METHOD OF TREATING SANDSTONE FORMATIONS WITH REDUCED PRECIPITATION OF SILICA.

摘要

A method of treating a sandstone-containing formation penetrated by a wellbore is carried out by forming a treatment fluid comprising an aqueous fluid containing a hydrogen fluoride source and an amorphous silica precipitation inhibitor. The treatment fluid is introduced into the formation through the wellbore at a pressure below the fracture pressure of the formation to facilitate dissolution of formation materials, optionally as a single stage. The amorphous silica inhibitor may be a polycarboxylate and/or polycarboxylic acid, an organosilane or a phosphonate compound. The amorphous silica inhibitor may be capable of inhibiting precipitation of amorphous silica so that the treatment fluid contains at least about 500 ppm of silicon after at least about 100 minutes subsequent to the treatment fluid being introduced into the formation.