IDENTIFICATION OF RESERVOIR THICKNESS OF IJEN (GEOTHERMAL PROSPECT AREA, INDONESIA) USING RESISTIVITY METHOD WITH SCHLUMBERGER CONFIGURATION

Abstract

This research has been conducted to study geothermal potential in the Ijen area of
Banyuwangi - East Java, Indonesia based on the resistivity method with Schlumberger configuration by using
a Nanura resistivity meter device, model NRD 22S, and Garmin GPS. This study aims to understand the
distribution and the thickness of the reservoir. The results showed that the lithology found in Ijen are tuff,
volcanic breccia, lava, sulfur, and a mix of sand and tuff is found with acidic create water. The reservoir is
characterized by a low resistivity value of tuff (10.49 Ωm – 89.78 Ωm). The reservoir of Ijen Geothermal
area is encountered at point 1 at a depth of 18.04 - 30.44 m with a thickness of 12.4 m and at a depth 63.38 m
– 90 m with a thickness 26.62 m, at point 3 at a depth of 73.93 m - 110 m with a thickness of 36.07 m and at
point 5 at a depth of 1.91 m - 24.95 m with thickness of 23.04 m and a depth of 32.56 m - 45 m with
thickness of 12.44 m. The 3D modeling is done on the resulting lithology, where reservoir which is the main
target of this study has a volume of 20.802.000 m3 which is about 42.7% of the total volume of the 3D model.