Gemini surfactants containing an arylene linker for clay swelling inhibition
Amidoamine-based gemini surfactants having dual chains connected via an arylene or heteroarylene linker. Each chain contains a quaternary ammonium head group and an ethoxylated alkyl tail. A water-based drilling fluid containing the gemini surfactant is also provided. As examined by linear swelling and free swelling tests, the gemini surfactant is effective in reducing clay swelling.
1. A surfactant of formula (I)
or a solvate thereof, a tautomer thereof, a stereoisomer thereof, or a mixture thereof;
wherein:
each of R 1 and R 2 are independently selected from the group consisting of a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, and an optionally substituted arylalkyl;
each of R 3 and R 4 are independently selected from the group consisting of an optionally substituted alkyl, an optionally substituted cycloalkyl, and an optionally substituted arylalkyl;
L is an optionally substituted C 6-30 arylene or an optionally substituted C 3-30 heteroarylene linker;
each of n is independently an integer in a range of 1-15;
each of x is independently an integer in a range of 5-21;
each of y is independently an integer in a range of 2-5; and
X is an anion selected from the group consisting of a halide ion, a hexafluorophosphate ion, a trifluoromethanesulfonate ion, and a tetrafluoroborate ion.
2. The surfactant of claim 1 , wherein each of R 1 and R 2 are independently a hydrogen or a methyl.
3. The surfactant of claim 1 , wherein each of R 1 and R 2 are hydrogen.
4. The surfactant of claim 1 , wherein each of R 3 and R 4 are independently selected from the group consisting of a methyl, an ethyl, and an isopropyl.
5. The surfactant of claim 1 , wherein each of R 3 and R 4 are a methyl.
6. The surfactant of claim 1 , wherein L is an unsubstituted C 6-30 arylene.
7. The surfactant of claim 1 , wherein L is an unsubstituted C 6-18 arylene.
8. The surfactant of claim 1 , wherein L is selected from the group consisting of 1,4-phenylene, 1,2-phenylene, 1,3-phenylene, 4,4′-biphenylene, 2,2′-biphenylene, 3,3′-biphenylene, 1,4-naphthylene, 1,8-naphthylene, 2,6-naphthylene, 2,7-naphthylene, 4,4″-m-terphenylene, and 4,4″-p-terphenylene.
9. The surfactant of claim 1 , wherein L is 1,4-phenylene or 4,4′-biphenylene.
10. The surfactant of claim 1 , wherein L is 4,4′-biphenylene.
11. The surfactant of claim 1 , wherein each of n is an integer in a range of 2-11.
12. The surfactant of claim 1 , wherein each of x is an integer in a range of 11-13.
13. The surfactant of claim 1 , wherein each of y is 3.
14. The surfactant of claim 1 , wherein X is bromide or chloride.
15. The surfactant of claim 1 , wherein X is chloride.
16. The surfactant of claim 1 , which is selected from the group consisting of:
a surfactant represented by formula (II)
a surfactant represented by formula (III)
a surfactant represented by formula (IV)
and
a surfactant represented by formula (V)
wherein:
each of n 1 , n 2 , n 3 , and n 4 are independently an integer in a range of 2-11; and
each of x 1 , x 2 , x 3 , and x 4 are independently an integer in a range of 11-13.
17. A drilling fluid, comprising:
an aqueous base fluid; and
the surfactant of claim 1 .
18. The drilling fluid of claim 17 , wherein the surfactant is represented by formula (V)
wherein:
each of n 4 is independently an integer in a range of 2-11; and
each of x 4 is independently an integer in a range of 11-13.
19. The drilling fluid of claim 17 , wherein the surfactant is present in an amount of 0.005-5 wt. % relative to a total weight of the drilling fluid.
20. The drilling fluid of claim 17 , which is substantially free of a potassium salt.