The permeable zone is one of the important parameters in the geothermal system. Its existence is influenced by fractures or faults generated within the geothermal reservoir. Due to the continuous influence of both high temperature and pressure, reservoir rocks are stressed and tend to cause a fracture. Unfortunately, some fractures are generally not continuous to the surface, so that geological data are not able to map out the presence of this structure. While the presence of the fracture zone greatly facilitates fluid mobility in the reservoir including heat transfer from the heat source convectively. Mapping the presence of a subsurface fracture zone is not easy. The study aims to identify the existing fracture zone through curve splitting analysis of MT data (magnetotelluric). The data used here is synthetic MT data. The fracture zone is a heterogeneous zone and anisotropy for EM waves. Splitting TE and TM curves will happen when the MT wave passes through this zone. The analysis of curve splitting provides depth penetration value. Therefore, the existence of fault as the cause of curve splitting can be mapped. From the results of forward modelling, the curve splitting approach can map very well the existence of the subsurface fault. For medium/rock resistive, the deviation of its dip value is only 1.36%. When the rock medium is highly conductive the deviation of its dip value up to about 3.48%. This is due to the absorption of EM waves by the conductive layer so that it is not effective in mapping the underlying layer.
|Journal||Journal of Physics: Conference Series|
|Publication status||Published - 8 Mar 2021|
|Event||10th International Conference on Theoretical and Applied Physics, ICTAP 2020 - Mataram, West Nusa Tenggara, Indonesia|
Duration: 20 Nov 2020 → 22 Nov 2020