Cationic polymers for foam fracturing applications
A method of foam fracturing a subterranean formation includes providing an fracturing foam fluid comprising an aqueous base fluid, a cationic polymer, optionally a foam surfactant comprising at least one of an amphoteric surfactant, cationic surfactant, an anionic surfactant, and combinations thereof, and sufficient gas to form a foamed fracturing fluid; and fracturing the subterranean formation with the foamed fracturing fluid. Stable fracturing foams include an aqueous base fluid, a cationic polymer, optionally a foam surfactant comprising at least one of an amphoteric surfactant, cationic surfactant, an anionic surfactant, and combinations thereof, and sufficient gas to form a foamed fracturing fluid.
1. A method of fracturing a subterranean formation comprising:
providing a foamed fracturing fluid including:
an aqueous base fluid;
a cationic polymer, wherein the cationic polymer comprises a high molecular weight hydroxyl alkyl cellulose and a low molecular weight hydroxyl alkyl cellulose, wherein the high molecular weight hydroxyl alkyl cellulose has a molecular weight of about 500K to about 2.5 million, wherein the low molecular weight hydroxyl alkyl cellulose has a molecular weight of about 2K to about 400K;
a foam surfactant, wherein the foam surfactant comprises at least one surfactant selected from the group consisting of a betaine, a sultaine, imidazolinium, a polyoxyethylene fatty alcohol, a polyoxyethylene sorbitol ester, an alkanolamide, a sulfosuccinates, a phospholipids, glycolipid, sodium lauryl sulfoacetate, and combinations thereof, wherein the foam surfactant is present in the foamed fracturing fluid at a concentration of about 0.005% to about 2% w/w of the aqueous base fluid; and
sufficient gas to form a foam; and
introducing the foamed fracturing fluid into the subterranean formation under conditions effective to create at least one fracture therein.
2. The method of claim 1 , wherein the cationic polymer further comprises at least one of hydroxyethylcellulose, quaternary hydroxyl alkyl cellulose, hydroxyethyl cellulose dimethyl diallylammonium chloride copolymer; diallyldimethylammonium chloride-hydroxyethyl cellulose copolymer; quaternized hydroxyethyl cellulose; cellulose, and combinations thereof.
3. The method of claim 1 , wherein the cationic polymer comprises at least two cationic functional groups.
4. The method of claim 1 , wherein the ratio of high molecular weight polymer to low molecular weight polymer is 3:1.
5. The method of claim 1 , wherein the quality of the foam is from about 5% gas volume to about 99% gas volume.
6. The method of claim 1 , wherein the gas is selected from the group consisting of nitrogen, carbon dioxide, air, methane, helium, argon, and any combination thereof.
7. The method of claim 1 , wherein the foamed fracturing fluid further comprises a proppant.
8. A method comprising:
combining an aqueous base fluid; a cationic polymer, wherein the cationic polymer comprises a high molecular weight hydroxyl alkyl cellulose and a low molecular weight hydroxyl alkyl cellulose, wherein the high molecular weight hydroxyl alkyl cellulose has a molecular weight of about 500K to about 2.5 million, wherein the low molecular weight hydroxyl alkyl cellulose has a molecular weight of about 2K to about 400K, and proppant with sufficient gas to form a foamed fracturing fluid;
introducing the foamed fracturing fluid into a subterranean formation under conditions effective to create or enhance at least one fracture in at least a portion of the subterranean formation; and
depositing at least a portion of the proppant into the fracture; and
wherein the foamed fracturing fluid comprises no foam surfactant.
9. The method of claim 8 , wherein the ratio of high molecular weight polymer to low molecular weight polymer is 3:1.
10. The method of claim 8 , wherein the quality of the foam is from about 5% gas volume to about 99% gas volume.