Modeling the Pauzhetsky Geothermal Field, Kamchatka, Russia

Abstract

The forward TOUGH2 modeling study of the Pauzhetsky geothermal field (Kiryukhin and Yampolsky, 2004) was followed by an iTOUGH2 analysis to obtain more reliable reservoir parameter estimations. The model was automatically calibrated against (1) natural state and (2) production data. For the natural state modeling, calibration data include 68 points (2 natural discharge rates, 14 reservoir pressures at -250 m.a.s.l., and 52 reservoir vertically averaged temperatures). The different quality of the calibration points was expressed by specifying appropriate standard deviations. Preliminary estimates of the principal parameters are: (1) permeability k = 83 mD, and (2) an upflow rate Qb = 46.5 kg/s. For the modeling of the exploitation phase, calibration data include 60 datasets: enthalpies of the exploitation wells (10 data sets), pressures in monitoring wells (24 data sets), and temperatures in monitoring wells (26 data sets), with a total of 15,030 calibration points. The following parameters are estimated: (1) reservoir fracture porosity, (2) basement porosity, and (3) infiltration “window” permeabilities. Model calibration will be followed by an analysis of the sustainable capacity of the Pauzhetsky field.