REAGENT FOR EXPLOITING NATURAL GAS HYDRATES AND APPLICATION METHOD THEREOF

Abstract

The present invention relates to a reagent for exploiting natural gas hydrates, which includes a regent A and a regent B. The reagent A is PEG400-polyurethane prepolymer; the reagent B includes PEG400 and an initiator; and a volume ratio of the PEG400-polyurethane prepolymer, the PEG400 and the initiator is (1-3000):(1-1000):(1-2000). The reagent of the present invention has excellent performance and high stability, and can effectively “replace” the “water” of the natural gas hydrate; and moreover, the reaction is exothermic reaction to effectively increase the reaction rate, which reduces the energy loss on the one hand, and reduces the blockage of a gas passage caused by the secondary generation of the natural gas hydrates in a low-temperature high-pressure pipeline during transferring on the other hand.

Claims

1. A reagent for exploiting natural gas hydrates, comprising a reagent A and a reagent B, wherein the reagent A is PEG400-polyurethane prepolymer; the reagent B comprises PEG400 and an initiator; a volume ratio of the PEG400-polyurethane prepolymer, the PEG400 and the initiator is (1-3000):(1-1000):(1-2000); a preparation method of the PEG400-polyurethane prepolymer comprises: mixing PEG400 and cyclohexanone which are separately dehydrated; stirring in an inert protective atmosphere under an acid condition; dropwise adding diphenyl methane diisocyanate; after the dropwise addition, increasing the temperature to 4012-7012, and carrying out a reaction for 2-4 hours to obtain the PEG400-polyurethane prepolymer, wherein a mass ratio of PEG400, cyclohexanone and diphenyl methane diisocyanate is (1-880):(1-1300):(1-1600); the initiator comprises components by mass percentage: water: 50-55 wt % triethanolamine: 5-10 wt % triethylene diamine: 5-10 wt % 1, 4-butanediol: 20-30 wt % and methanol: 5-15 wt %.

2. The reagent for exploiting the natural gas hydrates according to claim 1, wherein the volume ratio of the PEG400-polyurethane prepolymer, the PEG400 in the reagent B and the initiator is (1-800):(1-400):(1-600).

3. The reagent for exploiting the natural gas hydrates according to claim 2, wherein the volume ratio of the PEG400-polyurethane prepolymer, the PEG400 in the reagent B and the initiator is (1-60):(1-20):(1-40).

4. The reagent for exploiting the natural gas hydrates according to claim 3, wherein the volume ratio of the PEG400-polyurethane prepolymer, the PEG400 in the reagent B and the initiator is (1-5):(1-2):(1-4).

5. The reagent for exploiting the natural gas hydrates according to claim 1, wherein the mass ratio of the PEG400, the cyclohexanone and the diphenyl methane diisocyanate is (1-70):(1-120):(1-160).

6. The reagent for exploiting the natural gas hydrates according to claim 5, wherein the mass ratio of the PEG400, the cyclohexanone and the diphenyl methane diisocyanate is (1-4):(2-7):(1-10).

7. An application method of the reagent for exploiting the natural gas hydrates according to claim 1, comprising: injecting a reagent A into a tube A; injecting a reagent B into a tube B; stretching the tube A and the tube B into a hydrate reservoir by using a reagent injection instrument; regulating a flow rate according to a proportion of each component; allowing the reagent to react at a preset reservoir position; and allowing water in the reservoir to participate in the reaction at the same time, wherein a reaction product is used for supporting the reservoir.

Description

DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 is a sectional view of a product obtained after foaming and cross-linking in embodiment 1; and

[0030] FIG. 2 is a sectional view of a product obtained after foaming and cross-linking under sediment conditions.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0031] The present invention is further described in detail below through specific embodiments. The following embodiments are only descriptive rather than limiting, and shall not be used to limit the protection scope of the present invention.

Embodiment 1

[0032] A reagent for exploiting natural gas hydrates is composed of PEG400-polyurethane prepolymer, PEG400 and an initiator, and a volume ratio of the components is 3:2:2.

[0033] A preparation method of the PEG400-polyurethane prepolymer includes the following steps:

[0034] S1, 20 g of polyethylene glycol 400 (PEG400) is dehydrated;

[0035] S2, 50 g of cyclohexanone is dehydrated for 24 hours;

[0036] S3, the dehydrated PEG400 and cyclohexanone are mixed, and stirred in an inert protective atmosphere under an acid condition (pH is regulated to 2-6 with phosphoric acid); 45 g of diphenyl methane diisocyanate is dropwise added; and after the dropwise addition, the temperature increases to 60° C., and the reaction is carried out for 2 hours to obtain the PEG400-polyurethane prepolymer.

[0037] A preparation method of the initiator: 10 g (52.63 wt %) of water, 1 g (5.26 wt %) of triethanolamine, 1 g (5.26 wt %) of triethylene diamine, 5 g (26.32 wt %) of 1, 4-butanediol and 2 g (10.53 wt %) of methanol are mixed at room temperature to obtain the initiator.

[0038] The PEG400-polyurethane prepolymer prepared above is foamed and cross-linked with the PEG400 and the initiator at room temperature to obtain a product as shown in FIG. 1. An HPB-type digital pull and push dynamometer produced by Yueqing Handpi Instruments Co., Ltd, and a sample with a height of 2 cm are used; and the bearing pressure of the product is 107 N when being compressed by 25%, which proves that the product has excellent pressure resistance. As shown in FIG. 2, under a sediment condition, the reagent can still be foamed and polymerized normally and has a through-hole structure, which ensures the smooth escape of the natural gas.

Embodiment 2

[0039] Different from embodiment 1, the volume ratio of the PEG400-polyurethane prepolymer, the PEG400 and the initiator is 5:2:2.

Embodiment 3

[0040] Different from embodiment 1, the volume ratio of the PEG400-polyurethane prepolymer, the PEG400 and the initiator is 4:2:3.

Comparative Example 1

[0041] Different from embodiment 1, the volume ratio of the PEG400-polyurethane prepolymer, the PEG400 and the initiator is 1:1:1.

Comparative Example 2

[0042] Different from embodiment 1, the volume ratio of the PEG400-polyurethane prepolymer, the PEG400 and the initiator is 2:5:5.

TABLE-US-00001 TABLE 1 Volume ratio of components and material Comparative Comparative performance Embodiment 1 Embodiment 2 Embodiment 3 example 1 example 2 PEG400- 3 5 4 1 2 polyurethane prepolymer PEG400 2 2 2 1 5 Initiator 2 2 3 1 5 Bearing 107N 191N 166N 90N 0N pressure

[0043] It may be seen from data in Table 1 that when the volume ratio of the PEG400-polyurethane prepolymer, the PEG400 and the initiator is controlled in a range of (1-5):(1-2):(1-4), the bearing pressure is highest.

Embodiment 4

[0044] Different from embodiment 1, the mass percentage of the initiator is as follows: 50 wt % of water, 5 wt % of triethanolamine, 5 wt % of triethylene diamine, 30 wt % of 1, 4-butanediol and 10 wt % of methanol.

Embodiment 5

[0045] Different from embodiment 1, the mass percentage of the initiator is as follows: 50 wt % of water, 5 wt % of triethanolamine, 5 wt % of triethylene diamine, 25 wt % of 1, 4-butanediol and 15 wt % of methanol.

Embodiment 6

[0046] Different from embodiment 1, the mass percentage of the initiator is as follows: 55 wt % of water, 5 wt % of triethanolamine, 5 wt % of triethylene diamine, 25 wt % of 1, 4-butanediol and 10 wt % of methanol.

Comparative Example 3

[0047] Different from embodiment 1, the mass percentage of the initiator is as follows: 70 wt % of water, 5 wt % of triethanolamine, 5 wt % of triethylene diamine, 15 wt % of 1, 4-butanediol and 5 wt % of methanol.

Comparative Example 4

[0048] Different from embodiment 1, the mass percentage of the initiator is as follows: 59 wt % of water, 6 wt % of triethanolamine, 6 wt % of triethylene diamine and 29 wt % of 1, 4-butanediol.

TABLE-US-00002 TABLE 2 Content of initiator components and material Comparative Comparative performance Embodiment 4 Embodiment 5 Embodiment 6 example 3 example 4 Water 50% 50% 55% 70%  59% Triethanolamine  5%  5%  5% 5%  6% Triethylene  5%  5%  5% 5%  6% diamine 1,4- 30% 25% 25% 15%  29% butanediol Methanol 10% 15% 10% 5% 0 Bearing 104N 106N 107N 75N 69N pressure

[0049] It may be seen from data in Table 2 that when the content of the initiator components is in a preferred range, the bearing pressure is highest.

[0050] The above only describes preferred embodiments of the present invention. It should be pointed out that several transformations and improvements may be made by those ordinary skilled in the art without departing from the concept of the present invention, and these transformations and improvements shall fall into the protection scope of the present invention.