The Kamojang Geothermal Field: 25 Years Operation

Abstract

Kamojang is the first Geothermal Field in Indonesia, and it is known as one of vapor dominated systems in the world. It first started producing steam in 1978 in order to generate electricity for its own use through a 250 KW monobloc unit. The first commercial operations of 30 MW started in 1982. Subsequently, an additional 110 MW started commercials operations in 1987. Further, a 60 MW unit is now under preparation to be constructed, and it is expected to be on line in 2006. In addition, the possibility of having another 60 MW unit is now being evaluated.

The current rate of mass withdrawal shows the unbalance of discharge and recharge induce decreasing of water level to deeper parts of reservoir. And, the 22 years continuous commercial production has led to slight decline in the well head pressure and temperature within the active production sector. As a result, 80% of 31 productive wells tend to approach superheated condition. The re-injection programmed may have slowed down this entire phenomenon, especially that of the reservoir being superheated.