Method and device for building underground storehouse by dissolving limestone with carbon dioxide

Patent metadata

Field	Value
Publication number	US-9850756-B2
Application number	US-201214351138-A
Country	US
Kind code	B2
Filing date	Apr 26, 2012
Priority date	May 6, 2011
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A method for building an underground storehouse by dissolving limestone with carbon dioxide, the method comprising the following steps: a.) drilling two wells extending from the ground surface ( 1 ) to a limestone layer ( 2 ), building a channel ( 5 ) allowing the two wells to communicate, and installing casing pipes ( 3, 4 ) respectively in the two wells; b.) introducing CO 2 gas having at least 1 MPa of pressure into a CO 2 absorbing solution having the same pressure to form a CO 2 solution, flowing the CO 2 solution into underground via the casing pipe ( 3 ) to react with the limestone to form a calcium bicarbonate solution, forming a cavern in the meanwhile, and discharging the calcium bicarbonate solution via the other casing pipe ( 4 ); c.) decompressing the discharged calcium bicarbonate solution to decompose the calcium bicarbonate contained in the solution into CO 2 , water and calcium carbonate, and recycling the separated CO 2 absorption solution and the CO 2 ; repeating steps b.) and c.) until a cavern meeting design requirements is formed, and discharging the solution from the cavern to form the underground storehouse ( 6 ). Also disclosed is a device for building an underground storehouse by dissolving limestone with carbon dioxide, the device comprising a CO 2 storage tank ( 7 ), an absorption tower ( 8 ), a crystallizer ( 11 ), a pressure relief valve ( 9 ), a gas-liquid separator ( 10 ), a vacuum pump ( 13 ), a buffer ( 14 ) and booster pumps ( 12, 15, 16 ).

First claim

The invention claimed is:

1. A method for construction of an underground reservoir, the method comprising the steps of:
a) drilling a first well and a second well extending from a ground surface to a limestone layer, disposing at least one channel in the limestone layer to connect the first well and the second well, and inserting a first sleeve and a second sleeve in the first well and the second well, respectively;
b) introducing carbon dioxide having a gas pressure of at least 1 MPa from a carbon dioxide storage tank into a first carbon dioxide absorption solution in an absorption tower to yield a carbon dioxide solution, injecting the carbon dioxide solution into the first sleeve and allowing the carbon dioxide solution to flow to the limestone layer through the first sleeve and react with limestone to yield a solution of calcium bicarbonate, thereby forming a cavern with the solution of calcium bicarbonate being contained in the cavern, and discharging the solution of calcium bicarbonate out of the second sleeve;
c) collecting the solution of calcium bicarbonate; decompressing the solution of calcium bicarbonate; decomposing calcium bicarbonate in the solution of calcium bicarbonate to carbon dioxide, water, calcium carbonate, and a second carbon dioxide absorption solution; separating carbon dioxide from the second carbon dioxide absorption solution by using a vacuum pump; crystallizing, precipitating, and discharging calcium carbonate by using a crystallizer; then transporting the second carbon dioxide absorption solution to the absorption tower; transporting carbon dioxide to the carbon dioxide storage tank; and storing calcium carbonate; and
d) repeating steps b) and c) until the cavern reaches a desired size, discharging solutions from the cavern to yield the underground reservoir.

2. The method of claim 1 , wherein the gas pressure of the carbon dioxide introduced from the carbon dioxide storage tank is between 1 and 15 MPa.

3. The method of claim 2 , wherein the gas pressure of the carbon dioxide introduced from the carbon dioxide storage tank is between 2 and 6 MPa.

4. The method of any one of claims 1 - 3 , wherein the first carbon dioxide absorption solution is selected from the group consisting of water, between 0.001 and 10 mol/L of sodium chloride solution, between 0.001 and 5 mol/L of sodium oxalate solution, between 0.001 and 5 mol/L of sodium acetate solution, or a mixture thereof.

5. The method of any one of claims 1 - 3 , wherein the solution of calcium bicarbonate is decompressed at a temperature of between 20 and 80° C. to have a pressure of between 5×10 5 Pa and 1×10 2 Pa.

6. The method of claim 5 , wherein the solution of calcium bicarbonate is decompressed at a temperature of between 20 and 80° C. to have a pressure of between 1.01×10 5 Pa and 1×10 3 Pa.

Assignees

• Xie Heping
• Wang Yufei
• Liu Jianfeng
• Xie Lingzhi
• Zhang Ru
• Univ Sichuan

Inventors

• Xie Heping
• Wang Yufei
• Liu Jianfeng
• Xie Lingzhi
• Zhang Ru

Classifications

• C09K8/38

  Gaseous or foamed well-drilling compositions · CPC title

• E21B43/28 Primary

  Dissolving minerals other than hydrocarbons, e.g. by an alkaline or acid leaching agent (E21B43/241 takes precedence) · CPC title

• B65G5/00

  Storing fluids in natural or artificial cavities or chambers in the earth · CPC title

• E21D13/00 Primary

  Large underground chambers; Methods or apparatus for making them (lining E21D11/00) · CPC title

• E21B43/40

  Separation associated with re-injection of separated materials {(E21B43/385 takes precedence)} · CPC title