Patent ID: 9175207
Filing Date: 2015-11-03
Classification: C09K

Abstract:
1. A surfactant-less alkaline-polymer composition for treating a hydrocarbon-bearing formation, said composition comprising: (a) water selected from the group consisting of hard water and hard brine, wherein the water comprises divalent cations selected from the group consisting of Ca (b) a chelating agent, wherein the agent is operable for forming a soluble salt with the divalent cations when subjected to reservoir conditions of the hydrocarbon-bearing formation, and wherein the chelating agent is selected from the group consisting of ethylenediaminetetraacetic acid (EDTA), ethylenediamine tetracetic acid tetra sodium salt (EDTA Na (c) an alkaline agent, wherein (d) a non-ionic co-solvent, wherein (e) a polymer, wherein the water, the chelating agent, the alkaline agent, the co-solvent, and the polymer are mixed together in the composition, and wherein the surfactant-less alkaline-polymer composition does not include a surfactant other than the non-ionic co-solvent.