Abstract: This disclosure describes formulations and methods for remediating subterranean-formed metal-polymer complexes in wells in subterranean formations. In one embodiment, the method includes injecting a metal-polymer complex remediation mixture containing a metal complexing agent into a subterranean formation adjacent to a well at a pressure below the fracture pressure of the formation. A sufficient contact time is allowed and then the metal-polymer complex remediation mixture is pumped from the subsurface. This has been shown to remediate polymer-containing, subterranean-formed metal-polymer complexes in shale formations. Without being held to a particular theory it appears that the metal complexing agent is forming metal complexes with the metals in the complexes, and particularly divalent metal ions. This removal of naturally occurring metals may be un-crosslinking and causing the metal-polymer complexes to go into solution, thereby removing the blockages caused by the metal-polymer complexes.

Abstract: This disclosure describes formulations and methods for stimulating the production from wells in nano-darcy shale formations. In one embodiment, the method includes injecting a treatment mixture containing a metal complexing agent into a nano-darcy shale formation adjacent to a well at a pressure below the fracture pressure of the formation. A sufficient contact time is allowed and then the treatment mixture is pumped from the subsurface. This has been shown to stimulate well production in shale formations. Without being held to a particular theory it appears that the metal complexing agent is binding with naturally occurring metals in the shale formation, and particularly divalent metal ions, which are then extracted with the spent fluid. This removal of naturally occurring metals may be increasing the permeability of the formation in the contact region adjacent to the well, thereby causing the observed increased production.

Abstract: Formulations and methods for stimulating the production from wells in nano-darcy shale formations. In one embodiment, the method includes injecting a treatment mixture containing a metal complexing agent into a nano-darcy shale formation adjacent to a well at a pressure below the fracture pressure of the formation. A sufficient contact time is allowed and then the treatment mixture is pumped from the subsurface. This has been shown to stimulate well production in shale formations. Without being held to a particular theory it appears that the metal complexing agent is binding with naturally occurring metals in the shale formation, and particularly divalent metal ions, which are then extracted with the spent fluid. This removal of naturally occurring metals may be increasing the permeability of the formation in the contact region adjacent to the well, thereby causing the observed increased production.

Abstract: 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.

Abstract: 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.

Abstract: This disclosure describes formulations and methods for stimulating the production from wells in nano-darcy shale formations. In one embodiment, the method includes injecting a treatment mixture containing a metal complexing agent into a nano-darcy shale formation adjacent to a well at a pressure below the fracture pressure of the formation. A sufficient contact time is allowed and then the treatment mixture is pumped from the subsurface. This has been shown to stimulate well production in shale formations. Without being held to a particular theory it appears that the metal complexing agent is binding with naturally occurring metals in the shale formation, and particularly divalent metal ions, which are then extracted with the spent fluid. This removal of naturally occurring metals may be increasing the permeability of the formation in the contact region adjacent to the well, thereby causing the observed increased production.

Abstract: This disclosure describes formulations and methods for remediating subterranean-formed metal-polymer complexes in wells in subterranean formations. In one embodiment, the method includes injecting a metal-polymer complex remediation mixture containing a metal complexing agent into a subterranean formation adjacent to a well at a pressure below the fracture pressure of the formation. A sufficient contact time is allowed and then the metal-polymer complex remediation mixture is pumped from the subsurface. This has been shown to remediate polymer-containing, subterranean-formed metal-polymer complexes in shale formations. Without being held to a particular theory it appears that the metal complexing agent is forming metal complexes with the metals in the complexes, and particularly divalent metal ions. This removal of naturally occurring metals may be un-crosslinking and causing the metal-polymer complexes to go into solution, thereby removing the blockages caused by the metal-polymer complexes.