Mud acid composition and methods of using such
An inhibited mud acid composition, said composition comprising: hydrofluoric acid in solution; an alkanolamine; and a mineral acid selected from a group consisting of: HCl; MEA-HCl and other modified acids, wherein said alkanolamine and hydrofluoric acid are present in a molar ratio of at least 1:1.
1. A mud acid composition consisting of:
an inhibited hydrofluoric acid aqueous composition, said composition consisting of:
hydrofluoric acid in solution; and
an alkanolamine; and
an acid composition comprising an acid having a pKa value of less than 3;
wherein said alkanolamine and hydrofluoric acid are present in an alkanolamine to hydrofluoric acid molar ratio of at least 1:1.
2. The mud acid composition according to claim 1 , wherein the acid with a pKa of less than 3 is selected from the group consisting of: HCl; MEA-HCl; urea-HCl; methanesulfonic acid; sulfuric acid; sulfamic acid; and lysine-HCl.
3. The mud acid composition according to claim 1 , wherein the alkanolamine to hydrofluoric acid molar ratio of at least 1.1:1.
4. The mud acid composition according to claim 1 , wherein the alkanolamine is selected from the group consisting of: monoethanolamine; diethanolamine; triethanolamine and combinations thereof.
5. The mud acid composition according to claim 1 , wherein the alkanolamine is monoethanolamine.
6. The mud acid composition according to claim 1 , wherein the alkanolamine is diethanolamine.
7. The mud acid composition according to claim 1 , wherein the alkanolamine is triethanolamine.
8. The mud acid composition according to claim 1 , wherein the acid with a pKa of less than 3 is selected from the group consisting of: MEA-HCl; urea-HCl; and lysine-HCl.
9. The mud acid composition according to claim 1 , wherein the acid with a pKa of less than 3 is MEA-HCl having an MEA to HCl molar ratio ranging from 1:3 to 1:15.
10. The mud acid composition according to claim 9 , wherein the composition has 0.5% to 3% of free hydrofluoric acid by mass.