Foaming and silt suspending agent
AssigneeThe Dow Chemical Company
InventorJames L. Thompson
Life of this patent
Estimating the term…
Abstract
A foaming and silt suspending agent is disclosed containing at least one alkyltrimethylammonium chloride and an amine oxide selected from the group consisting of bis-(2-hydroxyethyl) cocoamine oxide, dimethylhexadecylamine oxide, and dimethyl-hydrogenated tallowamine oxide. The agent is particularly useful in a variety of aqueous based fluids of the type used in treating subterranean formations, including fluids containing other cationic additives such as certain acid inhibitors and clay stabilization agents which tend to impair the effectiveness of prior art agents.
Claims45
A composition suitable for imparting foaming and silt suspending properties to aqueous based fluids of the type suitable for use in treating subterranean formations, comprising a blend of:
- (a) at least one alkyltrimmethylammonium chloride, wherein the alkyl chain length is from 8 to 18 carbon atoms and the mode alkyl chain length is 12 or 14 carbon atoms, and
- (b) an amine oxide selected from the group consisting of bis(2-hydroxyethyl) cocoamine oxide, dimethylhexadecylamine oxide, and dimethyl-hydrogenated tallowamine oxide, wherein
- Component (a) and Component (b) are in a weight ratio to one another of
- (i) from about 45:55 to about 85:15 when Component (a) is cocotrimethyl ammonium chloride and Component (b) is bis(2-hydroxyethyl) cocoammine oxide, and
- (ii) from about 40:60 to about 95:5 when said Components (a) and (b) are selected so as to provide a combination other than cocotrimethyl ammonium chloride and bis(2-hydroxyethyl) cocoamine oxide.
A foam comprised of an aqueous based fluid, an inert gas, and a blend of
- (a) at least one alkyltrimethylammmonium chloride, wherein the alkyl chain length is from 8 to 18 carbon atoms and the mode alkyl chain length is 12 or 14 carbon atoms,
- (b) an amine oxide selected from the group consisting of bis(2-hydroxyetyl) cocoamine oxide, dimethylhexadecylamine oxide, and dimethyl-hydrogenated tallowamine oxide, said blend being present in an amount effective to impart foaming and silt suspending properties to said aqueous based fluid, wherein Components (a) and (b) are in a synergistic weight ratio to one another within the range of
- (i) from about 45:55 to about 85:15 when Component (a) is cocotrimethyl ammonium chloride and Component (b) is bis(2-hydroxyethyl) cocoamine oxide, and
- (ii) from about 40:60 to about 95:5 when said Components (a) and (b) are selected so as to provide a combination other than cocotrimethyl ammonium chloride and bis(2-hydroxyethyl) cocoamine oxide.
The foam of claim 25 wherein the aqueous based fluid is inhibited hydrochloric acid.
A method of acidizing or fracturing a subterranean formation penetrated by a borehole, comprising injecting into the formation via the borehole so that said formation is acidized or fractured, an aqueous based acidizing or fracturing fluid containing a foaming and silt suspending quantity of a blend of
- (a) at least one alkyltrimethylammonium chloride, wherein the alkyl chain length is from 8 to 18 carbon atoms and the mode alkyl chain length is 12 or 14 carbon atoms, and
- (b) an amine oxide selected from the group consisting of bis(2-hydroxyethyl) cocoamine oxide, dimethylhexadecylamine oxide, and dimethyl-hydrogenated tallowamine oxide, wherein Components (a) and (b) are in a synergistic weight ratio to one another of
- (i) from about 45:55 to about 85:15 when Component (a) is cocotrimethyl ammonium chloride and Component (b) is bis(2-hydroxyethyl) cocoammine oxide, and
- (ii) from about 40:60 to about 95:5 when said Components (a) and (b) are selected so as to provide a combination other than cocotrimethyl ammonium chloride and bis(2-hydroxyethyl) cocoamine oxide,
- said fluid being admixed with an inert gas to form a foam.
Dependencies are inferred from the claim text.