US 12,410,357 B2
Use of percitric acid in oil- and gas-field operations
Taryn Forster, Okotoks (CA); David Rauser, Calgary (CA); and Douglas Bruce, Calgary (CA)
Assigned to Secure Specialty Chemicals Corp., Calgary (CA)
Appl. No. 18/578,654
Filed by Secure Specialty Chemicals Corp., Calgary (CA)
PCT Filed Jul. 11, 2022, PCT No. PCT/CA2022/051079
§ 371(c)(1), (2) Date Jan. 11, 2024,
PCT Pub. No. WO2023/283727, PCT Pub. Date Jan. 19, 2023.
Claims priority of provisional application 63/220,738, filed on Jul. 12, 2021.
Prior Publication US 2024/0254381 A1, Aug. 1, 2024
Int. Cl. E21B 37/06 (2006.01); C09K 8/528 (2006.01)
CPC C09K 8/528 (2013.01) [E21B 37/06 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for degrading a polymer from a subterranean formation in fluid communication with a wellbore, wherein the method comprises:
contacting citric acid and hydrogen peroxide to form a composition comprising percitric acid, wherein contacting citric acid and hydrogen peroxide to form a composition comprising percitric acid further comprises contacting citric acid and hydrogen peroxide and a base to form a composition comprising a conjugate base of percitric acid;
adding one or more chemical additives to the composition to define a treatment fluid, wherein the percitric acid is present in an amount from about 0.001 wt. % to about 70 wt. %, based on the total weight of the treatment fluid, wherein the treatment fluid is substantially free of peracetic acid and performic acid;
injecting the treatment fluid into the wellbore; and
contacting the polymer with the treatment fluid for an effective amount time to degrade the polymer.