Shale gas development in Denmark with special reference to groundwater protection

Transcription

1 Shale gas development in Denmark with special reference to groundwater protection Geological Survey of Denmark and Greenland Danish Ministry of Energy, Utilities and Climate Ole Stig Jacobsen Niels H. Schovsbo, Jacob B. Kidmose, Peter Gravesen, Anders R. Johnsen M4ShaleGas - EERA, London, UK, February 2017

2 Energy consumption in Denmark 800 PJ Agriculture Household Service Industry Transport

3 Energy produced in Denmark Oil Coal Wind Gas Waste

4 North Sea gas Danish self-sufficiency until about 2024 Plan to phase-out coal and oil for heating before 2030

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6 USGS assessment of the gas potential in Denmark

7 Thermal maturity of the Palaeozoic interval Thermal maturity increase towards the Caledonian Fronts reflecting deep burial in L. Silurian-E. Devonian Maturity traditionally mapped using Vitrinite like particles (Buchardt & Lewan 1990). GEUS is currently re-addressing the origin of the vitrinitelike particles Buchardt et al. (1997) & Schovsbo et al. (2012) (Map under revision not up to date)

8 Danish unconventional gas resource An estimation of resources gave the result that the Alum Shale contains approx. 159 billion cubic meters of undiscovered technically recoverable natural gas, according to the US Geological Survey.

9 GEUS studies on Bornholm Billegrav-2 drilling in 2010: Funded by a scientific consortium consisting of GEUS, University of Copenhagen, University of South Denmark and the local authorities

10 Terne-1: TOC and Gamma Ray GEUS archive data Drilled 1985 by Amoco. Courtesy of Total E&P, Denmark B.V. 10

11 TOTAL in Denmark

12 Vendsyssel -1; geological model USGS Undiscovered Gas Resources in the Alum Shale, Denmark, 2013

13 The environmental risks What are the environmental risks associated with shale gas drilling and hydraulic fracking? Water The main questions: Is the water resources sufficient? Does shale gas drilling and hydro-fracking cause contamination of drinking water wells? Does produced water disposal cause long-term ecological effects and health risks? Is the handling of wastewater safe in regards to surface water and groundwater?

14 The environmental risks What are the environmental risks associated with shale gas drilling and hydraulic fracking? Solid Waste The main questions: Are the temporary deposits sufficient safe? Does drilling and wastewater solids disposals cause contamination of the groundwater? Does disposal solid waste with heavy metals and xenobiotic compounds by leaching cause long-term ecological effects and health risks? Does disposal of radioactive solid waste cause long-term ecological effects and health risks?

15 Water resources and demand Determination of baselines and monitoring should be based on a local characterization of the hydrogeological system to: 1. identify areas where water flow or groundwater level will be affected least 2. designing an optimal monitoring network for streamflow and groundwater levels 3. be able to implement remediation of inappropriate influences.

16 Water balance in Denmark Net precipitation

17 Water consumption in relation to water resources The average water consumption of seven US shale formations is about 18,000 m 3 / well, but with a span of 2000 to 100,000 m 3 / well. The effect of water abstraction for shale gas must always be assessed from a local analyses and modeling of the water balance Water abstraction for shale gas production can affect water flow in particular small groundwater fed streams.

18 River discharge in Denmark Median discharge L s -1 km -2

19 Calculation of usable areas in Denmark 3 area Sweetspot area Urban area Water protection Natura 2000 Forest COMBINED

20 Water resources and demands Compilation of area interests within the on shore sweet spot areas in Denmark All Sweet spot areas Upper sweet spot areas ( km ) Deeper sweet sport areas ( 5-7 km ) km 2 % km 2 % km 2 % Sweet spot OSD Urban areas Natura Forest Protected nature ( 3) Combined* * Denmarks total onshore area is 44,000 km 2

21 Flowback water and produced water Potential effects of inorganic substances Inorganic substances in flowback water from hydraulic fracking has a high content of inorganic substances, TDS and salts in dissolved form A comparison of the mean content of salts in formation waters from deep onshore wells shows an exceed the limit of EU Drinking Water Directive, recommended values of the WHO and the US Environmental Protection Agency (US EPA)

22 Methane in drinking water wells There is observed high concentrations of methane in drinking water wells around producing shale gas wells in the United States. A high concentration of methane is not synonymous with contamination from shale gas abstraction Biologically produced methane (biogenic methane) in groundwater occurs in many groundwater aquifers Shale gas contains thermogenic methane which is formed deep in the subsoil indicates a leak (natural or induced) for example from a deep drilling, a gas pipeline or faults.

23 Produced water inorganic salts USA: wastewater ,300 m 3 / well during 5 10 years First 6 months: % Formation water: % Fracking liquid: 4 8 % Reference: Kondash et al., 2017 Inorganic salts in brines from onshore wells in Denmark, g / L

24 Management of produced water Inject underground through a disposal well (onsite or offsite) Discharge to a nearby surface water body Haul to a municipal wastewater treatment plant Haul to a commercial industrial wastewater treatment facility Reuse for a future fracking job either with or without treatment

25 Accidental spills and poor handling of waste Potential effects of contaminated soils Waste from fracking, drilling muds and / or formation water to land may occur by accident due. Fracking fluid, salts and hazardous organic compounds, metals and radioactive substances can damage soil quality, which is considered as the main risk of spillage and may affect the underlying groundwater.

26 Cuttings and solid waste

27 Radioactive substances: (TE)NORM Shales and Alum Shale formations contain radioactive minerals and decay products from these Sewage, drill cuttings, precipitations and produced gas could therefore contain radioactive material such as uranium, thorium, radium and radon. The radioactivity in the waste material from the drilling, sewage etc. must be examined regularly during the drilling process to determine the waste fate. Radioactive substances in the wastewater, especially radium, can be a significant problem in relation spreading, and accumulation in the environment / groundwater

28 Trace elements in Alum shales (mg/kg) Area Well Outcrop Formation Skåne-1 Scania, Sweden Albjära Alum Shale Bille-2 Bornholm, Denmark Billegrav-2 Alum Shale Öland-1 Öland, Sweden Öland Alum Shale As Ba Ce Cr Cs Cu Nd Ni Bille Öland Skåne Pb Rb Th Sr V Y U Bille Öland Skåne

29 Content of trace metals in Scandinavian Alum Shale Kattegat (Terne-1 well, data cited from Schovsbo 2012a), Oslo area (data cited from Gautneb & Sæther 2009), Scania (Gislövshammar-2 well, data cited from Buchardt et al. 1997), Bornholm (Billegrav-2 well, data cited from Schovsbo 2012b). Element Unit Kattegat Oslo area Scania Bornholm Average Max. Min. Average Max. Min. Average Average Max. Min. Th mg/kg Ba mg/kg Cd mg/kg ,6 Co mg/kg Cu mg/kg Pb mg/kg Mo mg/kg Ni mg/kg U mg/kg V mg/kg Zn mg/kg Radium found in Bornholm Billegrav showed 51, 104 and 118 mg/kg

30 Monitoring requirements In addition to the environmental parameters identified in the baseline survey, Member States should ensure that the operator monitors the effects of operational parameters: a) the exact composition of the fracturing fluid used in each well b) the amount of water used for fracturing for each well c) the pressure used in the high-volume fracturing d) the liquids that come to the surface after hydraulic fracturing: backflow, quantities, properties, amounts recycled and / or treated volumes for each well

31 Dissemination of information a) the operator publishes information about the chemical substances and the amounts of water intended to be used and the quantities that ultimately was used for high volume hydraulic fracturing for each well. Information should include a list of names and CAS numbers (Chemical Abstracts Service) for all substances and include a safety data sheet, if available, and the maximal concentration in the fracturing fluid b) the competent authorities should disclose the following information on a public website within 6 months after publication of this Recommendation and thereafter at least every 12 months: i) the number of completed wells and planned projects involving hydraulic fracturing high volume ii) the number of licenses issued, the names of the operators involved and of authorization conditions iii) baseline survey and monitoring results.

32 Responsibility Member States should ensure that the operator has a financial guarantee or equivalent, which covers the permit and potential liabilities for environmental damage before the start of activities involving high-volume hydraulic fracturing.

33 Status at present in Denmark TOTAL Exits Shale Gas Exploration In Dybvad, Denmark Reuters Wednesday, June 1, :32am Denmark will evaluate the project before the government decides whether to issue new licenses for shale gas explorations, according to Lars Christian Lilleholt, Danish minister for energy, utilities and climate.

34 Thank you for your attention This presentation is part of a project that received funding by the European Union s Horizon 2020 research and innovation programme under grant agreement number The content of this presentation reflects only the authors view. The Innovation and Networks Executive Agency (INEA) is not responsible for any use that may be made of the information it contains.