| Abstract |
Commercial Exploitation of the Ahuachapan Geothermal field started on June 1975 from reservoir conditions which were firstly evolutioned by well discharges and reinjection tests performed in the period 1968-1975. In these experiments, some 2 3 . 6 ~ 1 0 ~ and 1 . 7 ~ 1 0 ~ metric tons were extracted and reinjected respectively. This paper describes the wells and field behaviour over the period 1975-1985, in which the exploitation has been continuous and has had, for the first seven years, a massive reinjection of 160?C separated brine. Mass withdrawal from the field has had maximum rates in the order of 700 kg/sec and is approaching 2 0 0 ~ 1 0 ~ met r i c tons in this year. Reinjection rates were up to 300 kg/sec and amounted to 38x106 metric tons. As both extraction and injection have so far taken place in an area no more than 1 km2, a concentrated exploitation has been experienced. Since 1982, the field has been more carefully exploited to reduce risks in wells performance and to maintain in operation the three generating units although not to their full capacity. Parallel , this period has allowed to observe the behaviour of wells and field without reinjection, which is also discussed here. |