CN116064013A - Temporary plugging agent for shale gas exploitation fracturing and preparation method thereof - Google Patents
Temporary plugging agent for shale gas exploitation fracturing and preparation method thereof Download PDFInfo
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- 238000011161 development Methods 0.000 claims abstract description 11
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- 239000000243 solution Substances 0.000 claims description 34
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- LUEWUZLMQUOBSB-FSKGGBMCSA-N (2s,3s,4s,5s,6r)-2-[(2r,3s,4r,5r,6s)-6-[(2r,3s,4r,5s,6s)-4,5-dihydroxy-2-(hydroxymethyl)-6-[(2r,4r,5s,6r)-4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxyoxan-3-yl]oxy-4,5-dihydroxy-2-(hydroxymethyl)oxan-3-yl]oxy-6-(hydroxymethyl)oxane-3,4,5-triol Chemical compound O[C@H]1[C@@H](O)[C@H](O)[C@@H](CO)O[C@H]1O[C@@H]1[C@@H](CO)O[C@@H](O[C@@H]2[C@H](O[C@@H](OC3[C@H](O[C@@H](O)[C@@H](O)[C@H]3O)CO)[C@@H](O)[C@H]2O)CO)[C@H](O)[C@H]1O LUEWUZLMQUOBSB-FSKGGBMCSA-N 0.000 claims description 17
- 235000001206 Amorphophallus rivieri Nutrition 0.000 claims description 17
- 229920002581 Glucomannan Polymers 0.000 claims description 17
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- 229940088598 enzyme Drugs 0.000 claims description 12
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- 239000004365 Protease Substances 0.000 claims description 11
- 102100037486 Reverse transcriptase/ribonuclease H Human genes 0.000 claims description 11
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- 230000000694 effects Effects 0.000 claims description 10
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- 238000001132 ultrasonic dispersion Methods 0.000 claims description 7
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- 230000036571 hydration Effects 0.000 claims description 5
- 238000006703 hydration reaction Methods 0.000 claims description 5
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical group [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 claims description 5
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- 230000000593 degrading effect Effects 0.000 claims description 2
- 238000010298 pulverizing process Methods 0.000 claims description 2
- 241001312219 Amorphophallus konjac Species 0.000 claims 3
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- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 2
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
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- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
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Classifications
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/50—Compositions for plastering borehole walls, i.e. compositions for temporary consolidation of borehole walls
- C09K8/504—Compositions based on water or polar solvents
- C09K8/506—Compositions based on water or polar solvents containing organic compounds
- C09K8/508—Compositions based on water or polar solvents containing organic compounds macromolecular compounds
- C09K8/512—Compositions based on water or polar solvents containing organic compounds macromolecular compounds containing cross-linking agents
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/60—Compositions for stimulating production by acting on the underground formation
- C09K8/84—Compositions based on water or polar solvents
- C09K8/86—Compositions based on water or polar solvents containing organic compounds
- C09K8/88—Compositions based on water or polar solvents containing organic compounds macromolecular compounds
- C09K8/887—Compositions based on water or polar solvents containing organic compounds macromolecular compounds containing cross-linking agents
Abstract
The invention relates to the technical field of auxiliary agents for shale gas development, and discloses a temporary plugging agent for shale gas development fracturing and a preparation method thereof, wherein polyacrylamide and modified konjak gum are added into deionized water when the temporary plugging agent is prepared, so that the concentration of the polyacrylamide is 0.05-0.1%, the concentration of the modified konjak gum is 1%, and the mixture is stirred uniformly and then kept stand for 1-2 hours to obtain glue solution; preparing a cross-linking agent, a porous starch degradation agent and a high-temperature stabilizer into a mixed water agent, uniformly stirring, adding the mixed water agent into the glue solution prepared in the step A1, and stirring for 10-20min under the stirring of 100-200r/min to obtain mixed glue; standing the mixed gel at 30-40 ℃ for 48-72h to obtain gel; and C, crushing the gel obtained in the step A3 into particles with the particle size of 10-20 meshes, and then drying at the temperature of 50-60 ℃ to obtain temporary plugging agent particles. The invention can temporarily block large cracks which are fractured in the stratum during fracturing, and after a period of time, the temporary plugging agent can be automatically decomposed, so that pollution to the bottom layer is avoided.
Description
Technical Field
The invention relates to the technical field of auxiliary agents for shale gas development, in particular to a temporary plugging agent for shale gas development fracturing and a preparation method thereof.
Background
In recent years, the staged fracturing technology of the horizontal well enables shale gas to be effectively developed, the bridge plug perforation continuous operation technology is a standard technology for fracturing the shale gas horizontal well, and the technology is adopted in 90% of the United states and more than 95% of the shale gas horizontal wells in China. However, the researches of micro seismic wave monitoring, liquid production profile testing, tracer testing and the like show that about 1/3 of perforation clusters are not transformed or insufficiently transformed by fracturing, and the non-transformed perforation clusters do not contribute to the yield. In addition, the Chinese shale gas has the characteristics of large horizontal stress difference, single crack form after fracturing and difficulty in forming complex cracks. Shale gas production is controlled by means of artificial fracture complexity and effective reform volume, i.e. "fracture control yield". Therefore, how to solve the problems of low perforation cluster transformation efficiency, poor uniformity and improved fracture complexity is one of the problems faced by the current Chinese shale gas fracturing transformation.
The temporary plugging steering fracturing technology can solve the problems, and the technology utilizes temporary plugging agent to plug to cause liquid steering, improves net pressure in cracks, opens up perforation clusters which are not fully modified, enables the number of the perforation clusters which are not modified to be more than that of liquid and sand, and realizes the maximization of the contact between a shaft and an oil and gas reservoir, thereby improving the recovery ratio. The technology mainly comprises two processes of seam steering and seam steering, and the core is that temporary plugging agents with different particle diameters are utilized to plug perforation holes, cracks or natural cracks; and adding a temporary plugging agent in the hydraulic fracturing process, wherein the temporary plugging agent forms bridge plugs in the main fracture channel, and after the pressure is increased, fracturing new branch fractures or more micro-fractures. Through various crack turning, the complexity of the crack is increased, the transformation volume is increased, and the perforation cluster transformation efficiency is improved.
The patent with the application publication number of CN108300442A discloses a shale oil shale gas fracturing temporary plugging agent which is prepared from the following raw materials: modified polyacrylamide, a high-temperature stabilizer, a toughening agent, a thickening agent and a dispersing agent; the modified polyacrylamide is prepared from the following raw materials: acrylic acid, acrylamide, guar gum, a cross-linking agent, an oxidizing agent, a reducing agent, graphene oxide, inorganic nanoparticles and a silane coupling agent.
The temporary plugging agent in the scheme can ensure that the temporary plugging agent has good plugging effect in a short time, can ensure that the good plugging effect is effective for a long time, and can be completely degraded or dissolved until the whole repeated fracturing construction is completed, so that the use efficiency and the repeated fracturing success rate of the temporary plugging agent are improved. However, a large amount of synthetic polymers such as acrylic acid, acrylamide, sulfonated asphalt and the like are used in the temporary plugging agent, the degradation speed of the temporary plugging agent in a stratum is low, the partial gaps of the stratum are easy to block, and a large amount of the thickening agent is used, because the thickening agent mainly uses bentonite or silica gel, the substances in the stratum are easy to block the tiny gaps in the stratum shale, so shale gas cannot well escape from the shale, and the recovery ratio of the shale gas is reduced; in addition, graphene oxide is used in the technical scheme, and the graphene is high in price, so that the temporary plugging agent is high in use cost.
Disclosure of Invention
In view of the above, the invention aims to provide a temporary plugging agent for shale gas development and fracturing and a preparation method thereof, which can temporarily plug large cracks which are fractured in a stratum during fracturing, and after a period of time, the temporary plugging agent can be automatically decomposed without polluting a bottom layer.
The invention solves the technical problems by the following technical means:
the temporary plugging agent for shale gas exploitation fracturing comprises the following raw materials in parts by mass: 100 parts of konjak gum, 5-10 parts of polyacrylamide, 3-5 parts of cross-linking agent, 2-5 parts of porous starch degradation agent and 0.8-1.2 parts of high-temperature stabilizer; the porous starch degrading agent contains alpha-amylase and protease.
Further, the crosslinking agent is Al (OH) 3 The high-temperature stabilizer is sodium thiosulfate, and the molecular weight of the polyacrylamide is 1000-2000 ten thousand.
Further, in the raw materials of the temporary plugging agent, 100 parts of konjak gum, 7.5 parts of polyacrylamide, 4 parts of cross-linking agent, 3.5 parts of porous starch degradation agent and 1.0 part of high-temperature stabilizer.
Further, the konjac gum is modified konjac gum, and the preparation method of the modified konjac gum comprises the following steps: taking 10-12 parts by mass of konjak gum, adding the konjak gum into 120-150 parts by mass of deionized water in a stirring state with the rotating speed of 800-1000r/min, stirring for 30-40min at the rotating speed of 100-200r/min, and standing for hydration for 2-3h to obtain konjak gum solution; adding 2-3 parts of absolute ethyl alcohol, 1-2 parts of chloroacetic acid and 1-2 parts of sodium hydroxide into the konjak gum solution, stirring and stirring for 5-8min under the stirring of 2000-3000r/min, and then placing the konjak gum solution in the environment of 40-50 ℃ for 1-2h to modify the konjak gum to obtain the modified konjak gum.
The invention also discloses a preparation method of the temporary plugging agent for shale gas exploitation fracturing, which comprises the following steps:
a1, adding polyacrylamide and modified konjak gum into deionized water to ensure that the concentration of the polyacrylamide is 0.05-0.1% and the concentration of the modified konjak gum is 1%, uniformly stirring, and standing for 1-2 hours to obtain a glue solution;
a2, preparing a cross-linking agent, a porous starch degradation agent and a high-temperature stabilizer into a mixed water agent, uniformly stirring, adding the mixed water agent into the glue solution prepared in the step A1, and stirring for 10-20min under the stirring of 100-200r/min to obtain mixed glue;
a3, standing the mixed gel at the temperature of 30-40 ℃ for 48-72h to obtain gel;
and A4, crushing the gel obtained in the step A3 into particles with the particle size of 10-20 meshes, and then drying at the temperature of 50-60 ℃ to obtain temporary plugging agent particles.
Further, the preparation method of the porous starch degradation agent comprises the following steps:
b1, dissolving starch in ethanol, regulating the pH value to be 4.5-5.5, then adding beta-amylase and debranching enzyme, and carrying out enzymolysis for 1-2h in a stirring state;
b2, adding sodium hydroxide into the mixed solution obtained after enzymolysis in the step B1, adjusting the pH value to 8.0-9.0, heating to 45-55 ℃, centrifuging the mixed solution, and collecting precipitate;
b3, washing the precipitate cleanly, drying at 50-60 ℃ and pulverizing into powder to obtain porous starch;
and B4, dispersing alpha-amylase and protease in an ethanol solution, adding the porous starch prepared in the step B3, performing ultrasonic dispersion, drying at 50-60 ℃ after dispersion, and crushing into powder to obtain the porous starch degradation agent.
Further, the enzyme activity of the beta-amylase in the step B1 is 20000 to 30000U/g, and the enzyme activity of the debranching enzyme is 1000 to 1500U/g.
Further, the frequency of ultrasonic dispersion in the step B4 is 10000-15000 Hz, and the time of ultrasonic dispersion is 60-90min.
Further, the total mass of the alpha-amylase and the protease in the step B4 is equal to the mass of the porous starch, and the mass ratio of the alpha-amylase to the protease is 7:3.
The invention has the beneficial effects that:
1. the temporary plugging agent disclosed by the invention comprises main raw materials of konjak gum, polyacrylamide, a cross-linking agent, a porous starch degradation agent and a high-temperature stabilizer, wherein most of the raw materials are natural konjak gum, and only a small amount of polyacrylamide with large molecular weight is bridged in the temporary plugging agent, so that the strength of the temporary plugging agent is higher; after the konjac glucomannan is modified, the konjac glucomannan has a large molecular weight and a large amount of hydrophilic groups, and Al (OH) is used 3 After being crosslinked to form gel as a crosslinking agent, the gel has higher strength and high water expansion coefficient, and can be selected after being injected into a bottom layer together with fracturing fluid during fracturingThe method comprises the steps of (1) entering into a large crack of a low-pressure stratum in a sex manner, then absorbing water to expand, and temporarily plugging the large crack which is fractured in the stratum; in the fracturing process, large cracks are selectively plugged, and the pressure generated by ground fracturing equipment can be increased in the stratum, so that new branch cracks or more micro cracks are fractured, the complexity of the stratum cracks is increased, the transformation volume is increased, and the perforation cluster transformation efficiency is improved.
2. The temporary plugging agent disclosed by the invention is used for plugging a large crack after entering the large crack, alpha-amylase and protease in porous starch are gradually dispersed from gaps of the porous starch after fracturing, the alpha-amylase and the protease can be used for gradually hydrating and decomposing the porous starch and the konjac gum, and a single-molecule compound is formed after the konjac gum is decomposed, so that the whole temporary plugging agent is gradually hydrated and decomposed, and the decomposed temporary plugging agent is returned to the ground along with fracturing fluid to unseal the temporarily plugged large crack; therefore, the temporary plugging agent can be decomposed by itself, and the stratum is not polluted after the temporary plugging agent is decomposed, so that the recovery ratio of shale gas is improved.
3. The temporary plugging agent adopts the raw materials which are cheaper and easily available in the market, is not complex in preparation process, has good temporary plugging effect, has lower manufacturing cost and strong industrial application, and does not pollute the environment after hydrolysis of the flowback fluid, thereby being beneficial to large-area popularization.
Detailed Description
The present invention will be described in detail with reference to examples below:
example 1,
The embodiment is a preparation method of modified konjac glucomannan, which comprises the following steps: taking 10kg of konjak gum, adding the konjak gum into 120kg of deionized water under the stirring state with the rotating speed of 800r/min, stirring for 30min at the rotating speed of 100r/min, and standing for hydration for 2h to obtain konjak gum solution; adding 2kg of absolute ethyl alcohol, 1kg of chloroacetic acid and 1kg of sodium hydroxide into the konjak gum solution, stirring for 5min under 2000r/min, and then placing the konjak gum solution in an environment of 40 ℃ for 1h to modify the konjak gum to obtain modified konjak gum.
EXAMPLE 2,
The embodiment is a preparation method of modified konjac glucomannan, which comprises the following steps: taking 11kg of konjak gum, adding the konjak gum into 135kg of deionized water under the stirring state with the rotating speed of 900r/min, stirring for 35min with the rotating speed of 150r/min, and standing for hydration for 2.5h to obtain konjak gum solution; adding 2.3kg of absolute ethyl alcohol, 1.5kg of chloroacetic acid and 1.5kg of sodium hydroxide into the konjak gum solution, stirring for 7min under 2500r/min, and then placing the konjak gum solution in an environment of 45 ℃ for 1.5h to modify the konjak gum to obtain modified konjak gum.
EXAMPLE 3,
The embodiment is a preparation method of modified konjac glucomannan, which comprises the following steps: taking 12kg of konjak gum, adding the konjak gum into 150kg of deionized water under the stirring state with the rotating speed of 1000r/min, stirring for 40min with the rotating speed of 200r/min, and standing for hydration for 3h to obtain konjak gum solution; adding 3kg of absolute ethyl alcohol, 2kg of chloroacetic acid and 2kg of sodium hydroxide into the konjak gum solution, stirring for 8min under the stirring of 3000r/min, and then placing the konjak gum solution in the environment of 50 ℃ for 2h to modify the konjak gum, thus obtaining the modified konjak gum.
EXAMPLE 4,
The embodiment is a preparation method of a porous starch degradation agent, comprising the following steps:
b1, dissolving 10kg of corn starch in 30kg of ethanol, regulating the pH value to be 5, then adding 0.5kg of beta-amylase and 0.5kg of debranching enzyme, and carrying out enzymolysis for 1.5h in a stirring state, wherein the enzyme activity of the beta-amylase is 25000U/g, and the enzyme activity of the debranching enzyme is 1250U/g;
b2, adding 3kg of sodium hydroxide into the mixed solution obtained after the enzymolysis in the step B1, adjusting the pH value to 8.5, heating to 50 ℃, centrifuging the mixed solution, and collecting a precipitate;
b3, washing the precipitate cleanly, drying at 55 ℃ and crushing into powder to obtain porous starch;
and B4, dispersing 7kg of alpha-amylase and 3kg of protease in 30kg of ethanol solution, adding the porous starch prepared in the step B3 after uniform dispersion, performing ultrasonic dispersion at the frequency of 12500 Hz for 75min, drying at the temperature of 55 ℃ after dispersion, and crushing into powder to obtain the porous starch degradation agent.
EXAMPLE 5,
The embodiment relates to a preparation method of a temporary plugging agent for shale gas development and fracturing, which comprises the following steps:
a1, adding polyacrylamide with the molecular weight of 1000 ten thousand and the modified konjac glucomannan prepared in the embodiment 1 into deionized water to ensure that the concentration of the polyacrylamide is 0.05 percent and the concentration of the modified konjac glucomannan is 1 percent, uniformly stirring and standing for 1h to obtain a glue solution, wherein in the embodiment, the modified konjac glucomannan is 100kg and the polyacrylamide is 5kg;
a2, 3kg of Al (OH) 3 Preparing 2kg of the porous starch degradation agent prepared in the embodiment 4 and 0.8kg of sodium thiosulfate into a mixed water agent, uniformly stirring, adding the mixed water agent into the glue solution prepared in the step A1, and stirring for 10min under the stirring of 100r/min to obtain mixed glue;
a3, standing the mixed gel at the temperature of 30 ℃ for 48 hours to obtain gel;
and A4, crushing the gel obtained in the step A3 into 15-mesh particles, and then drying at 50 ℃ to obtain temporary plugging agent particles.
EXAMPLE 6,
The embodiment relates to a preparation method of a temporary plugging agent for shale gas development and fracturing, which comprises the following steps:
a1, adding polyacrylamide with molecular weight of 1500 ten thousand and the modified konjac glucomannan prepared in the embodiment 2 into deionized water to ensure that the concentration of the polyacrylamide is 0.075 percent and the concentration of the modified konjac glucomannan is 1 percent, and standing for 1-2 hours after uniformly stirring to obtain glue solution; in the embodiment, the modified konjac glucomannan is 100kg, and the polyacrylamide is 7.5kg;
a2, 4kg of Al (OH) 3 3.5kg of the porous starch degradation agent prepared in the embodiment 4 and 1.0kg of sodium thiosulfate are prepared into a mixed water agent, after being uniformly stirred, the mixed water agent is added into the glue solution prepared in the step A1, and the glue solution is stirred for 15min under 150r/min to obtain mixed glue;
a3, standing the mixed gel at 35 ℃ for 60 hours to obtain gel;
and A4, crushing the gel obtained in the step A3 into 15-mesh particles, and then drying at the temperature of 55 ℃ to obtain temporary plugging agent particles.
EXAMPLE 7,
The embodiment relates to a preparation method of a temporary plugging agent for shale gas development and fracturing, which comprises the following steps:
a1, adding polyacrylamide with the molecular weight of 2000 ten thousand and the modified konjac glucomannan prepared in the embodiment 3 into deionized water to ensure that the concentration of the polyacrylamide is 0.1 percent and the concentration of the modified konjac glucomannan is 1 percent, uniformly stirring and standing for 2 hours to obtain a glue solution; in the embodiment, the modified konjac glucomannan is 100kg, and the polyacrylamide is 10kg;
a2, 5kg of Al (OH) 3 5kg of the porous starch degradation agent prepared in the embodiment 4 and 1.2kg of sodium thiosulfate are prepared into a mixed water agent, after being uniformly stirred, the mixed water agent is added into the glue solution prepared in the step A1, and the glue solution is stirred for 20min under the stirring of 200r/min to obtain mixed glue;
a3, standing the mixed gel at 40 ℃ for 72 hours to obtain gel;
and A4, crushing the gel obtained in the step A3 into particles with 20 meshes, and then drying at the temperature of 60 ℃ to obtain temporary plugging agent particles.
The temporary plugging agents prepared in examples 5-7 were tested for performance, and the temporary plugging agents prepared in the patents mentioned in the background art were used as comparative examples, and the same fracturing fluid formulations were used, and were tested at 120 ℃ as follows:
| examples | Example 5 | Example 6 | Example 7 | Comparative examples |
| Degradation time (h) | 20 | 20 | 21 | 22 |
| Degradation rate (%) | 100 | 100 | 100 | 100 |
| Temporary blocking ratio (%) | 99 | 99 | 99 | 98 |
| Compressive strength (MPa) | 84 | 88 | 87 | 82 |
| Core permeability recovery (%) | 98 | 99 | 98 | 97 |
| Surface tension of the post-dissolution gel breaking solution (mN/m) | 21.8 | 20.9 | 21.3 | 22.4 |
| After dissolution, the gel breaking solution is prevented from swelling (%) | 87.6 | 87.9 | 87.6 | 87.9 |
From the above test results, the temporary plugging agent of the present invention is compared with the comparative example, and the temporary plugging agent performance of the present invention and the comparative example are suitably superior to those of the comparative example in terms of temporary plugging rate, compressive strength and core permeability recovery rate.
The temporary plugging agent provided by the invention is tested in a Yuxi plot to obtain 10 shale gas horizontal wells, and after the temporary plugging agent is tested, the temporary plugging agent provided by the invention has an obvious effect of increasing a fracture network for shale gas fracturing, and the daily yield of shale gas is improved by more than 10%.
The above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made thereto without departing from the spirit and scope of the technical solution of the present invention, which is intended to be covered by the scope of the claims of the present invention. The technology, shape, and construction parts of the present invention, which are not described in detail, are known in the art.
Claims (9)
1. The temporary plugging agent for shale gas exploitation fracturing is characterized by comprising the following raw materials in parts by mass: 100 parts of konjak gum, 5-10 parts of polyacrylamide, 3-5 parts of cross-linking agent, 2-5 parts of porous starch degradation agent and 0.8-1.2 parts of high-temperature stabilizer; the porous starch degrading agent contains alpha-amylase and protease.
2. The temporary plugging agent for shale gas development fracturing of claim 1, wherein the temporary plugging agent comprises the following components: the cross-linking agent is Al (OH) 3 The high-temperature stabilizer is sodium thiosulfate, and the molecular weight of the polyacrylamide is 1000-2000 ten thousand.
3. The temporary plugging agent for shale gas development fracturing of claim 2, wherein the temporary plugging agent comprises the following components: in the raw materials of the temporary plugging agent, 100 parts of konjak gum, 7.5 parts of polyacrylamide, 4 parts of cross-linking agent, 3.5 parts of porous starch degradation agent and 1.0 part of high-temperature stabilizer.
4. The temporary plugging agent for shale gas development fracturing of claim 3, wherein the temporary plugging agent comprises the following components in percentage by weight: the konjac glucomannan is modified konjac glucomannan, and the preparation method of the modified konjac glucomannan comprises the following steps: taking 10-12 parts by mass of konjak gum, adding the konjak gum into 120-150 parts by mass of deionized water in a stirring state with the rotating speed of 800-1000r/min, stirring for 30-40min at the rotating speed of 100-200r/min, and standing for hydration for 2-3h to obtain konjak gum solution; adding 2-3 parts of absolute ethyl alcohol, 1-2 parts of chloroacetic acid and 1-2 parts of sodium hydroxide into the konjak gum solution, stirring and stirring for 5-8min under the stirring of 2000-3000r/min, and then placing the konjak gum solution in the environment of 40-50 ℃ for 1-2h to modify the konjak gum to obtain the modified konjak gum.
5. The preparation method of the temporary plugging agent for shale gas exploitation fracturing is characterized by comprising the following steps of:
a1, adding polyacrylamide and modified konjak gum into deionized water to ensure that the concentration of the polyacrylamide is 0.05-0.1% and the concentration of the modified konjak gum is 1%, uniformly stirring, and standing for 1-2 hours to obtain a glue solution;
a2, preparing a cross-linking agent, a porous starch degradation agent and a high-temperature stabilizer into a mixed water agent, uniformly stirring, adding the mixed water agent into the glue solution prepared in the step A1, and stirring for 10-20min under the stirring of 100-200r/min to obtain mixed glue;
a3, standing the mixed gel at the temperature of 30-40 ℃ for 48-72h to obtain gel;
and A4, crushing the gel obtained in the step A3 into particles with the particle size of 10-20 meshes, and then drying at the temperature of 50-60 ℃ to obtain temporary plugging agent particles.
6. The preparation method of the temporary plugging agent for shale gas exploitation fracturing, which is disclosed in claim 5, is characterized by comprising the following steps: the preparation method of the porous starch degradation agent comprises the following steps:
b1, dissolving starch in ethanol, regulating the pH value to be 4.5-5.5, then adding beta-amylase and debranching enzyme, and carrying out enzymolysis for 1-2h in a stirring state;
b2, adding sodium hydroxide into the mixed solution obtained after enzymolysis in the step B1, adjusting the pH value to 8.0-9.0, heating to 45-55 ℃, centrifuging the mixed solution, and collecting precipitate;
b3, washing the precipitate cleanly, drying at 50-60 ℃ and pulverizing into powder to obtain porous starch;
and B4, dispersing alpha-amylase and protease in an ethanol solution, adding the porous starch prepared in the step B3, performing ultrasonic dispersion, drying at 50-60 ℃ after dispersion, and crushing into powder to obtain the porous starch degradation agent.
7. The preparation method of the temporary plugging agent for shale gas exploitation fracturing, which is disclosed in claim 6, is characterized by comprising the following steps: the enzyme activity of the beta-amylase in the step B1 is 20000-30000U/g, and the enzyme activity of the debranching enzyme is 1000-1500U/g.
8. The preparation method of the temporary plugging agent for shale gas exploitation fracturing, which is disclosed in claim 7, is characterized in that: and B4, the ultrasonic dispersion frequency is 10000-15000 Hz, and the ultrasonic dispersion time is 60-90min.
9. The preparation method of the temporary plugging agent for shale gas exploitation fracturing, which is disclosed in claim 8, is characterized by comprising the following steps: the total mass of the alpha-amylase and the protease in the step B4 is equal to that of the porous starch, and the mass ratio of the alpha-amylase to the protease is 7:3.
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