Hululais Prospect in Rejang Lebong, Bengkulu is one of the geothermal fields developed by Pertamina Geothermal Energy. The field is situated within the Bukit Barisan Mountain Range, an NW-SE volcanic arc of Sumatra, and located 8 km western from Musi Segment of Sumatra Fault Zone Zone. Based on field data from geological mapping, remote sensing analyses and borehole data these regional structures influence the occurrence of the NW-SE volcanic axis in Hululais Volcanic Complex (HVC). The Hululais Volcanic Complex (HVC) itself is a Quaternary volcanic complex which comprised of six crown units namely: (Bukit Resam, Suban Agung, Bukit Beriti, Bukit Gedang, Bukit Lumut and Bukit Pabuar) with its associated Hummocks and primary/secondary deposits. These NW-SE distributed of Subang Agung, Bukit Beriti and Bukit Gedang volcanic crowns can be grouped as Hululais Brigade. The manifestations distribution in Hululais also depict the influence of the NW-SE geological structure and its volcanic activity. This is validated by the presence of geothermal manifestation such as fumarole in the central of Hululais Volcanic Complex and hot spring in the medial – distal part of the field.
Lumut Balai is geothermal field that occurs in the caldera system, named Lumut Tua Caldera, approximately 9 km in diameter. Located in Penindaian Village, Muara Enim Regency, South Sumatra Province. Lumut Balai is one of the fields operated by Pertamina Geothermal Energy. The volcanism in Lumut Balai is closely related to the Sumatra Fault Systems activity. Surface data such as outcrops provide information regarding lithology, alteration type, and geological structures, while manifestations provide fluid geochemistry data. Subsurface data are acquired from rock cuttings and core samples (which are then further analyzed through petrographic analysis and XRD analysis), drilling parameters, and borehole image logging. These provide information and interpretation of subsurface geological conditions such as lithology distribution, alteration distribution, reservoir zone, heat source, and permeability. The methods above result in an interpretation of the Lumut Balai geological model. Lumut Balai is a geothermal system located within the Lumut Balai caldera, composed of andesite, andesite breccia, basaltic andesite, basalt, limestone, meta-sediment, tuff, and tuff breccia which are all altered to certain extents. There are five stratigraphic units, starting from the oldest to youngest are Tertiary Basement Unit, Pre-Old Lumut Unit, Pre-Caldera Unit, Caldera Unit, and Post-Caldera Unit. Alteration zones in Lumut Balai could be classified into smectite+chlorite zone, silica+chlorite zone, and chlorite+epidote zone. Productive faults in Lumut Balai are Air Ringkih Fault with NE-SW trend, Air Udangan Fault trending NE-SW, Lumut Tua Caldera and Gemurah Besar which trends N-S. This study aims to confirm the productive geological structure in Lumut Balai and gives better understanding for future field development, such as well targeting for makeup wells and reservoir simulation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.