Preparation method of supercritical carbon dioxide thickener for tight oil and gas reservoir

Abstract

The present invention disclosed a method for preparing a thickener for tight oil and gas reservoir, which relieves damages. The technical solution includes the following steps: putting a three-flask in ice; adding perfluoroalkyl alcohol, P-toluenesulfonyl chloride and pyridine; reacting for 3 h at 0-20° C.; adding filter paper; ultrasonic dispersing for 1 h; removing the filter paper; washing the solution for 3-5 times by adding dilute hydrochloric acid to collect the intermediate product (I); adding 1,3-dihydroxy-propane-2-tert-butyl carbamate and the intermediate product (I) in another three-flask; adding potassium carbonate and N,N-dimethylformamide; reacting for 4 h at 40° C. to collect the intermediate product (II); adding trifluoroacetic acid and methylene chloride into the intermediate product (II); reacting at 45° C. for 2 h; extracting and vacuum drying; and adding 1,6-hexamethylene diisocyanate; reacting for 2 h to collect the final product (III).

Claims

1. A method for preparing a supercritical carbon dioxide thickener for a tight oil and gas reservoir, comprising following steps: (1) preparing P-toluene perfluoroalkyl ethylenesulfonates (TFES), which further comprises following sub-steps: after adding a perfluoroalkyl alcohol and a P-toluenesulfonyl chloride in a three-neck flask, wherein a molar ratio of the perfluoroalkyl alcohol and the P-toluenesulfonyl chloride is 1:1.1-1.2, and adding a pyridine; forming a system; wherein the system has reacted for 3 h under stirring thoroughly; maintaining a temperature at 0-20° C.; adding filter paper and carrying out ultrasonic dispersion for 1 h after a reaction is over; after removing unreacted residue P-toluenesulfonyl chloride and the filter paper; forming a system; washing the system with 15% dilute hydrochloric acid many times to remove the pyridine and collect a white solid; washing the white solid with distilled water for multiple times, drying the white solid by a vacuum drying oven at 40° C. for 3 h to prepare an intermediate product (I) TFES; (2) preparing intermediate product (II) (1,3-bis(perfluoroalkyl ethoxy) isopropyl-2-tertbutyl carbamate) (PFEIT), which further comprises the following sub-steps: adding a 1,3-dihydroxy-propane-2-tert-butyl carbamate and the intermediate product (I) TFES in a three-neck flask, wherein a molar ratio of the 1,3-dihydroxy-propane-2-tert-butyl carbamate and the TFES is 2.1-2.2:1; then adding potassium carbonate and N,N-dimethylformamide; forming a system; wherein the system has been reacted for 4 h under stirring thoroughly at 40° C.; washing a reaction liquid with distilled water repeatedly after a reaction process is over; then carrying out vacuum drying to collect an intermediate product (II) PFEIT; and (3) preparing a final product (III) 1,6-bis[1,3-bis(perfluoroalkyl ethoxy) isopropyl-2-urea] hexane (PFEIUH), which further comprises the following sub-steps: adding a mixture of methylene chloride and trifluoroacetic acid in a three-neck flask; wherein a volume ratio of the methylene chloride and the three trifluoroacetic acid is 2:1; adding the intermediate product (III) PFEIT to the mixture; maintaining a temperature at 45° C.; reacting for 2 h; adding the methylene chloride for extracting for 3 times to form an organic layer; drying the organic layer with a Na.sub.2SO.sub.4; adding 1,6-hexamethylene diisocyanate (HMDI), wherein a molar ratio of the HMDI and the PFEIT is 1:2.05-2.10, reacting under a temperature of 50° C. for 2 h, washing a crude product with a mixture of ethyl acetate and benzene for multiple times; filtering and carrying out vacuum drying to collect a final product (III) PFEIUH, wherein a perfluoro alkyl is one from these groups C.sub.5F.sub.11, C.sub.6F.sub.13, C.sub.7F.sub.15, C.sub.8F.sub.17, C.sub.9F.sub.19, C.sub.10F.sub.21.

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(1) The present invention is illustrated by the below embodiments which are not a limitation of the present invention.

Embodiment 1

(2) (1) Preparing the intermediate product (1) P-toluene perfluorooctyl ethylidene sulfonate, which further comprises following sub-steps: adding a perfluorooctyl alcohol and a P-toluenesulfonyl chloride in a three-neck flask, wherein a molar ratio of the perfluorooctyl alcohol and P-toluenesulfonyl chloride is 1:1.1; finally, adding a pyridine; wherein the system has reacted for 3 h under stirring thoroughly; maintaining a temperature at 0° C.; adding filter paper after a reaction process is over; carrying out ultrasonic dispersion for 1 h; removing unreacted residue P-toluenesulfonyl chloride; removing the filter paper; washing the system with 15% dilute hydrochloric acid for 3 times to remove the pyridine and collect a white solid; washing the solid with distilled water for 5 times; drying the solid by vacuum drying oven at 40° C. for 3 h to prepare an intermediate product (I) P-toluene perfluorooctyl ethylidene sulfonate; and

(3) (2) Preparing intermediate product (II) 1,3-bis(perfluorooctyl ethoxy) isopropyl-2-tertbutyl carbamate, which further comprises the following sub-steps: adding a 1,3-dihydroxy-propane-2-tert-butyl carbamate and the P-toluene perfluorooctyl ethylidene sulfonate in a three-neck flask, wherein a molar ratio of the (1,3-dihydroxy-propane-2-tert-butyl carbamate and P-toluene perfluorooctyl ethylidene sulfonate is 2.1:1; then adding potassium carbonate and N,N-dimethylformamide; wherein the system has been reacted for 4 h under stirring thoroughly at 40° C.; washing the reaction liquid with distilled water for five times after a reaction process is over; then carrying out the vacuum drying to collect an intermediate product (II) (1,3-bis(perfluorooctyl ethoxy) isopropyl-2-tertbutyl carbamate); and

(4) (3) Preparing a final product (III) 1,6-bis[1,3-bis(perfluorooctyl ethoxy) isopropyl-2-urea] hexane, which further comprises the following sub-steps: adding a mixture of methylene chloride and trifluoroacetic acid in a three-neck flask; a volume ratio of the methylene chloride and the three trifluoroacetic acid is 2:1; adding the intermediate product (II) 1,3-bis(perfluorooctyl ethoxy) isopropyl-2-tertbutyl carbamate to the mixture; maintaining a temperature at 45° C.; reacting for 2 h; adding the methylene chloride and extracting for 3 times to form an organic layer; drying the organic layer with a Na.sub.2SO.sub.4; adding HMDI, wherein a molar ratio of HMDI and 1,3-bis(perfluorooctyl ethoxy) isopropyl-2-tertbutyl carbamate is 1:2.05, reacting under a temperature of 50° C. for 2 h, washing a crude product with a mixture of ethyl acetate and benzene for 4 times; filtering and carrying out vacuum drying to collect a final product (III) 1,6-bis[1,3-bis(perfluorooctyl ethoxy) isopropyl-2-urea]hexane; and

(5) adding the supercritical carbon dioxide thickener 1,6-bis[1,3-bis(perfluorooctyl ethoxy) isopropyl-2-urea] hexane with a mass fraction of 0.5 wt %, 1.0 wt %, 1.5 wt %, 2.0 wt %, 2.5 wt %, 3.0 wt % in a high temperature and high pressure closed system assembled with supporting equipment, respectively; injecting the corresponding supercritical carbon dioxide into the closed system through a sampling valve; rotating the rotor and adjusting a system pressure and a system temperature; stirring a mixture of the thickener 1,6-bis[1,3-bis(perfluorooctyl ethoxy) isopropyl-2-urea]hexane and the corresponding supercritical carbon dioxide thoroughly to fully dissolve the supercritical carbon dioxide thickener; completing the mixing of two compounds and formatting the thickening supercritical carbon dioxide gel; setting a pressure at 28 MPa and a temperature at 60° C.; turning on a rheometer and maintaining a shear rate at 100 s.sup.−1 during the experiment; measuring the viscosity of the mixture, wherein the viscosities are 2.35 mPa.Math.s 4.12 mPa.Math.s, 4.45 mPa.Math.s 4.73 mPa.Math.s, 5.01 mPa.Math.s and 5.24 mPa.Math.s, respectively, which are 58.8 times, 103.0 times, 111.3 times 118.5 times, 125.3 times and 131.0 times of the supercritical carbon dioxide without the thickener, respectively; evaluating the damage of the thickening supercritical carbon dioxide gel to the permeability of the tight matrix core and fracturing core by core flooding experiment, wherein the permeability damage rate of the tight matrix core and the fracturing core is 2.47% and 1.27%, respectively.

Embodiment 2

(6) (1) Preparing the P-toluene perfluoropentyl ethylene sulfonate, which further comprises following sub-steps: adding a perfluoropentyl alcohol and a P-toluenesulfonyl chloride in a three-neck flask, wherein a molar ratio of the perfluoropentyl ethanol and P-toluenesulfonyl chloride is 1:1.2; finally, adding a pyridine; wherein the system has reacted for 3 h under stirring thoroughly; maintaining a temperature at 0° C.; adding filter paper after a reaction process is over, carrying out ultrasonic dispersion for 3 h; removing unreacted residue P-toluenesulfonyl chloride; removing the filter paper; washing the system with 15% dilute hydrochloric acid for 4 times to remove the pyridine and collect a white solid; washing the solid with distilled water for 5 times; drying the solid by vacuum drying oven at 40° C. for 3 hours to prepare an intermediate product (I) P-toluene perfluoropentyl ethylidene sulfonate; and

(7) (2) Preparing intermediate product (II) 1,3-bis(perfluoropentyl ethoxy) isopropyl-2-tertbutyl carbamate, which further comprises the following sub-steps: adding a 1,3-dihydroxy-propane-2-tert-butyl carbamate and the intermediate product (I) P-toluene perfluoropentyl ethylidene sulfonate in a three-neck flask, wherein a molar ratio of the (1,3-dihydroxy-propane-2-tert-butyl carbamate and intermediate product (I) P-toluene perfluoropentyl ethylidene sulfonate is 2.2:1; then adding potassium carbonate and N,N-dimethylformamide; wherein the system has been reacted for 4 h under stirring thoroughly at 40° C.; washing the reaction liquid with distilled water for 4 times after a reaction process is over; then carrying out the vacuum drying to collect an intermediate product (II) 1,3-bis(perfluoropentyl ethoxy) isopropyl-2-tertbutyl carbamate; and

(8) (3) Preparing a final product (III) 1,6-bis[1,3-bis(perfluoropentyl ethoxy) isopropyl-2-urea]hexane, which further comprises the following sub-steps: adding a mixture of methylene chloride and trifluoroacetic acid in a three-neck flask; a volume ratio of the methylene chloride and the three trifluoroacetic acid is 2:1; adding the intermediate product (II) 1,3-bis(perfluoropentyl ethoxy) isopropyl-2-tertbutyl carbamate to the mixture; maintaining a temperature at 45° C.; reacting for 2 h; adding the methylene chloride and extracting for 3 times to form an organic layer; drying the organic layer with a Na.sub.2SO.sub.4; adding HMDI, wherein a molar ratio of HMDI and 1,3-bis(perfluoropentyl ethoxy) isopropyl-2-tertbutyl carbamate is 1:2.10, reacting under a temperature of 50° C. for 2 h, washing a crude product with a mixture of ethyl acetate and benzene for 4 times; filtering and carrying out vacuum drying to collect a final product (III) 1,6-bis[1,3-bis(perfluoropentyl ethoxy) isopropyl-2-urea] hexane; and

(9) adding the supercritical carbon dioxide thickener 1,6-bis[1,3-bis(perfluoropentyl ethoxy) isopropyl-2-urea] hexane with a mass fraction of 0.5 wt %, 1.0 wt %, 1.5 wt %, 2.0 wt %, 2.5 wt %, 3.0 wt % in a high temperature and high pressure closed system assembled with supporting equipment, respectively; injecting the corresponding supercritical carbon dioxide into the closed system through a sampling valve; rotating the rotor and adjusting a system pressure and a system temperature; stirring a mixture of the thickener 1,6-bis[1,3-bis(perfluoropentyl ethoxy) isopropyl-2-urea] hexane and the corresponding supercritical carbon dioxide thoroughly to fully dissolve the supercritical carbon dioxide thickener; completing the mixing of two compounds and formatting the thickening supercritical carbon dioxide gel; setting a pressure at 28 MPa and a temperature at 60° C.; turning on a rheometer and maintaining a shear rate at 100 s.sup.−1 during the experiment; measuring the viscosity of the mixture, wherein the viscosities are 1.87 mPa.Math.s 3.35 mPa.Math.s, 3.52 mPa.Math.s 3.76 mPa.Math.s, 3.98 mPa.Math.s and 4.13 mPa.Math.s, which are 46.8 times, 83.8 times, 88.0 times 94.0 times, 99.5 times and 103.3 times of the supercritical carbon dioxide without the thickener, respectively; evaluating the damage of the thickening supercritical carbon dioxide gel to the permeability of the tight matrix core and fracturing core by core flooding experiment, wherein the permeability damage rate of the tight matrix core and the fracturing core is 3.36% and 1.73%, respectively.

Embodiment 3

(10) (1) Preparing the P-toluene perfluoroheptyl ethylene sulfonate, which further comprises following sub-steps: adding a perfluoroheptyl alcohol and a P-toluenesulfonyl chloride in a three-neck flask, wherein a molar ratio of the perfluoroheptyl ethanol and P-toluenesulfonyl chloride is 1:1.15; finally, adding a pyridine; wherein the system has reacted for 3 h under stirring thoroughly; maintaining a temperature at 10° C.; adding filter paper after a reaction process is over; carrying out ultrasonic dispersion for 1 h; removing unreacted residue P-toluenesulfonyl chloride; removing the filter paper washing the system with 15% dilute hydrochloric acid for 5 times to remove the pyridine and collect a white solid; washing the solid with distilled water for 5 times; drying the solid by vacuum drying oven at 40° C. for 3 h to prepare an intermediate product (I) P-toluene perfluoroheptyl ethylidene sulfonate; and

(11) (2) Preparing intermediate product (II) 1,3-bis(perfluoroheptyl ethoxy) isopropyl-2-tertbutyl carbamate, which further comprises the following sub-steps: adding a 1,3-dihydroxy-propane-2-tert-butyl carbamate and the intermediate product (I) P-toluene perfluoroheptyl ethylidene sulfonate in a three-neck flask, wherein a molar ratio of the (1,3-dihydroxy-propane-2-tert-butyl carbamate and intermediate product (I) P-toluene perfluoroheptyl ethylidene sulfonate is 2.15:1; then adding potassium carbonate and N,N-dimethylformamide; wherein the system has been reacted for 4 h under stirring thoroughly at 40° C.; washing the reaction liquid with distilled water for 4 times after a reaction process is over; then carrying out the vacuum drying to collect an intermediate product (II) 1,3-bis(perfluoroheptyl ethoxy) isopropyl-2-tertbutyl carbamate; and

(12) (3) Preparing a final product (III) 1,6-bis[1,3-bis(perfluoroheptyl ethoxy) isopropyl-2-urea]hexane, which further comprises the following sub-steps: adding a mixture of methylene chloride and trifluoroacetic acid in a three-neck flask; a volume ratio of the methylene chloride and the three trifluoroacetic acid is 2:1; adding the intermediate product (II) 1,3-bis(perfluoroheptyl ethoxy) isopropyl-2-tertbutyl carbamate to the mixture; maintaining a temperature at 45° C.; reacting for 2 h; adding to the methylene chloride and extracting for 3 times to form an organic layer; drying the organic layer with a Na.sub.2SO.sub.4; adding HMDI wherein a molar ratio of HMDI and 1,3-bis(perfluoroheptyl ethoxy) isopropyl-2-tertbutyl carbamate is 1:2.10, reacting under a temperature of 50° C. for 2 h, washing a crude product with a mixture of ethyl acetate and benzene for 5 times; filtering and carrying out vacuum drying to collect a final product (III) 1,6-bis[1,3-bis(perfluoroheptyl ethoxy) isopropyl-2-urea]hexane; and

(13) adding the supercritical carbon dioxide thickener 1,6-bis[1,3-bis(perfluoroheptyl ethoxy) isopropyl-2-urea]hexane with a mass fraction of 0.5 wt %, 1.0 wt %, 1.5 wt %, 2.0 wt %, 2.5 wt %, 3.0 wt % in a high temperature and high pressure closed system assembled with supporting equipment, respectively; injecting the corresponding supercritical carbon dioxide into the closed system through a sampling valve; rotating the rotor and adjusting a system pressure and a system temperature; stirring a mixture of the thickener 1,6-bis[1,3-bis(perfluoroheptyl ethoxy) isopropyl-2-urea]hexane and the corresponding supercritical carbon dioxide thoroughly to fully dissolve the supercritical carbon dioxide thickener; completing the mixing of two compounds and formatting the thickening supercritical carbon dioxide gel; setting a pressure at 28 MPa and a temperature at 60° C.; turning on a rheometer and maintaining a shear rate at 100 s.sup.−1 during the experiment; measuring the viscosity of the mixture, wherein the viscosities are 1.99 mPa.Math.s 3.46 mPa.Math.s, 3.63 mPa.Math.s 3.84 mPa.Math.s, 4.12 mPa.Math.s and 4.48 mPa.Math.s, which are 49.8 times, 86.5 times, 90.8 times, 96.0 times, 103.0 times and 112.0 times of the supercritical carbon dioxide without the thickener, respectively evaluating the damage of the thickening supercritical carbon dioxide gel to the permeability of the tight matrix core and fracturing core by core flooding experiment, wherein the permeability damage rate of the tight matrix core and the fracturing core is 3.67% and 1.58%, respectively.

Embodiment 4

(14) (1) Preparing the P-toluene perfluorohexyl ethylene sulfonate, which further comprises following sub-steps: adding perfluorohexyl alcohol and a P-toluenesulfonyl chloride in a three-neck flask, wherein a molar ratio of the perfluorohexyl ethanol and P-toluenesulfonyl chloride is 1:1.12; finally, adding a pyridine; wherein the system has reacted for 3 h under stirring thoroughly; maintaining a temperature at 10° C.; adding filter paper after a reaction process is over; carrying out ultrasonic dispersion for 1 hour; removing unreacted residue P-toluenesulfonyl chloride; removing the filter paper; washing the system with 15% dilute hydrochloric acid for 5 times to remove the pyridine and collect a white solid; washing the solid with distilled water for five times; drying the solid by vacuum drying oven at 40° C. for 3 h to prepare an intermediate product (I) P-toluene perfluorohexyl ethylidene sulfonate; and

(15) (2) Preparing intermediate product (II) 1,3-bis(perfluorohexyl ethoxy) isopropyl-2-tertbutyl carbamate, which further comprises the following sub-steps: adding a 1,3-dihydroxy-propane-2-tert-butyl carbamate and the intermediate product (I) P-toluene perfluorohexyl ethylidene sulfonate in a three-neck flask, wherein a molar ratio of the (1,3-dihydroxy-propane-2-tert-butyl carbamate and intermediate product (I) P-toluene perfluorohexyl ethylidene sulfonate is 2.10:1; then adding potassium carbonate and N,N-dimethylformamide; wherein the system has been reacted for 4 h under stirring thoroughly at 40° C.; washing the reaction liquid with distilled water for 4 times after a reaction process is over; then carrying out the vacuum drying to collect an intermediate product (II) 1,3-bis(perfluorohexyl ethoxy) isopropyl-2-tertbutyl carbamate; and

(16) (3) Preparing a final product (III) 1,6-bis[1,3-bis(perfluorohexyl ethoxy) isopropyl-2-urea]hexane, which further comprises the following sub-steps: adding a mixture of methylene chloride and trifluoroacetic acid in a three-neck flask; a volume ratio of the methylene chloride and the three trifluoroacetic acid is 2:1; adding the intermediate product (II) 1,3-bis(perfluorohexyl ethoxy) isopropyl-2-tertbutyl carbamate to the mixture; maintaining a temperature at 45° C.; reacting for 2 h; adding the methylene chloride and extracting for 3 times to form an organic layer drying the organic layer with a Na.sub.2SO.sub.4; adding HMDI, wherein a molar ratio of HMDI and 1,3-bis(perfluorohexyl ethoxy) isopropyl-2-tertbutyl carbamate is 1:2.05, reacting under a temperature of 50° C. for 2 h, washing a crude product with a mixture of ethyl acetate and benzene for 5 times; filtering and carrying out vacuum drying to collect a final product (III) 1,6-bis[1,3-bis(perfluorohexyl ethoxy) isopropyl-2-urea] hexane; and

(17) adding the supercritical carbon dioxide thickener 1,6-bis[1,3-bis(perfluorohexyl ethoxy) isopropyl-2-urea]hexane with a mass fraction of 0.5 wt %, 1.0 wt %, 1.5 wt %, 2.0 wt %, 2.5 wt %, 3.0 wt % in a high temperature and high pressure closed system assembled with supporting equipment, respectively; injecting the corresponding supercritical carbon dioxide into the closed system through a sampling valve; rotating the rotor and adjusting a system pressure and a system temperature; stirring a mixture of the thickener 1,6-bis[1,3-bis(perfluorohexyl ethoxy) isopropyl-2-urea]hexane and the corresponding supercritical carbon dioxide thoroughly to fully dissolve the supercritical carbon dioxide thickener; completing the mixing of two compounds and formatting the thickening supercritical carbon dioxide gel; setting a pressure at 28 MPa and a temperature at 60° C.; turning on a rheometer and maintaining a shear rate at 100 s.sup.−1 during the experiment; measuring the viscosity of the mixture, wherein the viscosities are 1.90 mPa.Math.s 3.42 mPa.Math.s, 3.56 mPa.Math.s 3.79 mPa.Math.s, 4.06 mPa.Math.s and 4.33 mPa.Math.s, which are 47.5 times, 85.5 times, 89.0 times, 94.8 times, 101.5 times and 108.3 times of the supercritical carbon dioxide without the thickener, respectively; evaluating the damage of the thickening supercritical carbon dioxide gel to the permeability of the tight matrix core and fracturing core by core flooding experiment, wherein the permeability damage rate of the tight matrix core and the fracturing core is 3.85% and 1.36%, respectively.

Embodiment 5

(18) (1) Preparing the P-toluene perfluorodecyl ethylene sulfonate, which further comprises following sub-steps: adding a perfluorodecyl alcohol and a P-toluenesulfonyl chloride in a three-neck flask, wherein a molar ratio of the perfluorodecyl ethanol and P-toluenesulfonyl chloride is 1:1.12; finally, adding a pyridine; wherein the system has reacted for 3 h under stirring thoroughly; maintaining a temperature at 10° C.; adding filter paper after a reaction process is over, carrying out ultrasonic dispersion for 1 h; removing unreacted residue P-toluenesulfonyl chloride; removing the filter paper; washing the system with 15% dilute hydrochloric acid for 5 times to remove the pyridine and collect a white solid; washing the solid with distilled water for 5 times; drying the solid by vacuum drying oven at 40° C. for 3 h to prepare an intermediate product (I) P-toluene perfluorodecyl ethylidene sulfonate; and

(19) (2) Preparing intermediate product (II) 1,3-bis(perfluorodecyl ethoxy) isopropyl-2-tertbutyl carbamate, which further comprises the following sub-steps: adding a 1,3-dihydroxy-propane-2-tert-butyl carbamate and the intermediate product (I) P-toluene perfluorodecyl ethylidene sulfonate in a three-neck flask, wherein a molar ratio of the (1,3-dihydroxy-propane-2-tert-butyl carbamate and intermediate product (1) P-toluene perfluorodecyl ethylidene sulfonate is 2.10:1; then adding potassium carbonate and N,N-dimethylformamide; wherein the system has been reacted for 4 h under stirring thoroughly at 40° C.; washing the reaction liquid with distilled water for 4 times after a reaction process is over; then carrying out the vacuum drying to collect an intermediate product (II) 1,3-bis(perfluorodecyl ethoxy) isopropyl-2-tertbutyl carbamate; and

(20) (3) Preparing a final product (III) 1,6-bis[1,3-bis(perfluorodecyl ethoxy) isopropyl-2-urea] hexane, which further comprises the following sub-steps: adding a mixture of methylene chloride and trifluoroacetic acid in a three-neck flask; a volume ratio of the methylene chloride and the three trifluoroacetic acid is 2:1; adding the intermediate product (II) 1,3-bis(perfluorodecyl ethoxy) isopropyl-2-tertbutyl carbamate to the mixture; maintaining a temperature at 45° C.; reacting for 2 h; adding the methylene chloride and extracting for 3 times to form an organic layer, drying the organic layer with a Na.sub.2SO.sub.4; adding HMDI, wherein a molar ratio of HMDI and 1,3-bis(perfluorodecyl ethoxy) isopropyl-2-tertbutyl carbamate is 1:2.05, reacting under a temperature of 50° C. for 2 h, washing a crude product with a mixture of ethyl acetate and benzene for 5 times; filtering and carrying out vacuum drying to collect a final product (III) 1,6-bis[1,3-bis(perfluorodecyl ethoxy) isopropyl-2-urea] hexane; and

(21) adding the supercritical carbon dioxide thickener 1,6-bis[1,3-bis(perfluorodecyl ethoxy) isopropyl-2-urea] hexane with a mass fraction of 0.5 wt %, 1.0 wt %, 1.5 wt %, 2.0 wt %, 2.5 wt %, 3.0 wt % in a high temperature and high pressure closed system assembled with supporting equipment, respectively; injecting the corresponding supercritical carbon dioxide into the closed system through a sampling valve; rotating the rotor and adjusting a system pressure and a system temperature; stirring a mixture of the thickener 1,6-bis[1,3-bis(perfluorodecyl ethoxy) isopropyl-2-urea]hexane and the corresponding supercritical carbon dioxide thoroughly to fully dissolve the supercritical carbon dioxide thickener; completing the mixing of two compounds and formatting the thickening supercritical carbon dioxide gel; setting a pressure at 28 MPa and a temperature at 60° C.; turning on a rheometer and maintaining a shear rate at 100 s.sup.−1 during the experiment; measuring the viscosity of the mixture, wherein the viscosities are 1.55 mPa.Math.s 2.76 mPa.Math.s, 3.22 mPa.Math.s 3.43 mPa.Math.s, 3.61 mPa.Math.s and 3.78 mPa.Math.s, which are 38.8 times, 69.0 times, 80.5 times, 85.8 times, 90.3 times and 94.5 times of the supercritical carbon dioxide without the thickener, respectively; evaluating the damage of the thickening supercritical carbon dioxide gel to the permeability of the tight matrix core and fracturing core by core flooding experiment, wherein the permeability damage rate of the tight matrix core and the fracturing core is 2.23% and 1.45%, respectively.