Varies with reservoir environment. Many paramters need to be considered before reachin to a drilling fluid planning or preparation for employment during drilling. So, in short there is no one answer for the same.
I agree with Saket Kumar's opinion. This may lead to some multiobjective optimization problem formulation with no feasible solutions in the actual scenario. Even AI applications cant solve all the problems. However, at the lab scale, researchers are still trying to solve this problem with controlled experiments. Best of luck !!!!!