Zimmermann, Günter

[["dc.bibliographiccitation.firstpage","228"],["dc.bibliographiccitation.journal","Geothermics"],["dc.bibliographiccitation.lastpage","239"],["dc.bibliographiccitation.volume","51"],["dc.contributor.author","Brehme, Maren"],["dc.contributor.author","Moeck, Inga"],["dc.contributor.author","Kamah, Yustin"],["dc.contributor.author","Zimmermann, Guenter"],["dc.contributor.author","Sauter, Martin"],["dc.date.accessioned","2018-11-07T09:38:41Z"],["dc.date.available","2018-11-07T09:38:41Z"],["dc.date.issued","2014"],["dc.description.abstract","In this study tectonic structural features and their hydraulic characteristics of fault zones were integrated into a consistent hydrotectonic model of the Lahendong geothermal reservoir, Indonesia. Moreover, these elements were analysed with respect to their relevance for the operation of the geothermal power plant at initial conditions, i.e. before the start of operation. The complex tectonic setting with volcanic activity provides evidence for relevant structural and hydrogeological elements, such as fault zones, surface spring discharge and joints at different spatial scales. The study area is highly variable with respect to hydraulic properties and chemical composition of the fluids. It consists of two types of fluids. Acid brine water with a pH of around 3 and an electrical conductivity ranging between 462011 mu S/cm and 9700 p,S/cm is characteristic for the reservoir in the North with temperatures up to 274 C. A moderate pH between 4 and 7, an electrical conductivity in the range of 400-1730 mu S/cm and temperatures of up to 340 C characterise the southern study area. The Lahendong geothermal field is subdivided into two sub-reservoirs. Faults are less permeable perpendicular to the strike of the faults than parallel to the strike. The characteristics of the complex reservoir system could be explained by the combination of hydrotectonics and hydrogeological parameters. Understanding the permeability distribution along fault zones is crucial to investigate subsurface fluid pathways as well as to sustainably use the reservoir. A compartmentalisation of the reservoir was derived from a stress field analysis of the tectonic elements and from hydrogeological observations. The information on underground fluid flow is essential to understand the subsurface flow of geothermal fluids. Here, the permeability of structures is identified as the limiting factor. (C) 2014 Elsevier Ltd. All rights reserved."],["dc.description.sponsorship","German Federal Ministry for Education and Research (BMBF) [03G0753A]"],["dc.identifier.doi","10.1016/j.geothermics.2014.01.010"],["dc.identifier.isi","000336778700019"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/33121"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Pergamon-elsevier Science Ltd"],["dc.relation.issn","1879-3576"],["dc.relation.issn","0375-6505"],["dc.title","A hydrotectonic model of a geothermal reservoir - A study in Lahendong, Indonesia"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","1088"],["dc.bibliographiccitation.issue","14"],["dc.bibliographiccitation.journal","ENVIRONMENTAL EARTH SCIENCES"],["dc.bibliographiccitation.volume","75"],["dc.contributor.author","Brehme, Maren"],["dc.contributor.author","Bloecher, Guido"],["dc.contributor.author","Cacace, Mauro"],["dc.contributor.author","Kamah, Yustin"],["dc.contributor.author","Sauter, Martin"],["dc.contributor.author","Zimmermann, Guenter"],["dc.date.accessioned","2018-11-07T10:12:02Z"],["dc.date.available","2018-11-07T10:12:02Z"],["dc.date.issued","2016"],["dc.description.abstract","Subsurface fluid flow of reservoirs in active tectonic regions is mainly controlled by permeability of fault zones. Therefore, the characterization of fault zones is an important step toward performance assessment of a reservoir. The fluid flow is controlled also by pressure and temperature conditions. In this context, we simulated pressure and temperature fields to elaborate on the influence of permeability on subsurface fluid flow in the Lahendong geothermal reservoir. Thermal-hydraulic simulation is performed using a finite element approach. Adjusting the permeability through 370 different cases, modeling results converged to the observed data within a misfit range of 0-7 %. The best fitting models identified a deep-seated fault that has previously not been traced at the surface. Simulated temperature distribution suggests a prominent convective heat flow, driven by an upward migrating and SW-NE oriented fluid flow. This hydraulic gradient causes a pressure drop along the reservoir. High-pressure patterns are used to constrain recharge areas, in addition to infiltration measurements. Discharge flow occurs from SW to NE migrating also upward toward the hot springs. In that frame, thermal-hydraulic simulations identified previously unresolved subsurface faults, which now allow a better understanding of the subsurface permeability and its influence on fluid flow."],["dc.description.sponsorship","German Federal Ministry for Education and Research (BMBF) [03G0753A]"],["dc.identifier.doi","10.1007/s12665-016-5878-9"],["dc.identifier.isi","000380141500020"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/40161"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","1866-6299"],["dc.relation.issn","1866-6280"],["dc.title","Permeability distribution in the Lahendong geothermal field: A blind fault captured by thermal-hydraulic simulation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]