FORMATION DAMAGE IS ONE OF THE PRODUCTIVITY DECREASING AGENTS WHICH CAN HAVE MANY OTHER PROBLEMS CONSEQUENTLY; FORMATION DAMAGE MAY BE BECAUSE OF MANY DIFFERENT REASONS THAT ONE OF THEM IS USING UNSUITABLE AND UNDESIRED DRILLING FLUIDS, SO THIS PAPER INVESTIGATES CONVENTIONAL DRILLING FLUIDS AND THE PROBLEMS THAT EACH OF THEM CAN CAUSE IN THE FORMATION AND BOREHOLE, REPRESENTS A COMPARISON OF DIFFERENT PROPERTIES OF COMMON TYPES OF DRILLING FLUIDS INCLUDING OIL-BASED AND WATER-BASED VERSUS NANO-BASED TYPE, AND EVALUATES OTHER WORKS IN THE SAME FIELD, CURRENT INVESTIGATION AND EARLIER EXPERIMENTAL AND NUMERICAL STUDIES DEMONSTRATE THE SIGNIFICANT BENEFITS OF USING NANO-BASED DRILLING FLUIDS IN ORDER TO REDUCE FORMATION DAMAGE PROBLEMS CAUSED BY DRILLING FLUIDS AND THEIR EFFICIENT PROPERTIES.