Reagent for exploiting natural gas hydrates and application method thereof

Patent metadata

Field	Value
Publication number	US-11760923-B2
Application number	US-202218145133-A
Country	US
Kind code	B2
Filing date	Dec 22, 2022
Priority date	Jan 7, 2022
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

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.

First claim

We claim:

1. A composition 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 40° C.-70° C., 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 composition 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 composition 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 composition 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 composition 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 composition 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).

Assignees

• Univ Nankai
• Guangzhou Marine Geological Survey
• Institute Of Exploration Tech Chinese Academy Of Geological Sciences

Inventors

• Liu Xiaohang
• Guo annan
• Zhao Peng
• Li Xiaoyang
• Liang Jinqiang
• Huang Wei
• Zhang Yongqin

Classifications

• E21B43/01 Primary

  specially adapted for obtaining from underwater installations · CPC title

• C09K8/42 Primary

  Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells (compositions for plastering C09K8/50) · CPC title

• C09K8/80 Primary

  Compositions for reinforcing fractures, e.g. compositions of proppants used to keep the fractures open · CPC title

• E21B43/16

  Enhanced recovery methods for obtaining hydrocarbons · CPC title

• Y02P90/70

  Combining sequestration of CO2 and exploitation of hydrocarbons by injecting CO2 or carbonated water in oil wells · CPC title