Kontrol Struktur Geologi Terhadap Permeabilitas pada Prospek Panas Bumi Muara Laboh
Regionally, the Sumatra Island is controlled by the Sumatra Fault (Great Sumatra Fault, GSF) with the NW-SE tredning. This fault was a "dextral strike slip fault system" that occur due to collision of Eurasian Plate (movement to North) and Indoaustralia Plate (movement to south). Muara Laboh geothermal prospect area located in the "step-over transtensional" between Suliti and Siulak Segment of Great Sumatra Fault. Geological structures in the prospect area showed a pattern structure is controlled by the "oblique divergent strike-slip fault system" (releasing bend) as a result of the right lateral movement of Sumatra Fault and form openings "dilation zone" between the two segments, also forming groups of normal faults "negative flower structure " which direction dominantly NW-SE and NS, with a relatively vertical angle. The pattern of these geological structures thought to control occurrence of Muara Laboh geothermal system, which is associated with the presence of surface manifestations. The presence of surface manifestations indicate good permeability zones as the conduit of geothermal fluid from subsurface to surface area. The results of geological and geophysical data integration indicate continuity of geological structures from subsurface to surface area. Permeability determined by the pattern of extensional structural geology and the presence of surface manifestations. The area with the extensional geological structure and surface manifestations will become the best drilling targets.
Dr. Eng Suryantini ST. Dipl. Geothermal Tech., M.Sc