Mud acid composition and methods of using such
AssigneeFluid Energy Group Ltd.
InventorsClay PURDY, Markus WEISSENBERGER, Karl W. DAWSON, Kyle G. WYNNYK
Life of this patent
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Abstract
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.
Claims19
A method of using a mud acid to acidize a sandstone formation, said method comprising the steps of:
- providing an inhibited hydrofluoric acid composition, comprising a pre-determined amount of hydrofluoric acid;
- and a pre-determined amount of an alkanolamine;
- wherein the molar ratio of alkanolamine:hydrofluoric acid is at least 1:1;
- providing an acid composition, said acid composition having a low pH and adapted to activate the inhibited hydrofluoric acid composition when put in contact therewith;
- combining the inhibited hydrofluoric acid composition with said acid composition to create a mud acid;
- applying said mud acid to a silicate-containing formation and allowing said mud acid composition sufficient exposure time to dissolve a pre-determined amount of silica.
A method for removing silica or silicate deposits, said method comprising the steps of:
- providing an inhibited hydrofluoric acid composition, comprising a pre-determined amount of hydrofluoric acid;
- and a pre-determined amount of an alkanolamine;
- wherein the molar ratio of alkanolamine:hydrofluoric acid is at least 1:1;
- providing an acid composition, said acid composition having a low pH and adapted to activate the inhibited hydrofluoric acid composition when put in contact therewith;
- combining the inhibited hydrofluoric acid composition with said acid composition to create a mud acid;
- and
- applying the mud acid to a silica or silicate deposit.
A method for removing silica or silicate deposits on a metal surface, said method comprising the steps of:
- providing an inhibited hydrofluoric acid composition, comprising a pre-determined amount of hydrofluoric acid;
- and a pre-determined amount of an alkanolamine;
- wherein the molar ratio of alkanolamine:hydrofluoric acid is at least 1:1;
- providing an acid composition, said acid composition comprising a corrosion inhibitor package and having a low pH and adapted to activate the inhibited hydrofluoric acid composition when put in contact therewith;
- combining the inhibited hydrofluoric acid composition with said acid composition to create a mud acid;
- and
- applying the mud acid to a silica or silicate deposit of a metal surface.
Dependencies are inferred from the claim text.