Degradable temporary plugging agent material as well as preparation method, application and construction method thereof

Abstract

The invention belongs to the technical field of oil field crude oil extraction, and relates to a degradable temporary plugging agent material and a preparation method, application and construction method thereof. The degradable temporary plugging agent material comprises the following components: polyglycolic acid, an emulsifier and a thickener, wherein on the basis of the total weight of the degradable temporary plugging agent material, the content of the polyglycolic acid is 20-95 wt%, the content of the emulsifier is 4-70 wt%, and the content of the thickening agent is 0.5-50 wt%. The degradable temporary plugging agent material has the following advantages that the degradable temporary plugging agent material comprises polyglycolic acid, an emulsifier and a thickener, a novel particle and gel composite temporary plugging agent can be formed, compared with an existing temporary plugging agent material for oilfield fracturing, the temperature resistance, salt tolerance and pressure resistance are improved, original gaps are effectively plugged, the degradable temporary plugging agent material can be autonomously and completely degraded after the temporary plugging effect is achieved, and the service life of the temporary plugging agent material is prolonged. And blockage removal is not needed, no pollution or damage is caused to the stratum, oil reservoir transformation is facilitated, fracturing steering is achieved, and the single well productivity is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of oilfield crude oil exploitation, and specifically relates to a degradable temporary plugging agent material, a preparation method thereof, an application and a construction method. Background Art

[0002] China is rich in low-permeability oil and gas resources, and hydraulic fracturing is an important measure for exploiting such resources. However, as production progresses, the failure of hydraulic fractures will lead to a decline in oil and gas production. Chemical temporary plugging and diversion fracturing is one of the important methods to restore and increase the production of low-permeability oil and gas. The temporary plugging agent can block the high-permeability layer, forcing the fracturing fluid to divert, and realizing the fracturing transformation of the remaining oil accumulation area. Due to the disadvantages of traditional mechanical diversion technologies such as high construction risks, high costs, and long cycles, in recent years, chemical diversion technologies have become the mainstream methods for repeated fracturing of oil and gas wells, and temporary plugging agents have been widely used in this technology. The temporary plugging agent can block the mouth of the original fracture and the perforation holes, forming a high-strength filter cake, thereby generating a higher net fracture pressure, forcing the subsequent fracturing fluid not to flow into the original fracture, but promoting it to flow to the area where the remaining oil accumulates and generating new hydraulic fractures, thereby increasing the oil and gas drainage area. Compared with temporary plugging agents for other uses, the temporary plugging agent for fracturing has the characteristics of stronger pressure-bearing capacity, lower formation damage, and more controllable temporary plugging time.

[0003] The temporary plugging agents and materials for oilfield fracturing mainly include inert inorganic solid temporary plugging agents (such as silica powder, rock salt, plugging balls, calcium carbonate powder, etc.) and inert organic resin temporary plugging agents (such as oil-soluble resins, water-soluble polymer gels, etc.). However, the above-mentioned fracturing temporary plugging agents all need to be unblocked by acid dissolution, oil dissolution, or water dissolution subsequently to release the original gaps in the formation. On-site application requires supporting unblocking equipment, and there are easily incomplete and thorough unblocking situations, causing damage to the reservoir formation, which seriously restricts the application and promotion of the fracturing temporary plugging technology. Therefore, there is an urgent need to develop a self-degradable fracturing temporary plugging agent material with high temporary plugging strength, simple temporary plugging process, and reduced formation damage to support the development of oilfield fracturing technology. Summary of the Invention

[0004] Aiming at the defects existing in the prior art, the purpose of the present invention is to provide a degradable temporary plugging agent material and a preparation method thereof. Compared with the existing temporary plugging agent materials for oilfield fracturing, the temperature and salt resistance performance and its compressive capacity are improved, the original gaps can be effectively blocked, and after playing the temporary plugging role, it can be completely degraded autonomously without unblocking, realizing fracturing diversion and improving the single-well production capacity.

[0005] In order to achieve the purpose of the present invention, the first aspect of the present invention provides a degradable temporary plugging agent material, comprising the following components:

[0006] Polyglycolic acid, an emulsifier, and a thickener;

[0007] Among them, based on the total weight of the degradable temporary plugging agent material, the content of polyglycolic acid is 20-95 wt%, the content of emulsifier is 4-70 wt%, and the content of thickener is 0.5-50 wt%.

[0008] The second aspect of the present invention provides a preparation method of a degradable temporary plugging agent material, comprising the following steps:

[0009] (1) Add the thickener to the brine and stir well to form a stable polymer viscous fluid;

[0010] (2) Add the emulsifier to the polymer viscous fluid obtained in step (1) and stir well to form a stable polymer viscous emulsion;

[0011] (3) Add polyglycolic acid to the polymer viscous emulsion obtained in step (2) and stir well to form a stable suspension emulsion-like degradable temporary plugging agent material;

[0012] The addition amounts of the thickener, emulsifier and polyglycolic acid are such that in the degradable temporary plugging agent material, based on the total weight of the thickener, emulsifier and polyglycolic acid, the content of polyglycolic acid is 20-95 wt%, preferably 30-90 wt%, the content of emulsifier is 4-70 wt%, preferably 8-65 wt%, and the content of thickener is 0.5-50 wt%, preferably 1-50 wt%.

[0013] The third aspect of the present invention provides a degradable temporary plugging agent material prepared by the described preparation method.

[0014] The fourth aspect of the present invention provides the application of the described degradable temporary plugging agent material in oilfield fracturing.

[0015] The fifth aspect of the present invention provides a construction method of the described degradable temporary plugging agent material for use in oilfield fracturing, comprising the following steps:

[0016] (1) Prepare a suspension emulsion according to the described preparation method;

[0017] (2) Mix the suspension emulsion and the crosslinking agent evenly and inject them into the oil well of the oilfield; based on the total weight of the suspension emulsion and the crosslinking agent, the addition amount of the crosslinking agent is 10-150 ppm, preferably 20-100 ppm.

[0018] The degradable temporary plugging agent material and its preparation method of the present invention have the following advantages and effects compared with the prior art:

[0019] (1) The degradable temporary plugging agent material of the present invention includes polyglycolic acid, an emulsifier, and a thickener, and can form a novel composite temporary plugging agent of particles and gel. Compared with the existing temporary plugging agent materials for oilfield fracturing, its temperature and salt resistance performance and compressive capacity are improved, effectively plugging the original gaps, and it can be completely degraded autonomously after playing the temporary plugging role without the need for unplugging, realizing fracture diversion and enhancing the single-well production capacity.

[0020] (2) In the present invention, a sulfonic acid-based polymer is preferably used as the thickener, which can significantly increase the viscosity of the temporary plugging system, making the polyglycolic acid particles evenly dispersed in the three-dimensional space system of polymer chain entanglement. Moreover, the sulfonic acid groups in the polymer can enhance the temperature and salt resistance of the system, and under the combined action of the emulsifier, it can cooperate with the polyglycolic acid particles to prevent agglomeration and adhesion between the particles, greatly improving the suspension stability, injectability, and sand-carrying capacity of the particles.

[0021] (3) In the present invention, during the injection of the temporary plugging system into the formation, under the action of the high temperature (130 °C) of the reservoir, the crosslinking agent and the sulfonic acid-based polymer can achieve rapid crosslinking within 30 minutes to form a mobile gel, further enhancing the temporary plugging and compressive capacity of the temporary plugging material under high-temperature reservoir conditions.

[0022] (4) In the present invention, the polyglycolic acid particles (100 - 200 μm) are insensitive to the salinity of formation water, have strong salt resistance, high particle impact strength, and large compressive strength, playing a role in supporting temporary plugging. When the polyglycolic acid particles are injected into the formation cracks, they will degrade autonomously under high-temperature and high-salt reservoir conditions, and the plugging reduction rate is greater than 98% after 12 hours, without the need for unplugging, causing no pollution or damage to the formation, which is beneficial to the reservoir formation transformation.

[0023] (5) In the present invention, the added emulsifier and sulfonic acid-based polymer also do not need to be back-produced, and can enter the water flooding fluid together with the subsequent injected water, increasing the viscosity of the water phase, reducing the oil-water mobility ratio, and can emulsify with the crude oil, improving the oil washing efficiency and displacement efficiency, and further improving the crude oil recovery rate. Therefore, the degradable temporary plugging agent material of the present invention can provide technical support for acid fracturing and reservoir formation transformation under high oil prices.

[0024] Other features and advantages of the present invention will be described in detail in the following specific implementation manners section. Specific Embodiments

[0025] The following will detail the specific implementation manners of the present invention. It should be understood that the specific implementation manners described herein are only for explaining and illustrating the present invention, and are not used to limit the present invention.

[0026] To achieve the purpose of the present invention, a first aspect of the present invention provides a degradable temporary plugging agent material, including the following components:

[0027] Polyglycolic acid, an emulsifier, and a thickener;

[0028] Among them, based on the total weight of the degradable temporary plugging agent material, the content of polyglycolic acid is 20-95 wt%, the content of emulsifier is 4-70 wt%, and the content of thickener is 0.5-50 wt%.

[0029] According to the present invention, preferably, based on the total weight of the degradable temporary plugging agent material, the content of polyglycolic acid is 30-90 wt%, the content of emulsifier is 8-65 wt%, and the content of thickener is 1-50 wt%.

[0030] According to the present invention, preferably, the polyglycolic acid is micron-sized particles, preferably particles with a median particle size of 100-200 μm; the weight-average molecular weight of the polyglycolic acid is 100,000-150,000.

[0031] In the present invention, the emulsifier can be selected from Span series emulsifiers and / or Tween series emulsifiers, preferably at least one of Span 20, Span 40, Span 60, Span 80, Tween 20, Tween 40, Tween 60 and Tween 80.

[0032] According to the present invention, preferably, the thickener is a sulfonic acid type polyacrylamide with a weight-average molecular weight of 10 million - 15 million.

[0033] According to a preferred embodiment of the present invention, the degradable temporary plugging agent material further includes a crosslinking agent, and the crosslinking agent is preferably at least one of phenolic crosslinking agents, phenolic aldehyde crosslinking agents, amine crosslinking agents and amide crosslinking agents, and more preferably at least one of phenolic resin, hexamethylenetetramine, resorcinol and N,N-methylenebisacrylamide; based on the total weight of the degradable temporary plugging agent material, the content of the crosslinking agent is 0.01-0.5 wt%, preferably 0.03-0.4 wt%.

[0034] The second aspect of the present invention provides a preparation method of a degradable temporary plugging agent material, including the following steps:

[0035] (1) Add the thickener to the brine and stir well to form a stable polymer viscous fluid;

[0036] (2) Add the emulsifier to the polymer viscous fluid obtained in step (1) and stir well to form a stable polymer viscous emulsion;

[0037] (3) Add the polyglycolic acid to the polymer viscous emulsion obtained in step (2) and stir well to form a stable suspension emulsion-like degradable temporary plugging agent material;

[0038] The addition amounts of the thickener, emulsifier and polyglycolic acid are such that in the degradable temporary plugging agent material, based on the total weight of the thickener, emulsifier and polyglycolic acid, the content of polyglycolic acid is 20-95 wt%, preferably 30-90 wt%, the content of emulsifier is 4-70 wt%, preferably 8-65 wt%, and the content of thickener is 0.5-50 wt%, preferably 1-50 wt%.

[0039] In the present invention, first, emulsifier B is added to an aqueous solution of thickener C to form a stable viscous emulsion, then micron-sized particles of polyglycolic acid A are added to the above viscous emulsion, and finally, a degradable temporary plugging agent for fracturing is prepared.

[0040] According to the present invention, preferably, in step (1), the mass concentration of the thickener in the polymer viscous fluid is controlled to be 0.1 wt%-1 wt%, preferably 0.2 wt%-0.5 wt%.

[0041] According to the present invention, preferably, in step (2), the mass concentration of the emulsifier in the polymer viscous emulsion is controlled to be 0.05 wt%-3 wt%, preferably 0.1 wt%-2 wt%.

[0042] According to the present invention, preferably, in step (3), the mass concentration of the polyglycolic acid in the suspension emulsion is controlled to be 0.1 wt%-20 wt%, preferably 0.5 wt%-10 wt%.

[0043] In the preparation method of the present invention, the definitions of polyglycolic acid, emulsifier and thickener are as described above and will not be elaborated here.

[0044] According to the present invention, preferably, in step (1), the salinity of the brine is 30000-40000 mg / L, wherein the contents of Mg 2+ , Ca 2+ are each independently 800-1200 mg / L.

[0045] According to the present invention, preferably, in step (1), the temperature of the stirring is 15-40 °C and the time is 1-2 h.

[0046] According to the present invention, preferably, in step (2), the temperature of the stirring is 15-40 °C and the time is 10-15 min.

[0047] According to the present invention, preferably, in step (3), the temperature of the stirring is 15-40 °C and the time is 20-60 min.

[0048] According to the present invention, the crosslinking agent can be used as a component of the degradable temporary plugging agent material. In this case, preferably, the preparation method further includes step (4): uniformly mixing the suspension emulsion obtained in step (3) with the crosslinking agent.

[0049] According to the present invention, preferably, the crosslinking agent is preferably at least one of phenolic crosslinking agents, phenolic aldehyde crosslinking agents, amine crosslinking agents, and amide crosslinking agents, and more preferably at least one of phenolic resin, hexamethylenetetramine, resorcinol, and N,N-methylenebisacrylamide; based on the total weight of the thickener, emulsifier, polyglycolic acid, and crosslinking agent in the suspension emulsion, the addition amount of the crosslinking agent is 0.01 - 0.5 wt%, preferably 0.03 - 0.4 wt%.

[0050] The third aspect of the present invention provides a degradable temporary plugging agent material prepared by the above-mentioned preparation method.

[0051] The fourth aspect of the present invention provides the application of the above-mentioned degradable temporary plugging agent material in oilfield fracturing.

[0052] The fifth aspect of the present invention provides a construction method for using the above-mentioned degradable temporary plugging agent material in oilfield fracturing, including the following steps:

[0053] (1) Prepare a suspension emulsion according to the above-mentioned preparation method;

[0054] (2) Uniformly mix the suspension emulsion with the crosslinking agent and inject it into the oil well of the oilfield; based on the total weight of the suspension emulsion and the crosslinking agent, the addition amount of the crosslinking agent is 10 - 150 ppm, preferably 20 - 100 ppm.

[0055] During the workover process of the oilfield, it is necessary to use a crosslinking agent in combination. As mentioned above, the crosslinking agent can be used as a component of the degradable temporary plugging agent material or can be used as a component that is not a degradable temporary plugging agent material and is purchased separately during construction.

[0056] According to the present invention, preferably, the crosslinking agent is at least one of phenolic crosslinking agents, phenolic aldehyde crosslinking agents, amine crosslinking agents, and amide crosslinking agents, and is preferably at least one of phenolic resin, hexamethylenetetramine, resorcinol, and N,N-methylenebisacrylamide.

[0057] The present invention will be further described below in conjunction with examples, but the scope of the present invention is not limited to these examples.

[0058] All data are obtained by the test method in "Technical Requirements for Water-soluble Polymer Temporary Plugging Agents and Temporary Plugging Balls for Fracturing and Acidizing" Q / SH CG0152 - 2021 on a core flow test device.

[0059] Sulfonic acid type polyacrylamide: purchased from Shandong Baomo Biochemical Co., Ltd.

[0060] Polyglycolic acid particles: Purchased from Inner Mongolia Pujing Polymer Materials Technology Co., Ltd., with a weight-average molecular weight of 100,000 - 150,000.

[0061] Crosslinking agent water-soluble phenolic resin: Purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with the product number P195710.

[0062] The salinity of the simulated brine is 35000 mg / L, and the content of Mg 2+ , Ca 2+ is 1000 mg / L each.

[0063] Example 1

[0064] Step 1: Weigh 2.5 g of sulfonic acid type polyacrylamide (polymer molecular weight 12.8 million) and add it to 500 mL of simulated brine. After stirring well at 15 °C for 2.0 hours, a polymer viscous fluid is formed;

[0065] Step 2: Weigh 0.5 g of Span 40 and add it to the above polymer viscous fluid. After stirring well at 15 °C, a stable polymer viscous emulsion is formed;

[0066] Step 3: Weigh 2.5 g of polyglycolic acid particles (median particle size 130 - 150 μm) and add it to the above polymer viscous emulsion. After stirring well at 15 °C for 30 minutes to mix evenly, a stable suspension emulsion type temporary plugging agent is formed;

[0067] Add 0.015 g of crosslinking agent water-soluble phenolic resin to the above suspension emulsion type temporary plugging agent, mix evenly and then inject it into the core. Pressurize to 45.1 MPa at 130 °C, and measure the plugging rate, pressure stabilization time, and degradation rate after 12 h. The results are shown in Table 1.

[0068] Example 2

[0069] Step 1: Weigh 1.0 g of sulfonic acid type polyacrylamide (polymer molecular weight 12.8 million) and add it to 500 mL of simulated brine. After stirring well at 18 °C for 2.0 hours, a polymer viscous fluid is formed;

[0070] Step 2: Weigh 10 g of Span 20 and add it to the above polymer viscous fluid. After stirring well at 15 °C, a stable polymer viscous emulsion is formed;

[0071] Step 3: Weigh 5.0 g of polyglycolic acid particles (median particle size 130 - 150 μm) and add it to the above polymer viscous emulsion. After stirring well at 18 °C for 30 minutes to mix evenly, a stable suspension emulsion type temporary plugging agent is formed;

[0072] Add 0.05 g of crosslinking agent hexamethylenetetramine to the above suspension emulsion type temporary plugging agent, mix evenly and then inject it into the core. Pressurize to 46.2 MPa at 130 °C, and measure the plugging rate, pressure stabilization time, and degradation rate after 12 h. The results are shown in Table 1.

[0073] Example 3

[0074] Step 1: Weigh 2.0 g of sulfonic acid type polyacrylamide (polymer molecular weight 12.8 million) and add it to 500 mL of simulated brine. After fully stirring for 2.0 hours at 30 °C, a polymer viscous fluid is formed;

[0075] Step 2: Weigh 1.5 g of Tween 40 and add it to the above polymer viscous fluid. After fully stirring at 30 °C, a stable polymer viscous emulsion is formed;

[0076] Step 3: Weigh 10.0 g of polyglycolic acid particles (median particle size 130 - 150 μm) and add them to the above polymer viscous emulsion. After fully stirring for 30 minutes at 30 °C and mixing evenly, a stable suspension emulsion type temporary plugging agent is formed;

[0077] Add 0.03 g of crosslinking agent water-soluble phenolic resin to the above suspension emulsion type temporary plugging agent, mix evenly and then inject it into the core. Pressurize to 48.5 MPa at 130 °C, and measure the plugging rate, pressure stabilization time, and degradation rate after 12 h. The results are shown in Table 1.

[0078] Example 4

[0079] Step 1: Weigh 1.5 g of sulfonic acid type polyacrylamide (polymer molecular weight 12.8 million) and add it to 500 mL of simulated brine. After fully stirring for 2.0 hours at 36 °C, a polymer viscous fluid is formed;

[0080] Step 2: Weigh 4.5 g of Tween 60 and add it to the above polymer viscous fluid. After fully stirring at 36 °C, a stable polymer viscous emulsion is formed;

[0081] Step 3: Weigh 25.0 g of polyglycolic acid particles (median particle size 130 - 150 μm) and add them to the above polymer viscous emulsion. After fully stirring for 30 minutes at 36 °C and mixing evenly, a stable suspension emulsion type temporary plugging agent is formed;

[0082] Add 0.02 g of crosslinking agent resorcinol to the above suspension emulsion type temporary plugging agent, mix evenly and then inject it into the core. Pressurize to 49.2 MPa at 130 °C, and measure the plugging rate, pressure stabilization time, and degradation rate after 12 h. The results are shown in Table 1.

[0083] Example 5

[0084] Step 1: Weigh 1.0 g of sulfonic acid polyacrylamide (polymer molecular weight: 12.8 million) and add it to 500 mL of simulated brine. After stirring thoroughly at 40 °C for 2.0 hours, a polymer viscous fluid is formed;

[0085] Step 2: Weigh 9.0 g of Span 60 and add it to the above-mentioned polymer viscous fluid. After stirring thoroughly at 40 °C, a stable polymer viscous emulsion is formed;

[0086] Step 3: Weigh 40.0 g of polyglycolic acid particles (median particle size: 130 - 150 μm) and add them to the above-mentioned polymer viscous emulsion. After stirring thoroughly at 40 °C for 30 minutes to mix evenly, a stable suspension emulsion-like temporary plugging agent is formed;

[0087] Add 0.015 g of crosslinking agent N,N'-methylenebisacrylamide to the above suspension emulsion-like temporary plugging agent, mix evenly, and then inject it into the core. Pressurize to 47.6 MPa at 130 °C, and measure the plugging rate, pressure stabilization time, and degradation rate after 12 h. The results are shown in Table 1.

[0088] Example 6

[0089] Step 1: Weigh 1.5 g of sulfonic acid polyacrylamide (polymer molecular weight: 12.8 million) and add it to 500 mL of simulated brine. After stirring thoroughly at 25 °C for 2.0 hours, a polymer viscous fluid is formed;

[0090] Step 2: Weigh 6.0 g of Tween 20 and add it to the above-mentioned polymer viscous fluid. After stirring thoroughly at 25 °C, a stable polymer viscous emulsion is formed;

[0091] Step 3: Weigh 50.0 g of polyglycolic acid particles (median particle size: 130 - 150 μm) and add them to the above-mentioned polymer viscous emulsion. After stirring thoroughly at 25 °C for 30 minutes to mix evenly, a stable suspension emulsion-like temporary plugging agent is formed;

[0092] Add 0.04 g of crosslinking agent water-soluble phenolic resin to the above suspension emulsion-like temporary plugging agent, mix evenly, and then inject it into the core. Pressurize to 48.1 MPa at 130 °C, and measure the plugging rate, pressure stabilization time, and degradation rate after 12 h. The results are shown in Table 1.

[0093] Example 7

[0094] The difference from Example 1 is only that in Step 3, the polyglycolic acid particles have a median particle size of 250 - 400 μm, and the measurement results are shown in Table 1.

[0095] Example 8

[0096] The difference from Example 1 is only that in Step 3, the polyglycolic acid particles have a median particle size of 50 - 80 μm, and the measurement results are shown in Table 1.

[0097] Example 9

[0098] The difference from Example 1 is only that the sulfonic acid type polyacrylamide is replaced by partially hydrolyzed polyacrylamide, and the measurement results are shown in Table 1.

[0099] Comparative Example 1

[0100] The difference from Example 1 is only that the stable viscous emulsion obtained in the second step is directly mixed evenly with 0.015 g of the crosslinking agent water-soluble phenolic resin and then injected into the core, and the pressure is increased to 49.2 MPa at 130 °C, and the plugging rate, pressure stabilization time, and degradation rate after 12 h are measured. The results are shown in Table 1.

[0101] Test Example Results

[0102] Table 1

[0103] Example number Blocking rate Pressure difference Pressure-bearing time 12h degradation rate Example 1 97.2％ 45.1 ＞4h >98％ Example 2 98.6％ 46.2 ＞4h >98％ Example 3 99.5％ 48.5 ＞4h >98％ Example 4 99.8％ 49.2 ＞4h >98％ Example 5 99.1％ 47.6 ＞4h >98％ Example 6 99.2％ 48.1 ＞4h >98％ Example 7 97.5％ 46.7 ＞4h 84.3％ Example 8 85.4％ 33.7 2.5h >98％ Example 9 71.2％ 22.6 <2h 87.2％ Comparative example 1 3.6％ 49.2 - <1％

[0104] As shown in Table 1, the temporary plugging agent material obtained by the present invention has a higher plugging rate, a larger pressure-bearing difference, a longer pressure-bearing time, and a self-degradation rate > 98% after 12 hours compared with the existing temporary plugging agent materials. The difference between Comparative Example 1 and Example 1 is only that polyglycolic acid particles are not added, and the pressure-bearing capacity of the gel formed in Comparative Example 1 is insufficient.

[0105] The various embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

[0106] The endpoints and any values in the ranges disclosed herein are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and a single point value, and between single point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

Claims

1. A degradable temporary plugging agent material, characterized in that, It includes the following components: Polyglycolic acid, an emulsifier and a thickener; Among them, based on the total weight of the degradable temporary plugging agent material, the content of polyglycolic acid is 20-95 wt%, the content of the emulsifier is 4-70 wt%, and the content of the thickener is 0.5-50 wt%.

2. The degradable temporary plugging agent material according to claim 1, wherein, Based on the total weight of the degradable temporary plugging agent material, the content of polyglycolic acid is 30-90 wt%, the content of the emulsifier is 8-65 wt%, and the content of the thickener is 1-50 wt%.

3. The degradable temporary plugging agent material according to claim 1, wherein, The polyglycolic acid is micron-sized particles, preferably particles with a median particle size of 100-200 μm; the weight-average molecular weight of the polyglycolic acid is 100,000-150,000; The emulsifier is selected from Span series emulsifiers and / or Tween series emulsifiers, preferably at least one of Span 20, Span 40, Span 60, Span 80, Tween 20, Tween 40, Tween 60 and Tween 80; The thickener is a sulfonic acid type polyacrylamide with a weight-average molecular weight of 10 million-15 million; 4. The degradable temporary plugging agent material according to claim 1, wherein, The degradable temporary plugging agent material further includes a crosslinking agent, and the crosslinking agent is preferably at least one of phenolic crosslinking agents, phenolic aldehyde crosslinking agents, amine crosslinking agents and amide crosslinking agents, and more preferably at least one of phenolic resin, hexamethylenetetramine, resorcinol and N,N-methylenebisacrylamide; based on the total weight of the degradable temporary plugging agent material, the content of the crosslinking agent is 0.01-0.5 wt%, preferably 0.03-0.4 wt%.

5. A preparation method of a degradable temporary plugging agent material, characterized in that, It includes the following steps: (1) Add the thickener to the brine and stir well to form a stable polymer viscous fluid; (2) Add the emulsifier to the polymer viscous fluid obtained in step (1) and stir well to form a stable polymer viscous emulsion; (3) Add the polyglycolic acid to the polymer viscous emulsion obtained in step (2) and stir well to form a stable suspension emulsion-like degradable temporary plugging agent material; The addition amounts of the thickener, emulsifier and polyglycolic acid are such that: in the degradable temporary plugging agent material, based on the total weight of the thickener, emulsifier and polyglycolic acid, the content of polyglycolic acid is 20-95 wt%, preferably 30-90 wt%, the content of the emulsifier is 4-70 wt%, preferably 8-65 wt%, and the content of the thickener is 0.5-50 wt%, preferably 1-50 wt%.

6. The preparation method according to claim 5, wherein, In step (1), the mass concentration of the thickener in the polymer viscous fluid is 0.1 wt%-1 wt%, preferably 0.2 wt%-0.5 wt%; In step (2), the mass concentration of the emulsifier in the polymer viscous emulsion is 0.05 wt%-3 wt%, preferably 0.1 wt%-2 wt%; In step (3), the mass concentration of the polyglycolic acid in the suspension emulsion is 0.1 wt%-20 wt%, preferably 0.5 wt%-10 wt%.

7. The preparation method according to claim 5, wherein, In step (1), the polyglycolic acid is micron-sized particles, preferably particles with a median particle size of 100-200 μm; the weight-average molecular weight of the polyglycolic acid is 100,000-150,000; In step (2), the emulsifier is selected from Span series emulsifiers and / or Tween series emulsifiers, preferably at least one of Span 20, Span 40, Span 60, Span 80, Tween 20, Tween 40, Tween 60, and Tween 80; In step (3), the thickener is a sulfonic acid type polyacrylamide with a weight average molecular weight of 10 million to 15 million.

8. The preparation method according to claim 5, wherein In step (1), the salinity of the brine is 30000-40000 mg / L, wherein Mg 2+ , Ca 2+ The content of each is independently 800-1200 mg / L.

9. The preparation method according to claim 4, wherein In step (1), the temperature of the stirring is 15-40 °C and the time is 1-2 h; In step (2), the temperature of the stirring is 15-40 °C and the time is 5-10 min; In step (3), the temperature of the stirring is 15-40 °C and the time is 20-60 min.

10. The preparation method according to claim 5, wherein, It further includes step (4): mixing the suspension emulsion obtained in step (3) with a crosslinking agent evenly; The crosslinking agent is preferably at least one of phenolic crosslinking agents, phenolic aldehyde crosslinking agents, amine crosslinking agents, and amide crosslinking agents, and more preferably at least one of phenolic resin, hexamethylenetetramine, resorcinol, and N,N-methylenebisacrylamide; based on the total weight of the thickener, emulsifier, polyglycolic acid, and crosslinking agent in the suspension emulsion, the addition amount of the crosslinking agent is 0.01-0.5 wt%, preferably 0.03-0.4 wt%.

11. A degradable temporary plugging agent material prepared by the preparation method according to any one of claims 5-10.

12. The application of the degradable temporary plugging agent material according to any one of claims 1-4, 11 in oilfield fracturing.

13. The construction method of the degradable temporary plugging agent material according to any one of claims 1-4 and 11 for oilfield fracturing, characterized in that, It includes the following steps: (1) Prepare a suspension emulsion according to the preparation method according to any one of claims 5-9; (2) Mix the suspension emulsion with a crosslinking agent evenly and inject it into the oil well of the oilfield; based on the total weight of the suspension emulsion and the crosslinking agent, the addition amount of the crosslinking agent is 10-150 ppm, preferably 20-100 ppm.

14. The construction method according to claim 13, wherein, The crosslinking agent is at least one of phenolic crosslinking agents, phenolic aldehyde crosslinking agents, amine crosslinking agents, and amide crosslinking agents, and preferably at least one of phenolic resin, hexamethylenetetramine, resorcinol, and N,N-methylenebisacrylamide.