METHODS FOR PREVENTING OR REMEDIATING XANTHAN DEPOSITION

Methods for remediation and/or prevention of polymer deposition on surfaces, in particular, on surfaces of drilling machinery and earth formations in the petroleum industry are described herein. Embodiments disclosed herein relate to a method of remediating xanthan deposition, the method including the steps of contacting xanthan deposition, including xanthan complexed with polyvalent metal ions, with a remediation fluid containing at least one chelating agent; and allowing the fluid to dissolve the xanthan deposition. Also disclosed is a method of preventing polymer deposition, including emplacing a wellbore fluid including a crosslinkable polymer and at least one chelating agent in a wellbore; wherein the at least one chelating agent complexes with polyvalent metal ions present in the wellbore. Also disclosed is an improved wellbore fluid including a base fluid; a polymer comprising chemical groups reactive to polyvalent metal ions found downhole; and at least one chelating agent; wherein the least one chelating agent complexes with polyvalent metal ions downhole.