CO 2 natural analogs generated by methane oxidation in the Upper Silesian Basin, Czech Republic: experience from CO2 monitoring

Transcription

1 CO 2 natural analogs generated by methane oxidation in the Upper Silesian Basin, Czech Republic: experience from CO2 monitoring J. Francu 1, F. Buzek 1, P. Hemza 2, V. Hladík 1

2 CO2 natural analogs generated by methane oxidation in the Upper Silesian Basin, CZ: experience from CO2 monitoring Objectives 1. To find and map CO 2 and CH 4 emissions from the soil and subsurface associated with coal mining, petroleum systems, and deep biosphere 2. To collect evidence of genetic relationship between CO 2 and methane at surface and deep conditions 3. To improve the understanding of the effect of microbial oxidation of hydrocarbons on surface CO 2 monitoring in the Upper Silesian Basin

3 Mining related gas emissions Upper Sileasian Coal Basin Hranice - Teplice Fault Zone Natural CO2 Emission

4 CO2 natural analogs generated by methane oxidation in the Upper Silesian Basin, CZ: experience from CO2 monitoring Regional Tectonic Setting: Variscan x Alpine-Carpathian

5 Lithostratigraphy: West Carpathians Cerpathian Foredeep Upper Carboniferous of the Upper Silesian Basin Stratigraphic position of - source rocks -gas - oil reservoirs

6 Location of gas samples in the subsurface in the WE section 1. Carpathian Fold & Thrust Belt 2. Miocene Foreland Basin Surface monitoring 3. Paleozoic European Platform below the Carpathians

7 CO2 natural analogs Crustal/Mantle origin Gas sampling and Flux measurement Ecoprobe 5 GPS Garmin Snow disappearing on CO2 emissions Chamber with ventilator Geršl & Francu 2008

8 Seasonal variation of CO2 in soil gas above Teplice n.b. cave system Temperature CO CO2 2 (%vol) [obj. %] CO 2 (%v) Temperature Teplota [ C] ( C) /1/2004 2/17/2005 9/5/2005 3/24/ /10/2006 4/28/ /14/2007 6/1/2008 PLYN PR.ryb PLYN PR.pul1 PLYN PR.pul2 T PR.p T PR.ryb T PR.pul1 T PR.pul2 Geršl & Francu 2008

9 Interpreted Gas origin - Teplice & Hranice CO 2 in gas pools in the caves 13 C = -7,1 PDB (Šmejkal et al. 1974) 13 C = -5,0 PDB (Hladíková 1988) 3 He a 4 He Hranice 3 He/ 4 He = 4, (Meyberg a Rinne 1995) 13 C = -4,9; -3,1 PDB (Geršl,J. Franc ) CO 2 from mineral water, R-1 well Kropá v spring" 13 C = -4,2 PDB (Michalí ek et al. 1994) Crustal CO 2 Up.. Mantle ca 40 km

10 CO2 natural analogs in the Upper Silesian Basin SAMPLING SITES ABOVE COAL MINES COAL SEAM GAS OVER THRUST WEATHERED CRUST BASAL CLASTICS MIOCENE OLD WORKINGS GOB GAS CARBONIFEROUS DEVONIAN

11 CO2 natural analogs generated by methane oxidation in the Upper Silesian Basin, CZ: experience from CO2 monitoring Vegetation damage on methane + CO 2 site

12 Maps of Soil Gas Composition Contour maps based on 121 data Each probe 0.8 m CO 2 Portable instrument: Ecoprobe 5: CH4 Total HC CO2 O2 Location of increased emissions Site #1 Jn

13 Map of Methane in Soil Gas

14 Map of O 2 in Soil Gas

15 3D-Map of O 2 in Soil Gas (ECOPROBE 5)

16 3D-Map of CO 2 hydrocarbons and O2 in soil gas

17 Wet Gas C1/(C2+C3) Dry Gas Microbial Methane Gas 5% 10% 25% 50% Type II Genetic Types of Gases in Upper Silesian Basin 13 C (CH4) Isotopic comp. Gas Dryness C1/(C2+C3) 1. Type - Microbial Isotopically light Heavy 13 C(CH 4 )( ) 2. Type - Thermogenic

18 C = 90 Microbial Methane C = 40 Thermogenic Atm CH 4 aco C =5 Surface samples: CO 2 and CH 4 isotopic composition 13 C(CO 2 ) <1m <5m <35 m C = 13 C CO2-13 C CH C(CH 4 )( ) Origin: Subthrust gas system Below the West Carpathians (Paskov)

19 13 C(CO 2 ) C = 90 Microbial methane Atm CH 4 aco 2 C = 40 Thermogenic methane C(CH 4 )( ) C =5 <1m <5m <35 m C = 13 C CO2-13 C CH4 Surface sampling: CO 2 and CH 4 isotopic composition Above Old Mine Workings with microbial methane

20 Isotopic Analysis of CH 4 and CO 2 13 C(CH 4 and CO 2 )( ) Initial Methane oxidation Carbonate dissoution CO 2 Closed system CO 2 Thermogenic CH 4 Microbial CH Isotopic Fractionation Factor Extent of carbon fractionation during methane oxidation Closed system X Migration and Mixing 13 C CO C CH

21 Amount of methane and CO 2 x Isotopes Oxidation Reduction 100 Gob Gas CH 4 rich CH4 and CO2/(CH4+CO2) (% relative) Residual CH 4 methane oxidation Initial pore gas CO2 reduction CH 4 poor CO 2 rich CO 2 poor Isotopic Fractionation Factor 13 C CO C CH

22 Temperature and Depth range of microbial activity Microbi robial l methan ane generation and oxidation is limited by Temp< C Critical Temp occurrs at depth m

23 GIS - Surface Geology - 13 C methane

24 GIS - Surface and Subsurface Geology Upper Carboniferous Coal Bearing Strata

25 CONCLUSIONS On-site and laboratory analysis provides evidence on: Episodical CO2 emissions from deep fault system (Teplice - Hranice) CO 2 associated with methane from petroleum system CO 2 associated with microbial methane from old workings (gobs) Genetic relationship between CO 2 and microbial methane oxidation For CCS - distingush amongue genetic types and their proportions in mixed CO 2 gases!

26 Thank you for your attention