Thermally activated strong acids
An acid-generating fluid includes a thermally activated strong acid precursor. The thermally activated strong acid precursor can include a component selected from aldehydes, ketones, and combinations thereof, in combination with a precursor of a compound adapted to react to liberate sulfur dioxide; or it can include sulfur dioxide in combination with a precursor of a compound adapted to react to liberate a component selected from aldehydes, ketones, and combinations thereof.
1. A method comprising:
providing an acid-generating fluid that comprises water and a thermally activated strong acid precursor, the thermally activated strong acid precursor comprising:
sulfur dioxide, and
a precursor of a compound adapted to react to liberate a component selected from aldehydes, ketones, and combinations thereof;
placing the acid-generating fluid into a subterranean formation;
thermally activating the precursor, thereby liberating the component selected from aldehydes, ketones, and combinations thereof; and
reacting the sulfur dioxide and the component selected from aldehydes, ketones, and combinations thereof to form a thermally activated strong acid;
wherein the acid-generating fluid further comprises a dienophile.
2. The method of claim 1 , wherein the precursor is selected from the group consisting of: paraformaldehyde, polyoxymethylene, metaldehyde, trioxane, formaldehyde, acetaldehyde, and combinations thereof.
3. The method of claim 1 , wherein the dienophile and the thermally activated strong acid precursor are provided in a 1:1 molar ratio.
4. The method of claim 1 , wherein the acid-generating fluid further comprises a base.
5. The method of claim 4 , wherein the base is CaCO 3 .
6. The method of claim 1 , wherein the acid-generating fluid has a pH of greater than 4.
7. The method of claim 1 , wherein the acid-generating fluid is an emulsion.
8. The method of claim 1 , wherein the acid generating fluid is a component of a fluid loss control pill.
9. A method comprising:
providing an acid-generating fluid that comprises water and a thermally activated strong acid precursor, the thermally activated strong acid precursor comprising:
sulfur dioxide, and
a precursor of a compound adapted to react to liberate a component selected from aldehydes, ketones, and combinations thereof;
placing the acid-generating fluid into a subterranean formation;
thermally activating the precursor, thereby liberating the component selected from aldehydes, ketones, and combinations thereof; and
reacting the sulfur dioxide and the component selected from aldehydes, ketones, and combinations thereof to form a thermally activated strong acid;
wherein the acid-generating fluid is an emulsion.
10. The method of claim 9 , wherein the precursor is selected from the group consisting of: paraformaldehyde, polyoxymethylene, metaldehyde, trioxane, formaldehyde, acetaldehyde, and combinations thereof.
11. The method of claim 9 , wherein the acid-generating fluid further comprises a base.
12. The method of claim 11 , wherein the base is CaCO 3 .
13. The method of claim 9 , wherein the acid-generating fluid has a pH of greater than 4.
14. The method of claim 9 , wherein the acid generating fluid is a component of a fluid loss control pill.
15. A method comprising:
providing an acid-generating fluid that comprises water and a thermally activated strong acid precursor, the thermally activated strong acid precursor comprising:
sulfur dioxide, and
a precursor of a compound adapted to react to liberate a component selected from aldehydes, ketones, and combinations thereof;
placing the acid-generating fluid into a subterranean formation;
thermally activating the precursor, thereby liberating the component selected from aldehydes, ketones, and combinations thereof; and
reacting the sulfur dioxide and the component selected from aldehydes, ketones, and combinations thereof to form a thermally activated strong acid;
wherein the acid generating fluid is a component of a fluid loss control pill.
16. The method of claim 15 , wherein the precursor is selected from the group consisting of: paraformaldehyde, polyoxymethylene, metaldehyde, trioxane, formaldehyde, acetaldehyde, and combinations thereof.
17. The method of claim 15 , wherein the acid-generating fluid further comprises a base.
18. The method of claim 17 , wherein the base is CaCO 3 .
19. The method of claim 15 , wherein the acid-generating fluid has a pH of greater than 4.