Drilling into an active mofette: Pilot-hole study of the impact of CO2-rich mantle-derived fluids on the geo-bio interaction in the western Eger Rift (Czech Republic)

被引：20

作者：

Bussert, Robert ^{[1
]}

Kämpf, Horst ^{[2
]}

Flechsig, Christina ^{[3
]}

Hesse, Katja ^{[4
]}

Nickschick, Tobias ^{[2
,3
]}

Liu, Qi ^{[5
]}

Umlauft, Josefine ^{[3
]}

Vylita, Tomáš ^{[6
]}

Wagner, Dirk ^{[5
]}

Wonik, Thomas ^{[4
]}

Flores, Hortencia Estrella ^{[3
]}

Alawi, Mashal ^{[5
]}

机构：

[1] Institute of Applied Geosciences, Technische Universität Berlin, Berlin,13355, Germany

[2] GFZ German Research Centre for Geosciences, Section 3.2: Organic Geochemistry, Potsdam,14473, Germany

[3] Institute for Geophysics and Geology, University of Leipzig, Leipzig,04103, Germany

[4] Leibniz Institute for Applied Geophysics, Hannover,30655, Germany

[5] GFZ German Research Centre for Geosciences, Section 5.3: Geomicrobiology, Potsdam,14473, Germany

[6] Balneological Institute, Karlovy Vary,360 01, Czech Republic

来源：

Scientific Drilling | 2017年 / 23卷

关键词：

Sulfur compounds - Sodium compounds - Water - Faulting - Earthquakes - Reservoirs (water) - Calcium compounds - Sediments - Beverages - Drilling fluids;

D O I：

10.5194/sd-23-13-2017

中图分类号：

学科分类号：

摘要：

Microbial life in the continental deep biosphere is closely linked to geodynamic processes, yet this interaction is poorly studied. The Cheb Basin in the western Eger Rift (Czech Republic) is an ideal place for such a study because it displays almost permanent seismic activity along active faults with earthquake swarms up to ML 4.5 and intense degassing of mantle-derived CO2 in conduits that show up at the surface in form of mofettes. We hypothesize that microbial life is significantly accelerated in active fault zones and in CO2 conduits, due to increased fluid and substrate flow. To test this hypothesis, pilot hole HJB-1 was drilled in spring 2016 at the major mofette of the Hartoušov mofette field, after extensive pre-drill surveys to optimize the well location. After drilling through a thin caprock-like structure at 78.5 m, a CO2 blowout occurred indicating a CO2 reservoir in the underlying sandy clay. A pumping test revealed the presence of mineral water dominated by Na+, Ca2+, HCO3-, SO42- (Na-Ca-HCO3-SO4 type) having a temperature of 18.6 °C and a conductivity of 6760 μScm-1. The high content of sulfate (1470 mg L-1) is typical of Carlsbad Spa mineral waters. The hole penetrated about 90 m of Cenozoic sediments and reached a final depth of 108.50m in Palaeozoic schists. Core recovery was about 85 %. The cored sediments are mudstones with minor carbonates, sandstones and lignite coals that were deposited in a lacustrine environment. Deformation structures and alteration features are abundant in the core. Ongoing studies will show if they result from the flow of CO2-rich fluids or not. © Author(s) 2017.

引用

页码：13 / 27