlet valve, and an injection outlet valve.

[0033] In an exemplary embodiment, after manufacturing the slab, install and load the diverter, including the following steps:

[0034] Assemble the diversion test device in sequence:

[0035] First step: Install the bottom piston:

[0036] Adjust the bottom piston to fix the slab 0.02 mm (0.0008 in) below the pressure measurement port inside the diversion chamber.

[0037] Second step: Install the bottom slab:

[0038] Ensure there is no gap between the slab and the diversion chamber.

[0039] Third step: Place the filter screen:

[0040] The filter screen is placed to prevent proppant particles and sand production from flowing out of the proppant layer or blocking the diversion chamber ports. Place a filter screen made of 150 μm (100 US mesh) Monel alloy or other materials at all ports such as the liquid inlet and outlet ports and the pressure measurement ports of the diversion chamber. The filter screen should be replaced after each experiment.

[0041] Fourth step: Oil well sand production samples:

[0042] Obtain the sand production sample from the broken core and lay it appropriately at the front end of the diversion chamber to simulate the sand production in the oil well.

[0043] Step 5. Load the sand production sample and proppant in the diversion chamber: As Figure 2 shown, the total laying area of the sand production sample and multi-stage proppant is 64.5 cm 2 . Add the weighed sand production sample and proppant sample to the diversion chamber section by section and evenly, and use a leveling device to level the proppant in the diversion chamber.

[0044] Among them, the calculation of the proppant dosage: Calculate the weight of each stage of proppant by the equal-volume method.

[0045] M p = 0.635A n ρ

[0046] In the formula: M p is the mass of the proppant, in grams (g); ρ is the bulk density of the proppant, in grams per cubic centimeter (g / cm 3 ); A n is the laying area of the nth stage of proppant.

[0047] Step 6. Install the top rock plate:

[0048] Put the metal plate into the diversion chamber, measure the thickness of the metal plate and record it. Install the rock plate into the diversion chamber, fill the gap between the rock plate and the side wall of the diversion chamber with silicone rubber, install the upper piston, and adjust the piston to the appropriate position.

[0049] In an exemplary embodiment, the experimental parameters under steam stimulation injection-production conditions include: simulation duration, simulation temperature value, closure pressure, and closure pressure change rate.

[0050] Among them, the simulation duration is the experimental duration determined according to the steam stimulation cycle;

[0051] The simulation temperature value includes the injection steam temperature and the formation temperature;

[0052] The closure pressure is the pressure determined according to the reservoir conditions.

[0053] The closure pressure change rate takes the tested or predicted closure pressure as the minimum value, 80% of the fracture pressure as the maximum value, and 1 / 5 of the difference as the increment value of the closure pressure during the experiment for simulation experiments. Control the change rate of the closure pressure to maintain consistency.

[0054] Experimental fluid: Generate injection steam from distilled water through a steam generator. The produced fluid is deionized water or a potassium chloride solution with a mass concentration of 2% prepared from distilled water, removing substances with a size of 7 μm and above. The potassium chloride is a chemically pure reagent.

[0055] In an exemplary embodiment, under the conditions of simulating multiple rounds of steam stimulation injection and production, the closure pressure data, fluid displacement data, and diversion chamber port pressure difference data under multiple levels of proppants are monitored, including: As Figure 2 shown, from right to left is the steam stimulation injection process. The specific process is as follows: Open the injection valve, open the injection outlet valve, close the production valve, close the production outlet valve, and reverse pump steam into the diversion chamber through a steam generator and a gas booster pump to simulate the relevant data under the steam stimulation injection conditions. The relevant data under the steam stimulation injection conditions include closure pressure, test time, fluid displacement, and diversion chamber port pressure difference.

[0056] In an exemplary embodiment, under the conditions of simulating multiple rounds of steam stimulation injection and production, the closure pressure data, fluid displacement data, and diversion chamber port pressure difference data under multiple levels of proppants are monitored, including: As Figure 2 shown, from left to right is the steam stimulation production process. The specific process is as follows: Open the production valve, open the production outlet valve, close the injection valve, close the injection outlet valve, start the flat-plate pump, and forward pump the experimental fluid into the diversion chamber to simulate the relevant data under the steam stimulation production conditions; among them, the relevant data under the steam stimulation production conditions include closure pressure, test time, fluid displacement, and diversion chamber port pressure difference.

[0057] In an exemplary embodiment, simulate multiple rounds of steam stimulation production alternately. During the process, if the pressure difference is too large and the displacement is small enough, stop the test, check for equipment problems such as whether the filter screen is blocked, analyze the reasons. If it is a problem with the injection and production parameters, change the parameters and then conduct the test again. For the processing of the diversion capacity test data of multiple levels of proppants under the steam stimulation injection and production conditions, use the diversion capacity formula to calculate the proppant diversion capacity at different stages. The permeability of the fracture during fluid injection can be reflected by the flow rate of fluid seepage. After measuring the flow rates of the fluid at different inlet and outlet pressures, the proppant diversion capacity can be determined through the Darcy formula for fluid radial seepage. The expression of the diversion capacity formula is:

[0058]

[0059] In the formula, Q f represents the diversion capacity of the proppant combination at the closure pressure f, k f represents the permeability of the proppant combination at the closure pressure f, W represents the sand-laying thickness of the proppant combination, Δp represents the pressure difference in the flow direction, A represents the support cross-sectional area of the diversion chamber, L represents the length between the pressure ports, μ represents the fluid viscosity, and Q represents the fluid displacement.

[0060] The multi-level particle size proppant diversion capacity test method implemented in this embodiment has the following technical effects:

[0061] 1. Considering the influence of multi - stage particle size proppants and sand production after multiple - round steam stimulation comprehensively, it is more in line with production practice and can obtain a more accurate test of the proppant conductivity.

[0062] 2. The test results of the proppant conductivity for multiple - round steam stimulation under different injection - production intensities can be obtained, providing sufficient basis for the selection of steam stimulation process parameters.

[0063] 3. The provided test method for the conductivity of multi - stage particle size proppants in steam stimulation fractures considers the influence of multi - stage particle size proppants and sand production after multiple - round steam stimulation comprehensively, providing sufficient basis for the optimization of multi - stage particle sizes.

[0064] Example 1

[0065] A test method for the conductivity of fracturing multi - stage particle size proppants in steam - stimulated loose sandstone reservoirs is used to test the conductivity of multi - stage particle size proppants in steam stimulation fractures. The specific implementation process is as follows:

[0066] Taking the multi - stage particle size proppant combination: particle size 0.85 - 1.4mm / 1.4 - 2mm / 2 - 2.8mm as an example, the implementation of the conductivity test is described in detail:

[0067] (1) Conduct tests on the loose sandstone core according to the core, including the triaxial mechanical strength, rock mineral composition and microscopic structure of the loose sandstone.

[0068] 1) Use a rock triaxial testing machine to conduct triaxial compressive strength tests on the core.

[0069] 2) Select the core, clean, dry, grind and sieve it to prepare rock powder with a particle size of about 10μm.

[0070] 3) Use an X - ray diffractometer to analyze the rock mineral composition of the core.

[0071] 4) Use a nuclear magnetic resonance imaging analyzer to obtain the porosity and density of the core.

[0072] (2) Prepare a simulated loose sandstone slab according to the obtained rock mechanical strength, rock mineral composition and microscopic structure:

[0073] Prepare simulated loose sandstone according to the obtained rock mechanical strength, rock mineral composition and microscopic structure. Use the simulated loose sandstone to process a slab. The slab is 17.70cm - 17.78cm long, 3.7 - 3.81cm wide and the thickness is greater than 0.90cm. Both ends of the slab are ground into a round shape to match the experimental device, and the parallelism is maintained within 0.008cm.

[0074] (3) Install and load the conductivity test device:

[0075] Install the bottom piston, install the bottom rock slab, and place the filter screen. Obtain the sand production sample of the oil well by crushing the core, and spread an appropriate amount at the front end of the diversion chamber to simulate the sand production of the oil well. Calculate the weight of each stage of proppant by the equal-volume method. Add the weighed oil well sand production sample and proppant sample to the diversion chamber section by section and evenly, and use a leveling device to level the proppant in the diversion chamber. Installation of the top rock slab: Put the metal plate into the diversion chamber, measure the thickness of the metal plate and record it. Install the rock slab into the diversion chamber, fill the gap between the rock slab and the side wall of the diversion chamber with silicone rubber, install the upper piston, and adjust the piston to the appropriate position.

[0076] (4) Conduct the diversion capacity test of multi-stage proppant under steam soak injection and production conditions.

[0077] 1) Application of experimental parameters under steam soak injection and production conditions: Determine the experimental duration according to the steam soak cycle. Set the injection steam temperature and formation temperature. Set the closure pressure according to the reservoir conditions. Generate injection steam from distilled water through a steam generator. The produced fluid is a potassium chloride solution with a mass concentration of 2% prepared from distilled water, removing substances with a size of 7 μm and above. The potassium chloride is a chemically pure reagent.

[0078] 2) Open the production valve, open the production outlet valve, close the injection valve, close the injection outlet valve, and start the peristaltic pump to pump the experimental fluid into the diversion chamber in the forward direction to simulate production. Record including the closure pressure, test time, fluid displacement, and the pressure difference at the diversion chamber ports.

[0079] 3) Open the injection valve, open the injection outlet valve, close the production valve, close the production outlet valve, and pump steam into the diversion chamber in the reverse direction through a steam generator and a gas booster pump to simulate injection. Record including the closure pressure, test time, fluid displacement, and the pressure difference at the diversion chamber ports.

[0080] 4) Alternate steps 2) and 3) 5 times to simulate multiple rounds of steam soak production.

[0081] (5) Process the test data of the diversion capacity of multi-stage proppant under steam soak injection and production conditions. After measuring the flow rate of the fluid at different inlet and outlet pressures, determine the proppant diversion capacity through the Darcy formula for radial seepage of the fluid.

[0082] Those of ordinary skill in the art will understand that all or some of the steps in the methods disclosed above, and the functional modules / units in systems and devices, can be implemented as software, firmware, hardware, and appropriate combinations thereof. In the hardware implementation, the division of functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be executed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include a computer storage medium (or non-transitory medium) and a communication medium (or transitory medium). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cassettes, tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those of ordinary skill in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and can include any information delivery medium.

Claims

1. A testing method for the flow conductivity of proppants with multi-level particle sizes, characterized in that, Applied to a diversion test device, the method includes: Conducting sandstone core tests on the core to obtain the triaxial mechanical strength, rock mineral composition, and microstructure of the sandstone; Preparing a simulated sandstone slab based on the triaxial mechanical strength, rock mineral composition, and microstructure of the sandstone; Loading the simulated sandstone slab into the diversion test device and setting the corresponding experimental parameters under steam huff and puff injection and production conditions; Simulating multiple rounds of steam huff and puff injection and production to obtain closure pressure data, fluid displacement data, and diversion chamber port pressure difference data under multi - stage particle size proppants; Determining the proppant conductivity using the conductivity formula based on the closure pressure data, fluid displacement data, and diversion chamber port pressure difference data.

2. The multi-level particle size proppant flow conductivity testing method according to claim 1, wherein The diversion test device includes: a diversion chamber, a laminar flow pump, a steam generator, a gas booster pump, a production valve, an injection valve, a production outlet valve, and an injection outlet valve.

3. The multi-level particle size proppant flow conductivity testing method according to claim 1, wherein The conducting sandstone core tests on the core to obtain the triaxial mechanical strength, rock mineral composition, and microstructure of the sandstone includes: Using a rock triaxial testing machine to conduct triaxial compressive strength tests on the core to obtain the triaxial mechanical strength of the sandstone; Using an X - ray diffractometer to analyze the rock mineral composition of the core to obtain the rock mineral composition; Using a nuclear magnetic resonance imaging analyzer to obtain the microstructure of the core, and the microstructure includes porosity and density.

4. The multi-stage particle size proppant flow conductivity testing method according to claim 1, wherein, The preparing a simulated sandstone slab based on the triaxial mechanical strength, rock mineral composition, and microstructure of the sandstone includes: Selecting a core, cleaning, drying, grinding, and sieving the core to prepare rock powder; Using the rock powder to prepare a simulated sandstone slab.

5. The method for testing the flow conductivity of the multi-stage particle size proppant according to claim 2, wherein, The corresponding experimental parameters under steam huff and puff injection and production conditions include: simulation duration, simulation temperature value, closure pressure, and closure pressure change rate.

6. The method for testing the conductivity of multi - stage particle size proppants according to claim 5, wherein The simulation duration is determined according to the steam huff and puff cycle; The closure pressure is determined according to reservoir conditions.

7. The method for testing the conductivity of multi - stage particle size proppants according to claim 6, wherein The simulation temperature value includes the injected steam temperature and the formation temperature.

8. The method for testing the flow conductivity of the multi-stage particle size proppant according to claim 7, wherein, The simulating multiple rounds of steam huff and puff injection and production to obtain closure pressure data, fluid displacement data, and diversion chamber port pressure difference data under multi - stage particle size proppants includes: Opening the injection valve, opening the injection outlet valve, closing the production valve, and closing the production outlet valve; Pumping steam reversely into the diversion chamber through the steam generator and the gas booster pump to simulate and obtain relevant data under steam huff and puff injection conditions; Among them, the relevant data under steam huff and puff injection conditions include closure pressure, test time, fluid displacement, and diversion chamber port pressure difference.

9. The multi-stage particle size proppant flow conductivity testing method according to claim 7, characterized in that, The simulating multiple rounds of steam huff and puff injection and production to obtain closure pressure data, fluid displacement data, and diversion chamber port pressure difference data under multi - stage particle size proppants includes: Opening the production valve, opening the production outlet valve, closing the injection valve, and closing the injection outlet valve; Turn on the advection pump and pump the experimental fluid into the diversion chamber in the positive direction to simulate and obtain relevant data under the conditions of steam huff and puff production; Among them, the relevant data under the conditions of steam huff and puff production include closure pressure, test time, fluid displacement, and pressure difference at the diversion chamber ports.

10. The multi-stage particle size proppant flow conductivity testing method according to claim 1, wherein The formula for the diversion capacity is as follows: In the above formula, Q f represents the conductivity of the proppant at the closure pressure f, k f represents the permeability of the proppant at the closure pressure f, W represents the proppant placement thickness, Δp represents the pressure difference in the flow direction, A represents the proppant support cross-sectional area of the flow-through chamber, L represents the length between the pressure ports, μ represents the fluid viscosity, and Q represents the fluid displacement rate.

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