<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Shale formations have been recently treated only as source rocks and sealing packages mainly of conventional deposits. At present shales, which have a considerable concentration of highly mature organic matter appearing in complexes of over 30 m thick are used as unconventional sources for natural gas production with the use of advanced drilling technologies. Natural gas production in such rock formations necessitates performing a horizontal section in the borehole and a big number of hydraulic fracturing jobs. The unconventional shale gas deposits have been prospected also in Poland for a couple of years. Exploration works mainly concentrate on a vast area passing from Pomerania through Mazowsze to the Lublin region in Poland. The analysis of the geologic analyses reveals that the most perspective are shales in the Lower Paleozoic at a depth of 2500 m in the eastern part to about 4000 m in the western part of the area. The paper is focused on the quantitative and qualitative evaluation of environmental impact of natural gas exploration works from unconventional deposits. Special attention was paid to the hydraulic fracturing jobs in shales, which create particular hazard for water and soil environment. These hazards already appear at the stage of preliminary works, when big quantities of chemicals and water for frac jobs are stored in the rig area, and then, during realization of works, when the spent hydraulic fracturing fluid may penetrate the water-bearing horizons in the caprock. The composition of fracturing fluid used in Gapowo B-1A well are given along with the results of chemical analyses of a few parts of spent fracturing fluid samples pumped out from the borehole. The fluid turned out to be high in salt (high specific electrolyte conductance (SEC) and total dissolved substances (TDS) and a high toxicity for most of the living organisms). For this reason the spent fracturing fluid should not enter the environment without control.</p></abstract>

Shale formations have been recently treated only as source rocks and sealing packages mainly of conventional deposits. At present shales, which have a considerable concentration of highly mature organic matter appearing in complexes of over 30 m thick are used as unconventional sources for natural gas production with the use of advanced drilling technologies. Natural gas production in such rock formations necessitates performing a horizontal section in the borehole and a big number of hydraulic fracturing jobs. The unconventional shale gas deposits have been prospected also in Poland for a couple of years. Exploration works mainly concentrate on a vast area passing from Pomerania through Mazowsze to the Lublin region in Poland. The analysis of the geologic analyses reveals that the most perspective are shales in the Lower Paleozoic at a depth of 2500 m in the eastern part to about 4000 m in the western part of the area. The paper is focused on the quantitative and qualitative evaluation of environmental impact of natural gas exploration works from unconventional deposits. Special attention was paid to the hydraulic fracturing jobs in shales, which create particular hazard for water and soil environment. These hazards already appear at the stage of preliminary works, when big quantities of chemicals and water for frac jobs are stored in the rig area, and then, during realization of works, when the spent hydraulic fracturing fluid may penetrate the water-bearing horizons in the caprock. The composition of fracturing fluid used in Gapowo B-1A well are given along with the results of chemical analyses of a few parts of spent fracturing fluid samples pumped out from the borehole. The fluid turned out to be high in salt (high specific electrolyte conductance (SEC) and total dissolved substances (TDS) and a high toxicity for most of the living organisms). For this reason the spent fracturing fluid should not enter the environment without control.

Environmental Impact of Exploration from Unconventional Gas Deposits in Poland

Faculty of Drilling, Oil and Gas, AGH University of Science and Technology in Kraków, al. A. Mickiewicza 30, 30-059 Kraków, Poland, phone +48 12 617 22 26, fax +48 12 634 00 52

Polish Geological Institute - National Research Institute, ul. Rakowiecka 4, 00-975 Warszawa, Poland, phone +48 22 459 20 25, fax +48 22 459 20 01

Ecological Chemistry and Engineering S

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Environmental Impact of Exploration from Unconventional Gas Deposits in Poland"}

Shale formations have been recently treated only as source rocks and sealing packages mainly of conventional deposits. At present shales, which have a...

Environmental Impact of Exploration from Unconventional Gas Deposits in Poland

Published Online: Jan 22, 2016

Page range: 703 - 717

DOI: https://doi.org/10.1515/eces-2015-0043

Keywords
natural gas, unconventional deposits, shale gas, exploration boreholes, environment, noise, drilling waste, hydraulic fracturing, fracturing fluid, spent fracturing fluid

© 2015 Jan Macuda et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Environmental Impact of Exploration from Unconventional Gas Deposits in Poland

Published Online: Jan 22, 2016

Page range: 703 - 717

DOI: https://doi.org/10.1515/eces-2015-0043

Keywordsnatural gas, unconventional deposits, shale gas, exploration boreholes, environment, noise, drilling waste, hydraulic fracturing, fracturing fluid, spent fracturing fluid

© 2015 Jan Macuda et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
natural gas, unconventional deposits, shale gas, exploration boreholes, environment, noise, drilling waste, hydraulic fracturing, fracturing fluid, spent fracturing fluid