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In a slick-water fracturing operation, a composition is used to prevent the interaction between a polymer in a water-based fracturing fluid and naturally-occurring metal ions. The composition includes a metal-complexing agent, such as a chelating agent. The chelating agent can also be biodegradable

In a slick-water fracturing operation, a composition is used to prevent the interaction between a polymer in a water-based fracturing fluid and naturally-occurring metal ions. The composition includes a metal-complexing agent, such as a chelating agent. The chelating agent can also be biodegradable and is citric acid in embodiments. The metal-complexing agent can be coated with one or two coatings to create a time-released form. The time-released form prevents loss of the agent prior to delivery at the shale.

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1. A slick-water fracturing fluid comprising: a friction reducer; anda time-released form of a metal complexing agent, wherein the metal complexing agent is encapsulated by a coating, the coating being a porous cross-linked hydrophilic polymer. 2. The slick-water fracturing fluid of claim 1, wherein

1. A slick-water fracturing fluid comprising: a friction reducer; anda time-released form of a metal complexing agent, wherein the metal complexing agent is encapsulated by a coating, the coating being a porous cross-linked hydrophilic polymer. 2. The slick-water fracturing fluid of claim 1, wherein the metal complexing agent is citric acid. 3. The slick-water fracturing fluid of claim 2, wherein the coating includes a second coating, the second coating being a paraffin coating. 4. The slick-water fracturing fluid of claim 2, wherein the coating includes a second coating, the second coating being a cottonseed oil coating. 5. The slick-water fracturing fluid of claim 1, wherein the metal complexing agent is present in the slick-water fracturing fluid in an amount of about 0.1 pound per thousand gallons to about 50 pounds per thousand gallons. 6. The slick-water fracturing fluid of claim 5, wherein the metal complexing agent is present in the slick-water fracturing fluid in an amount of about 0.5 pound per thousand gallons to about 25 pounds per thousand gallons. 7. The slick-water fracturing fluid of claim 5, wherein the metal complexing agent is present in the slick-water fracturing fluid in an amount of about 2 pounds per thousand gallons to about 5 pounds per thousand gallons. 8. A method for slick-water fracturing, comprising: adding a time-released form of a metal-complexing agent to a slick-water fracturing fluid wherein the metal complexing agent is encapsulated by a coating, the coating being a porous cross-linked hydrophilic polymer,wherein the time-release form of the metal-complexing agent is added in an amount of about 0.1 pound per thousand gallons to about 50 pounds per thousand gallons; andintroducing the combined slick-water fracturing fluid and time-released form of a metal complexing agent into a subterranean zone. 9. The method for slick-water fracturing of claim 8, wherein the metal-complexing agent is a biodegradable chelating agent. 10. The method for slick-water fracturing of claim 9, wherein the metal-complexing agent is citric acid. 11. The method for slick-water fracturing of claim 10, wherein the time-released form of the metal-complexing agent is added in an amount of about 0.5 pound per thousand gallons to about 25 pounds per thousand gallons. 12. The method for slick-water fracturing of claim 11, the time-release form of the metal-complexing agent is added in an amount of about 2 pounds per thousand gallons to about 5 pounds per thousand gallons. 13. A slick-water fracturing fluid comprising: a friction reducing polymer; anda time-released form of a metal complexing agent, wherein the time released form of the metal complexing agent is present in the slick-water fracturing fluid at about 0.1 pound per thousand gallons to about 50 pounds per thousand gallons, wherein the time-released form of the metal complexing agent is encapsulated with a coating, the coating being a porous cross-linked hydrophilic polymer. 14. The slick-water fracturing fluid of claim 13, wherein the time-released metal complexing agent is solid citric acid. 15. The slick-water fracturing fluid of claim 14, wherein the coating includes a second coating, the second coating being a dry hydrophobic film forming material. 16. The slick-water fracturing fluid of claim 14, wherein the time released form of the metal complexing agent is present in the slick-water fracturing fluid at about 0.5 pounds per thousand gallons to about 25 pounds per thousand gallons. 17. The slick-water fracturing fluid of claim 15, wherein the time released form of the metal complexing agent is present in the slick-water fracturing fluid at about 2 pounds per thousand gallons to about 5 pounds per thousand gallons. 18. A slick-water fracturing fluid comprising: a friction reducer; anda time-released form of a metal complexing agent, wherein the metal complexing agent is present in the slick-water fracturing fluid in an amount of about 0.1 pounds per thousand gallons to about 5 pounds per thousand gallons.