Patent ID: 8006761
Filing Date: 2011-08-30
Classification: C09K

Abstract:
1. A method of forming a filter cake on the walls of a water injection wellbore or a production wellbore that penetrates a porous and permeable rock formation and of subsequently removing the filter cake from the walls of the wellbore comprising the steps of: (a) placing a wellbore fluid in the wellbore wherein the wellbore comprises a base fluid and a particular bridging agent comprised of a sparingly water-soluble material selected from the group consisting of lithium carbonate, lithium phosphate, and magnesium sulfite; (b) permitting the particulate bridging agent to deposit from the wellbore fluid onto and/or onto the walls of the wellbore thereby forming the filter cake, whereby fluid loss to the formation through the filter cake is reduced; and (c) removing the filter cake from the walls of the wellbore by injecting water that is undersaturated with respect of the bridging agent from the injection wellbore into the formation or producing fluid comprising hydrocarbon and co-produced water from the formation into the production wellbore wherein the co-produced water is undersaturated with respect to the bridging agent.