A method for enhanced oil recovery in an underground reservoir involving use of system including at least one injection well having an injection pump for establishing an injection stream, the injection pump includes a carrier system and an enzyme system; at least one production well having at least one fluid output; a mixed injection stream through the at least one injection well including a first injection stream having a flow rate S1 produced by the carrier system and a second injection stream having a flow rate S2 produced by the enzyme system; a concentration of enzyme Cen,3 in the mixed injection stream established using the formula C en , 3 = ( C en , 1 · S 1 + C en , 2 · S 2 S 1 + S 2 ) , where Cen,1 and Cen,2 are the enzyme concentration of the first and second injection streams; and an underground water stream in fluid connection with the injection well and production well, the stream including water injected by the carrier system and enzyme solution injected by the enzyme system.