The Importance of Volcanic Rocks and Thin Sediments on Thermal Gradient

Abstract

Temperature gradients determined from well bottom-hole temperatures were regressed against eleven variables, to understand what determines gradient variations. Sediment thickness and orogeny most successfully explain temperature gradient variations both within Colorado, California and Pennsylvania, and across the three states. In particular, thin sediments and volcanic rocks are most influential, and can predict within which interval temperature gradient will fall with statistical significance and an R(^{2}) value of 0.96. Harnessing abandoned oil and gas wells for geothermal heating can provide vast energy savings, as well as reducing the amount of methane they are leaking. In areas with high temperature gradients, these abandoned wells can even be used for steam generation.