A composition of an aqueous drilling fluid comprising a cationic formation control additive and potassium formate, wherein the cationic formation control additive contains a homopolymer, a copolymer or an oligomer of an allyl ammonium compound with a chemical structure of [(CH2=CHCH2)nN(CH3)4-n][X], wherein X is an anion and n is 1, 2, 3 or 4, and wherein the cationic formation control additive an