University of Hull logo

Tectonic evolution of the Southern Negros Geothermal Field and implications for the development of fractured geothermal systems

Pastoriza, Loraine R.; Holdsworth, Robert E.; Mccaffrey, Kenneth J. W.; Dempsey, Edward

Authors

Loraine R. Pastoriza

Robert E. Holdsworth

Kenneth J. W. Mccaffrey

Profile Image

Dr Edward Dempsey E.Dempsey@hull.ac.uk
Lecturer in Structural Geology, Programme Director (Geology and GPG)



Contributors

Abstract

Fluid flow pathway characterisation is critical to geothermal exploration and exploitation. In fractured geothermal reservoirs, it requires a good understanding of the structural evolution together with the fracture distribution and fluid flow properties. A fieldwork-based approach has been used to evaluate the potential fracture permeability characteristics of a typical high temperature geothermal reservoir in the Southern Negros Geothermal Field, Philippines. This is a liquid-dominated resource hosted in the andesitic Quaternary Cuernos de Negros Volcano, Negros Island. Fieldwork reveals two main fracture groups based on fault rock characteristics, alteration type, relative age of deformation, and associated thermal manifestation, with the youngest fractures mainly related to the development of the current geothermal system. Fault kinematics, cross cutting relationships, and palaeostress analysis suggest at least two distinct deformation events under changing stress fields since probably the Pliocene. We propose that this deformation history was influenced by the development of the Cuernos de Negros Volcano and the northward propagation of a major neotectonic structure located to the northwest, the Yupisan Fault. A combined slip and dilation tendency analysis of the mapped faults indicates that NW-SE structures should be particularly promising drilling targets under the inferred current stress regime, consistent with drilling results. However, existing boreholes also suggest that NE-SW structures can act as effective channels for geothermal fluids. Our observations suggest that these features were initiated as the dominant features in the older kinematic system and have then been reactivated at the present-day

Journal Article Type Article
Publication Date Nov 19, 2018
Print ISSN 1468-8115
Electronic ISSN 1468-8123
Publisher Hindawi
Peer Reviewed Peer Reviewed
Volume 2018
Article Number 6025038
Institution Citation Pastoriza, L. R., Holdsworth, R. E., Mccaffrey, K. J. W., & Dempsey, E. (2018). Tectonic evolution of the Southern Negros Geothermal Field and implications for the development of fractured geothermal systems. Geofluids, 2018, doi:10.1155/2018/6025038
DOI https://doi.org/10.1155/2018/6025038
Keywords General Earth and Planetary Sciences
Publisher URL https://www.hindawi.com/journals/geofluids/2018/6025038/

Files

Article (130.2 Mb)
PDF

Copyright Statement
Copyright © 2018 Loraine R. Pastoriza et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.



You might also like


Downloadable Citations