Stabilized friction reducer emulsions
The instant invention friction reducer formulation comprising friction reducer polymers such as PAM within the dispersed phase of an inverse emulsion containing a composition C which comprises a mixture of: —at least an alkanolamide emulsifier; and —a block copolymer comprising: —a hydrophilic block A comprising units deriving from a mono-alpha-ethylenically-unsaturated monomers; and —a hydrophobic block B.
1. A friction reducer formulation comprising friction reducer polymers within the dispersed phase of an inverse emulsion, wherein said inverse emulsion contains a composition C comprising a mixture of:
from 1% to 5% of at least an alkanolamide emulsifier selected from the group consisting of alkyl and alkenyl diethanolamides; and
from 0.01 to 0.5% of a block copolymer, wherein the copolymer is a di-block copolymer comprising:
a block A comprising repeating units derived from N-vinyl pyrrolidone; and
a block B comprising repeating units derived from 2-ethyl-hexyl acrylate, and
wherein % is in mass, based on a total mass of the inverse emulsion containing the composition C.
2. The friction reducer formulation of claim 1 , wherein the ratio copolymer/alkanolamide corresponding to the quotient of the total mass of copolymer contained in composition C, to the total mass of the alkanolamide emulsifier contained in composition C is between 1 and 40%.
3. The friction reducer formulation of claim 2 , wherein the ratio copolymer/alkanolamide corresponding to the quotient of the total mass of copolymer contained in composition C, to the total mass of the alkanolamide emulsifier contained in composition C is between 2 and 20%.
4. The friction reducer formulation of claim 1 , wherein the friction reducer polymers are inverse polyacrylamide homo- or co-polymers.
5. The friction reducer formulation of claim 1 , wherein the content of composition C is between 1.01% and 5%, in mass, based on the total mass of the emulsion containing the composition C.
6. The friction reducer formulation of claim 5 , wherein the content of composition C is between 1.01% and 4% in mass, based on the total mass of the emulsion containing the composition C.
7. A fracturing fluid comprising a friction reducer formulation as defined in claim 1 .
8. A method, comprising providing a friction reducer effect during a hydraulic fracturing operation using the inverse emulsion containing a composition C as defined in claim 1 .