Współczesny reżim tektoniczny w Polsce na podstawie analizy testów szczelinowania hydraulicznego ścian otworów wiertniczych
Abstract
Recent tectonic stress regime in Poland based on analyses of hydraulic fracturing of borehole walls.
S u m m a r y. Magnitudes of the recent tectonic stress were estimated based on the hydraulic fracturing data from Poland. In spite of a low quality of the tests, consistent results for particular regions were obtained. For the Outer Carpathians three hydraulic fracturing tests indicate strike-slip stress regime with the local deviation towards the thrust fault regime. Along the front of the Carpathians within the foredeep complex and its basement, low intensity of strike-slip regime with local tendency towards normal fault regime is revealed from tests performed in four wells. Stable, strike-slip stress regime is determined for the Lublin Basin, based on fracturing tests from four wells. Singular result from the Fore-Sudetic Monocline suggests normal fault stress regime for the Permian complex below Zechstein evaporates. Heterogeneity of the stress field within each of these regions is presumably controlled by tectonic structures inherited after the Variscan and the Alpine epochs. For the SE part of Poland, an estimation of the general trend of stress increase with depth gives 2.9 MPa/km for the maximum horizontal stress and 1.9 MPa/km for the minimum horizontal stress.
S u m m a r y. Magnitudes of the recent tectonic stress were estimated based on the hydraulic fracturing data from Poland. In spite of a low quality of the tests, consistent results for particular regions were obtained. For the Outer Carpathians three hydraulic fracturing tests indicate strike-slip stress regime with the local deviation towards the thrust fault regime. Along the front of the Carpathians within the foredeep complex and its basement, low intensity of strike-slip regime with local tendency towards normal fault regime is revealed from tests performed in four wells. Stable, strike-slip stress regime is determined for the Lublin Basin, based on fracturing tests from four wells. Singular result from the Fore-Sudetic Monocline suggests normal fault stress regime for the Permian complex below Zechstein evaporates. Heterogeneity of the stress field within each of these regions is presumably controlled by tectonic structures inherited after the Variscan and the Alpine epochs. For the SE part of Poland, an estimation of the general trend of stress increase with depth gives 2.9 MPa/km for the maximum horizontal stress and 1.9 MPa/km for the minimum horizontal stress.