| Abstract |
ABS TRACT An estimate of the chemistry of the fluid within a geothermal reservoir is required to establish the geological source and the possible environmental impact of the fluid as well as scaling and corrosion problems which might develop during production. While a detailed analysis of the chemical composition of a geothermal fluid can only be obtained from a water sample, an estimate of the total dissolved solids (TDS) in equivalent sodium chloride (NaC1) concentration can be obtained from well logs. TDS can also be useful in geological correlation between wells. TDS can be determined direct l y from a pulsed neutron log and a porosity log , ( i f the type of formation is known), or from the water resistivity , %, and the temperature, T. method uses a dual induction focused log and information from the log heading. Next, is found by employing an electrical log and a porosity log. The last approach utilizes the spontaneous potential log and header data. Examples are provided to illustrate the techniques described which utilize calculated values of % to determine TDS. Three approaches are used to find R, and thus TDS. |