Compositions and methods for foam stimulation
Disclosed are foam precursor compositions, foamed compositions, and methods of using these foamed compositions for the stimulation of unconventional reservoirs.
1 . An aqueous foam precursor composition for use in stimulating an unconventional subterranean formation comprising hydrocarbons, the aqueous foam precursor composition comprising:
a surfactant package comprising a primary foaming surfactant and one or more secondary surfactants, wherein the primary foaming surfactant comprises an anionic surfactant and the one or more secondary surfactants comprise an alkoxylated C6-C32 alcohol wherein the primary foaming surfactant is present in an amount of from 0.1% to 2.5% by weight, based on a total weight of the aqueous foam precursor composition; and
water, wherein the water is present in an amount of 50% to less than 100% by weight, based on a total weight of the aqueous foam precursor composition;
wherein the aqueous foam precursor composition exhibits an interfacial tension (IFT) of from 0.05 dynes/cm to 0.5 dynes/cm, between the foam precursor composition and the hydrocarbons present in the unconventional subterranean formation.
2 . The aqueous foam precursor composition of claim 1 , wherein when foamed with an expansion gas to produce a foamed composition having a foam quality of from 0.8 to 0.98, the foamed composition exhibits an apparent viscosity of at least 1.5 cP to 5 cP at 25° C.
3 . The aqueous foam precursor composition of claim 1 , wherein the primary foaming surfactant comprises a sulfonate surfactant, a disulfonate surfactant, or an alkoxylated C6-C32 alcohol.
4 . The aqueous foam precursor composition of claim 1 , wherein the aqueous foam precursor composition further comprises a viscosity-modifying polymer.
5 . The aqueous foam precursor composition of claim 4 , wherein the viscosity-modifying polymer comprises a biopolymer.
6 . The aqueous foam precursor composition of claim 4 , wherein the viscosity-modifying polymer is present in the aqueous foam precursor composition in an amount of from 0.01% to 1% by weight, based on the total weight of the aqueous foam precursor composition.
7 . The aqueous foam precursor composition of claim 1 , wherein the aqueous foam precursor composition further comprises a foam stabilizer.
8 . The aqueous foam precursor composition of claim 7 , wherein the foam stabilizer comprises a crosslinker, a particulate stabilizer, or any combination thereof.
9 . The aqueous foam precursor composition of claim 7 , wherein the foam stabilizer is present in an amount of from 0.01% to 5%, based on the total weight of the aqueous foam precursor composition.
10 . The aqueous foam precursor composition of claim 1 , wherein the aqueous foam precursor composition further comprises a co-solvent.
11 . The aqueous foam precursor composition of claim 10 , wherein the co-solvent comprises a C1-C5 alcohol, an alkoxylated C1-C5 alcohol, a glycol ether, a polyalkylene glycol, or any combination thereof.
12 . The aqueous foam precursor composition of claim 10 , wherein the co-solvent is present in an amount of from 0.01% to 1% by weight, based on the total weight of the aqueous foam precursor composition.
13 . The aqueous foam precursor composition of claim 1 , wherein the aqueous foam precursor composition is substantially free of proppant.
14 . The aqueous foam precursor composition of claim 1 , wherein the aqueous foam precursor composition is foamed and further comprises from 30% to 98% expansion gas.
15 . The aqueous foam precursor composition of claim 14 , wherein the expansion gas comprises air, helium, carbon dioxide, nitrogen, natural gas or a hydrocarbon component thereof, or any combination thereof.