Maibarara Power Plant

Company Profile Maibarara Geothermal Power  The development of Maibarara field started in the midseventies as part of the development of the Mak-Ban potential. However, due to the failure to define a field large enough to support a bigger capacity plant, the existing productive wells remained untapped and idle. The Maibarara resource was initially suspected to contain substantial reserve because of the presence of surface manifestations similar to those that had characteried well-known geothermal fields. These include fumaroles, hydrothermally altered ground emitting odor of H !" gas and low resistivity anomalies within the area. The first deepwell drilled, Maibarara #, was-initially completed at $%# m where a two-phased rig test suggested that the well flowed about &.$ kg'sec of high steam fraction at (.&( kg'cm well head pressure. However, when the well was developed, an extreme temperature reversal occurred that resulted in the damaging of the shallow production one. The well was found to be no longer commercial eventually. Maibarara )o. ! on the northern side of the hydrothermally-altered ground was also a failure. "imilar temperature reversal was encountered. The third well however was successful. *t is believed currently to tap the heart of the Maibarara geothermal field. +hile Maibarara )o. &%-ll"H was drilled as a slim hole and as such is not commercially productive. The #$  resource encountered extended from -&#/ m to the bottom of -#, 01! m elevation. "ubse2uent drilling of Maibarara, )umbers , $, /, % and ## has expanded the known productive area only slightly. "ignificant area expansion outside of the general Maibarara )o. &%-ll"H area has been unsuccessful in every direction so far. #n the southern part, two wells 3Maibarara 0 and (4 were drilled but intercepted hot formation only below -#,1/& m elevation with extensive cool rock above said depth. The inability of these two wells to flow had discouraged additional exploration towards the south.

5urther exploration was undertaken to determine the, boundary of the reservoir, with a total of twelve wells drilled for a period of six years. 5inally, it was concluded that Maibarara reserve is limited in sie, underpressured, and of limited capacity. *t has also been characteried as a high temperature resource with five wells surrently capable of supplying / 6g'sec at #1.% kg'cm wellrheacl pressure and at most ## M+ in 7utput.

The pro8ect is to be located in "itio apus, Barangay "an 9afael, "to. Tonas, Batangas, about /$ km south of Manila. The site is accessible from the "to. Tomas - alamba road thru a $ km feeder road.

Site Evaluation

:valuation of the candidate sites were made according to the following criteria; a. eothermal