Abstract: A method for recovery of oil housed in a reservoir comprising injecting an aqueous solution or slurry of a carbonate salt into a wellbore and allowing the aqueous solution or slurry of the carbonate salt to enter into the reservoir. An aqueous solution of an acid is then injected into the wellbore and allowed to enter into the reservoir. The carbonate salt and the acid are allowed to react with each other and form carbon dioxide (CO2) gas, inside the reservoir, which mixes with the reservoir oil and thereby reduces the viscosity of the oil within the reservoir. The method also provides for a rapid effervescence of carbon dioxide that may enhance oil recovery by improving oil flow to the wellbore by increasing reservoir pressure, increasing rock permeability from sand production, causing oil swelling, inducing foamy oil creation and/or removing formation skin damage.

Abstract: A method for recovery of oil housed in a reservoir comprising injecting an aqueous solution or slurry of a carbonate salt into a wellbore and allowing the aqueous solution or slurry of the carbonate salt to enter into the reservoir. An aqueous solution of an acid is then injected into the wellbore and allowed to enter into the reservoir. The carbonate salt and the acid are allowed to react with each other and form carbon dioxide (CO2) gas, inside the reservoir, which mixes with the reservoir oil and thereby reduces the viscosity of the oil within the reservoir. The method also provides for a rapid effervescence of carbon dioxide that may enhance oil recovery by improving oil flow to the wellbore by increasing reservoir pressure, increasing rock permeability from sand production, causing oil swelling, inducing foamy oil creation and/or removing formation skin damage.