Process and fluid to improve the permeability of sandstone formations using a chelating agent

摘要

A process for treating a sandstone formation comprising introducing a fluid containing glutamic acid N,N·diacetic acid or a salt thereof (GLDA) and having a pH of between 1 and 14 into the formation is disclosed. Further disclosed is a fluid suitable for use in the above described process having a pH between 1 and containing 5 - 30 wt% on the basis of total fluid of glutamic acid N,N-diacetic acid or a salt thereof (GLDA), a corrosion inhibitor, a surfactant, and optionally a mutual solvent.