Compositions and methods for breaking a viscosity increasing polymer at very low temperature used in downhole well applications

A method for treating a portion of a wellbore or a portion of a subterranean formation, the method comprising the steps of:

• (A) forming or providing a composition comprising:
• (a) water;
• (b) a source of hydrogen peroxide, and
• (c) a water-soluble alkanoyl-donor compound has a leaving group with a pKa in the range of about 6 to about 13;
• wherein the pH of the composition is adjusted in the range of 3 to 8;
• (B) introducing the composition through a wellbore to treat a portion of a wellbore or a portion of a subterranean formation, wherein the portion of the wellbore or the portion of the subterranean formation is at a static temperature of less than 100° F. (38° C.);
• (C) after the step of introducing, allowing the composition to contact a filtercake that had been previously formed with xanthan on a wall of the wellbore or a wall of the subterranean formation for a sufficient time at the static temperature thereof to substantially break the xanthan in the filtercake;
• and
• (D) after the step of allowing, flowing back through the wellbore to recover at least some of the composition from the portion of the wellbore or the portion of the subterranean formation, wherein the alkanoyl-donor compound is selected from the group consisting of:
• ethyl acetate, ethyl acetoacetate;
• tetracetylethylenediamine (“TAED”);
• sodium nonanoyloxybenzenesulfonate (“NOBS”);
• and any combination thereof in any proportion.

A method for treating a portion of a wellbore or a portion of a subterranean formation, the method comprising the steps of:

• (A) forming or providing a composition comprising:
• (a) water;
• (b) xanthan;
• (c) a source of hydrogen peroxide, and
• (d) a water-soluble alkanoyl-donor compound has a leaving group with a pKa in the range of about 6 to about 13;
• wherein the pH of the composition is adjusted in the range of 3 to 8;
• (B) introducing the composition through a wellbore to treat a portion of the wellbore or the portion of the subterranean formation, wherein the portion of the wellbore or the portion of the subterranean formation is at a static temperature of less than 100° F. (38° C.);
• (C) after the step of introducing the composition, allowing sufficient time at the static temperature thereof to substantially break the xanthan;
• and
• (D) after the step of allowing, flowing back through the wellbore to recover at least some of the composition from the portion of the wellbore or the portion of the subterranean formation, wherein the alkanoyl-donor compound is selected from the group consisting of:
• ethyl acetate, ethyl acetoacetate;
• tetracetylethylenediamine (“TAED”);
• sodium nonanoyloxybenzenesulfonate (“NOBS”);
• and any combination thereof in any proportion.