Gas reservoir water plugging pore radius boundary determination method and device based on capillary tube bundle

Abstract

The invention discloses a method and a device for determining a gas reservoir water plugging and pore plugging radius boundary based on a capillary tube bundle, and the method is characterized in that the method comprises the following steps: collecting physical property data of a tight gas reservoir, and obtaining a capillary tube bundle pore diameter sample set; according to the capillary tube bundle pore diameter sample set, single-tube gas-water two-phase flow is calculated one by one; accumulating the single-tube gas-water two-phase flow to obtain the total flow of a capillary tube bundle under different water saturations, and obtaining a simulated water-gas ratio according to the total flow of the capillary tube bundle; according to the simulated water-gas ratio, obtaining a global optimal solution of the maximum permissible plugging pore radius; and obtaining a field recommendation scheme according to the global optimal solution of the maximum allowable plugging radius. According to the method, the critical plugging aperture under different reservoir conditions can be accurately identified, and the gas production capacity and the water control effect are effectively considered.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas field development engineering, and particularly relates to a method and device for determining a gas reservoir water plugging pore radius limit for selective water plugging in a tight gas reservoir. BACKGROUND

[0002] In the development process of a tight gas reservoir, water production seriously affects the stable production of a gas well, and a conventional water plugging measure often simultaneously plugs a gas flow channel, thereby reducing gas production capacity. In order to avoid this drawback, a selective water plugging strategy is proposed in recent years, that is, only large pores are plugged, and small pores are reserved, so as to simultaneously achieve water control and gas increase. However, accurate determination of a water plugging pore radius limit is always one of the bottlenecks for popularization and implementation of the technology. Conventional methods mostly rely on physical experiments, and have long cycle, high cost, and are difficult to be rapidly popularized under different reservoir conditions. Therefore, it is urgent to develop a theoretical calculation method which is efficient, rapid and low in cost, so as to accurately determine a critical limit of a water plugging pore radius, and improve the implementation effect of a selective water plugging process in a gas reservoir. SUMMARY

[0003] In order to overcome the defects of the prior art, the present application aims to provide a method and device for determining a gas reservoir water plugging pore radius limit based on a capillary bundle, which quantitatively determines a water plugging pore radius limit in a tight gas reservoir by a numerical simulation and a probability statistical method, and points to an optimized strategy for selective water plugging in a tight gas reservoir.

[0004] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0005] In a first aspect, the present application provides a method for determining a gas reservoir water plugging pore radius limit based on a capillary bundle, comprising:

[0006] S1, collecting reservoir physical property data of a tight gas reservoir to obtain a capillary bundle pore diameter sample set;

[0007] S2, obtaining total capillary bundle flow rates under different water saturations according to the capillary bundle pore diameter sample set;

[0008] S3, obtaining a simulated water-gas ratio according to the total capillary bundle flow rates;

[0009] S4, obtaining a global optimal solution of a maximum allowable plugging pore radius according to the simulated water-gas ratio;

[0010] S5, obtaining a field recommended scheme according to the global optimal solution of the maximum allowable plugging radius.

[0011] In some embodiments, the step of obtaining the total flow rate of the capillary bundle at different water saturations in S2 further comprises calculating the single pipe gas-water two-phase flow rate for each of the capillary bundle pore diameter sample set, and accumulating the single pipe gas-water two-phase flow rates to obtain the total flow rate of the capillary bundle at different water saturations.

[0012] In some embodiments, S2 further comprises a step of establishing a single pipe gas-water two-phase flow rate model, which comprises:

[0013] For the case of incomplete plugging of gas-water co-flow, a single pipe water film thickness-flow pattern partitioning-flow rate model is constructed as an element model for the equivalent parallel calculation of the capillary bundle, which outputs the effective radius and water film thickness;

[0014] Effective radius r s , as shown in the following formula:

[0015] ;

[0016] wherein, is the wall residual water film thickness;

[0017] Water film thickness r wg , as shown in the following formula:

[0018] ;

[0019] wherein, S w ∈(0, 1) represents the water saturation, r o represents the pore radius of any single pipe.

[0020] In some embodiments, the step of establishing a single pipe gas-water two-phase flow rate model under different water saturation conditions further comprises using the water film thickness to make a flow pattern judgment, and according to the relationship between the water film thickness and the effective radius, three cases are divided: the first case is gas phase laminar flow only, r wg ≥ r s ; the second case is gas-water two-phase simultaneous flow, 0 < r wg < r s , and the third case is water phase laminar flow only, r wg ≥ 0, and a flow rate sub-model is constructed for each case, including a gas flow rate sub-model for the first case, a gas-water two-phase flow rate sub-model for the second case, and a water phase flow rate sub-model for the third case.

[0021] In some embodiments, for the first case of gas phase laminar flow only, a single pipe gas phase flow rate sub-model is established, as shown in the following formula:

[0022] ;

[0023] wherein, Qg,i Let μ represent the gas flow rate in the i-th capillary, G represent the pressure gradient, and μ represent the flow rate in the i-th capillary. g r represents the viscosity of a gas. s L represents the effective gas phase flow radius. s Indicates the slip length.

[0024] In some implementations, for the second scenario of simultaneous gas-water flow, a single-pipe gas-water two-phase flow sub-model is established, including a water phase flow component and a gas phase flow component:

[0025] The single-pipe water phase flow rate is shown in the following formula:

[0026] ;

[0027] Among them, Q w,i μ represents the water flow rate in the i-th capillary. w Indicates the viscosity of water;

[0028] The single-tube gas phase flow rate is shown in the following formula:

[0029] ;

[0031] In some implementations, a single-pipe water phase flow rate model is established for the third scenario of laminar flow only, as shown below:

[0032] ;

[0033] Where, r o μ represents the pore radius of any single tube. w The viscosity of water is represented by G, which represents the pressure gradient.

[0034] In some implementations, the step of obtaining the global optimal solution for the maximum permissible pore radius in S4 further includes screening out the maximum permissible pore radius, using the maximum permissible pore radius as input to the capillary bundle micromodel, and finally obtaining the global optimal solution for the maximum permissible pore radius after iteration.

[0035] In some implementations, the total flow rate of the capillary bundle gas-water two-phase flow at different water saturation levels is shown in the following formula:

[0036] ;

[0037] in, For different saturation conditions Total gas flow rate in the lower capillary bundle Different saturation conditions Total aqueous phase flow rate in the lower capillary bundle;

[0038] The simulated water-to-air ratio is shown in the following formula:

[0039] ;

[0041] Secondly, this invention proposes a device for determining the pore radius boundary of gas reservoir water shut-off based on capillary bundles, comprising:

[0042] The collection module is used to collect reservoir physical property data of tight gas reservoirs and obtain a sample set of capillary bundle pore diameters;

[0043] The total flow calculation module is used to obtain the total flow of the capillary bundle under different water saturation levels based on the capillary bundle pore diameter sample set.

[0044] The water-to-air ratio calculation module is used to obtain the simulated water-to-air ratio based on the total flow rate of the capillary bundle.

[0045] The screening module is used to obtain the globally optimal solution for the maximum allowable pore radius based on the simulated water-air ratio;

[0046] The recommendation module is used to obtain a recommended solution for the field based on the global optimal solution of the maximum allowable blocking radius.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0048] (1) Collect the reservoir physical property data of tight gas reservoirs, sample from the pore diameter distribution, and obtain the capillary bundle pore diameter sample set. This design relies on numerical simulation and probability statistics, avoids the high cost and long cycle of experiments, and realizes the rapid and efficient determination of water shut-off parameters.

[0049] (2) The total flow rate of the single-pipe gas-water two-phase flow is obtained by summing the flow rates of the capillary bundle under different water saturation. The simulated water-gas ratio is obtained based on the total flow rate of the capillary bundle. That is, the flow superposition calculation at the multi-pore scale is performed to obtain the influence of different critical plugging pore diameters on the flow law of gas-water two-phase flow.

[0050] (3) The step of obtaining the recommended maximum allowable plugging pore radius global optimal solution to construct the capillary bundle micro model further includes screening out the maximum allowable plugging pore radius, using the maximum allowable plugging pore radius as the input of the capillary bundle micro model, and finally obtaining the maximum allowable plugging pore radius global optimal solution after iteration. Through this design, the critical plugging pore diameter under different reservoir conditions is accurately identified, effectively balancing gas production capacity and water control effect. Attached Figure Description

[0051] Figure 1 This is an overall flowchart of a method for determining the pore radius limit of a gas reservoir water plugging and sealing system based on capillary bundles, according to the present invention.

[0052] Figure 2 This is a module diagram of a device for determining the pore radius limit of a gas reservoir water plugging and sealing system based on capillary bundles, according to the present invention.

[0053] Figure 3 The graph shows the relationship between the plugging radius and the gas flow rate under different porosity conditions.

[0054] Figure 4 The graph shows the relationship between the plugging radius and the water flow rate under different porosity conditions.

[0055] Figure 5 The graph shows the relationship between the plugging radius and the water-air ratio under different porosity conditions. Detailed Implementation

[0056] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0057] Example 1: As Figure 1 The diagram shows the overall process of a method for determining the pore radius limit for water shut-off and sealing of gas reservoirs based on capillary bundles, according to the present invention. The method specifically includes the following steps:

[0058] Step 1: Collect reservoir physical property data of tight gas reservoirs to obtain a sample set of capillary bundle pore diameters;

[0059] Specifically, the reservoir physical property data of the tight gas reservoir includes porosity and permeability; and the pore size frequency distribution is obtained by quantitative characterization experiments of pore structure (e.g., using MICP, NMR, SEM, etc.), as described in detail below:

[0060] The set of pore diameters is simulated using normal distribution or fractal theory to obtain the mean and standard deviation of the pore diameters.

[0061] Assuming the reservoir pore size follows a normal distribution, N pore diameter samples (e.g., 5000) are generated using a normal distribution random sampling method. These samples are then screened, removing those that do not conform to physical meaning (e.g., negative or excessively large values) to ensure physical plausibility. This step further includes constructing a capillary bundle microscopic model. This model takes the pore diameter sample set as input and performs statistical analysis based on the Monte Carlo method to generate pore diameter distribution parameters, as shown below:

[0062] ; (1)

[0063] Based on the pore diameter distribution parameters, a sample set of capillary bundle pore diameters {d1, d2, ... d} is obtained. 𝑖 …,d N}, d 𝑖This represents a single-tube pore diameter sample. In practice, multiple samplings can be performed to select the capillary bundle pore diameter sample that best matches the actual pore structure. The sampling process is as follows:

[0064] (2)

[0065] Where, d 𝑖 This represents a sample of single-tube pore diameter, 𝜇 d This represents the average pore diameter, 𝜎 d Indicates the standard deviation of pore diameter;

[0066] Step 2: Based on the capillary bundle pore diameter sample set, calculate the gas-water two-phase flow rate of a single tube one by one; this includes establishing a single-tube gas-water two-phase flow rate model, which considers the gas phase slippage effect and the water phase boundary layer influence, using the single-tube pore diameter sample d 𝑖 The gas-water two-phase flow rate in a single pipe is calculated using the simulation input parameters; the specific description is as follows:

[0067] Depending on the different water saturation conditions, the following two scenarios are used to calculate the gas-water two-phase flow rate in a single pipe. The specific calculation process is as follows:

[0068] ① For the incomplete blockage of air-water co-flow, a single-pipe water film thickness-flow pattern partition-parallel flow model is constructed as an element model for equivalent parallel calculation of capillary bundles. This element model outputs the effective radius and water film thickness.

[0069] Effective radius r s As shown in the following formula:

[0070] (3)

[0071] in, The thickness of the residual water film on the wall surface;

[0072] Water film thickness r wg As shown in the following formula:

[0073] (4)

[0074] Among them, S w ∈(0,1) represents water saturation, where 0 corresponds to no water in the capillary section and 1 corresponds to full water in the capillary section. o Let r represent the pore radius of any single tube. o =d 𝑖 / 2, water mainly forms a membrane flow along the edge of the capillary, while gas flows along the central axis;

[0075] ② Flow differentiation is based on water film thickness. The first case is laminar flow only: if r wg ≥r sIn the first case, the water film is stationary, and only the gas flows in laminar form in the contraction channel. The second case involves simultaneous flow of both gas and water: if 0 <r wg <r s This corresponds to the gas-water two-phase flow rate. The third case is laminar flow only in the water phase, with zero flow in the gas phase: if r wg ≥0, water flows along the annular region; construct flow sub-models for the first case, the gas flow sub-model for the second case, and the water flow sub-model for the third case.

[0076] i. For the first scenario above, only laminar gas flow (r wg ≥r s A single-pipe gas phase flow sub-model is established, as shown in the following equation:

[0077] (5)

[0078] Taking further consideration of slip flow and surface effect corrections, the corrected single-pipe gas phase flow sub-model is obtained, as shown in the following equation:

[0079] (6)

[0080] Among them, Q g,i Let μ represent the gas flow rate in the i-th capillary, G represent the pressure gradient, and μ represent the flow rate in the i-th capillary. g r represents the viscosity of a gas. s L represents the effective gas phase flow radius. s Indicates the slip length;

[0081] ii. For the second scenario above, simultaneous air-water flow (0 <r wg <r s Establish a single-pipe gas-water two-phase flow sub-model, including the water phase flow component and the gas phase flow component:

[0082] The single-pipe water phase flow rate is shown in the following formula:

[0083] (7)

[0084] Among them, Q w,i μ represents the water flow rate in the i-th capillary. w Indicates the viscosity of water;

[0085] The single-tube gas phase flow rate is shown in the following formula:

[0086] (8)

[0087] iii. For the third scenario above, only laminar flow of the aqueous phase (r) wg(≥0), establish a single-pipe water phase flow model as follows:

[0088] (9)

[0089] Step 3: Accumulate the gas-water two-phase flow rates of the single tube to obtain the total flow rate of the capillary bundle under different water saturation levels. Based on the total flow rate of the capillary bundle, obtain the simulated water-gas ratio, that is, perform multi-pore scale flow superposition calculation to obtain the influence of different critical plugging pore diameters on the gas-water two-phase flow law.

[0090] Assuming that the large pores are blocked, a set of candidate threshold values ​​for the blocking radius d is set for the entire capillary bundle. cutoff For example: 30–100 μm, step size 1 μm, perform sequential scanning: retain only diameter d i ≤d cutoff The total flow rate of the capillary bundle gas-water two-phase system is calculated by adding individual tubes together at different water saturation levels, as shown in the following formula:

[0091] (10)

[0092] in, For different saturation conditions Total gas flow rate in the lower capillary bundle Different saturation conditions Total aqueous phase flow rate in the lower capillary bundle

[0093] And, the simulated water-to-gas ratio per unit volume of gas production is obtained, as shown in the following formula:

[0094] (11)

[0095] Step 4: Based on the simulated water-air ratio described in Step 3, the critical plugging radius is screened to obtain the maximum allowable plugging radius. Finally, after iteration, the globally optimal solution for the maximum allowable plugging radius is obtained. The specific description is as follows:

[0096] Based on the economically limited water production requirements proposed by the mine (e.g., no more than 0.5 m³ water / 10 4 (m³ gas), based on the simulated water-to-gas ratio, the plugging radius is screened, and the rules and criteria for determining the critical plugging aperture limit are established, as shown in the following formula:

[0097] (12)

[0098] Where, d critThis represents the maximum permissible plugging radius; the maximum permissible plugging radius is the most acceptable value of the plugging radius that can meet the field constraints (such as the water-to-gas ratio not exceeding a certain limit, the gas flow rate not being lower than a threshold, etc.) under the current aperture sample, and is the upper limit of the allowable range;

[0099] Filter out the maximum allowable blocking radius d crit Using this as input to the capillary bundle microscopic model, a new sample set of capillary bundle pore diameters is obtained. Steps 2 to 4 are then executed, and the global optimal solution for the maximum allowable plugging radius is finally obtained after iteration. The final output of the model is the recommended optimal solution d for the maximum allowable plugging pore radius limit. crit-全局； This serves as a key reference for the design of water-blocking agent particles.

[0100] Step 5: Based on the globally optimal solution for the maximum permissible blocking radius, obtain the recommended on-site solution; on-site guidance includes diagram output and mining field application, using program output such as... Figure 3 , Figure 4 , Figure 5 The gas flow rate, water flow rate, and water-to-gas ratio curves shown provide the following guidance for on-site operations:

[0101] The injection pressure must not exceed the pressure gradient set in the model to avoid accidentally sealing the small holes;

[0102] We recommend using plugging agent granules. 90 ≈0.8×d crit-全局 ;

[0103] Reasonable segmentation and regulation of the production layer blocking zone can improve water control efficiency.

[0104] Example 2: Figure 2 The diagram shown is a module diagram of a capillary bundle-based device for determining the pore radius limit of gas reservoir water shut-off and sealing, as proposed in this invention, comprising:

[0105] The collection module 100 is used to collect reservoir physical property data of tight gas reservoirs and obtain a sample set of capillary bundle pore diameters.

[0106] The single-pipe flow calculation module 200 is used to calculate the gas-water two-phase flow rate of a single pipe one by one according to the capillary bundle pore diameter sample set.

[0107] The water-gas ratio calculation module 300 is used to accumulate the gas-water two-phase flow rates of the single tube to obtain the total flow rate of the capillary bundle under different water saturation levels, and to obtain the simulated water-gas ratio based on the total flow rate of the capillary bundle.

[0108] The screening module 400 is used to obtain the global optimal solution for the maximum allowable pore radius based on the simulated water-air ratio;

[0109] The recommendation module 500 is used to obtain a field recommendation scheme based on the global optimal solution of the maximum allowable blocking radius, so as to provide field guidance.

[0110] The following verification of the technical solution is based on numerical plugging aperture optimization for a tight gas reservoir:

[0111] 1) The basic parameters of the reservoir include porosity of 8% and permeability of 0.2mD. Based on the core test data, the mean pore size is determined to be 50μm and the standard deviation is 10. (2) 5000 pore size samples are randomly generated by normal distribution, and the pore size range of the samples is reasonably limited to 1 to 500μm. (3) Gas and water flow rates are calculated using a single-pore scale gas-water flow model. (4) The water saturation Sw is set to 0.3, 0.5, 0.7 and 0.9 respectively, and the range of the plugging diameter threshold is set to 30 to 100μm with a step size of 1μm. Gas flow rate, water flow rate and water-gas ratio curves under different threshold conditions are obtained. (5) Based on the target water-gas ratio (e.g., 10 cubic meters / 10,000 cubic meters), the optimal plugging radius is determined to be 45μm. (6) Water plugging measures are implemented on site. Production monitoring shows that the gas production capacity is maintained at more than 95% of that before water plugging, water production is reduced by 60%, and the water-gas ratio is significantly optimized, which verifies the effectiveness of the method.

[0112] Analysis of the relationship between plugging radius and two-phase flow rate under porous conditions:

[0113] (1) Parameter setting

[0114] The gas reservoir has a porosity of 4%–10%, with pore sizes concentrated in the range of 10–100 μm. Gas-water two-phase flow is prevalent, and the water saturation is approximately 0.5. The following simulation parameters are set:

[0115] Pore ​​radius distribution: 5000 pore radius samples were generated using a normal distribution, with a mean of 50 μm, a standard deviation of 10 μm, and a range of 1~500 μm.

[0116] The pressure gradient is set to G = 1×10 5 Pa / m.

[0117] The gas / water viscosity is set to μ. g = 1.8 × 10 -5 Pa-s, μ w =1.0×10 -3 Pa-S.

[0118] The sliding length is set to L s = 1×10 -7 m.

[0119] Surface plugging film thickness (equivalent porosity shrinkage) = 2 × 10 -6 m.

[0120] The target value for water saturation is set to S. w =0.5.

[0121] (2) Simulation process

[0122] ① Aperture sampling: A set of apertures {r} is generated using a random function based on a normal distribution. i}, unit μm.

[0123] ② Set the range of blocking radius values: r cutoff ∈[30,100]μm, with a step size of 0.7μm.

[0124] ③ Two-phase flow simulation: At each plugging threshold, remove all capillary tubes with ri>rcutof, and calculate the gas and water phase volumetric flow rates of the remaining capillary tubes at Su=0.5, denoted as Q. g Q w .

[0125] ④ The water-to-air ratio is calculated as: R = Q w Q g / 10 4 Unit: cubic meters / 10,000 cubic meters

[0126] ⑤ Repeat the above process to perform a series of calculations under different porosity conditions (by adjusting the sample size and cutoff range) to obtain the curves of gas flow rate, water flow rate and water-gas ratio as a function of the plugging radius.

[0127] (3) Results analysis and recommendations for sealing radius

[0128] Low porosity zone (≤8%): As the plugging radius increases, the gas flow rate rises significantly, but the water-to-gas ratio remains low. When the plugging radius is controlled between 40 and 55 μm, the main gas channel can be effectively released without causing significant water intrusion. Within this range, the water-to-gas ratio is stable, resulting in optimal economy and drainage cost.

[0129] Medium-to-high porosity blocks (8-10%): To increase gas production, the plugging radius can be increased to 55-70 μm, but enhanced drainage measures are required. When the plugging radius exceeds 70 μm, although the gas flow rate increases slightly, the water flow rate increases dramatically, the water-to-gas ratio rises rapidly, leading to increased production costs and decreased economic efficiency.

[0130] (4) Recommended critical closure radius

[0131] Based on the trends in water-to-gas ratio and gas production capacity, the following plugging strategies are recommended:

[0132]

[0133] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0134] The above specific embodiments illustrate the principles and implementation methods of the present invention using specific examples. The descriptions of the embodiments are merely for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. Additionally, any improvements and modifications made without departing from the principles of the present invention should also be considered to fall within the protection scope of the present invention.

Claims

1. A method for determining the pore radius boundary for water shut-off and sealing in gas reservoirs based on capillary bundles, characterized in that, include: S1. Collect reservoir physical property data of tight gas reservoirs and obtain a sample set of capillary bundle pore diameters; S2. Based on the capillary bundle pore diameter sample set, obtain the total flow rate of the capillary bundle under different water saturation levels; S3. Obtain the simulated water-air ratio based on the total flow rate of the capillary bundle; S4. Based on the simulated water-air ratio, obtain the global optimal solution for the maximum allowable pore radius for plugging; S5. Based on the global optimal solution of the maximum allowable blocking radius, obtain the recommended solution for the field.

2. The method for determining the pore radius boundary for water shut-off and sealing of gas reservoirs based on capillary bundles according to claim 1, characterized in that, The step S2, obtaining the total flow rate of the capillary bundle under different water saturation levels, further includes calculating the gas-water two-phase flow rate of a single tube for each sample set of pore diameters of the capillary bundle, and accumulating the gas-water two-phase flow rates of the single tubes to obtain the total flow rate of the capillary bundle under different water saturation levels.

3. The method for determining the pore radius boundary for water shut-off and sealing of gas reservoirs based on capillary bundles according to claim 1, characterized in that, S2 further includes the step of establishing a single-pipe gas-water two-phase flow model, which includes: For the incomplete blockage of gas-water co-flow, a single-pipe water film thickness-flow pattern partitioning-parallel flow rate model is constructed as an element model for equivalent parallel calculation of capillary bundles. This element model outputs the effective radius and water film thickness. Effective radius r s As shown in the following formula: ; in, The thickness of the residual water film on the wall surface; Water film thickness r wg As shown in the following formula: ; Among them, S w ∈(0,1) represents water saturation, r o This represents the pore radius of any single tube.

4. The method for determining the pore radius boundary for water shut-off and sealing of gas reservoirs based on capillary bundles according to claim 3, characterized in that, The step of establishing a single-pipe gas-water two-phase flow model under different water saturation conditions further includes using water film thickness to distinguish and judge flow patterns, and classifying them into three cases based on the relationship between water film thickness and effective radius: the first case is laminar flow only in the gas phase, r wg ≥r s The second scenario involves simultaneous flow of both air and water, 0 <r wg <r s The third scenario involves laminar flow only in the aqueous phase, r wg For values ​​≥0, flow sub-models are constructed, including the gas flow sub-model for the first case, the gas-water two-phase flow sub-model for the second case, and the water phase flow sub-model for the third case.

5. The method for determining the pore radius boundary for water shut-off and sealing of gas reservoirs based on capillary bundles according to claim 4, characterized in that, For the first scenario of laminar gas flow only, a single-pipe gas flow sub-model is established, as shown in the following equation: ; Among them, Q g,i Let G represent the gas flow rate in the i-th capillary, and let G represent the pressure gradient, μ g r represents the viscosity of a gas. s L represents the effective gas phase flow radius. s Indicates the slip length.

6. The method for determining the pore radius boundary for water shut-off and sealing of gas reservoirs based on capillary bundles according to claim 4, characterized in that, For the second scenario of simultaneous gas-water flow, a single-pipe gas-water two-phase flow sub-model is established, including the water phase flow component and the gas phase flow component: The single-pipe water phase flow rate is shown in the following formula: ; Among them, Q w,i μ represents the water flow rate in the i-th capillary. w Indicates the viscosity of water; The single-tube gas phase flow rate is shown in the following formula: ;。 7. The method for determining the pore radius boundary for water shut-off and sealing of gas reservoirs based on capillary bundles according to claim 4, characterized in that, For the third scenario of laminar flow only, a single-pipe water phase flow rate model is established as follows: ; Where, r o μ represents the pore radius of any single tube. w The viscosity of water is represented by G, which represents the pressure gradient.

8. The method for determining the pore radius boundary of water shut-off sealing in gas reservoirs based on capillary bundles according to claim 1, characterized in that, The step of obtaining the global optimal solution for the maximum permissible pore radius described in S4 further includes screening out the maximum permissible pore radius, using the maximum permissible pore radius as input to the capillary bundle micro-model, and finally obtaining the global optimal solution for the maximum permissible pore radius after iteration.

9. The method for determining the pore radius boundary for water shut-off and sealing of gas reservoirs based on capillary bundles according to claim 1, characterized in that, The total flow rate of the capillary bundle gas-water two-phase flow at different water saturation levels is shown in the following formula: ; in, For different saturation conditions Total gas flow rate in the lower capillary bundle Different saturation conditions Total aqueous phase flow rate in the lower capillary bundle; The simulated water-to-air ratio is shown in the following formula: ;。 10. A device for determining the pore radius boundary of water shut-off sealing in gas reservoirs based on capillary bundles, characterized in that, include: The collection module is used to collect reservoir physical property data of tight gas reservoirs and obtain a sample set of capillary bundle pore diameters; The total flow calculation module is used to obtain the total flow of the capillary bundle under different water saturation levels based on the capillary bundle pore diameter sample set. The water-to-air ratio calculation module is used to obtain the simulated water-to-air ratio based on the total flow rate of the capillary bundle. The screening module is used to obtain the globally optimal solution for the maximum allowable pore radius based on the simulated water-air ratio; The recommendation module is used to obtain a recommended solution for the field based on the global optimal solution of the maximum allowable blocking radius.

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