what is the psi of the subsurface
principal in-situ stresses in a subsurface formation, as summarized in the textbook Petroleum Production Systems (Economides and others, 1994), is given below. Vertical Stress The absolute vertical stress, Ï v, in pounds per square inch (psi) corresponds to the weight of the overburden, and is given by: Ï v = ÏD/144 where