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US 11,692,128 B2Granted
Diversion acid containing a water-soluble retarding agent and methods of making and using
AssigneeSchlumberget Technology Corporation
InventorsAndrey Yakovlev, Xuehao Tan, Christopher Daeffler, Mohan Kanaka Raju Panga
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Abstract
Described herein are aqueous composition(s) containing water; a viscoelastic surfactant; an acid; and a water-soluble acid retarding agent. Further described are methods of making and using such compositions.
Claims17
An aqueous composition, comprising:
- water;
- a viscoelastic diverting acid comprising hydrochloric acid (HCl) and a zwitterionic viscoelastic surfactant (VES);
- a non-surface active, substituted ammonium containing amino acid derivative corrosion inhibitor;
- and
- a water-soluble acid retarding agent comprising at least one salt compound and urea or a urea derivative,
- wherein the retarding agent is present in the aqueous composition in an amount between about 1 and about 40 weight percent based on a total weight of the aqueous composition,
- wherein the zwitterionic viscoelastic surfactant has a structure in accordance with Formula III:
- in which R1 is a hydrocarbyl group that may be branched or straight chained, aromatic, aliphatic or olefinic and contains from about 17 to about 26 carbon atoms and may include an amine;
- R2 is hydrogen or alkyl group having from 1 to about 4 carbon atoms;
- R3 is a hydrocarbyl group having from 1 to about 5 carbon atoms;
- and
- Y is an electron withdrawing group.
9 more elements
A method, comprising:
- dissolving a water-soluble acid retarding agent comprising at least one salt compound and urea or a urea derivative in an amount between about 1 weight percent and about 40 weight percent in water to form a mixture;
- concurrently, or subsequently, adding to the mixture a viscoelastic diverting acid comprising hydrochloric acid (HCl) and a zwitterionic viscoelastic surfactant (VES) to form an aqueous composition;
- and
- treating a formation traversed by a wellbore with the aqueous composition,
- wherein the zwitterionic viscoelastic surfactant has a structure in accordance with Formula III:
- in which R1 is a hydrocarbyl group that may be branched or straight chained, aromatic, aliphatic or olefinic and contains from about 17 to about 26 carbon atoms and may include an amine;
- R2 is hydrogen or alkyl group having from 1 to about 4 carbon atoms;
- R3 is a hydrocarbyl group having from 1 to about 5 carbon atoms;
- and
- Y is an electron withdrawing group.
7 more elements
Dependencies are inferred from the claim text.