Marek Jarosiński , Kinga Bobek , Michał Wojtowicz , Radomir Pachytel , Maciej Trzeciak , Alicja Piłacik
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引用次数: 0
Abstract
We performed an analysis of present-day stress profiles for four wells penetrating the Lower Palaeozoic shale sequence of the Baltic Basin (northern Poland). Breakouts, hydraulic fracturing and leak-off tests were used to calibrate stress models based on anisotropic elastic shale properties. Initial stress models, balancing the lengths of the modelled and observed breakouts, indicated a degradation of the mechanical properties reconstructed from the density and dipole acoustic tool logs. Taking this adverse effect into account, final stress models were calculated which showed a stratification of the stress regime consistent with the lithostratigraphic shale units. A clear dominance of the horizontal stress-generating gravity factor over the horizontal tectonic strain was demonstrated. The obtained values of tectonic strain in the shale sequence compared to the previously determined strain in the crystalline basement of the same study area suggest a significant role of viscoelastic relaxation of the shale sequence.
期刊介绍:
The prime focus of Tectonophysics will be high-impact original research and reviews in the fields of kinematics, structure, composition, and dynamics of the solid arth at all scales. Tectonophysics particularly encourages submission of papers based on the integration of a multitude of geophysical, geological, geochemical, geodynamic, and geotectonic methods