METHOD FOR REMEDIATION OF SUBTERRANEAN-FORMED METAL-POLYMER COMPLEXES USING A METAL COMPLEXING AGENT

摘要

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.