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Second EAGE Sustainable Earth Sciences (SES) Conference and Exhibition
- Conference date: 30 Sep 2013 - 04 Oct 2013
- Location: Pau, France
- ISBN: 978-90-73834-53-8
- Published: 30 September 2013
21 - 40 of 74 results
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Study of Recorded Seismicity at the In Salah (Algeria) Carbon Capture and Storage Project
Authors A.L. Stork, J.P. Verdon and J.M. KendallThe In Salah Joint Venture carbon capture and storage project at Krechba, Algeria began injecting CO2 in 2004. This study makes use of microseismic event data recorded by a single geophone. Information from shear waves enables fracture directions and densities to be inferred and we find fractures striking N145°E, in agreement with the regional direction of maximum horizontal stress. There is no evidence for any temporal change in shear-wave splitting parameters in the time frame studied. This implies that CO2 injection is reactivating pre-existing fractures. We are able to obtain only very approximate event locations which suggest that events occur at or below the reservoir level, with no change over time.
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Effective Detection Capability of a Local Seismic Network
By E. GaucherIn applications such as geothermal energy, underground storage, mining, hydraulic fracturing, it becomes current practice to implement local seismic networks to monitor induced seismicity and to help mitigating the associated risks. In such contexts, it is crucial to guarantee that the network is able to detect a seismic event of predefined magnitude in a specific area. We propose a method to estimate this detection capability for existing kilometric-scale seismic networks which did not record any seismicity in the target zone yet. However, the network should be running for a time period long enough to record several local events listed in a reference catalogue. These earthquakes are used to calibrate an amplitude-magnitude relationship, knowing that the amplitudes are at the basis of the detection of seismic event candidates. This observation-based approach can take into account uncertainties in the magnitude estimate. The procedure was applied on the seismic network deployed over Bruchsal (Germany) geothermal field. Since mid-2010, no seismicity in the reservoir has been recorded by the network despite its good working order. The proposed technique suggests that there is 95% probability that no seismic event with ML ≥ 0.7 occurred below the network down to the reservoir depth at 2400 m.
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A Comparison of Geomechanical Effects at Three 'Megatonne' CO2 Storage Sites - Sleipner, Weyburn and In Salah
Authors J.P. Verdon, J.M. Kendall, A.L. Stork, R.A. Chadwick, D.J. White and R.C. BissellOne of the major leakage risks during CO2 sequestration operations is that injection-induced geomechanical deformation may compromise the integrity of the sealing caprock through the creation or reactivation of fracture networks. In this paper we examine three major commercial-scale storage sites where CO2 is injected at rates approaching or greater than 1 megatonne of CO2 per year: Sleipner, Weyburn and In Salah. We find that deformation is controlled by the pore pressure increase during injection, meaning that large aquifers with good flow properties, such as Sleipner, represent the best targets for CO2 storage. Mature hydrocarbon reservoir targets, such as Weyburn, may already have a complex stress history with decades of production and fluid injection. In such cases numerical modelling is needed to fully understand a geomechanical response to CO2 injection that may not be expected or immediately intuitive. Where pore pressures do become elevated, such as at In Salah, deformation is likely to be more pronounced. In such situations, a comprehensive geomechanical monitoring and modelling program is recommended. In addition to our site-by-site analysis, we assess the efficacy of seismic, microseismic and geodetic methods for monitoring geomechanical deformation during operations.
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Petrophysical Evaluation for a Geothermal Project in Tønder
Authors J. Sanchez and Y. OforiThe paper focuses on the petrophysical evaluation of wells for the development of a geothermal district heating plant in Tønder,Denmark. The evaluation was carried out by analysis and interpretation of available data. The data used included completion reports, well logs, conventional core and side wall core data. The results from interpretation of the data include total porosity, permeability, clay volume and effective porosity for three wells. An unusual finding was the inverse relationship between porosity and permeability in the targeted layer of the reservoir. This inverse relationship, maybe attributed to the precipitation of salt and the presence of caverns or fractures.
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Late Field Life of the East Midlands Petroleum Province - A New Geothermal Prospect?
Authors C.M. Hirst, J.G. Gluyas and S.A. MathiasProduction data for the East Midlands Petroleum Province has been reviewed in order to ascertain peak production volumes for both oil and water. This has been used to provide a quantification of the available geothermal resource located within Carboniferous strata within the oil field. A conservative initial estimate of 3.6 MWt has been calculated for the Welton field, based on peak production volumes of just under 350,000 m3/year. Lincoln City, located 6 miles west of the field, could obtain just over 5% of its heating requirement by exploitation of this geothermal resource. Modification of existing oil well infrastructure can produce a cost effective way to extend the field life of onshore oilfields, significantly reducing the costs that are usually associated with geothermal exploration.
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3D Seismic Exploration for Deep Geothermal Reservoirs in the Crystalline Basement in Germany
Authors H. von Hartmann, E. Lüschen, R. Thomas and R. SchulzA 100 sqkm seiscmic survey was acquired to search for faults in the crystalline basement of the Westerzgebirge (Saxony). The aim is to explore the crystalline basement for deep geothermal reservoirs over 5 km in depth . The subsurface is formed by large granitic intrusions which are partly covered by metaphorphc piles and the area is located in a main fault zone. The seismic image show a detailed structure of the granitic body and a complex fault system, which in this type was not predicted by the prelimenary study. The aim of the project, which is funded by the German Ministry of Environment, Nature Conservation and Nuclear Safety, is to adapt the seismic method for the exploration of deep geothermal reservoirs in the crystalline basement.
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Geothermal Fluid and Reservoir Properties in the Upper Rhine Graben, Europe
By I. StoberHydraulic and hydrochemical data from several hundred deep wells in three different geothermal reservoirs of the Upper Rhine Graben area in France and Germany have been compiled, examined, validated, and analyzed with the aim to characterize the fluids and reservoir properties for supporting geothermal projects. The hydraulic conductivity of the examined geothermal reservoir formations are quite different and reflect the diverse flow structures of the fractured and the karstified rocks. The hydraulic conductivity decreases very little with depth, probably because the Upper Rhine Graben is a young tectonically active structure. The chemical composition of the waters at shallow depth (500 - 800 m) results from intensive chemical interaction with the rocks. The total of dissolved solids increases with depth and thermal waters in the three different aquifer formations all grade into NaCl-rich saline fluids independent of the dominant reservoir rock.
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3D ERT in Boreholes for Mapping CAES Plume in Saline Aquifers
Authors S. Siebrands, S.A. Al Hagrey and W. RabbelRenewable energy resources are intermittent and need buffer storage to the bridge time-gap between production and demand peaks. North German Basin has a very large capacity for CAES in saline aquifers and cavities. Replacement of brine by gas in aquifer cause strong changes in electrical resistivity. Previously we have shown the applicability of 2D electric resistivity tomography (ERT) for monitoring sequestered CO2 in these reservoirs. Towards more real world problems, this paper aims at studying resolution of 3D ERT in boreholes for CAES mapping in deep saline aquifers. We used for this 3D surveys 3-9 vertical arrays of borehole electrodes installed surrounding the targets (caprock, aquifer, CAES plume, aquitard). We applied non classical electrode configurations of pseudo (optimized) and real 3D measurements in different boreholes. The results show that the applied 3D technique can generally map the dome structure targets with varying resolution, smearing and artefacts. However, resistivity amplitudes are less correctly recovered. The resolution increases with increasing number of borehole electrode arrays, increasing of layer thicknesses and the a priori fixing of boundaries in the inversion. Optimized 2D arrays have better resolution than the other arrays and thus needs to be developed to real 3D arrays.
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Lacq Pilot - The History of Selecting the Reservoir, Injecting and On-going Long Term Stability Demonstration
Authors C. Prinet, J. Monne and S. ThibeauTotal is committed to reducing the impact of its activities on the environment, especially its greenhouse gas emissions. It has been involved in CO2 injection and geological storage for over 15 years, in Canada (Weyburn oil field) for EOR and Norway (Sleipner, Snohvit) for aquifer storage. In 2006, the company decided to invest 60 million euros to experiment CO2 capture, transportation and injection in a depleted gas reservoir. The pilot in the Lacq basin, was on stream from January 2010 to March 2013. This paper summarizes the main features encountered during the whole life of the project from: storage site selection including risk analysis and environmental impact studies, baseline preliminary monitoring, injection and monitoring-verification plan conducted, up to post-injection monitoring plan and long term stability on-going demonstration. After three years of injection, the monitoring of the Lacq french pilot has demonstrated that the CO2 remains so far well confined within the reservoir. Reservoir behavior was also well anticipated by dynamic models (low monitoring-models offset). As anticipated, no problem of injectivity was detected either. The post-injection monitoring plan, based on an update of the risk analysis is now being reviewed by French administration. Long term stability demonstration is still on-going.
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Linking Microseismic Activity with CO2 Injection Data at In Salah, Algeria
Authors B.P. Goertz-Allmann, V. Oye, K. Iranpour, D. Kühn, E. Aker and B. BohloliWe analyse microseismic data from a pilot installation in the commercial sized CO2 injection project at Krechba, Algeria. Over 5000 microseismic events were detected from August 2009 to June 2011 using a master event waveform cross-correlation method. Most events can be directly related to the injection at well KB502. The period with the highest microseismic activity correlates with a period where the maximum applied pressure has most probably exceeded the minimum principal stress in the injection interval. Using S-P wave traveltime differences and event azimuth we can separate various distinct event clusters. Although an accurate event location is not possible due to the limited receiver network, the events most probably come from the injection reservoir interval. Moment magnitudes of the events have been determined and range between MW -1 and MW 0 with a few larger magnitude events up to MW 1. Differences in b-value between event clusters may give some insight about different types of fracturing and may be related to the in-situ stress regime.
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Regional Simulations of the Well-related Migration Risk at Weyburn, the World’s Largest CO2 Project
More LessThe IEAGHG Weyburn-Midale CO2 Monitoring and Storage Project is an industrial-scale geological storage project associated with enhanced oil recovery at the Weyburn oil field, Saskatchewan, Canada. To date, over 17 Mt of CO2 has been stored at 1.4 km depth. The storage site and four overlying aquitards are penetrated by a large number of oil wells. The Weyburn region has more than 4,000 wells within a risk assessment area of 2,000 km2. This well density is typical of prospective CCUS storage areas in the USA and Canada. The average well separation is 275 meters, with about 5% of the population less than 20 meters apart. These wells are considered to have an elevated risk potential for leakage pathways above the storage site. The high well density and regional scale presents a major challenge for flow modeling. We use a hydrodynamic invasion percolation approach, assuming capillary limit conditions, to simulate CO2 migration throughout the region at a high resolution. The resolution is sufficient to identify wells that lie along migration pathways and trap structures where leakage may occur. This indicates a subset of 62 wells within the regional population of 4012 wells that are marked for further risk assessment.
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The Validation of the Capture, Transportation and Storage of CO2 Sourced from a Coal-fired Power
Authors R.A. Esposito and G. HillIssues related to Carbon Capture and Storage (CCS) includes technical, economic, and public acceptance challenges. Only though field scale demonstration projects can industry address these challenges in preparation for commercial deployment. The capture component takes place at the James M. Barry Electric Generating Plant in Bucks, Alabama utilizing capture technology licensed by Mitsubishi Heavy Industries America. CO2 captured at the plant is being transported by pipeline for underground storage in a deep, saline geologic formation within the Citronelle Dome located in Citronelle, Alabama. A 12-mile pipeline was constructed to transport CO2 to the injection site located on the flank of Citronelle Dome. Operations started in 2012, up to 550 metric tons of CO2 per day, the equivalent emissions from 25 MW of the plant’s capacity are being captured. To date over 160 metric tons of CO2 have been captured and over 65,000 metric tons have been injected for storage. The injection target is the lower Cretaceous Paluxy Formation (a sandstone saline reservoir) which occurs at a depth of 2,865 meters (9,400 feet). Transportation and injection operations will continue for one to two years. Subsurface monitoring will be deployed through 2017 to track plume movement and monitor for leakage.
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Different Stimulation Strategies to Enhance the Performance of Subsurface Feat Exchangers Based on Tensile Fractures
Authors M.P.D. Pluymaekers, J.D.A.M. van Wees, G.C. Hoedeman and P.A. FokkerTensile fraccing in non-critically stressed tectonic environments, such as occur in large parts of the Netherlands, allows stimulation with a negligible level of seismicity. In this paper we analyse the performance of two tensile hydraulic stimulation strategies, for geothermal systems at large depth. In a reference case with reservoir temperature of 190C at 5 km depth, tensile fracturing can result in significant flow rates when multiple fractures are generated in a low permeable formation. LCOE range from 15 to 27 cts/kWh depending on subsurface conditions and costs for hydraulic stimulation. The economics of the case can be significantly enhanced by developing these subsurface engineering scenarios in higher subsurface temperature environments.
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Geothermal Simulation Applied to the Optimization of Underground Energy Storage Systems
Authors A. Yapparova, J.E. Mindel, M. Maierhofer and S.K. MatthäiTo optimize the design and to model the working cycle of an underground thermal energy storage facility (UTES) a geothermal reservoir simulator was created on the basis of the Complex Systems Modelling Platform C++ (CSMP++) software library (Matthhäi, et al., 2001) following two different approaches: a Boussinesq approximation and a full Pressure-Temperature-Enthalpy scheme (based on Coumou et.al. 2009). A series of benchmark tests were performed to assess efficiency and accuracy of both schemes, given the standard operating temperature ranges. The simulator is then used to determine optimal well locations and operating schedules for a UTES construction project.
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Fluid Flow Behavior of a Faulted Reservoir - Development of Hydraulic Models of Fault Zones
Authors M. Loubaud, S. Gentier, X. Rachez and J. RissFlow and transport modeling of a deep faulted geothermal reservoir is necessary to optimize the heat exploitation. To build these models, a good understanding of the fluid flow in the faults is an important issue. To improve the knowledge of the main flow paths in a geothermal system like the one of Soultz-Sous-Forêts, we propose an approach based on the development of a hydraulic model of fault zones. The flow model is based on the identification of hydraulically efficient segments along the fault zone which are associated conceptual model. The integration of geological and structural data leads to the construction of a numerical model based on a DFN approach. It allows the evaluation of an equivalent permeability. It is a first step towards a more global reservoir model where the fault zone is assimilated to a single disk. Indeed, defining more precisely the main hydraulic and transport properties of fault zones should permit to be more consistent with the tectonic and structural history of the reservoir and thus the improvement of the reservoir modeling.
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Double-difference Tomography for Geothermal Reservoir Characterisation - A Case Study at Paralana, South Australia
Authors J. Albaric, M. Calò, S. Husen, V. Oye, V. Maupin and M. HastingWe performed a series of tests for passive seismic tomography with data from Paralana, a new Enhanced Geothermal System (EGS) located in South Australia. An injection well was drilled at Paralana in 2009 into a sedimentary basin down to a high heat-producing basement at ~4000 m depth. The first main hydraulic stimulation of the well took place in July 2011 in order to create/enhance a geothermal reservoir. Induced seismicity was monitored by a network of 20 stations (from surface to 1800 m depth) and more than 7000 microearthquakes were detected during the five days of injection. The synthetic tests indicate that small velocity heterogeneities into the reservoir can be resolved at Paralana if high-precision relative arrival times are used, such as provided by waveform-cross correlation. Preliminary results indicate a low P-wave velocity anomaly at the base of the well.
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Monitoring of Underground Gas Storage Sites by Elastic 2D Time-lapse Waveform Inversion
Authors D. Köhn, S.A. Al Hagrey and W. RabbelMitigation of anthropogenic green house gas GHG, including CO2 emissions in the atmosphere demand developments of renewable energy resources. However, most renewable energy sources are fluctuating and therefore need energy storage to match power supply and demand. One possible solution is energy geostorage by injecting compressed air in sealed underground structures. After a short introduction to the theory of time-lapse waveform inversion, the theoretical resolution of the isotropic elastic material parameters, as well as the density, will be demonstrated by a synthetic injection scenario using the Marmousi-II model as complex geological background model. Another, more realistic example is based on accurate simulations of the gas migration within a geological simple background model and the use of poroelastic equations to derive suitable effective media parameters.
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Feasibility Study of Applying Geoelectric and Gravity Techniques for CAES Reservoir Monitoring
Authors S.A. Al Hagrey, D. Köhn and W. RabbelMitigations of anthropogenic GHG demand developments of renewable energy resources. These energy resources are intermittent and need buffer storage to bridge the time-gap between production and demand peaks. North German Basin has a very large capacity for CAES in porous saltwater aquifers and salt cavities (natural and artificial). Replacement of brine by compressed gas in saline formations cause strong changes in electrical resistivity and density, and therefore justify the application of geoelectrics, electromagnetics and gravity etc. In this study we study the applicability of these geophysical techniques in mapping CAES reservoirs (pore and cavern) in the underground of NW Germany. Our constrained techniques of electric resistivity tomography in boreholes are able to highly resolve the unusual problem of super resistive air caverns within the extreme resistive salt rocks. For gravity techniques, we could determine the lowest detectable mass deficit and offset of double caverns (2-fold their depth) in the underground resulting from pore and salt cavern CAES at some study sites.
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Sustainable Management of our Basin Contained Crustal Services - An Australian Perspective
Authors T.J. Rawling and M. SandifordWith the advent of a number of new geo-energy technologies such as geothermal coal seam gas, shale gas and tight gas as well as geological storage of water, fuel and waste the demands on the shallow crust are becoming extreme, especially in our sedimentary basins. As a result the likelihood of resource conflict increases along with the potential for sterilization of potential future uses of portions of a basin due to poor planning (ie geothermal reservoirs used to store CO2). In this presentation we will present the current state of play with regard to Sustainable Sedimentary Basin Management in Australia and discuss a number of new research programs that are installing monitoring systems to assess the impact of developments in the shallow crust. We will also discuss the associated research being conducted into the modelling complex basin systems and the new integrated management workflows that are being developed to help scientists and policy makers sustainably manage these crustal services into the future.
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