Resistivity Analysis of Geothermal Area “T” Based on the Result of 2D Finite Element Inversion of Magnetotelluric Data

Abstract

Resistivity analysis of magnetotelluric data was made at geothermal area“T”, located in southern Indonesia. The process was based on the modeling result of 2D magnetotelluric data. And the data modeling was obtained with an inverse finite element method. This method is a numerical method, which requires discretization on the boundaries of the modeling domain. The modeling result of the magnetotelluric data shows relativity structure distribution on a scale of 0 ohm.m – 10 ohm.m at a height of 0 km – 1 km above sea level (clay cap), on a scale of 10 ohm.m – 100 ohm.m at a height of 0 km – 1 km below sea level (reservoir), and on a scale of 100 ohm.m – 1000 ohm.m at a height of 1 km – 2 km below sea level (heat source). The result of resistivity structure distribution can image the subsurface structure of a geothermal prospect area around 12 km2. Geothermal potency at geothermal area “T” was found up to 96 Mwe.