Drilling shale formations remains one of the biggest challenges to the drilling fluids industry. Successful drilling of swelling clay/shale sections requires specially formulated inhibitors to control the uptake of water into the formation and cuttings. Proper inhibition stops tight hole, sticky cuttings and unstable mud properties leading to massive dilution. Proper inhibition reduces drilling time and reduces mud costs. Specific amine chemistries have been shown to be particularly effective additives in many regions of the world. The OS CLAY HIB products offer some unique advantages over the common amines in use today.