Use of Observation Well Data in Determining Optimum Well Spacing and Recharge in a Geothermal Field (CERRO Prieto)

Abstract

Change of standing water level or pressure in an observation well within the drainage area of an exploited field can be analyzed to give an important well parameter which relates recharge, storativity, and total field drainage area. This parameter then can be used to determine the optimum well spacing within the field, assuming that the production rate and enthalpy do not change appreciably during the foreseen economic life of the field, and that the field can be considered approximately isotropic and "pseudo-porous." An example of this application is given using the data of the Cerro Prieto Geothermal Field, Baja California, Mexico, between May 1974 and March 1977, one expects changes in both enthalpy and production rate in years to come (usually a decline in production rate and an increase in enthalpy), the figures obtained may serve as first approximations of guidelines forth e field development.