Multicomponent viscoelastic surfactant fluid and method of using as a fracturing fluid
View Patent ↗There is a viscoelastic fluid. The fluid has one or more cationic surfactants selected from the group consisting of certain quaternary salts, certain amines, and combinations thereof; one or more anionic polymers/anionic surfactants; one or more of certain zwitterionic/amphoteric surfactants; and water. There is also a method of fracturing a subterranean formation. The viscoelastic fluid is pumped through a wellbore and into a subterranean formation at a pressure sufficient to fracture the formation. There is also a method for gravel packing a subterranean formation.
1. A viscoelastic fluid, comprising:
one or more cationic surfactants;
one or more anionic surfactants having alkyl chains of about 6 to about 18 carbon atoms with at least one negatively charged moiety;
one or more zwitterionic surfactants and/or one or more amphoteric surfactants; and water; wherein the one or more cationic surfactants is selected from the group consisting of methylpolyoxyethylene (2-12) cocoalkylammonium chloride, isotridecyloxypropyl polyoxyethylene (2-12) methyl ammonium chloride, and combinations thereof; and wherein the one or more amphoteric surfactants has the following structural formula:
wherein, R 1 is a hydrophobic moiety of alkyl, alkylarylalkyl, alkoxyalkyl, alkylaminoalkyl or alkylamidoalkyl, wherein R 1 has from about 18 to about 30 carbon atoms and may be branched or straight-chained and saturated or unsaturated; R 2 is selected from the group consisting of an aliphatic moiety having from 1 to about 30 carbon atoms and an aromatic moiety having from 7 to about 30 carbon atoms; the aliphatic moiety being branched or straight-chained and saturated or unsaturated; and R 4 is a hydrocarbyl radical with a chain length of 1 to 4.
2. The fluid of claim 1 , wherein the anionic surfactant has the following structural formula selected from the group consisting of:
and combinations thereof;
wherein R 6 is selected from a group consisting of alkyl, aryl, alkaryl, alkylarylalkyl, arylalkyl, alkylamidoalkyl, alkylaminoalkyl; wherein the alkyl group has from about 6 to about 18 carbon atoms; wherein the aryl group represents a phenyl, diphenyl, diphenylether, or naphthalene moiety; wherein the total carbon atom content of R 6 is no more than about 18 carbon atoms; wherein M is selected from the group consisting of hydrogen, an alkali metal, and—[R 7 -(EO) a (PO)b(BO) c ] m -O-] q -P(O)(OM) 2 ; wherein Y is a counter-ion; wherein EO is an ethyleneoxy radical; wherein PO is an propyleneoxy radical; wherein BO is a butoxy radical;
wherein each of the EO, PO, and BO radicals can be randomly mixed or in discrete blocks;
wherein a, b, and c are, independently, integers from 0 to 50; wherein “m” is 0 or 1; wherein “R 7 ” is C 8 to C 18 alkylene; wherein R 8 is C 8 -C 18 alkyl or C 8 -C 18 alkylamido; wherein “R 9 ” is C 1 to C 4 alkyl or Y; wherein R 10 is C 4 -C 8 alkyl; and wherein “q” is an integer from 1 to about 10.
3. The fluid of claim 1 , wherein the one or more cationic surfactants is present at from about 1 to about 40 wt % based on weight of active surfactant.
4. The fluid of claim 1 , wherein the one or more cationic surfactants is present at from about 5 to about 20 wt % based on weight of active surfactant.
5. The fluid of claim 1 , wherein the water is present at about 50 wt % or more based on fluid weight.
6. The fluid of claim 5 , wherein the water is present at about 70 wt % or more based on fluid weight.
7. The fluid of claim 1 , wherein the one or more cationic surfactants and one or more zwitterionic surfactants and/or the one or more amphoteric surfactants are present at about 0.1 to about 10 wt % based on fluid weight.
8. The fluid of claim 1 , wherein the one or more cationic surfactants and one or more zwitterionic surfactants and/or the one or more amphoteric surfactants are present at about 0.25 to about 2 wt % based on fluid weight.
9. The fluid of claim 1 , wherein the one or more cationic surfactants and one or more zwitterionic surfactants and/or the one or more amphoteric surfactants are present at less than 2 wt % based on fluid weight.
10. The fluid of claim 1 , further comprising a component selected from the group consisting of organic acids, organic acid salts, inorganic salts, and combinations thereof.
11. The fluid of claim 10 , wherein the component is selected from the group consisting of potassium chloride and trimethylammonium chloride.
12. The fluid of claim 10 , wherein the component is present at about 0.1 wt % to about 10 wt %.
13. The fluid of claim 1 , further comprising a proppant.
14. The fluid of claim 1 , wherein the one or more cationic surfactants is present at from about 1 to about 40 wt % based on weight of active surfactant, wherein the one or more anionic surfactants is present at from about 0.1 wt % to about 5 wt % based on fluid weight, wherein the water is present at about 50 wt % or more based on fluid weight, wherein the one or more cationic surfactants and one or more zwitterionic surfactants and/or the one or more amphoteric surfactants is present at about 0.1 to about 10 wt % based on fluid weight, the fluid further comprising a component selected from the group consisting of organic acids, organic acid salts, inorganic salts, and combinations thereof, wherein the component is present at about 0.1 wt % to about 10 wt % based on fluid weight.
15. The fluid of claim 1 , wherein the one or more zwitterionic surfactants is selected from the group consisting of the following structural formulas:
and combinations thereof,
wherein R 1 is a hydrophobic moiety of alkyl, alkylarylalkyl, alkoxyalkyl, alkylaminoalkyl or alkylamidoalkyl of from about 18 to about 30 carbon atoms and is branched or straight-chained and saturated or unsaturated.
16. The fluid of claim 1 , wherein the one or more zwitterionic surfactants is erucyl amidopropyl betaine.