“…Depth is given in feet (ft) and fracture gradients are given in pounds per gallon (ppg). Willis, 1957;Matthews and Kelley, 1967;Pennebaker, 1968;Eaton, 1969;Christman, 1973). Use of the Eaton method (Eaton, 1969;Eaton and Eaton, 1997), which considers overburden stress, Poisson's ratio, and pore-pressure gradient, is considered to be the most accurate and widely used of the methods for fracture gradient determination.…”