Method of dissolving organic filter cake obtained from polysaccharide based fluids used in production operations and completions of oil and gas wells

A method of increasing the flow of production fluids from a subterranean formation by removing a polysaccharide-containing filter cake formed during production operations and found within the subterranean formation which surrounds a completed well bore comprising the steps of:

• allowing production fluids to flow from the well bore;
• reducing the flow of production fluids from the formation below expected flow rates;
• formulating an enzyme treatment by blending together an aqueous fluid and enzymes;
• pumping the enzyme treatment to a desired location within the well bore;
• allowing the enzyme treatment to degrade the polysaccharide-containing filter cake, whereby the filter cake can be removed from the subterranean formation to the well surface;
• and
• wherein the enzyme treatment has activity in the pH range of about 2.0 to 10.0 and effective to attack only specific linkages in the polysaccharide-containing filter cake.

A method of increasing the flow of production fluids from a subterranean formation by removing a guar-containing filter cake formed during production operations and found within the subterranean formation which surrounds a completed well bore comprising the steps of:

• allowing production fluids to flow from the well bore;
• reducing the flow of production fluids from the formation below expected flow rates;
• formulating an enzyme treatment by blending together an aqueous fluid and enzymes;
• pumping the enzyme treatment to a desired location within the well bore;
• allowing the enzyme treatment to degrade the guar-containing filter cake having repeating units of mannose and galactose linked by mannosidic and galactomannosidic linkages, whereby the filter cake can be removed from the subterranean formation to the well surface;
• and
• wherein the enzyme treatment has activity in the pH range of about 2.0 to 10.0 and effective to attack only specific linkages within the guar-containing filter cake.

A method of increasing the flow of production fluids from a subterranean formation by removing a guar-containing filter cake formed during production operations and found within the subterranean formation which surrounds a completed well bore comprising the steps of:

• allowing production fluids to flow from the well bore;
• reducing the flow of production fluids from the formation below expected flow rates;
• formulating an enzyme treatment by blending together an aqueous fluid and enzymes;
• pumping the enzyme treatment to a desired location within the well bore;
• allowing the enzyme treatment to degrade the guar-containing filter cake having repeating units of mannose and galactose linked by (1,4)-.beta.-D-mannosidic and (1,6)-.alpha.-D-galactomannosidic linkages, whereby the filter cake can be removed from the subterranean formation to the well surface;
• and
• wherein the enzyme treatment is effective to attack the (1,4)-.beta.-D-mannosidic and (1,6)-.alpha.-D-galactomannosidic linkages.

A method of increasing the flow of production fluids from a subterranean formation by removing a cellulose-containing filter cake formed during production operations and found within the subterranean formation which surrounds a completed well bore comprising the steps of:

• allowing production fluids to flow from the well bore;
• reducing the flow of production fluids from the formation below expected flow rates;
• formulating an enzyme treatment by blending together an aqueous fluid and enzymes;
• pumping the enzyme treatment to a desired location within the well bore;
• allowing the enzyme treatment to degrade the cellulose-containing filter cake having repeating units of glucose linked by glucosidic linkages, whereby the filter cake can be removed from the subterranean formation to the well surface;
• and
• wherein the enzyme treatment has activity in the pH range of about 2.0 to 8.0 and effective to attack only specific linkages within the polysaccharide-containing filter cake.

A method of increasing the flow of production fluids from a subterranean formation by removing a cellulose-containing filter cake formed during production operations and found within the subterranean formation which surrounds a completed well bore comprising the steps of:

• allowing production fluids to flow from the well bore;
• reducing the flow of production fluids from the formation below expected flow rates;
• formulating an enzyme treatment by blending together an aqueous fluid and an enzyme;
• pumping the enzyme treatment to a desired location within the well bore;
• allowing the enzyme treatment to degrade the cellulose-containing filter cake having repeating units of glucose linked by (1,4)-.beta.-D-glucosidic linkages, whereby the filter cake can be removed from the subterranean formation to the well surface;
• and
• wherein the enzyme treatment is effective to attack the (1,4)-.beta.-D-glucosidic linkages.

A method of increasing the flow of production fluids from a subterranean formation by removing a noncrosslinked, viscous, polysaccharide-containing, damaging fluid formed during production operations and found within the subterranean formation which surrounds a completed well bore comprising the steps of:

• allowing production fluids to flow from the well bore;
• reducing the flow of production fluids from the formation below expected flow rates;
• formulating an enzyme treatment by blending together an aqueous fluid and enzymes;
• pumping the enzyme treatment to a desired location within the well bore;
• and
• allowing the enzyme treatment to degrade the noncrosslinked, viscous, polysaccharide-containing, damaging fluid, whereby the fluid can be removed from the subterranean formation to the well surface.

A method of increasing the flow of production fluids from a subterranean formation by removing a noncrosslinked, viscous, polysaccharide-containing, damaging fluid formed during production operations and found within the subterranean formation which surrounds a completed well bore comprising the steps of:

• allowing production fluids to flow from the well bore;
• reducing the flow of production fluids from the formation below expected flow rates;
• formulating an enzyme treatment by blending together an aqueous fluid and enzymes;
• pumping the enzyme treatment to a desired location within the well bore;
• allowing the enzyme treatment to degrade the noncrosslinked, viscous, polysaccharide-containing, damaging fluid, whereby the fluid can be removed from the subterranean formation to the well surface;
• and
• wherein the enzyme treatment has activity in the pH range of about 2.0 to 10.0 and effective to attack only specific linkages in the polysaccharide-containing, damaging fluid.

A method of increasing the flow of production fluids from a subterranean formation by removing a viscous, starch-containing, damaging fluid formed during production operations and found within the subterranean formation which surrounds a completed well bore comprising the steps of:

• allowing production fluids to flow from the well bore;
• reducing the flow of production fluids from the formation below expected flow rates;
• formulating an enzyme treatment by blending together an aqueous fluid and enzymes;
• pumping the enzyme treatment to a desired location within the well bore;
• allowing the enzyme treatment to degrade the viscous, starch-containing, damaging fluid, having repeating units linked by .alpha.-glucosidic linkages, whereby the fluid can be removed from the subterranean formation to the well surface;
• and
• wherein the enzyme treatment is effective to attack the .alpha.-glucosidic linkages in the starch-containing fluid.

A method of increasing the flow of production fluids from a subterranean formation by removing a noncrosslinked, viscous, starch-containing, damaging fluid formed during production operations and found within the subterranean formation which surrounds a completed well bore comprising the steps of:

• allowing production fluids to flow from the well bore;
• reducing the flow of production fluids from the formation below expected flow rates;
• formulating an enzyme treatment by blending together an aqueous fluid and enzymes;
• pumping the enzyme treatment to a desired location within the well bore;
• allowing the enzyme treatment to degrade the noncrosslinked, viscous, starch-containing, damaging fluid, having subunits of amylose with repeating units of glucose linked by (1,4)-.alpha.-D-glucoidic linkages and amylopectin with a backbone of (1,4)-.alpha.-D-glucosidic linkages and side chains of glucose linked to the backbone by (1,6)-.alpha.-D-glucosidic linkages, whereby the fluid can be removed from the subterranean formation to the well surface;
• and
• wherein the enzyme treatment is to attack the internal (1,4)-.alpha.-D-glucosidic linkages in the starch-containing, damaging fluid.

A method of increasing the flow of production fluids from a subterranean formation by removing a noncrosslinked, viscous, cellulose-containing, damaging fluid formed during production operations and found within the subterranean formation which surrounds a completed well bore comprising the steps of:

• allowing production fluids to flow from the well bore;
• reducing the flow of production fluids from the formation below expected flow rates;
• formulating an enzyme treatment by blending together an aqueous fluid and enzymes;
• pumping the enzyme treatment to a desired location within the well bore;
• allowing the enzyme treatment to degrade the noncrosslinked, viscous, cellulose-containing, damaging fluid having a backbone of repeating units of glucose linked by .beta.-glucosidic linkages, whereby the fluid can be removed from the subterranean formation to the well surface;
• and
• wherein the enzyme treatment has activity in the pH range of about 2.0 to 10.0, a temperature range between about 50.degree. F. and 150.degree. F. and is effective to attack only specific linkages in the cellulose-containing, damaging fluid.

A method of increasing the flow of production fluids from a subterranean formation by removing a noncrosslinked, viscous, cellulose-containing, damaging fluid formed during production operations and found within the subterranean formation which surrounds a completed well bore comprising the steps of:

• allowing production fluids to flow from the well bore;
• reducing the flow of production fluids from the formation below expected flow rates;
• formulating an enzyme treatment by blending together an aqueous fluid and an enzyme;
• pumping the enzyme treatment to a desired location within the well bore;
• allowing the enzyme treatment to degrade the noncrosslinked, viscous, cellulose-containing damaging fluid having repeating units of glucose linked by (1,4)-.beta.-D-glucosidic linkages in the backbone, whereby the fluid can be removed from the subterranean formation to the well surface;
• and
• wherein the enzyme treatment is effective to attack the (1,4)-.beta.-D-glucosidic linkages.

A method of increasing the flow of production fluids from a subterranean formation by removing a noncrosslinked, viscous, xanthan-containing, damaging fluid formed during production operations and found within the subterranean formation which surrounds a completed well bore comprising the steps of:

• allowing production fluids to flow from the well bore;
• reducing the flow of production fluids from the formation below expected flow rates;
• formulating an enzyme treatment by blending together an aqueous fluid and enzymes;
• pumping the enzyme treatment to a desired location within the well bore;
• allowing the enzyme treatment to degrade the noncrosslinked, viscous, xanthan-containing, damaging fluid having a backbone of repeating units of glucose linked by .beta.-glucosidic linkages and trisaccharide side chains, whereby the fluid can be removed from the subterranean formation to the well surface;
• and
• wherein the enzyme treatment has activity in the pH range of about 2.0 to 10.0, a temperature range between about 50.degree. F. and 150.degree. F. and is effective to attack only specific linkages in the xanthan-containing, damaging fluid.

A method of increasing the flow of production fluids from a subterranean formation by removing a noncrosslinked, viscous, xanthan-containing, damaging fluid formed during production operations and found within the subterranean formation which surrounds a completed well bore comprising the steps of:

• allowing production fluids to flow from the well bore;
• reducing the flow of production fluids from the formation below expected flow rates;
• formulating an enzyme treatment by blending together an aqueous fluid and enzymes;
• pumping the enzyme treatment to a desired location within the well bore;
• allowing the enzyme treatment to degrade the noncrosslinked, viscous, xanthan-containing, damaging fluid having a backbone of repeating units of glucose linked by (1,4)-.beta.-D-glucosidic linkages and trisaccharide side chains with (1,2)-.beta.-D-mannosidic linkages and attached to alternating glucose molecules in the backbone, whereby the fluid can be removed from the subterranean formation to the well surface;
• and
• wherein the enzyme treatment is effective to attack only specific linkages in the xanthan-containing, damaging fluid.