A composition of an aqueous drilling fluid comprising potassium formate and a cationic formation control additive containing 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 and the potassium formate have a weight ratio with a range from about 75:25 to about 25:75.