Administratively, the research area is located in around Cikopomayak Village, Jasinga, Bogor, West Java, Indonesia. Based on the Hydrogeological and Groundwater Basin Map, this research area was classified to non-potential groundwater basin. In addition, when the summer comes, the lack of water will be happened around the area. Consequently, the water reserve wasn't enough to fulfill the necessity of freshwater. Thus, the research about identifying aquifer location was needed. This research aims to determine the depth and thickness of aquifer for the alternative ways to overcome the problem, particularly, for the Cikopomayak Village. The research used the geophysical method by modeling the several data such as Geoelectric 1-D to know the aquifer location based on the section of medium resistivity value. Then, the geoelectric data was correlated to the borehole drilling data that is Gamma Ray (GR) Log, Spontaneous Potential (SP) Log, Resistivity Log, and the cutting data. Commonly, the most suitable lithology for an aquifer is sandstone because of its good characteristic of permeability and porosity. Logging data result will show the small value of GR log, SP Log leaning to the right, and low-value resistivity for indicating the aquifer zone. Based on geoelectric data, the research zone has 3 groups of resistivity value and lithology that are shaly claystone and siltstone with low-value resistivity (0 -50 Ω.m), sandy claystone, medium sandstone, and coarse sandstone with medium value resistivity (50 -150 Ω.m), fine sandstone, sandy claystone, and andesite with high-value resistivity (> 150Ω.m). The aquifer system in the research area was classified into 3 groups that are aquifer, aquitard, and aquiqlud.

Thick sediment (over 2,500 m), fractured basement and high thermal gradient (up to 19.10 C/100 m) of Central Sumatra Basin are suitable factors to have the Enhanced Geothermal System (EGS) potential. A number of 130 wells data were used to evaluate the EGS of the basin. The assessment is divided into the number of estimation within the grid cell (1x1 km) of sediment thickness, heat flow, thermal conductivity and technical potential calculated starting from basement-sediment layer interface. The distribution of heat flow and gradient thermal values correspond to the sediment layer. The autocorrelation test indicates the data is stationary. The variance of data gets bigger after a depth over 5.5 km. According to the Beardsmore protocol, the technical potential value ranged from 0.5 MW up to 4.7 MW at a depth of 3.5 km. In addition, the lowest technical potential is 0.66 MW and the highest is 5.76 MW at a depth of 4.5 km. The ordinary kriging, using the number of lags 10 in variogram modeling, estimated the technical potential distribution is higher to the southwest.