TITLE:
Reservoir Processes Related to Exploitation in Los Azufres (México) Geothermal Field Indicated by Geochemical and Production Monitoring Data
AUTHORS:
Víctor Manuel Arellano, Rosa María Barragán, Miguel Ramírez, Siomara López, Alfonso Aragón, Adriana Paredes, Emigdio Casimiro, Lisette Reyes
KEYWORDS:
Los Azufres Geothermal Field, Well Simulation, Fluid Geochemistry, Well Bottom Conditions, Production Wells
JOURNAL NAME:
International Journal of Geosciences,
Vol.6 No.9,
September
28,
2015
ABSTRACT: A combined analysis of
geochemical and production data of 39 wells of the Los Azufres (Mexico)
geothermal field (227.4 MWe) over time was developed to investigate the
exploitation-related processes for 2003-2011. In the south zone, important
effects of reinjection were observed through Cl increases in some wells (up to
8000 mg/kg) while in wells with significant boiling, Cl has decreased. In most
of the north zone wells, the variations in gas data indicated boiling and
condensation of a highly gas-depleted brine, which seems to consist of
reinjection fluids. It is suggested that this process maintains the production
in the zone relatively stable. The main reservoir exploitation-related
processes found were: 1) production of reinjection returns; for this, it was possible
to distinguish a) wells that produce liquid and steam from injection, and b)
wells that produce steam from injection and sometimes condensed steam from
injection; 2) boiling: two types of boiling were identified: a) boiling with
steam gain, and b) boiling with steam loss. The results indicated that an
effective reservoir recharge occurs since very moderate production declining
rates were found.