A WELL BORE TREATMENT FLUID CONTAINING VISCOELASTIC SURFACTANT GELS WITH REDUCED SALT CONCENTRATION

摘要

The invention relates to a well bore treatment fluid for injection into subterranean formation, comprising an anionic surfactant for forming a viscoelastic (VES) gel; a hydrophilic-lipophilic organic compound with a carbon chain and one or more polar groups; wherein the polar groups are OH- or –NH; and a salt, wherein an organic hydrophilic-lipophilic compound is present at such a concentration as to raise the critical temperature above which VES of said fluid decreases and reducing the salt concentration below 6 wt %. The invention also discloses a well bore treatment fluid for injection into subterranean formation, comprising an anionic surfactant for forming a viscoelastic (VES) gel; a hydrophilic-lipophilic organic compound with a carbon chain and one or more polar groups; wherein the polar groups are OH- or –NH; and inorganic salt, where the organic hydrophilic-lipophilic compound is present at such a concentration as to raise the critical temperature above which VES of said fluid decreases and reducing the salt concentration below 2 wt %. There also disclosed a method for treating subterranean formation using said bore hole fluid and a method for increasing the temperature range of the fluid for treating bore holes.