Papers by Gudmundur Fridleifsson
Goldschmidt2022 abstracts
HS Orka owns and operates 100 MW geothermal power plant at Reykjanes, Iceland. In August 2013 a t... more HS Orka owns and operates 100 MW geothermal power plant at Reykjanes, Iceland. In August 2013 a two phase tracer test, one for the liquid phase and one for the steam phase, was carried out in Reykjanes geothermal field. The objective was to explore hydrological properties and pathways in the geothermal system at Reykjanes. The chemical tracers chosen for this test were 2.7 naphtalene disulfonic acid (2.7 NDS) for the liquid phase and methanol for the steam phase. The two phase tracer was injected into an injection well located to the east of the main production field, directionally drilled and cased down to 719 m. Samples of both brine and condensate have been collected from the beginning from each of the production wells, frequently for the first month, then twice a week for one month and weekly after that. Achieved experience from the two phase tracer test, encourage a tracer test on a newly drilled well located on a proposed injection area, more than 1 km north east to the produc...
The DEEPEGS demonstration well at Reykjanes, SW Iceland, was drilled to a depth of 4,659 m and ca... more The DEEPEGS demonstration well at Reykjanes, SW Iceland, was drilled to a depth of 4,659 m and cased with a production casing to almost 3,000 m depth. The well was angled towards the main up-flow zone of the Reykjanes high temperature geothermal system. Based on alteration mineral assemblages, the bottom hole temperature is estimated to be approaching 600°C. The DEEPEGS project, supported by the EU Horizon 2020 research and innovation programme, has the principal aim to demonstrate the feasibility of Enhanced Geothermal Systems (EGS) for delivering renewable energy for European citizens. The DEEPEGS project was meant to demonstrate advanced technologies in three types of geothermal reservoirs, a high enthalpy system at Reykjanes with temperatures up to 550°C, and in two deep hydrothermal reservoirs in southern France with temperatures up to 220°C. The Reykjanes demonstrator is just about to be flow tested at TRL level 6 in expected environment. The flow testing and pilot study is ex...
The major energy companies of Iceland initiated the Iceland Deep Drilling Project (IDDP) to inves... more The major energy companies of Iceland initiated the Iceland Deep Drilling Project (IDDP) to investigate the deeper levels of hydrothermal systems and determine if utilizing supercritical fluids could increase power production from such wells by a factor of 5-10 relative to that from conventional geothermal wells. The primary objective of IDDP is to find >450°C supercritical geothermal fluids at drillable depths, and to study their physical and chemical nature and energy potential. Over the next decade this will require drilling a series of wells 4–5km deep. Such deep, hot wells present both technical challenges and opportunities for important scientific studies. Early in 2005 an Icelandic energy company will drill and flow test a 2.7 km deep well on the Reykjanes Peninsula at the southwest tip of Iceland, where the Mid-Atlantic Ridge emerges from the ocean. In 2006 the IDDP plans to deepen this well to 4.0 km, obtain several spot cores, and then carry out a second flow test at th...
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Enhanced/Engineered Geothermal System (EGS) generally requires well stimulation to enhance the in... more Enhanced/Engineered Geothermal System (EGS) generally requires well stimulation to enhance the injectivity to commercial levels. This stimulation step still constitutes a challenge to permit large-scale deployment of this renewable energy. The present work is focused on thermal stimulation, which is often underestimated, and very little investigated. However, it may constitute a key effect especially in geothermal wells, for which temperature differences between the fluid and the formation are expected (either intentionally during dedicated stimulation, or less intentionally during drilling and operations). Thermal stimulation can lead to both thermal shearing and thermal fracturing. We model both processes, respectively through analytical and numerical modelling, applied to two EGS demonstrators in the frame of the H2020-DEEPEGS project. The first demonstrator, located in Iceland, is characterized by very high rock temperature, and is likely to encounter high thermal stimulation (b...
The Iceland Deep Drilling Project (IDDP) is a research and development project that is investigat... more The Iceland Deep Drilling Project (IDDP) is a research and development project that is investigating the possibility of greatly increasing the power output of geothermal wells by producing high-enthalpy supercritical geothermal fluid from 4-5 km depths. The aim is to increase the power output per well by an order of magnitude. IDDP is a collaboration project of three energy companies - HS Orka hf (HS), Landsvirkjun (LV) and Reykjavik Energy (OR), and Orkustofnun (OS) (the National Energy Authority of Iceland) that was established in 2000 to investigate the feasibility of utilizing geothermal fluid at substantially higher temperatures and from deeper wells than currently used today. From the onset of the IDDP, international collaboration has been one of the trade mark of the project. Scientists from at least 15 countries have contributed to the science program in various ways by participating in workshops and by publishing articles in international journals. Since 2005 ICDP (Internat...
Journal of Volcanology and Geothermal Research, 2018
One of the World's premier field geologists, Kristján Saemundsson led immense geological mapping ... more One of the World's premier field geologists, Kristján Saemundsson led immense geological mapping programs and authored or co-authored nearly all geological maps of Iceland during the past half century, including the first modern bedrock and tectonic maps of the whole country. These monumental achievements collectively yield the most inclusive view of an extensional plate boundary anywhere on Earth. When Kristján began his work in 1961, the relation of Iceland to sea-floor spreading was not clear, and plate tectonics had not yet been invented. Kristján resolved key obstacles by demonstrating that the active rifting zones in Iceland had shifted over time and were linked by complex transforms to the mid-ocean spreading ridge, thus making the concept of sea-floor spreading in Iceland acceptable to those previously skeptical. Further, his insights and vast geological and tectonic knowledge on both high-and low-temperature geothermal areas in Iceland yielded a major increase in knowledge of geothermal systems, and probably no one has contributed more than he to Icelandic energy development. Kristján's legacy is comprised by his numerous superb maps on a variety of scales, the high quality papers he produced, the impactful ideas generated that were internationally diffused, and the generations of colleagues and younger people he inspired, mentored, or otherwise positively influenced with his knowledge and generous attitude.
Journal of Volcanology and Geothermal Research, 2018
The aim of the Iceland Deep Drilling Project is to drill into supercritical geothermal systems an... more The aim of the Iceland Deep Drilling Project is to drill into supercritical geothermal systems and examine their economic potential. The exploratory well IDDP-2 was drilled in the Reykjanes geothermal field in SW Iceland, on the landward extension of the Mid-Atlantic Ridge. The Reykjanes geothermal field produces from a b300°C reservoir at 1 to 2.5 km depth and is unusual because it is recharged by seawater. The well was cased to 3000 m depth, and then angled towards the main up-flow zone of the system, to a total slant depth of 4659 m (~4500 m vertical depth). Based on alteration mineral assemblages, joint inversion of wireline logging, and rate of heating measurements, the bottom hole temperature is estimated to be about 535°C. The major problem encountered during drilling was the total loss of circulation below 3 km depth and continuing to the final depth. Drilling continued without recovering drill cuttings, consequently spot coring provided the only deep rock samples from the well. These cores are characteristic of a basaltic sheeted dike complex, with hydrothermal alteration mineral assemblages that range from greenschist to amphibolite facies, hornblende hornfels, and pyroxene hornfels, allowing the opportunity to investigate water-rock interaction in the active roots of an analog of a submarine hydrothermal system. As they have not yet been sampled, the composition of the deep fluids at Reykjanes is unknown at present. Cold water is currently being injected with the aim of enhancing permeability at depth, before allowing the well to heat up prior to flow tests planned for early 2019. The well has at least two fluid feed zones, a dominant one at 3.4 km depth and a second smaller one at 4.5 km. Extensive geophysical surveys of the Reykjanes Peninsula completed recently allow correlation of geophysical signals with rocks properties and in-situ conditions in the subsurface. Earthquake activity monitored with a local seismic network during drilling the IDDP-2 drilling detected abundant small earthquakes (M L ≤ 2) within the depth range of 3-5 km. A zone at 3-5 km depth below the producing geothermal field that was generally aseismic prior to drilling, but became seismically active during the drilling. The drilling of the IDDP-2 has achieved number of scientific and engineering firsts. It is the deepest and hottest drill hole so far sited on an active mid-ocean spreading center. It penetrated an active supercritical hydrothermal environment at depths analogous to those postulated as the high temperature reaction zones feeding black smoker systems.
Scientific Drilling, 2017
The Iceland Deep Drilling Project research well RN-15/IDDP-2 at Reykjanes, Iceland, reached its t... more The Iceland Deep Drilling Project research well RN-15/IDDP-2 at Reykjanes, Iceland, reached its target of supercritical conditions at a depth of 4.5 km in January 2017. After only 6 days of heating, the measured bottom hole temperature was 426 • C, and the fluid pressure was 34 MPa. The southern tip of the Reykjanes peninsula is the landward extension of the Mid-Atlantic Ridge in Iceland. Reykjanes is unique among Icelandic geothermal systems in that it is recharged by seawater, which has a critical point of 406 • C at 29.8 MPa. The geologic setting and fluid characteristics at Reykjanes provide a geochemical analog that allows us to investigate the roots of a mid-ocean ridge submarine black smoker hydrothermal system. Drilling began with deepening an existing 2.5 km deep vertical production well (RN-15) to 3 km depth, followed by inclined drilling directed towards the main upflow zone of the system, for a total slant depth of 4659 m (∼ 4.5 km vertical depth). Total circulation losses of drilling fluid were encountered below 2.5 km, which could not be cured using lost circulation blocking materials or multiple cement jobs. Accordingly, drilling continued to the total depth without return of drill cuttings. Thirteen spot coring attempts were made below 3 km depth. Rocks in the cores are basalts and dolerites with alteration ranging from upper greenschist facies to amphibolite facies, suggesting that formation temperatures at depth exceed 450 • C. High-permeability circulation-fluid loss zones (feed points or feed zones) were detected at multiple depth levels below 3 km depth to bottom. The largest circulation losses (most permeable zones) occurred between the bottom of the casing and 3.4 km depth. Permeable zones encountered below 3.4 km accepted less than 5 % of the injected water. Currently, the project is attempting soft stimulation to increase deep permeability. While it is too early to speculate on the energy potential of this well and its economics, the IDDP-2 is a milestone in the development of geothermal resources and the study of hydrothermal systems. It is the first well that successfully encountered supercritical hydrothermal conditions, with potential high-power output, and in which ongoing hydrothermal metamorphism at amphibolite facies conditions can be observed. The next step will be to carry out flow testing and fluid sampling to determine the chemical and thermodynamic properties of the formation fluids.
Geophysical Monograph Series, 2010
ABSTRACT
The main goal of this development and research program in Iceland is to investigate interaction o... more The main goal of this development and research program in Iceland is to investigate interaction of high-temperature, supercritical (400-600 o C) hydrothermal fluids with basaltic crust in Iceland, where the Mid-Atlantic Ridge emerges from the ocean. The Iceland Deep Drilling Project (IDDP) is a long-term collaboration between a consortium of Icelandic power companies and the Icelandic government, together with two international partners, formed to investigate the economics of deeper, hotter, geothermal resources. The consortium agreed that the operators on the Reykjanes, Hellisheidi, and Krafla geothermal fields would each fund the drilling of a well 3 to 4 km deep and that the IDDP would fund the deepening these wells to >4 km deep, to reach temperatures >450 o C with the basic aim of exploring supercritical hydrothermal fluids as a possible energy source. Supercritical fluids have high enthalpy and greatly enhanced rates of mass transfer and chemical reaction. Drilling the f...
Scientific Drilling, 2013
A summary workshop report describing the progress made so far by the Iceland Deep Drilling Projec... more A summary workshop report describing the progress made so far by the Iceland Deep Drilling Project (IDDP) is presented below. The report provides recommendations concerning technical aspects related to deep drilling, and invites international participation in both the engineering and the scientific activities of the next phase of the IDDP. No issues were identified at the workshop that should rule out attempting the drilling, sampling and testing of the proposed IDDP-2 well. Although technically challenging, the consensus of the workshop was that the drilling of such a hot deep well, and producing potentially hostile fluids, is possible but requires careful contingency planning. The future well will be explored for supercritical fluid and/or superheated steam beneath the current production zone of the Reykjanes geothermal field in SW Iceland. This deep borehole will provide the first opportunity worldwide to directly investigate the root zone of a magma-hydrothermal system which is likely to be similar to those beneath the black smokers on the worldencircling mid-ocean rift systems.
The Iceland Deep Drilling Project (IDDP) well IDDP-2 was drilled to 4,659 m in the seawaterrechar... more The Iceland Deep Drilling Project (IDDP) well IDDP-2 was drilled to 4,659 m in the seawaterrecharged and basalt-hosted Reykjanes geothermal system in Iceland. Spot drill cores were recovered between drilling depths of 3,648.00 m and 4,657.58 m. Temperature and pressure conditions at the base of IDDP-2 were over 426oC and 340 bar immediately following drilling, exceeding the critical point of seawater (406oC and 298 bar). The IDDP-2 cores are the first samples ever recovered from the supercritical roots of an active basalt-hosted hydrothermal system. We provide some preliminary hand sample descriptions, supplemented where possible by thin section petrography and mineral composition analyses for the IDDP-2 drill cores. The cores recovered between 3,648 m and the bottom of the hole at 4,659 m are from a sheeted dike complex and are generally pervasively altered. Despite the extensive alteration, veining is relatively minor and open space veins are very rare. Veins tend to be discontinu...
The DEEPEGS Horizon 2020 Innovation action project “Deployment of deep enhanced geothermal system... more The DEEPEGS Horizon 2020 Innovation action project “Deployment of deep enhanced geothermal systems for sustainable energy business” was selected for funding in 2015, and its official launch was in December 2015. The project’s total budget of 44 million Euro received an EU grant of about 20 million Euro for its four years duration, making this one of the larger publicly funded H2020 projects. The consortium of 10 partner organisations is from the geothermal industry, technical and oiland gas sectors, and research organisations coming from five European countries. The main objective was to test and demonstrate Enhanced Geothermal System (EGS) technology in three different geothermal systems and geological settings with the goal of facilitating the transferability of the expected results to other deep geothermal sites throughout Europe and worldwide. The project has over its life cycle encountered several hurdles that have needed to be addressed by the consortium management. Number of ...
The Reykjanes and Krafla geothermal systems, located within the active rift zone of Iceland, are ... more The Reykjanes and Krafla geothermal systems, located within the active rift zone of Iceland, are both sites that will be drilled to 4-5 km by the Iceland Deep Drilling Project (IDDP). To effectively characterize geochemical and hydrologic processes occurring at these depths, it is essential to establish the source, composition and evolution of geothermal fluids. We use oxygen and hydrogen stable isotopes in hydrothermal minerals to resolve the fluid history in these IDDP geothermal systems. Here we report the results from existing drillholes to depths of ≤ 3 km. The stable isotope composition of hydrothermal epidote in the Reykjanes geothermal system demonstrates a complex history of fluid source and fluid-rock interaction since at least the Pleistocene. The chlorine concentration of modern
A summary workshop report describing the progress made so far by the Iceland Deep Drilling Projec... more A summary workshop report describing the progress made so far by the Iceland Deep Drilling Project (IDDP) is presented below. The report provides recommendations concerning technical aspects related to deep drilling, and invites international participation in both the engineering and the scientific activities of the next phase of the IDDP. No issues were identified at the workshop that should rule out attempting the drilling, sampling and testing of the proposed IDDP-2 well. Although technically challenging, the consensus of the workshop was that the drilling of such a hot deep well, and producing potentially hostile fluids, is possible but requires careful contingency planning. The future well will be explored for supercritical fluid and/or superheated steam beneath the current production zone of the Reykjanes geothermal field in SW Iceland. This deep borehole will provide the first opportunity worldwide to directly investigate the root zone of a magma-hydrothermal system which is likely to be similar to those beneath the black smokers on the worldencircling mid-ocean rift systems.
The IDDP-2 drilling project at Reykjanes, Iceland is a continuation of the ongoing Iceland Deep D... more The IDDP-2 drilling project at Reykjanes, Iceland is a continuation of the ongoing Iceland Deep Drilling Project (IDDP). It was launched in the year 2000 and the IDDP-1 well was drilled during 2008-2009 in Krafla, North Iceland. A 5 km deep well, IDDP-2, is proposed near the Reykjanes Power Plant in South-West Iceland. Expected enthalpy of superheated steam from the well is 2800 to 3100 kJ/kg, resulting in shut-off pressure of up to 250 bar and temperature of up to 480°C at the well head. The well head branch, mounted on the well head, consists of redundant valves, pipes and fittings designed to withstand these conditions with low risk of failure of critical components. The inside of these valves and fittings are coated with corrosion and erosion resistant stainless steel alloys. The branch is connected to two full flow lines and two test flow lines, the former being used for maximum well discharge, the latter for further studies of thermodynamics, fluid flow and chemistry of the we...
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Papers by Gudmundur Fridleifsson