Environmentally friendly stimulation fluids, processes to create wormholes in carbonate reservoirs, and processes to remove wellbore damage in carbonate reservoirs
View Patent ↗The present invention includes processes to create wormholes in carbonate reservoirs by contacting a formation with a solution comprising glutamic acid N,N-diacetic acid (GLDA) and/or a salt thereof, methylglycine-N,N-diacetic acid (MGDA) and/or a salt thereof, or a combination thereof. The present invention also includes processes to remove wellbore damage in a carbonate reservoir by contacting a damaged zone of the carbonate reservoir with a solution comprising GLDA and/or a salt thereof, methylglycine-N,N-diacetic acid (MGDA) and/or a salt thereof, or a combination thereof. The present invention further includes solutions comprising a salt and further comprising GLDA and/or a salt thereof, methylglycine-N,N-diacetic acid (MGDA) and/or a salt thereof, or a combination thereof.
1. Process to create wormholes in a carbonate reservoir by contacting a formation with a solution comprising a wormhole-forming agent, said wormhole forming agent consisting of a chelating agent selected from the group consisting of glutamic acid N,N-diacetic acid (GLDA) and/or a salt thereof, methylglycine-N,N-diacetic acid (MGDA) and/or a salt thereof, or a combination thereof.
2. Process of claim 1 , wherein the solution is an aqueous solution of about 10 to about 30 wt % of GLDA and/or a salt thereof, MGDA and/or a salt thereof, or a combination thereof.
3. Process of claim 1 , wherein the solution further comprises a salt other than a salt of either GLDA or MGDA.
4. Process of claim 3 , wherein the salt other than a salt of either GLDA or MGDA comprises a chloride salt, a formate salt, a bromide salt, or a combination thereof.
5. Process of claim 1 , wherein the pH of the solution is about 3 to about 5.
6. Process of claim 1 , wherein the injection rate of the solution is about 0.25 to about 5 barrels/min.
7. Process to remove wellbore damage in a carbonate reservoir by contacting a damaged zone of the carbonate reservoir with a solution comprising a wormhole- forming agent, said wormhole forming agent consisting of a chelating agent selected from the group consisting of glutamic acid N,N-diacetic acid (GLDA) and/or a salt thereof, methylglycine-N,N-diacetic acid (MGDA) and/or a salt thereof, or a combination thereof.
8. Process of claim 7 , wherein the solution is an aqueous solution of about 10 to about 30 wt % of GLDA and/or a salt thereof, MGDA and/or a salt thereof, or a combination thereof.
9. Process of claim 7 , wherein the solution further comprises a salt other than a salt of either GLDA or MGDA.
10. Process of claim 9 , wherein the salt other than a salt of either GLDA or MGDA comprises a chloride salt, a formate salt, a bromide salt, or a combination thereof.
11. Process of claim 7 , wherein the pH of the solution is about 3 to about 5.
12. Process of claim 7 , wherein the injection rate of the solution is about 0.25 to about 5 barrels/min.
13. A solution consisting of a salt other than a salt of either GLDA or MGDA and glutamic acid N,N-diacetic acid (GLDA) and/or a salt thereof, methylglycine- N,N-diacetic acid (MGDA) and/or a salt thereof, or a combination thereof.
14. The solution of claim 13 , wherein the salt other than a salt of either GLDA or MGDA comprises a chloride salt, a formate salt, a bromide salt, or a combination thereof.
15. The solution of claim 13 , wherein the solution is an aqueous solution of a salt other than a salt of either GLDA or MGDA and about 10 to about 30 wt % of GLDA and/or a salt thereof, MGDA and/or a salt thereof, or a combination thereof.
16. The solution of claim 13 , wherein the pH of the solution is about 3 to about 5.
17. The process of claim 1 wherein said wormhole forming agent consists of said chelating agent.
18. The process of claim 7 wherein said wormhole forming agent consists of said chelating agent.
19. The process of claim 1 wherein said chelating agent is selected from the group consisting of GLDA, salts of GLDA, and combinations thereof.
20. The process of claim 7 wherein said chelating agent is selected from the group consisting of GLDA, salts of GLDA, and combinations thereof.