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CN-122012062-A - Temporary plugging agent for fracturing and preparation method thereof

CN122012062ACN 122012062 ACN122012062 ACN 122012062ACN-122012062-A

Abstract

The invention relates to the technical field of oil and gas field development and discloses a temporary plugging agent for fracturing and a preparation method thereof, wherein the temporary plugging agent comprises 25-30 parts by weight of phenyl polyester, 3-5 parts by weight of modified carbon nano tubes, 0.5-2 parts by weight of coupling agent and 0.3-1 part by weight of nano calcium carbonate. The temporary plugging agent has the advantages of excellent temperature resistance, high plugging efficiency, low formation injury rate, good compatibility with fracturing fluid, simple and controllable preparation process and suitability for temporary plugging steering operation of hydraulic fracturing of unconventional oil and gas reservoirs.

Inventors

  • LIU WEIBO
  • WU JI
  • ZHENG RUIXUE
  • LI HUI

Assignees

  • 陕西日新石油化工有限公司

Dates

Publication Date
20260512
Application Date
20260325

Claims (8)

  1. 1. 25-30 Parts by weight of phenyl polyester, 3-5 parts by weight of organosilicon compatibilizer modified carbon nano-tubes, 0.5-2 parts by weight of coupling agent and 0.3-1 part by weight of nano-calcium carbonate; the preparation method of the phenyl polyester comprises the following steps: s1, in tetrahydrofuran solvent, 4' -dibromodiphenyl ether, undecylenic alcohol and copper acetylacetonate are taken as raw materials, and the materials undergo reflux reaction under alkaline conditions to prepare dienyl diphenyl ether with carbon-carbon double bonds at two ends; S2, in a DMF solvent, generating a thiol-ene click reaction by using dienyl diphenyl ether and thioglycollic acid under the initiation of ultraviolet light, and introducing carboxyl to obtain dicarboxyl modified diphenyl ether; S3, in the nitrogen atmosphere, firstly, the dicarboxyl diphenyl ether and the 1, 3-butanediol are subjected to sectional heating polycondensation, and then terephthalic acid and the 1, 4-butanediol are added for reaction, so that the phenyl polyester is prepared.
  2. 2. The temporary plugging agent for fracturing according to claim 1, wherein the phenyl polyester is prepared by the following steps: S1, adding 4,4' -dibromodiphenyl ether, undecylenic alcohol and copper acetylacetonate into a reactor filled with tetrahydrofuran solvent, stirring and mixing, continuously adding potassium carbonate and 8-hydroxyquinoline, carrying out reflux reaction for 6-8h at 80-85 ℃, and carrying out reduced pressure distillation, washing and drying after the completion to obtain the dienyl diphenyl ether; S2, adding dienyl diphenyl ether and thioglycollic acid into an N, N-dimethylformamide solvent, stirring and mixing, continuously adding benzoin dimethyl ether photoinitiator, irradiating with ultraviolet light of 365nm at 20-25 ℃, centrifuging after finishing, washing and drying to obtain dicarboxyl modified diphenyl ether; S3, placing the dicarboxyl modified diphenyl ether, the 1, 3-butanediol and the tetrabutyl titanate in a reactor, heating to 175-180 ℃ under the atmosphere of N 2 , reacting until water is not evaporated, heating to 190-200 ℃ again, reacting for 1-1.5 hours, vacuumizing to 220-230 ℃ for 0.5-1 hour, cooling to 150-155 ℃ after finishing, continuously adding terephthalic acid and 1, 4-butanediol, heating to 175-180 ℃ for reacting until water is not evaporated again, heating to 190-200 ℃ for 1-1.5 hours, vacuumizing to 220-230 ℃ for 0.5-1 hour, and obtaining the phenyl polyester.
  3. 3. The temporary plugging agent for fracturing according to claim 2, wherein in the S1, the dosage ratio of 4,4' -dibromodiphenyl ether, undecylenol, copper acetylacetonate, tetrahydrofuran, potassium carbonate and 8-hydroxyquinoline is 5-10 mmol/12-25 mmol/35-45 mL/5-6 mmol/0.1-0.2 mmol.
  4. 4. The temporary plugging agent for fracturing according to claim 2, wherein the dosage ratio of the N, N-dimethylformamide, the dienyl diphenyl ether, the thioglycollic acid and the benzoin dimethyl ether photoinitiator in the S2 is 30-40mL:6-10mmol:15-25mmol:0.04-0.06mmol.
  5. 5. The temporary plugging agent for fracturing according to claim 2, wherein in S2, the ultraviolet irradiation time of 365nm is 2-4 hours.
  6. 6. The temporary plugging agent for fracturing according to claim 2, wherein in the S3, the dosage ratio of the dicarboxyl modified diphenyl ether, the 1, 3-butanediol, the tetrabutyl titanate, the terephthalic acid and the 1, 4-butanediol is 8-10 mmol/8-12 mmol/0.05-0.06 mmol/5-8 mmol/10-15 mmol.
  7. 7. The temporary plugging agent for fracturing according to claim 1, wherein said coupling agent is one of KH550 and KH 560.
  8. 8. A method for preparing the temporary plugging agent for fracturing according to any one of claims 1to 7, wherein the preparation method of the temporary plugging agent for fracturing comprises the following steps: Firstly, weighing raw materials according to parts by weight, adding an organosilicon compatibilizer modified carbon nano tube, nano calcium carbonate and a coupling agent into a high-speed mixer, and mixing at a high speed of 80-90 ℃ and a rotating speed of 1500-2000r/min for 10-15min to obtain a surface modified inorganic filler; Adding phenyl polyester into a double-screw extruder, heating to 210-220 ℃ to melt, adding the surface modified inorganic filler obtained in the step one into the double-screw extruder, melt-blending for 15-20min at 210-220 ℃ and the rotating speed of 300-350r/min, and extruding to obtain a blend; And thirdly, cooling the blend to room temperature through circulating water, granulating by a granulator, sieving by a standard sieve to obtain four temporary plugging agent particles with particle size classification of 20-40 meshes, 40-60 meshes, 60-80 meshes and 80-100 meshes, and compounding according to the mass ratio of 1:2:3:2 to obtain the temporary plugging agent for fracturing.

Description

Temporary plugging agent for fracturing and preparation method thereof Technical Field The invention relates to the technical field of oil and gas field development, in particular to a temporary plugging agent for fracturing and a preparation method thereof. Background Hydraulic fracturing is a core yield increasing technology for efficiently developing unconventional oil and gas reservoirs (shale oil, dense gas, coal bed gas and the like), while temporary plugging diversion fracturing is a key technology for realizing manual fracture diversion, expanding fracture network sweep volume and improving the utilization degree of a reservoir, wherein temporary plugging agents are core materials for determining temporary plugging diversion effects. The conventional granular temporary plugging agent has poor suitability for artificial cracks and natural cracks with different widths, is difficult to form a step-by-step plugging structure of bridging-filling-compact plugging, has insufficient plugging pressure-bearing capacity in a high-temperature high-pressure deep well environment, is easy to cause temporary plugging failure and crack turning failure, has poor dispersibility in fracturing fluid, is easy to agglomerate and agglomerate, is easy to cause plugging pump risk in the pumping process, has low plugging efficiency when being singly used, needs to be compounded with granular materials, has solid phase residues after being degraded, has irreversible damage to the flow guiding capacity of a reservoir matrix and cracks, and does not meet the requirement of environment-friendly development. Therefore, developing a temporary plugging agent for fracturing, which is resistant to temperature and salt, high in pressure bearing, low in stratum injury, good in compatibility with fracturing fluid and simple in preparation process, becomes a technical problem to be solved in the field. Disclosure of Invention In order to overcome the defects of the prior art, the invention aims to provide a temporary plugging agent for fracturing and a preparation method thereof, and solve the problems of insufficient bearing capacity, poor temperature resistance and large formation damage of the conventional temporary plugging agent. The temporary plugging agent for fracturing comprises, by weight, 25-30 parts of phenyl polyester, 3-5 parts of organosilicon compatibilizer modified carbon nanotubes, 0.5-2 parts of coupling agent and 0.3-1 part of nano calcium carbonate; The modified carbon nano tube is modified by adopting an organosilicon compatibilizer to be matched with nano calcium carbonate as an inorganic filler, the compatibility of the modified carbon nano tube with a phenyl polyester substrate is greatly improved after the surface modification of a coupling agent, the modified carbon nano tube can form a three-dimensional reticular reinforced structure, the pressure bearing capacity and the scouring resistance of a temporary plugging agent are obviously improved, and a step-by-step plugging structure of large-grain size bridging-medium grain size filling-small grain size compact plugging in cracks with different widths can be formed by adopting a four-level grain size grading compound design of 20-40 meshes, 40-60 meshes, 60-80 meshes and 80-100 meshes, so that the polyester has strong adaptability and excellent temporary plugging steering effect The preparation method of the phenyl polyester comprises the following steps: s1, in tetrahydrofuran solvent, 4' -dibromodiphenyl ether, undecylenic alcohol and copper acetylacetonate are taken as raw materials, and the materials undergo reflux reaction under alkaline conditions to prepare dienyl diphenyl ether with carbon-carbon double bonds at two ends; S2, in a DMF solvent, generating a thiol-ene click reaction by using dienyl diphenyl ether and thioglycollic acid under the initiation of ultraviolet light, and introducing carboxyl to obtain dicarboxyl modified diphenyl ether; S3, in the nitrogen atmosphere, firstly, the dicarboxyl diphenyl ether and the 1, 3-butanediol are subjected to sectional heating polycondensation, and then terephthalic acid and the 1, 4-butanediol are added for reaction, so that the phenyl polyester is prepared. Further, the preparation method of the phenyl polyester comprises the following steps: S1, adding 4,4' -dibromodiphenyl ether, undecylenic alcohol and copper acetylacetonate into a reactor filled with tetrahydrofuran solvent, stirring and mixing, continuously adding potassium carbonate and 8-hydroxyquinoline, carrying out reflux reaction for 6-8h at 80-85 ℃, and carrying out reduced pressure distillation, washing and drying after the completion to obtain the dienyl diphenyl ether; S2, adding dienyl diphenyl ether and thioglycollic acid into an N, N-dimethylformamide solvent, stirring and mixing, continuously adding benzoin dimethyl ether photoinitiator, irradiating with ultraviolet light of 365nm at 20-25 ℃, centrifuging after finishing, washing and dr