A water-base fluid for use in drilling wells and other drilling operation includes a shale clay which swells in the presence of water. The fluid preferably includes: an aqueous based continuous phase, and a shale hydration inhibition agent having the formula: H—(OR)x—[—NH—CH2—CH2—CH2—O—CH2—CH2—NH—]—(R′O)y—H wherein R and R′ are independently selectable alkylene groups having 2 to 4 carbon atoms, and wherein x and y have independently selected values such that the sum of x and y is at least 1. The shale hydration inhibition agent should be present in sufficient concentration to reduce the swelling of the shale clay. The fluid may be used for formulating drilling fluids such as water-base drilling muds or clear brine drilling fluids. The fluid may also be used in the slurrification and disposal of drill cuttings that contain water swellable clays or shale clays.