**6. Conclusions**

With the application of the seismic sequence stratigraphy method, it was possible to interpret system tracts and depositional sequences. This helped us to understand the depositional history and recovery of the depositional architecture of the sedimentary basin in the research area. Afterwards, seismic attributes were applied in order to verify the reservoir properties within the analyzed interval. The integration of these results enabled the identification of the prospective targets. Figure 5 summarizes the main findings of the analysis.

It should be stipulated that, otherwise all of the indicated prospective targets are both source and reservoir rocks, they should be considered as unconventional reservoirs. Moreover, there was no hydrocarbon migration to the Machów Formation from outside. Such an approach gives grea<sup>t</sup> insights into the interpretation of unconventional reservoirs.

Seismic sequence stratigraphy at the level of detail presented above is possible for high-resolution, preferably 3D, seismic surveys. A su fficient resolution, in this case, was acquired by the detailed design of the acquisition parameters, the importance of the survey design should be strongly advocated at this point. The data that were shown are unprecedented in the Carpathian Foredeep area, manifesting high vertical and horizontal resolutions. The results give weight to the argumen<sup>t</sup> that only high-resolution seismic data for heterogeneous sequence interpretation might reveal details that help to understand the depositional history of the Miocene formations in the Carpathian Foredeep sedimentary basin.

The detailed seismic image presented enabled accurate attribute interpretation, which was guided by sedimentary analysis. The attribute values are clearly changing, and the shapes of the presented anomalies are in agreemen<sup>t</sup> with the depositional interpretation. This proves that the choice of attributes and their parametrization suited the given problem.

For heterogeneous sequence interpretation, sedimentary analysis is a necessary step that can not only identify possible prospecting targets, but also define their geometry and tectonic involvement. The tectonic setting is crucial for a reliable estimation of the hydrocarbon reserves and for well planning. Such an approach is not routinely applied to the Miocene deposits of the Carpathian Foredeep. Instead, these prospects are mostly treated as convenient targets, for which structural positioning is almost exclusively applied. Based on the research results obtained, we propose a new methodological attitude utilizing both seismic sequence stratigraphy and attribute analysis, with a particular emphasis on frequency analysis.

**Figure 5.** Geological cross-section with marked system tracts and prospecting targets within the interpreted seismic interval.

**Author Contributions:** Conceptualization, A.K. and A.U.; methodology, A.K.; software, A.K.; validation, A.Ł.-B., A.U. and A.K.; formal analysis, A.U.; investigation, A.Ł.-B., A.K.; writing—original draft preparation, A.K., A.U., A.Ł.-B.; writing—review and editing, A.K.; visualization, A.Ł.-B. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding. The work was part of the ongoing investigation being carried out by the Department of Geophysics, University of Science and Technology (11.11.140.645). This paper was written on the basis of the statutory work entitled "Seismostratigraphic analyses of the Upper Jurassic carbonate complex in the central part of the Carpathian Foreland". The work of the Oil and Gas Institute–National

Research Institute was commissioned by the Ministry of Science and Higher Education (order number: 37/SR/2020; archive number: DK-4100-25/2020).

**Acknowledgments:** We would like to acknowledge the Polish Oil and Gas Company for sharing their data for research purposes and for their permission to publish the results. We extend our gratitude to DGB EarthSciences for granting the University of Science and Technology AGH's OpendTect application for the HorizonCube plugin that was used for the depositional analysis. The authors would like to thank two anonymous reviewers for their suggestions and recommendations, which helped to improve the manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest.
