Chemical and physical reservoir parameters at initial conditions in Berlingeothermal field, El Salvador: a first assessment

A study has been made to obtain the main chemical and physical reservoir conditions of the Berlin _eld "El Salvador#\ before the commencement of large!scale exploitation of the geo! thermal resource[ The up~ow zone and the main ~ow path within the geothermal system have been determined from the areal distribution of chemical parameters such as Cl concentrationsratios such as Na:K\ K:Mg\ K:Ca\ and temperatures computed from silica concentrations and cation ratios[ Gas compositions have been used to calculate reservoir parameters such as temperature\ steam fraction and PCO1 [ The computer code WATCH "new edition 0883# has been used to evaluate the temperature of equilibration between the aqueous species and selected alteration minerals in the reservoir[ The ~uid in Berlin ~ows to the exploited reservoir from the south\ entering it in the vicinity of well TR!4[ Along its ~ow!path "south north direction#\ the ~uid is cooled by boiling and conductive cooling[ The chloride!enthalpy diagram indicates the existence of a parent water\ with a chemical composition similar to well TR!4\ that boils and the residual brine produces the ~uid of well TR!2\ which is very concentrated in salts[ The ~uid of TR!4 is probably produced from this parent water\ generating the ~uids of wells TR!1 and TR!8 by boiling\ and the ~uids of wells TR!0 and TR!3 by conductive cooling[ The computed values for the deep steam fraction clearly indicate that this is a liquid!dominated system\ with computed temperature values decreasing from 209>C "up~ow zone# to about 129>C\ from south to north[ 0888 Published by Elsevier Science Ltd on behalf of CNR[ All rights reserved[