Geothermal Well Targeting in Consideration To Geological Structures of Mataloko Field, Flores

Abstract

Mataloko is one of the geothermal fields on the island of Flores, East Nusa Tenggara, which is an area of exploration, production and is expected to be able to be used for electricity generation. Geologically, Mataloko area is quite strong affected by faults and fractures geological structures. Drilling geothermal well should be considered carefully in respond to active tectonic activity in Nusa Tenggara islands in particular Flores. Directional drilling should be planned in an area where geological structures are less affection to the well drill direction. Wae Luja – Ratogesa area is an example area where geological structures should be considered accurately. Results of geological mapping have significant attention to geological structures while geophysical data analysis should be heavily considered for subsurface geological structural analysis. Exploration shallow wells have been drilled to a depth of 756.47 meters showing temperature of above 185 degrees Celsius. Using geological as well as geophysical data analysis, it is interpreted that base of cap rock is approximately at the elevation of +855 masl to +20 masl. Combining the analysis results directional drilling could be planned carefully.