Composite temperature resistance gel plugging agent, preparation method thereof and use thereof in profile control and water plugging of ultra-deepth reservoir

1. A composite temperature resistance gel plugging agent having a structure shown in formula (1);

wherein R 8 , R 9 and R 10 are derived from vinyl or propenyl;

wherein n is an integer of 56000-150000.

2. The composite temperature resistance gel plugging agent of claim 1 , wherein R 8 , R 9 and R 10 are derived from vinyl;

wherein n is an integer of 70000-120000.

3. A method for preparing a composite temperature resistance gel plugging agent, including:

(F1) dissolving modified nano graphite and polyacrylamide composite material in dispensing water to obtain a composite polymer solution;

(F2) contacting the composite polymer solution with phenolic crosslinking agent and aldehyde crosslinking agent, and standing to obtain a composite temperature resistance gel plugging agent;

wherein the modified nano graphite and polyacrylamide composite material has a structure shown in a formula (2);

wherein R 8 , R 9 and R 10 are derived from vinyl or propenyl;

wherein n is an integer of 56000-150000;

wherein the phenolic crosslinking agent is hydroquinone and/or resorcinol; the aldehyde crosslinking agent is urotropin and/or formaldehyde.

4. The method of claim 3 , wherein R 8 , R 9 , and R 10 are derived from vinyl; wherein n is an integer of 70000-120000.

5. The method of claim 3 , wherein the weight average molecular weight of the modified nano graphite and polyacrylamide composite material is 400-1000×10 4 .

6. The method of claim 3 , wherein the degree of mineralization of the dispensing water is 10-30×10 4 mg/L.

7. The method of claim 3 , wherein based on 100 parts by weight of the dispensing water, the modified nano graphite and polyacrylamide composite material is 0.3 to 0.6 parts by weight, the phenolic crosslinking agent is 0.1 to 0.5 parts by weight, and the aldehyde crosslinking agent is 0.2 to 0.6 parts by weight.

8. The method of claim 3 , wherein

in step (F1), the dissolving comprises conditions of dissolution including a temperature of 15-25° C., and a time of 120-240 min; and

in the step (F2), the contacting comprises conditions including a temperature of 20-40° C., and a time of 10-90 min, and the standing comprises conditions including a temperature of 80-200° C., and a time of 6-72 h.

9. The method of claim 3 , wherein the method for preparing the modified nano graphite and polyacrylamide composite material including: in a redox initiation system, contacting the modified nano graphite with the structure shown in the formula (3) with acrylamide monomer to perform polymerization reaction to obtain a modified nano graphite and polyacrylamide composite material shown in the formula (2)

wherein R 1 , R 2 and R 3 are vinyl or propenyl;

wherein R 8 , R 9 and R 10 are derived from vinyl or propenyl;

wherein is an integer of 1200-3200, and n is an integer of 2400-6400;

wherein the weight average molecular weight of the composite material is 400-1000×10 4 .

10. The method of claim 9 , wherein R 1 , R 2 and R 3 are vinyl.

11. The method of claim 10 , wherein the redox initiation system comprises reducing agent and oxidizing agent, wherein the reducing agent is one or more selected from the group consisting of sodium bisulfite, sodium sulfite and ferrous ions; the oxidizing agent is one or more selected from the group consisting of ammonium persulfate, potassium persulfate and sodium persulfate.

12. The method of claim 11 , wherein based on 100 parts by weight of deionized water, the reducing agent is 0.05 to 0.3 parts by weight, the oxidizing agent is 0.05 to 0.3 parts by weight, the modified nano graphite with the structure shown in the formula (3) is 0.01 to 0.05 parts by weight, and the acrylamide monomer is 20 to 30 parts by weight.

13. The method of claim 9 , wherein the polymerization reaction conditions comprise a temperature of 30-40° C. and a time of 2-5 h.

14. The method of claim 9 , wherein the modified nano graphite having the structure represented by formula (3) is prepared by a method comprising:

(a) dispersing a monomer shown in a formula (4) in deionized water to obtain dispersion liquid;

(b) contacting the dispersion liquid with monomer shown in a formula (5) to obtain modified nano graphite solution;

(c) washing and drying the modified nano graphite solution to obtain a drying products, then grinding and dispersing the drying products to obtain modified nano graphite;

wherein R 4 is vinyl or propenyl, respectivly;

wherein R 5 , R 6 and R 7 are methoxy, ethoxy or β-methoxyethoxy, respectivly.

15. The method of claim 14 , wherein R 4 is vinyl.

16. The method of claim 14 , wherein the monomer shown in the formula (5) is one or more selected from the group consisting of vinyl triethoxysilane, vinyl trimethoxysilane or vinyl tris (β-methoxyethoxy) silane.

17. The method of claim 14 , wherein the weight ratio of the monomer shown in the formula (4), the monomer shown in the formula (5) and the deionized water is (1-2.5):(0.1-0.25):100.

18. The method of claim 14 , wherein

in step (a), the dispersing is ultrasonic dispersion and comprises conditions including stirring at 400-800 rpm, ultrasonic power of 300-800 W, a temperature of 15-25° C., and a time of 1-6 h;

in step (b), the contacting comprises conditions including stirring at a speed of 400-800 rpm, a temperature of 60-80° C., and a time of 6-8 h;

in step (c), the washing comprises washing with a mixed solution of deionized water and ethanol, and the drying comprises conditions including a temperature of 35-50° C.

19. The method of claim 14 , wherein the volume ratio of the deionized water to the ethanol in the mixed solution is 1:(1-1.5).

20. A method of using a composite temperature resistance gel plugging agent in profile control and water shutoff of ultra-deep reservoirs,

wherein the method comprises placing the composite temperature resistance gel plugging agent of claim 1 into an ultra-deep reservoir.