Method for adding temporary plugging agent in dynamic temporary plugging of tight gas horizontal well

Abstract

The invention discloses a method for adding a temporary plugging agent in dynamic temporary plugging of a tight gas horizontal well. The method comprises the following steps: S1, establishing a single-cluster hole abrasion model through Ansys finite element analysis software; s2, calibrating the model through an indoor hole abrasion experiment; s3, simulating the fracturing process through the model in the S1, and obtaining the hole friction resistance Pperf and the diameter Dave of the pressed hole; s4, a step displacement reduction test is conducted after fracturing, and the total hole friction Pperf total is obtained through fracturing analysis software; and S5, the number of opened perforation clusters is judged, and the adding amount of the temporary plugging agent is determined. According to the method for adding the temporary plugging agent in dynamic temporary plugging of the tight gas horizontal well, through combination of indoor experiments and numerical simulation, accurate putting of the temporary plugging agent is achieved, the success rate of dynamic temporary plugging is increased, the fracturing transformation volume is increased, and the productivity after fracturing is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of reservoir transformation, and in particular relates to a method for adding a temporary plugging agent in dynamic temporary plugging of a tight gas horizontal well. Background Art

[0002] In recent years, through continuous research and development, the Changqing tight gas horizontal wells have developed a segmented multi-cluster transformation technology for horizontal wells with inter-segment bridge plug separation, intra-segment flow-limiting fracturing + dynamic temporary plugging.

[0003] At present, the following problems still exist in the staged multi-cluster fracturing of horizontal wells:

[0004] ① The perforation clusters within the segment do not fracture, fracture unevenly, and have large differences in gas production contribution rates, which greatly reduces the fracturing transformation volume and seriously affects the post-fracturing production capacity; ② Currently, dynamic temporary plugging is used to plug the blastholes to make the perforation clusters expand evenly, but there is a lack of an optimization method for the amount of temporary plugging agent added; ③ During the fracturing process, the shape of the blasthole changes irregularly due to abrasion, which affects the determination of the amount of temporary plugging agent added.

[0005] According to the survey, the currently disclosed optimization methods for temporary plugging agent dosage are difficult to apply to the dynamic temporary plugging of Changqing tight gas horizontal wells. For example, Zhao Xurong et al. optimized the dosage of temporary plugging agents in a certain block based on multiple field tests in the "Study on Optimization of Temporary Plugging Agent Combination Dosage Based on the Pressure Boosting Effect of Middle and Shallow Old Wells", but the dosage of temporary plugging agents lacks theoretical support.

[0006] The invention patent with publication number CN111502593A discloses a method for determining the dosage of a temporary plugging agent for temporary plugging in fractures, the invention patent with publication number CN113705011A discloses a method for determining the timing of temporary plugging and optimizing the dosage of temporary plugging materials based on the fracture extension morphology, and the invention patent with publication number CN111980652A discloses a method for determining the type, size combination and dosage of temporary plugging agents in fractures. The above patent technologies all disclose a method for optimizing the dosage of temporary plugging agents in fracture or sealing temporary plugging, but the dynamic temporary plugging of Changqing tight gas horizontal wells adopts the method of blasthole temporary plugging, and the above methods are not applicable. Crump introduced a method for obtaining borehole friction and blasthole morphology through indoor experiments in the article SPE-15474-PA, but the amount of fracturing sand and liquid in Changqing tight gas horizontal wells is large, making it difficult to conduct indoor experiments. Summary of the invention

[0007] The present invention provides a method for adding a temporary plugging agent in dynamic temporary plugging of a tight gas horizontal well, aiming to improve the balanced expansion of a perforation cluster by applying the provided design method, thereby improving the effectiveness of the perforation cluster and improving the post-pressure production capacity.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0009] A method for adding a temporary plugging agent in dynamic temporary plugging of a tight gas horizontal well comprises the following steps:

[0010] S1. Establish a single cluster hole abrasion model using Ansys finite element analysis software;

[0011] S2. Calibrate the single cluster hole abrasion model established in S1 through indoor hole abrasion experiments;

[0012] S3. Use the single cluster hole abrasion model established in S1 to simulate the fracturing process and obtain the hole friction resistance P perf , hole diameter after pressing D ave ;

[0013] S4. After fracturing, a step-down test is performed and the total perforation friction resistance Pperf is obtained through fracturing analysis software;

[0014] S5. Determine the number of perforation clusters to be opened and determine the amount of temporary plugging agent to be added.

[0015] Furthermore, the single-cluster hole abrasion model established by the Ansys finite element analysis software in step S1 is a solid-liquid bidirectional coupling mathematical model.

[0016] Furthermore, the model in step S1 considers the abrasive effect of the fracturing proppant on the hole, and the abrasive model uses Long's calculation model:

[0017]

[0018]

[0019] Where: D0 is the initial hole diameter, mm;

[0020] C e is the proppant concentration, kg / m 3 ;

[0021] v is the flow velocity of the liquid through the hole in m / s;

[0022] C d is the flow coefficient;

[0023] α and β are the hole abrasion coefficients.

[0024] Furthermore, the indoor hole abrasion experiment S2 calibrates the single cluster hole abrasion model established in S1, wherein the calibration parameters include hole abrasion coefficients α and β, and the calibration operation method specifically includes the following steps:

[0025] The S2 indoor hole abrasion experiment calibrates the single cluster hole abrasion model established in S1, wherein the calibration parameters include hole abrasion coefficients α and β. The calibration operation method specifically includes the following steps:

[0026] S201, conduct borehole erosion test under certain casing size, displacement, sand concentration and pumping procedure to obtain borehole friction resistance at the end of the test;

[0027] S202, using the single-cluster hole abrasion model established in S1 to simulate under the same parameters, changing the hole abrasion coefficients α and β for multiple times until the error between the hole friction results simulated by the single-cluster hole abrasion model and the experimental results is less than 0.1 MPa;

[0028] S203, changing the casing size, displacement, sand concentration and pumping program, repeating steps S201 and S202 for many times until the borehole abrasion coefficients α and β under different experimental conditions can satisfy the error between the simulated borehole friction result and the experimental result <0.1MPa.

[0029] Preferably, the casing in the above steps uses the same steel grade and size as the casing on site.

[0030] Preferably, the types and proportions of the fracturing fluid and proppant in step S2 are the same as those on site.

[0031] Preferably, in step S2, the model is calibrated by performing an indoor abrasion test at a small displacement and a small sand ratio.

[0032] Preferably, the experimental device used in the indoor hole abrasion experiment is an indoor hole abrasion experimental device, which includes a tank body, a liquid storage tank, a liquid inlet pipeline and a return pipeline. A transverse sleeve is arranged in the tank body, and a plurality of perforation holes are arranged at intervals on the transverse sleeve, and a pressure sensor is installed on each perforation hole; one end of the liquid inlet pipeline is connected to the liquid outlet of the liquid storage tank, and the other end of the liquid inlet pipeline extends into the tank body and is connected to the liquid inlet of the transverse sleeve, and the liquid outlet of the transverse sleeve is connected to the liquid inlet of the liquid storage tank through the return pipeline, and a horizontal flow pump and a pressure gauge are installed on the liquid inlet pipeline, and the pressure gauge is located between the horizontal flow pump and the liquid inlet of the tank body.

[0033] Furthermore, in step S3, the single cluster hole abrasion model established in S1 is used to simulate the fracturing process and obtain the hole friction P perf , hole diameter after pressing D ave The specific operation method is:

[0034] The single cluster hole abrasion model established by Ansys finite element analysis software is used to simulate the fracturing process and obtain the hole friction resistance P at the end time. perf , hole diameter after pressing D ave .

[0035] Preferably, the amount of liquid and sand in the above simulation experiment process are the same as those in the on-site pumping procedure.

[0036] During the simulated fracturing experiment, the pressure values ​​at both ends of the perforated holes are read. perf is the sum of the pressure differences of each perforation hole;

[0037] During the simulated fracturing experiment, the fluid is a mixture of fracturing fluid and sand, which will cause abrasion to the perforations when passing through them. At the end of the experiment, the perforations are abraded from the original regular circles to irregular circles. The diameter corresponding to the area of ​​the irregular circle is the post-fracturing hole diameter Dave.

[0038] Furthermore, the specific operation of the step-by-step reduction test after the mid-pressure in step S4 is as follows: for the fracturing section that needs temporary plugging, after all the liquid is pumped into the first-stage fracturing, the displacement is gradually reduced in a step-by-step manner, wherein the step-by-step reduction has at least 3 steps, and the highest displacement does not exceed the minimum displacement in the pumping procedure of the fracturing section. After the pressure stabilizes at each displacement, it drops to the next step, and the time for each displacement is not less than 3 minutes.

[0039] Furthermore, the number n of perforation clusters opened in step S5 is obtained by the following formula:

[0040]

[0041] Where P perf is the hole friction, P perf总 It is the total hole friction.

[0042] Furthermore, the principle of adding temporary plugging agent is For: When D ave ≤1.2D0, temporary plugging agent input amount n a =1.0n ρ ;

[0043] When D ave >1.2D0, temporary plugging agent input

[0044] where n p =n×ρ 孔

[0045] Where n p is the number of holes opened;

[0046] ρ 孔 is the number of perforations in a single cluster.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1. The present invention realizes the precise delivery of temporary plugging agent through the method combining indoor experiment with numerical simulation, improves the success rate of dynamic temporary plugging, increases the volume of fracturing transformation, and improves the post-fracturing production capacity.

[0049] 2. The present invention can carry out differentiated design of temporary plugging agents required for each fracturing stage, thereby achieving precise control of the amount of temporary plugging agents added.

[0050] 3. The amount of temporary plugging agent to be added is determined on site based on experience. The present invention fills the gap in the current method of adding the temporary plugging agent.

[0051] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other design solutions and drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 It is a flow chart of the method of adding temporary plugging agent in dynamic temporary plugging of tight gas horizontal wells;

[0054] Figure 2 Schematic diagram of the indoor hole abrasion experimental device.

[0055] Description of reference numerals:

[0056] 1. Tank body;

[0057] 101, transverse casing; 102, perforation holes;

[0058] 2. Liquid storage tank;

[0059] 3. Horizontal flow pump;

[0060] 4. Liquid inlet pipeline;

[0061] 5. Return pipeline;

[0062] 6. Pressure gauge. DETAILED DESCRIPTION

[0063] The content of the present invention can be further understood by combining the following detailed description of the preferred implementation method of the present invention and the embodiments included. Unless otherwise stated, all technical and scientific terms used in this article have the same meaning as those of ordinary skill in the art to which the present invention belongs. If the definition of a specific term disclosed in the prior art is inconsistent with any definition provided in the present invention, the definition of the term provided in the present invention shall prevail.

[0064] Reference Figure 1The present invention provides a method for adding a temporary plugging agent in dynamic temporary plugging of a tight gas horizontal well, comprising the following steps:

[0065] S1. Establish a single cluster hole abrasion model using Ansys finite element analysis software;

[0066] S2. Calibrate the single cluster hole abrasion model established in S1 through indoor hole abrasion experiments;

[0067] S3. Use the single cluster hole abrasion model in S1 to simulate the fracturing process and obtain the hole friction resistance P perf , hole diameter after pressing D ave ;

[0068] S4. After fracturing, conduct step-down test and obtain total hole friction resistance P through fracturing analysis software perf总 ;

[0069] S5. Determine the number of perforation clusters to be opened and determine the amount of temporary plugging agent to be added.

[0070] Furthermore, the single-cluster hole abrasion model established by Ansys finite element analysis software is a solid-liquid bidirectional coupling mathematical model.

[0071] The method of establishing a single cluster hole abrasion model by using Ansys finite element analysis software specifically includes:

[0072] S101, establishing a geometric model, according to the actual wellbore structure data of the target well, establishing a geometric model of the target well. Since the wellbore structure of the actual well is relatively complex, when modeling, the geometric model should be made to fit the actual wellbore structure of the target well as much as possible while ensuring that the depth measurement of the geometric model is the same as that of the target well;

[0073] S102, meshing, meshing the constructed geometric model

[0074] You can choose to divide the grid automatically or by your own choice. When dividing the grid, be careful not to divide the grid too finely, which will cause the model to run for a long time, nor divide the grid too coarsely, which will cause inaccurate running results.

[0075] S103, setting material parameters, including elastic modulus, Poisson's ratio, friction coefficient, etc., according to the actual wellbore material of the target well;

[0076] S104, generating a single cluster hole abrasion model.

[0077] Considering the abrasive effect of fracturing proppant on the perforations, the single cluster perforation abrasion model in step S1 uses Long's calculation model:

[0078]

[0079]

[0080] Where: D0 is the initial hole diameter, mm;

[0081] C e is the proppant concentration, kg / m 3 ;

[0082] v is the flow velocity of the liquid through the hole in m / s;

[0083] C d is the flow coefficient;

[0084] t is time, s;

[0085] α and β are the hole abrasion coefficients.

[0086] The single cluster hole abrasion model established by S1 was calibrated using an indoor hole abrasion experimental device, wherein the calibration parameters include hole abrasion coefficients α and β. The calibration operation method includes:

[0087] S201, conduct borehole erosion test under certain casing size, displacement, sand concentration and pumping procedure to obtain borehole friction resistance at the end of the test;

[0088] S202, using the single-cluster hole abrasion model established in S1 to simulate under the same parameters, changing the hole abrasion coefficients α and β for multiple times until the error between the hole friction results simulated by the single-cluster hole abrasion model and the experimental results is less than 0.1 MPa;

[0089] S203, changing the casing size, displacement, sand concentration and pumping program, repeating steps S201 and S202 for many times until the borehole abrasion coefficients α and β under different experimental conditions can satisfy the error between the simulated borehole friction result and the experimental result <0.1MPa.

[0090] Specifically, refer to Figure 2 The indoor hole abrasion experimental device includes a tank body 1, a liquid storage tank 2, a liquid inlet pipeline 4 and a return pipeline 5. A transverse sleeve 101 is arranged in the tank body 1, and a plurality of perforation holes 102 are arranged at intervals on the transverse sleeve 101, and a pressure sensor 103 is installed on each perforation hole 102; one end of the liquid inlet pipeline 4 is connected to the liquid outlet of the liquid storage tank 2, and the other end of the liquid inlet pipeline 4 extends into the tank body 1 and is connected to the liquid inlet of the transverse sleeve 101, and the liquid outlet of the transverse sleeve 101 is connected to the liquid inlet of the liquid storage tank 2 through the return pipeline 5, and a horizontal flow pump 3 and a pressure gauge 6 are installed on the liquid inlet pipeline 4, and the pressure gauge 6 is located between the horizontal flow pump 3 and the liquid inlet of the tank body 1.

[0091] It should be noted that the casing used in the above steps is of the same steel grade and size as that used on site.

[0092] Furthermore, the single cluster hole abrasion model established in S1 is used to simulate the fracturing process and obtain the hole friction resistance P perf , hole diameter after pressing D ave The specific operation method is:

[0093] The single cluster hole abrasion model established by Ansys finite element analysis software is used to simulate the fracturing process and obtain the hole friction resistance P at the end time. perf , hole diameter after pressing D ave .

[0094] During the simulated fracturing experiment, the fluid will generate a pressure difference at both ends of the perforation hole. The sum of the pressure differences of each perforation hole is the perforation friction P. perf , which is obtained by counting the pressure values ​​at both ends of the perforation hole.

[0095] During the simulated fracturing experiment, the fluid is a mixture of fracturing fluid and sand, which will cause abrasion to the perforations when passing through them. At the end of the experiment, the perforations are abraded from the original regular circles to irregular circles. The diameter corresponding to the area of ​​the irregular circle is the post-fracturing hole diameter Dave.

[0096] It should be further explained that the amount of liquid and sand in the simulated fracturing process in step S3 are the same as those in the on-site pumping procedure.

[0097] Furthermore, the specific operation of the step-by-step reduction test after the mid-pressure in step S4 is: for the fracturing section that needs temporary plugging, after all the liquid is pumped into the first-stage fracturing, the displacement is gradually reduced in a step-by-step manner. Preferably, the step-by-step reduction has at least 3 steps, the highest displacement does not exceed the minimum displacement in the pumping program of the fracturing section, and the pressure at each displacement is stabilized and then reduced to the next step, and the time for each displacement is not less than 3 minutes.

[0098] Specifically, the fracturing analysis software in step S4 includes FracproPT, Meyer or Stimplan.

[0099] The number of perforation clusters n opened in step S5 is obtained by the following formula:

[0100]

[0101] Where P perf is the hole friction, P perf总 It is the total hole friction.

[0102] The principle of adding temporary plugging agent in step S5 is: when the hole diameter D ave ≤1.2D0, temporary plugging agent input amount n a =1.0n ρ ; After pressing, the hole diameter D ave >1.2D0, temporary plugging agent input

[0103] Among them, n p =n×ρ 孔

[0104] Where n p is the number of holes opened;

[0105] ρ 孔 is the number of perforations in a single cluster.

[0106] In a specific embodiment, a method for adding a temporary plugging agent in dynamic temporary plugging of a tight gas horizontal well comprises the following steps:

[0107] S1. Ansys finite element analysis software was used to establish a single cluster hole abrasion model;

[0108] S2. Calibrate the model by indoor hole abrasion experiment;

[0109] S3. Simulate the fracturing process through the model in S1 and obtain the hole friction resistance P perf , hole diameter after pressing D ave ;

[0110] S4. After fracturing, conduct step-down test and obtain total hole friction resistance P through fracturing analysis software perf总 ;

[0111] S5. Determine the number of perforation clusters to be opened and determine the amount of temporary plugging agent to be added.

[0112] Furthermore, in the step S1, a solid-liquid bidirectional coupling mathematical model is established by using Ansys finite element analysis software.

[0113] Furthermore, the model in step S1 considers the abrasive effect of the fracturing proppant on the hole, and the abrasive model uses Long's calculation model:

[0114]

[0115]

[0116] Furthermore, in step S2, the casing uses the same steel grade and size as on-site, steel grade P110, casing outer diameter 114.3 mm, wall thickness 7.37 mm, initial hole diameter 9.7 mm.

[0117] Furthermore, the types and proportions of the fracturing fluid and proppant in step S2 are the same as those on site. Guar gum is used as the fracturing fluid, and 40 / 70 mesh quartz sand is used as the proppant.

[0118] Furthermore, the model correction parameters in step S2 include hole abrasion coefficients α and β. After correction, when α=1.2*10-13 β=2.0*10 -8 When the model simulation results are compared with the experimental results, the error is less than 0.1MPa.

[0119] Furthermore, in step S3, the model established in S1 is used to simulate the borehole erosion during the fracturing process, and the pressure difference between the inside and outside of the borehole at the end time and the borehole diameter after fracturing are obtained. The simulation results show that the pressure difference between the inside and outside of the borehole at the end time is 5.6MPa and the borehole diameter after fracturing is 11.3mm.

[0120] Furthermore, in the step S4, for the fracturing section that needs temporary plugging, after all the liquid is pumped into the first stage fracturing, the displacement is gradually reduced in a step-down manner.

[0121] Preferably, the stepwise reduction of displacement in step S4 has at least three steps, and the pressure at each displacement level is reduced to the next step after being stabilized, and the time for each displacement level is not less than 3 minutes.

[0122] Furthermore, the number n of perforation clusters opened in step S5 is obtained by the following formula:

[0123]

[0125] Furthermore, the number of holes opened in step S5 is n p Obtained by the following formula:

[0126] n p =n×ρ 孔 =3×16=48;

[0127] where is the number of perforations in a single cluster.

[0128] Furthermore, the principle of adding temporary plugging agent in step S5 is: when D ave ≤1.2D0, temporary plugging agent input amount n a =1.0n p When D ave >1.2D0, temporary plugging agent input

[0129] In this embodiment, D ave ≤1.2D0, the amount of temporary plugging agent input is n a =1.0n p =48.

[0130] In summary, the method for adding temporary plugging agent in dynamic temporary plugging of tight gas horizontal wells provided by the present invention combines indoor experiments with numerical simulations to achieve precise delivery of temporary plugging agent, improve the success rate of dynamic temporary plugging, increase the fracturing transformation volume, and improve the post-fracturing production capacity.

[0131] The preferred embodiments of the present invention are described above, but the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical scheme of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A method for adding a temporary plugging agent in dynamic temporary plugging of a tight gas horizontal well, characterized in that: The steps include: S1. Establish a single cluster hole abrasion model using Ansys finite element analysis software; S2. Calibrate the single cluster hole abrasion model established in S1 through indoor hole abrasion experiments; S3. Use the single cluster hole abrasion model established in S1 to simulate the fracturing process and obtain the hole friction resistance P perf , hole diameter after pressing D ave ; S4. After fracturing, conduct step-down test and obtain total hole friction resistance P through fracturing analysis software perf总 ; S5. Determine the number of perforation clusters to be opened and determine the amount of temporary plugging agent to be added.

2. The method for adding temporary plugging agent in dynamic temporary plugging of tight gas horizontal wells according to claim 1, characterized in that: The single-cluster hole abrasion model established by the Ansys finite element analysis software in step S1 is a solid-liquid bidirectional coupling mathematical model.

3. The method for adding temporary plugging agent in dynamic temporary plugging of tight gas horizontal wells according to claim 1, characterized in that: The single-cluster hole abrasion model in step S1 uses Long's calculation model, which is specifically: Where: D0 is the initial hole diameter, mm; C e is the proppant concentration, kg / m 3 ; v is the flow velocity of the liquid through the hole in m / s; C d is the flow coefficient; t is time, s; α and β are the hole abrasion coefficients.

4. The method for adding temporary plugging agent in dynamic temporary plugging of tight gas horizontal wells according to claim 1, characterized in that: The step S2 calibrates the single cluster hole abrasion model established in S1 through an indoor hole abrasion experiment, wherein the calibration parameters include hole abrasion coefficients α and β. The calibration operation method specifically includes the following steps: S201, conduct borehole erosion test under certain casing size, displacement, sand concentration and pumping procedure to obtain borehole friction resistance at the end of the test; S202, using the single-cluster hole abrasion model established in S1 to simulate under the same parameters, changing the hole abrasion coefficients α and β for multiple times until the error between the hole friction results simulated by the single-cluster hole abrasion model and the experimental results is less than 0.1 MPa; S203, changing the casing size, displacement, sand concentration and pumping program, repeating steps S201 and S202 for many times until the borehole abrasion coefficients α and β under different experimental conditions can satisfy the error between the simulated borehole friction result and the experimental result <0.1MPa.

5. The method for adding temporary plugging agent in dynamic temporary plugging of tight gas horizontal wells according to claim 4, characterized in that: The experimental device used in the indoor borehole abrasion experiment is an indoor borehole abrasion experiment device, which comprises a tank body (1), a liquid storage tank (2), a liquid inlet pipeline (4) and a return pipeline (5). A transverse casing (101) is arranged in the tank body (1), and a plurality of perforated holes (102) are arranged at intervals on the transverse casing (101). A pressure sensor is installed on each perforated hole (102); the liquid inlet pipeline (4) and the return pipeline (5) are provided with a pressure sensor. One end of the liquid inlet line (4) is connected to the liquid outlet of the liquid storage tank (2), the other end of the liquid inlet line (4) extends into the tank body (1) and is connected to the liquid inlet of the transverse sleeve (101), the liquid outlet of the transverse sleeve (101) is connected to the liquid inlet of the liquid storage tank (2) via a reflux line (5), a horizontal flow pump (3) and a pressure gauge (6) are installed on the liquid inlet line (4), and the pressure gauge (6) is located between the horizontal flow pump (3) and the liquid inlet of the tank body (1).

6. The method for adding temporary plugging agent in dynamic temporary plugging of tight gas horizontal wells according to claim 1, characterized in that: In step S3, the single-cluster hole abrasion model established in step S1 is used to simulate the fracturing process and obtain the hole friction P perf , hole diameter after pressing D ave The specific operation method is: The single cluster hole abrasion model established by Ansys finite element analysis software is used to simulate the fracturing process and obtain the hole friction resistance P at the end time. perf , hole diameter after pressing D ave .

7. The method for adding temporary plugging agent in dynamic temporary plugging of tight gas horizontal wells according to claim 6, characterized in that: During the simulated fracturing experiment, the pressure values ​​at both ends of the perforated holes are read. perf is the sum of the pressure differences of each perforation hole; During the simulated fracturing experiment, the fluid is a mixture of fracturing fluid and sand. When passing through the perforated holes, it will cause abrasion to the holes. At the end of the experiment, the perforated holes are abraded from the original regular circles to irregular circles. The diameter corresponding to the area of ​​the irregular circle is the hole diameter after fracturing D. ave .

8. The method for adding temporary plugging agent in dynamic temporary plugging of tight gas horizontal wells according to claim 1, characterized in that: The specific operation of the step-by-step reduction test after the medium pressure in step S4 is as follows: for the fracturing section that needs temporary plugging, after all the liquid is pumped into the first-stage fracturing, the displacement is gradually reduced in a step-by-step manner, wherein the step-by-step reduction has at least 3 steps, and the highest displacement does not exceed the minimum displacement in the pumping procedure of the fracturing section. After the pressure stabilizes at each displacement, it drops to the next step, and the time for each displacement is not less than 3 minutes.

9. The method for adding temporary plugging agent in dynamic temporary plugging of tight gas horizontal wells according to claim 1, characterized in that: The number of perforation clusters n opened in step S5 is obtained by the following formula: Where P perf is the hole friction, P perf总 It is the total hole friction.

10. The method for adding temporary plugging agent in dynamic temporary plugging of tight gas horizontal wells according to claim 1, characterized in that: The principle of adding temporary plugging agent is: when the hole diameter D ave ≤1.2D0, temporary plugging agent input amount n a =1.0n ρ ; After pressing, the hole diameter D ave >1.2D0, temporary plugging agent input Among them, n p =n×ρ 孔 Where n p is the number of holes opened; ρ 孔 is the number of perforations in a single cluster.

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