Controllable degradation polyglycolic acid temporary plugging agent, preparation method and temporary plugging agent degradation performance regulation and control method

Abstract

The invention belongs to the technical field of oil field chemical development, and relates to a controllably degradable polyglycolic acid temporary plugging agent, a preparation method and a temporary plugging agent degradation performance regulation and control method. The temporary plugging agent comprises polyglycolic acid, an adjusting auxiliary agent and an antioxidant, on the basis of the total weight of the temporary plugging agent, the content of the polyglycolic acid is 83-99.7 wt%, the content of the adjusting aid is 0.2-15 wt%, and the content of the antioxidant is 0.1-2 wt%; the adjusting auxiliary agent is a degradation accelerator or a chain extender; the degradation accelerant is selected from one or more of amine compounds, inorganic carbonate and metal hydroxides. According to the controllably degradable polyglycolic acid temporary plugging agent provided by the invention, the degradation rate of the temporary plugging agent is regulated and controlled through blending modification, different operation time requirements of an oil field can be met, the PGA is more easily crushed into superfine powder due to the high-rigidity characteristic of the PGA, and the controllable degradable polyglycolic acid temporary plugging agent is suitable for diversion fracturing of medium-permeability and low-permeability stratum structures.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield chemical development, and in particular relates to a controllably degradable polyglycolic acid temporary plugging agent, a preparation method of the controllably degradable polyglycolic acid temporary plugging agent, and a method for regulating the degradation performance of the degradable temporary plugging agent. Background Art

[0002] Temporary plugging and diversion fracturing technology is one of the common technical means to increase oil and gas production. The key to achieving temporary plugging and diversion fracturing technology is to inject temporary plugging agents into the target formation in advance, plug existing cracks or holes, form a dense temporary plugging layer, increase the seepage resistance in the high permeability area, and then increase the temporary plugging and diversion fracturing area. Polyester biodegradable materials cause the least damage to the formation. Without adding any additives, they can be degraded and eventually discharged from the formation smoothly, becoming a new development direction for temporary plugging materials.

[0003] Polyglycolic acid (PGA) is a polyester material with the lowest known carbon number per unit and is completely degradable. It has better degradation performance, higher mechanical strength and stiffness, and is one of the ideal materials for preparing degradable temporary plugging agents. The application of PGA in the oil field was first reported by Kureha of Japan. The company jointly built a 4000t / a PGA production unit with DuPont of the United States, and manufactured PGA-based fracturing balls and temporary plugging agents to assist in the development of oil and gas in the United States. US20150126414A1 discloses the use of SnCl4 as a catalyst to synthesize PGA materials with a relative molecular mass between 150000 and 200000, and PGA is made into short fibers. By controlling the length, diameter and relative molecular mass of the fibers, a high-strength fibrous degradable temporary plugging agent is prepared, which reduces the pollution to the formation environment during oil production. US20160298017A1 introduces a synthetic resin containing PGA as a drilling temporary plugging agent, which has a plugging function in the temperature range of 93 to 204°C for 2 to 40 days. At present, traditional biodegradable materials such as polylactic acid (PLA), polybutylene adipate / terephthalate (PBAT), polyhydroxyalkanoic acid (PHA) as temporary plugging materials have problems such as insufficient temporary plugging strength, slow degradation, and difficulty in crushing. The high rigidity of PGA makes it easy to crush and more suitable for preparing granular temporary plugging agents. This type of temporary plugging agent has the advantages of high plugging strength, wide applicable seam width range, wide operating temperature window, easy backflow and easy material processing.

[0004] PGA has various degradation forms, including photodegradation, water degradation, enzyme degradation, etc. In particular, the formation environment of oil fields is complex and harsh. As a temporary plugging agent, it should meet the time requirements of different operations in oil fields, and put forward further requirements for the controllability of PGA degradation rate. Therefore, it is necessary to properly regulate the degradation performance of PGA. Summary of the invention

[0005] Aiming at the problems that the current degradable temporary plugging agent materials are difficult to crush and the degradation time is uncontrollable, the present invention provides a degradation-controllable, ultrafine powder temporary plugging agent and a preparation method thereof, as well as a method for regulating the degradation performance of the degradable temporary plugging agent.

[0006] The first aspect of the present invention provides a controllably degradable PGA temporary plugging agent, which comprises PGA, a regulating aid and an antioxidant; based on the total weight of the temporary plugging agent, the content of PGA is 83-99.7wt%, the content of the regulating aid is 0.2-15wt%, and the content of the antioxidant is 0.1-2wt%; the regulating aid is a degradation accelerator or a chain extender; the degradation accelerator is selected from one or more of amine compounds, inorganic carbonates and metal hydroxides.

[0007] The second aspect of the present invention provides a method for preparing the above-mentioned controllable degradable PGA temporary plugging agent, comprising the following steps: blending PGA with a regulating aid and an antioxidant, and crushing PGA or the blend.

[0008] The third aspect of the present invention provides a method for regulating the degradation performance of a degradable temporary plugging agent, the method comprising the following steps:

[0009] S1. Selecting a regulating aid according to the regulation target, wherein the regulating aid is a degradation accelerator or a chain extender;

[0010] S2, blending PGA with a regulating aid and an antioxidant, wherein the PGA is crushed before blending or the blend is crushed to obtain a temporary plugging agent with the required degradation performance;

[0011] Based on the total weight of the temporary plugging agent, the content of PGA is 83-99.7wt%, the content of the regulating aid is 0.2-15wt%, and the content of the antioxidant is 0.1-2wt%; the degradation accelerator is selected from one or more of amine compounds, inorganic carbonates and metal hydroxides.

[0012] The present invention provides a controllably degradable PGA temporary plugging agent. The degradation rate of the temporary plugging agent is regulated by blending and modification, so as to meet the different operation time requirements of oil fields. The high stiffness of PGA makes it easier to be crushed into ultrafine powder, which is suitable for diverting fracturing of medium and low permeability formation structures.

[0013] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0014] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0015] The invention provides a controllably degradable PGA temporary plugging agent, which comprises PGA, a regulating aid and an antioxidant; based on the total weight of the temporary plugging agent, the content of the PGA is 83-99.7wt%, the content of the regulating aid is 0.2-15wt%, and the content of the antioxidant is 0.1-2wt%; the regulating aid is a degradation accelerator or a chain extender; and the degradation accelerator is selected from one or more of amine compounds, inorganic carbonates and metal hydroxides.

[0016] According to the present invention, the high stiffness of PGA makes it easier to crush, so it is preferred to crush the temporary plugging agent into ultrafine powder before actual application to obtain the best temporary plugging effect. The particle size after crushing can be determined as needed. Specifically, the particle size of the temporary plugging agent is 10-500 mesh, preferably 20-200 mesh.

[0017] The present invention has no particular limitation on the PGA, and any PGA prepared by glycolic acid liquid phase polycondensation, glycolic acid solid phase polycondensation, glycolic acid melt polycondensation, or glycolide ring-opening polymerization is acceptable, and usually the PGA prepared by glycolide ring-opening polymerization is used. The number average molecular weight of the PGA is preferably controlled within the range of 50,000-100,000 to provide sufficient viscosity, and is further preferably controlled within the range of 50,000-70,000.

[0018] For the degradation accelerator, the usage amount is preferably 3-15wt% based on the total weight of the temporary plugging agent.

[0019] The present invention uses liquid organic amines, melamine and its derivatives, imidazole and its derivatives, piperazine and its derivatives, inorganic carbonates, and metal hydroxides as additives to change the pH of the environment during the degradation of PGA, thereby accelerating the degradation rate of the temporary plugging agent.

[0020] Among them, the liquid organic amine compound is preferably one or more of ethylenediamine, polyethyleneimine, triethylenetetramine, triisopropanolamine and trihydroxyethylamine, preferably polyethyleneimine; based on the total weight of the temporary plugging agent, the content of the liquid organic amine compound is preferably 3-15wt%, more preferably 3-6wt%.

[0021] The imidazole compound is one or more of imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-propylimidazole, 2-aminoimidazole, 2-tert-butylimidazole and 2-(2-imidazolyl)ethanol, preferably one or more of imidazole, 2-methylimidazole, 2-ethylimidazole and 2-ethyl-4-methylimidazole; based on the total weight of the temporary plugging agent, the content of the imidazole compound is preferably 3-15wt%, more preferably 3-10wt%;

[0022] The piperazine compound is one or more of piperazine, N-methylpiperazine, 2-methylpiperazine, 1-butylpiperazine, 1-ethylhomopiperazine and 1-phenylpiperazine, preferably one or more of piperazine and 2-methylpiperazine; based on the total weight of the temporary plugging agent, the content of the piperazine compound is preferably 3-15wt%, more preferably 5-10wt%;

[0023] The melamine compound is one or more of melamine, melamine cyanurate, melamine phosphate, melamine polyphosphate and melamine hydrobromide, preferably one or more of melamine and melamine polyphosphate; based on the total weight of the temporary plugging agent, the content of the melamine compound is preferably 3-15wt%, more preferably 5-15wt%.

[0024] The inorganic carbonate is preferably one or more of potassium carbonate, sodium carbonate, sodium bicarbonate, calcium carbonate, calcium bicarbonate, barium carbonate, zinc carbonate, magnesium carbonate and ferrous carbonate, preferably one or more of barium carbonate, calcium carbonate and zinc carbonate; based on the total weight of the temporary plugging agent, the content of the inorganic carbonate is preferably 3-15wt%, more preferably 5-15wt%.

[0025] The metal hydroxide is preferably one or more of magnesium hydroxide, aluminum hydroxide, zinc hydroxide, iron hydroxide, lead hydroxide, tin hydroxide and cobalt hydroxide, preferably one or more of magnesium hydroxide, aluminum hydroxide and zinc hydroxide; based on the total weight of the temporary plugging agent, the content of the metal hydroxide is preferably 3-15wt%, more preferably 5-10wt%.

[0026] The present invention uses a chain extender to increase the molecular weight of PGA and slow down the degradation rate of PGA. The chain extender can be at least one of an epoxy chain extender and an isocyanate chain extender, preferably Celymer TM 8280、Celymer TM 8280E, ADR-4370S, ADR-4468, ADR-4400, SAG-008, SG-20, Celymer TM One or more of SBC and ZeMac-E60P, more preferably Celymer TM One or more of 8280, ADR-4468 and SAG-008, the content of the chain extender is 0.2-3wt%, preferably 0.5-2wt%.

[0027] The antioxidant in the present invention can be of conventional type, including but not limited to one or more of antioxidant 168, antioxidant 1010, antioxidant 626 and antioxidant 618, preferably one or more of antioxidant 168 and antioxidant 1010; the content of the antioxidant is 0.1-2wt%, preferably 0.1-1.2wt%.

[0028] The present invention also provides a method for preparing the above-mentioned controllably degradable PGA temporary plugging agent, comprising the following steps: blending PGA with a regulating aid and an antioxidant, and crushing PGA or the blend.

[0029] The blending can be screw melt blending or physical blending. The inventors of the present invention have found that screw melt blending can improve the dispersibility of the additive in the PGA matrix and obtain a more ideal regulating degradation effect. Therefore, the blending is preferably melt blending achieved by a twin-screw extruder. Specifically, the processing temperature of the twin-screw extruder is 180-240°C and the rotation speed is 150-300r / min. After extrusion, water cooling, pelletizing and drying are performed.

[0030] The temporary plugging agent of the present invention is made into ultrafine powder by crushing. If direct blending is adopted, the crushing can be carried out on PGA. If screw melt blending is adopted, the crushing is preferably carried out on the modified PGA (ie, the blend).

[0031] The crushing process can be at least one of high-speed mechanical impact crushing, disc-type airflow crushing, ultrafine crushing and liquid nitrogen freezing shock crushing, preferably at least one of disc-type airflow crushing and ultrafine crushing, and more preferably a high-speed impact crusher and / or disc-type airflow crushing.

[0032] The present invention also provides a method for regulating the degradation performance of a degradable temporary plugging agent, the method comprising the following steps:

[0033] S1. Selecting a regulating aid according to the regulation target, wherein the regulating aid is a degradation accelerator or a chain extender;

[0034] S2, blending PGA with a regulating aid and an antioxidant, wherein the PGA is crushed before blending or the blend is crushed to obtain a temporary plugging agent with the required degradation performance;

[0035] Based on the total weight of the temporary plugging agent, the content of PGA is 83-99.7wt%, the content of the regulating aid is 0.2-15wt%, and the content of the antioxidant is 0.1-2wt%; the degradation accelerator is selected from one or more of amine compounds, inorganic carbonates and metal hydroxides.

[0036] According to the present invention, the principle of selecting the regulating agent according to the regulating target is: if the regulating target is to accelerate degradation, a degradation promoter is selected as the regulating agent; if the regulating target is to slow down degradation, a chain extender is selected as the regulating agent.

[0037] In the method for regulating the degradation performance of the degradable temporary plugging agent, the limitations on PGA, the type and amount of the degradation accelerator, the type and amount of the chain extender, the type and amount of the antioxidant, and the blending and crushing steps are as described above and will not be repeated here.

[0038] The present invention will be further described below in conjunction with embodiments, but the scope of the present invention is not limited to these embodiments.

[0039] 1. Raw materials and equipment

[0040] Polyglycolic acid, Inner Mongolia Pujing Chemical Co., Ltd., number average molecular weight is 58,000.

[0041] Ground mineralized water, homemade, 30000ppm, its composition is 29400ppm sodium chloride, 300ppm calcium chloride, 300ppm magnesium chloride.

[0042] Laser particle size analyzer, Mastersizer 3000, Malvern Instruments Ltd., UK.

[0043] Disc type air flow mill, QS-100, Jiangsu Hongda Powder Equipment Co., Ltd.

[0044] Core displacement instrument, HB-2, Hai'an County Petroleum Research Instrument Co., Ltd.

[0045] 2. Test methods

[0046] Degradation performance evaluation: The blended samples were hot pressed into 10×10×2mm 3 The square slices were immersed in a 30000ppm mineralized aqueous solution at 90℃ for degradation. The samples were taken out and dried after 24h and 48h respectively. The mass of the undegraded part was measured and the degradation rate was calculated according to the following formula:

[0047] D(%)=(m0-m1) / m0×100%

[0048] Where m0 is the initial mass of the sample, and m1 is the remaining mass of the sample after 24h or 48h.

[0049] Temporary plugging performance test: The core displacement method was used to evaluate the temporary plugging performance of the PGA temporary plugging agent before and after modification, and a wedge-shaped mold with a narrow end width of 1 mm was used to simulate formation fractures.

[0050] First, sieve out the powders with mesh sizes of 200-500 mesh and 20-200 mesh in the temporary plugging agent product, take an appropriate amount of 200-500 mesh powder and mix it with the displacement fluid, and stir it for 30 minutes to make it evenly dispersed to form a temporary plugging agent solution for displacement. Then, fill the wedge-shaped mold with 20-200 mesh powder, and put the mold into the clamp. The wide end face of the wedge-shaped mold is the inlet end of the displacement fluid, and the narrow end face is the outlet end of the displacement fluid. Apply a confining pressure of 30MPa around the mold. Open the test software, heat the displacement device and keep the temperature at 90℃, turn on the displacement pump to inject the temporary plugging agent solution containing PGA powder into the displacement device, adjust the displacement speed, and stabilize the temporary plugging pressure at about 30MPa. The time when the pressure reaches a stable state is defined as the temporary plugging start time. Detect the change in the temporary plugging liquid seepage amount, and define the moment when the temporary plugging liquid seepage amount suddenly increases as the temporary plugging agent unblocking time. The difference between the start time and the unblocking time is the temporary blocking time of the PGA temporary blocking agent at 90°C and 30MPa.

[0051] Example 1

[0052] 89 parts by weight of PGA, 10 parts by weight of melamine and 1 part by weight of antioxidant 168 were mixed in a high-speed mixer for 10 minutes, added into a twin-screw extruder for extrusion granulation, and dried in a blast oven at 80°C for 12 hours to obtain a modified PGA sample, wherein the temperatures of the five screw zones are 180°C, 220°C, 230°C, 230°C, and 200°C, respectively, and the screw speed is 250 r / min. The modified PGA sample is crushed into 20-500 mesh powder using a disc-type air flow mill to obtain a temporary plugging agent product PGA-S1.

[0053] The temporary plugging agent product PGA-S1 was subjected to degradation performance test and temporary plugging performance test, and the results are shown in Table 1.

[0054] Example 2

[0055] 94 parts by weight of PGA, 5 parts by weight of melamine and 1 part by weight of antioxidant 168 were mixed in a high-speed mixer for 10 minutes. The other process was the same as in Example 1 to obtain a temporary plugging agent product PGA-S2, which was subjected to degradation performance tests and temporary plugging performance tests. The test results are shown in Table 1.

[0056] Comparative Example 1

[0057] 99 parts by weight of PGA and 1 part by weight of antioxidant 168 were mixed in a high-speed mixer for 10 minutes. The other process was the same as in Example 1 to obtain a temporary plugging agent product PGA-D1, which was tested for degradation performance and temporary plugging performance. The test results are shown in Table 1.

[0058] Example 3

[0059] PGA was crushed into 20-500 mesh powder using a disc air flow mill, 89 parts by weight of PGA powder, 10 parts by weight of melamine and 1 part by weight of antioxidant 168 were mixed in a high-speed mixer for 10 minutes, and dried in a blast oven at 80°C for 12 hours to obtain a temporary plugging agent product PGA-S3, which was subjected to degradation performance tests and temporary plugging performance tests. The test results are shown in Table 1.

[0060] Comparative Example 2

[0061] PGA was crushed into 20-500 mesh powder using a disc-type air flow mill, 99 parts by weight of PGA powder and 1 part by weight of antioxidant 168 were mixed in a high-speed mixer for 10 minutes, and the other process was the same as in Example 3 to obtain a temporary plugging agent product PGA-D2, which was subjected to degradation performance tests and temporary plugging performance tests. The test results are shown in Table 1.

[0062] Example 4

[0063] 94 parts by weight of PGA, 5 parts by weight of barium carbonate and 1 part by weight of antioxidant 168 were mixed in a high-speed mixer for 10 minutes. The other process was the same as in Example 1 to obtain a temporary plugging agent product PGA-S4, which was subjected to degradation performance tests and temporary plugging performance tests. The test results are shown in Table 1.

[0064] Example 5

[0065] 89 parts by weight of PGA, 10 parts by weight of piperazine and 1 part by weight of antioxidant 168 were mixed in a high-speed mixer for 10 minutes. The other process was the same as in Example 1 to obtain a temporary plugging agent product PGA-S5, which was subjected to degradation performance tests and temporary plugging performance tests. The test results are shown in Table 1.

[0066] Example 6

[0067] 94 parts by weight of PGA, 5 parts by weight of 2-methylimidazole and 1 part by weight of antioxidant 168 were mixed in a high-speed mixer for 10 minutes. The other process was the same as in Example 1 to obtain a temporary plugging agent product PGA-S6, which was subjected to degradation performance tests and temporary plugging performance tests. The test results are shown in Table 1.

[0068] Example 7

[0069] 94 parts by weight of PGA, 5 parts by weight of 2-ethyl-4-methylimidazole and 1 part by weight of antioxidant 168 were mixed in a high-speed mixer for 10 minutes. The other process was the same as in Example 1 to obtain a temporary plugging agent product PGA-S7, which was subjected to degradation performance tests and temporary plugging performance tests. The test results are shown in Table 1.

[0070] Example 8

[0071] 89 parts by weight of PGA, 10 parts by weight of zinc hydroxide and 1 part by weight of antioxidant 168 were mixed in a high-speed mixer for 10 minutes. The other process was the same as in Example 1 to obtain a temporary plugging agent product PGA-S8, which was subjected to degradation performance tests and temporary plugging performance tests. The test results are shown in Table 1.

[0072] Example 9

[0073] 94 parts by weight of PGA, 5 parts by weight of polyethyleneimine and 1 part by weight of antioxidant 168 were mixed in a high-speed mixer for 10 minutes. The other process was the same as in Example 1 to obtain a temporary plugging agent product PGA-S9, which was subjected to degradation performance tests and temporary plugging performance tests. The test results are shown in Table 1.

[0074] Example 10

[0075] 97 parts by weight of PGA, 2 parts by weight of chain extender ADR-4488 and 1 part by weight of antioxidant 168 were mixed in a high-speed mixer for 10 minutes. The other process was the same as in Example 1 to obtain a temporary plugging agent product PGA-S10, which was subjected to degradation performance tests and temporary plugging performance tests. The test results are shown in Table 1.

[0076] Embodiment 11

[0077] 97 parts by weight of PGA, 2 parts by weight of chain extender SAG-008 and 1 part by weight of antioxidant 168 were mixed in a high-speed mixer for 10 minutes. The other process was the same as in Example 1 to obtain a temporary plugging agent product PGA-S11, which was subjected to degradation performance tests and temporary plugging performance tests. The test results are shown in Table 1.

[0078] Table 1 Test results of degradation performance and temporary plugging performance before and after PGA modification

[0079]

[0080] Analysis of the test results in Table 1 shows that, compared with the unmodified PGA samples (ie, Comparative Example 1 and Comparative Example 2), the degradation rate and temporary plugging time of the PGA temporary plugging agent product of the embodiment are significantly extended, thereby achieving the degradation performance regulation of the PGA temporary plugging agent.

[0081] In Example 1-9, at 90°C, the degradation rate in 24 hours is increased to 74.2%, and the degradation rate in 48 hours is increased to 96.1%. The temporary plugging time at 90°C and 30MPa is correspondingly reduced to 2.8 hours. This is because different types and contents of degradation promoters are introduced in Example 1-9, which accelerate the degradation rate of PGA, help to achieve rapid degradation after temporary plugging in the oil field and turning to fracturing construction, and improve operating efficiency.

[0082] It can be seen from the data of Example 1, Example 2 and Comparative Example 1 that the addition of melamine promotes the degradation of PGA, and as the addition amount increases, the degradation rate increases, and the temporary blocking time is negatively correlated with the degradation rate.

[0083] From the data of Example 5, Example 6, Example 7 and Example 9, it can be seen that water-soluble degradation promoters such as piperazine and 2-methylimidazole have a greater influence on the degradation performance of PGA, and the corresponding temporary blocking time is shorter. This is because such degradation promoters are easily dissolved and lose weight, and make the aqueous solution alkaline, and the degradation-promoting effect on PGA is more obvious.

[0084] It can be seen from the data of Example 1, Example 3, Comparative Example 1 and Comparative Example 2 that both screw melt blending modification and physical blending modification can improve the degradation rate of PGA temporary plugging agent, but the screw melt blending modification effect is better than physical mixing. The former makes the additive evenly dispersed in the PGA matrix, preventing the additive from dissolving prematurely and washing away during temporary plugging application, and the degradation-promoting effect is more obvious.

[0085] In Example 10 and Example 11, the degradation rates at 90°C for 24h and 48h were reduced, and the temporary plugging time tested at 90°C and 30MPa was correspondingly increased, indicating that the chain extender helps to delay the degradation of PGA and help expand the application of temporary plugging and fracturing of PGA in high temperature environments.

[0086] The effects of accelerators and chain extenders on the degradation time of PGA are significant. By adjusting the content and type of auxiliaries, the unblocking time of PGA temporary plugging agent can be controlled to meet the needs of different oil field operation time. At the same time, the final degradation products of PGA temporary plugging agent are carbon dioxide and water, which do not pollute the formation environment.

[0087] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

[0088] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

Claims

1. A controllable degradable polyglycolic acid temporary plugging agent, characterized in that: The temporary plugging agent comprises polyglycolic acid, a regulating aid and an antioxidant; based on the total weight of the temporary plugging agent, the content of the polyglycolic acid is 83-99.7wt%, the content of the regulating aid is 0.2-15wt%, and the content of the antioxidant is 0.1-2wt%; the regulating aid is a degradation accelerator or a chain extender; the degradation accelerator is selected from one or more of amine compounds, inorganic carbonates and metal hydroxides.

2. The polyglycolic acid temporary plugging agent according to claim 1, wherein: The particle size of the temporary plugging agent is 10-500 mesh, preferably 20-200 mesh.

3. The polyglycolic acid temporary plugging agent according to claim 1, wherein: The number average molecular weight of the polyglycolic acid is 50,000-100,000, preferably 50,000-70,000.

4. The polyglycolic acid temporary plugging agent according to claim 1, wherein: Based on the total weight of the temporary plugging agent, the content of the degradation accelerator is 3-15wt%.

5. The polyglycolic acid temporary plugging agent according to claim 1, wherein: The amine compound is selected from one or more of liquid organic amine compounds, imidazole compounds, piperazine compounds and melamine compounds; The liquid organic amine compound is preferably one or more of ethylenediamine, polyethyleneimine, triethylenetetramine, triisopropanolamine and trihydroxyethylamine, preferably polyethyleneimine; based on the total weight of the temporary plugging agent, the content of the liquid organic amine compound is preferably 3-15wt%, more preferably 3-6wt%; The imidazole compound is one or more of imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-propylimidazole, 2-aminoimidazole, 2-tert-butylimidazole and 2-(2-imidazolyl)ethanol, preferably one or more of imidazole, 2-methylimidazole, 2-ethylimidazole and 2-ethyl-4-methylimidazole; based on the total weight of the temporary plugging agent, the content of the imidazole compound is preferably 3-15wt%, more preferably 3-10wt%; The piperazine compound is one or more of piperazine, N-methylpiperazine, 2-methylpiperazine, 1-butylpiperazine, 1-ethylhomopiperazine and 1-phenylpiperazine, preferably one or more of piperazine and 2-methylpiperazine; based on the total weight of the temporary plugging agent, the content of the piperazine compound is preferably 3-15wt%, more preferably 5-10wt%; The melamine compound is one or more of melamine, melamine cyanurate, melamine phosphate, melamine polyphosphate and melamine hydrobromide, preferably one or more of melamine and melamine polyphosphate; based on the total weight of the temporary plugging agent, the content of the melamine compound is preferably 3-15wt%, more preferably 5-15wt%.

6. The polyglycolic acid temporary plugging agent according to claim 1, wherein: The inorganic carbonate is one or more of potassium carbonate, sodium carbonate, sodium bicarbonate, calcium carbonate, calcium bicarbonate, barium carbonate, zinc carbonate, magnesium carbonate and ferrous carbonate, preferably one or more of barium carbonate, calcium carbonate and zinc carbonate; based on the total weight of the temporary plugging agent, the content of the inorganic carbonate is 3-15wt%, preferably 5-15wt%; The metal hydroxide is one or more of magnesium hydroxide, aluminum hydroxide, zinc hydroxide, iron hydroxide, lead hydroxide, tin hydroxide and cobalt hydroxide, preferably one or more of magnesium hydroxide, aluminum hydroxide and zinc hydroxide; based on the total weight of the temporary plugging agent, the content of the metal hydroxide is 3-15wt%, preferably 5-10wt%.

7. The controllably degradable polyglycolic acid temporary plugging agent according to claim 1, wherein: The chain extender is at least one of an epoxy chain extender and an isocyanate chain extender, preferably Celymer TM 8280、Celymer TM 8280E, ADR-4370S, ADR-4468, ADR-4400, SAG-008, SG-20, Celymer TM One or more of SBC and ZeMac-E60P, more preferably Celymer TM One or more of 8280, ADR-4468 and SAG-008, the content of the chain extender is 0.2-3wt%, preferably 0.5-2wt%.

8. The controllably degradable polyglycolic acid temporary plugging agent according to claim 1, wherein: The antioxidant is one or more of antioxidant 168, antioxidant 1010, antioxidant 626 and antioxidant 618, preferably one or more of antioxidant 168 and antioxidant 1010; the content of the antioxidant is 0.1-2wt%, preferably 0.1-1.2wt%.

9. The method for preparing the controllably degradable polyglycolic acid temporary plugging agent according to any one of claims 1 to 8, comprising the following steps: The polyglycolic acid is blended with a conditioning aid and an antioxidant, and the polyglycolic acid or the blend is subjected to a crushing treatment.

10. The preparation method according to claim 9, wherein: The blending is melt blending achieved by a twin-screw extruder, the processing temperature of the twin-screw extruder is 180-240° C., the rotation speed is 150-300 r / min, and water cooling, pelletizing and drying are performed after extrusion.

11. The preparation method according to claim 9, wherein: The crushing treatment method is at least one of high-speed mechanical impact crushing, disc-type airflow crushing, ultrafine crushing and liquid nitrogen freezing shock crushing, preferably at least one of disc-type airflow crushing and ultrafine crushing, and further preferably high-speed mechanical impact crushing and / or disc-type airflow crushing.

12. A method for regulating the degradation performance of a degradable temporary plugging agent, characterized in that: The method comprises the following steps: S1. Selecting a regulating aid according to the regulation target, wherein the regulating aid is a degradation accelerator or a chain extender; S2, blending polyglycolic acid with a regulating aid and an antioxidant, wherein the polyglycolic acid is crushed before blending or the blend is crushed to obtain a temporary plugging agent with desired degradation performance; Based on the total weight of the temporary plugging agent, the content of the polyglycolic acid is 83-99.7wt%, the content of the regulating aid is 0.2-15wt%, and the content of the antioxidant is 0.1-2wt%; the degradation accelerator is selected from one or more of amine compounds, inorganic carbonates and metal hydroxides.

13. The method for controlling the degradation performance of a degradable temporary plugging agent according to claim 12, wherein: If the control target is to accelerate degradation, a degradation promoter is selected as a control aid; if the control target is to slow down degradation, a chain extender is selected as a control aid.

14. The method for controlling the degradation performance of a degradable temporary plugging agent according to claim 12, wherein: The number average molecular weight of the polyglycolic acid is 50,000-100,000, preferably 50,000-70,000.

15. The method for controlling the degradation performance of a degradable temporary plugging agent according to claim 12, wherein: Based on the total weight of the temporary plugging agent, the content of the degradation accelerator is 3-15wt%.

16. The method for controlling the degradation performance of a degradable temporary plugging agent according to claim 12, wherein: The amine compound is selected from one or more of liquid organic amine compounds, imidazole compounds, piperazine compounds and melamine compounds; The liquid organic amine compound is preferably one or more of ethylenediamine, polyethyleneimine, triethylenetetramine, triisopropanolamine and trihydroxyethylamine, preferably polyethyleneimine; based on the total weight of the temporary plugging agent, the content of the liquid organic amine compound is preferably 3-15wt%, more preferably 3-6wt%; The imidazole compound is one or more of imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-propylimidazole, 2-aminoimidazole, 2-tert-butylimidazole and 2-(2-imidazolyl)ethanol, preferably one or more of imidazole, 2-methylimidazole, 2-ethylimidazole and 2-ethyl-4-methylimidazole; based on the total weight of the temporary plugging agent, the content of the imidazole compound is preferably 3-15wt%, more preferably 3-10wt%; The piperazine compound is one or more of piperazine, N-methylpiperazine, 2-methylpiperazine, 1-butylpiperazine, 1-ethylhomopiperazine and 1-phenylpiperazine, preferably one or more of piperazine and 2-methylpiperazine; based on the total weight of the temporary plugging agent, the content of the piperazine compound is preferably 3-15wt%, more preferably 5-10wt%; The melamine compound is one or more of melamine, melamine cyanurate, melamine phosphate, melamine polyphosphate and melamine hydrobromide, preferably one or more of melamine and melamine polyphosphate; based on the total weight of the temporary plugging agent, the content of the melamine compound is preferably 3-15wt%, more preferably 5-15wt%.

17. The method for controlling the degradation performance of a degradable temporary plugging agent according to claim 12, wherein: The inorganic carbonate is one or more of potassium carbonate, sodium carbonate, sodium bicarbonate, calcium carbonate, calcium bicarbonate, barium carbonate, zinc carbonate, magnesium carbonate and ferrous carbonate, preferably one or more of barium carbonate, calcium carbonate and zinc carbonate; based on the total weight of the temporary plugging agent, the content of the inorganic carbonate is 3-15wt%, preferably 5-15wt%; The metal hydroxide is one or more of magnesium hydroxide, aluminum hydroxide, zinc hydroxide, iron hydroxide, lead hydroxide, tin hydroxide and cobalt hydroxide, preferably one or more of magnesium hydroxide, aluminum hydroxide and zinc hydroxide; based on the total weight of the temporary plugging agent, the content of the metal hydroxide is 3-15wt%, preferably 5-10wt%.

18. The method for controlling the degradation performance of a controllably degradable temporary plugging agent according to claim 12, wherein: The chain extender is at least one of an epoxy chain extender and an isocyanate chain extender, preferably Celymer TM 8280、Celymer TM 8280E, ADR-4370S, ADR-4468, ADR-4400, SAG-008, SG-20, Celymer TM One or more of SBC and ZeMac-E60P, more preferably Celymer TM One or more of 8280, ADR-4468 and SAG-008, the content of the chain extender is 0.2-3wt%, preferably 0.5-2wt%.

19. The method for controlling the degradation performance of a controllably degradable temporary plugging agent according to claim 12, wherein: The antioxidant is one or more of antioxidant 168, antioxidant 1010, antioxidant 626 and antioxidant 618, preferably one or more of antioxidant 168 and antioxidant 1010; the content of the antioxidant is 0.1-2wt%, preferably 0.1-1.2wt%.

20. The method for controlling the degradation performance of a degradable temporary plugging agent according to claim 12, wherein: The blending is screw melt blending or physical blending, preferably melt blending achieved by a twin-screw extruder, the processing temperature of the twin-screw extruder is 180-240°C, the rotation speed is 150-300r / min, and water cooling, pelletizing and drying are performed after extrusion.

21. The method for controlling the degradation performance of a degradable temporary plugging agent according to claim 12, wherein: The crushing treatment conditions are such that the particle size of the temporary plugging agent finally formed is 10-500 mesh, preferably 20-200 mesh; The crushing treatment method is at least one of high-speed mechanical impact crushing, disc-type airflow crushing, ultrafine crushing and liquid nitrogen freezing shock crushing, preferably at least one of disc-type airflow crushing and ultrafine crushing, and further preferably high-speed mechanical impact crushing and / or disc-type airflow crushing.

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