MODEL INVERSI 2D PADA LAPANGAN PANASBUMI “BOGEL”, SUMATERA SELATAN MENGGUNAKAN TIGA DATA SETS BERBEDA; 2D INVERSION MODELS OF “BOGEL” GEOTHERMAL FIELD, SOUTH SUMATERA USING THREE DIFFERENT DATA SETS

NURDIANTORO, RAKHMAT, Imam Suyanto

2016 | Skripsi | FMIPA

Magnetotelluric (MT) is a geophysical method that is widely used in geothermal exploration. In MT method, there are geoelectrical and geological strike terminologies. In Indonesia, the research on these terms have not been commonly performed. In this study, 17 MT sites were used. Swift method was used to determine the geoelectrical strike. Geological strike was determined from the geological structure map. Here, the author found that geoelectrical strike was N158?E and the geological strike was N140?E. Then, the author conducted 2D inversion modelling using three data rotating in different angles (00, 1580, 1400). RMS error misfit of first 2D inversion models are 2.29% (line 1) and 2.41% (line 2). RMS error of the second 2D inversion models are 3.6% (line 1) and 2.63% (line 2). While, the RMS error of the third 2D inversion models are 2.23% (line 1) and 2.15% (line 2). These 2D inversion model results were compared to find a suitable model with geological study area. The conclusion of this study is that the geoelectrical strike and the geological strike are different. These differences can be influenced by rock resistivity and complex geological structure. The third 2D inversion models are the most suitable with the geological map. The model show the presence of reservoir rock (10 ?m – 100 ?m) and cap rock (<10 ?m) that is bordered by resistive bodies (>1000 ?m) and faults.

Kata Kunci : MT, geoelectrical strike, Swift, geological strike, 2D inversion models