Stable Isotope Applications in Geothermal and Environmental Settings
Maria Victoria M. Olivar and Francis Edward B. Bayon
Geosciences Department, PNOC Energy Development Corporation
Abstract
Stable isotopes of oxygen and hydrogen (oxygen-18 and deuterium) have proven their usefulness in many scientific investigations. In the geothermal environment, these are used to determine the origin of the different types of waters as well as the identification of the reservoir or subsurface processes in response to steam production. Sulfur-34 and Oxygen-18 in sulfate are also utilized in geothermal evaluations, to determine the sulfur genesis in the geothermal waters and predict fluid temperatures. Isotopes of carbon (Carbon-13) are used in geothermal systems as well; although not as commonly as its application and use in the oil and gas setting (i.e., for source determination of hydrocarbons).
The paper will present several investigations where these isotopes are utilized. Case studies conducted by PNOC-EDC in some of its geothermal production fields show the usefulness of these isotopes in this environment. Few examples where other stable isotopes are utilized will also be discussed briefly. |
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