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EN
Predicting how pollutants disperse in vegetation is necessary to protect natural watercourses. This can be done using the one-dimensional advection dispersion equation, which requires estimates of longitudinal dispersion coefficients in vegetation. Dye tracing was used to obtain longitudinal dispersion coefficients in emergent artificial vegetation of different densities and stem diameters. Based on these results, a simple non-dimensional model, depending on velocity and stem spacing, was developed to predict the longitudinal dispersion coefficient in uniform emergent vegetation at low densities (solid volume fractions < 0.1). Predictions of the longitudinal dispersion coefficient from this simple model were compared with predictions from a more complex expression for a range of experimental data, including real vegetation. The simple model was found to predict correct order of magnitude dispersion coefficients and to perform as well as the more complex expression. The simple model requires fewer parameters and provides a robust engineering approximation.
EN
Burial history, thermal maturity and timing of hydrocarbon generation were modelled for the Ordovician and Silurian source rocks in the basement of the Carpathian Foredeep. 1-D modelling was carried out for wells located in the area between Kraków and Rzeszów cities (SE Poland). The following wells were modelled: Będzienica 2, Hermanowa 1, Nawsie 1, Nosówka 2 and 12, Pilzno 40, and Zawada 8K. The Ordovician and Silurian source rocks, containing oil-prone Type-II kerogen, are generally immature showing less than 0.5% reflectance of vitrinite-like macerals (Ro), in most of the Kraków–Rzeszów area and only in the eastern part the organic matter is early mature, reaching 0.7% equivalent Ro. The highest thermal maturity is found in the eastern part of the study area, near Rzeszów city, where the Lower Palaeozoic strata are buried to the greatest depth. Maturity modelling shows that the source rocks reached the initial phase of the “oil window” only in the eastern part of the area, whereas they are immature in the larger, western portion of the area. In addition, modelling indicates that the onset of petroleum generation started in the late Miocene, after the Outer Carpathian overthrust phase. The generation processes in the eastern part of the analysed area reached the main and late generation phase. The generated hydrocarbons were mostly expelled from the source rocks. In the western part of the study area the generation process has not been initialized.
EN
Reconstruction of burial and thermal history was modelled for the Mesozoic strata in the basement of the Polish and Ukrainian parts of the Carpathian Foredeep and in the marginal part of the Outer Carpathians. The 1-D modelling was carried out in profiles of the wells located in the area between Tarnogród and Stryi towns. In the Polish part, the modelling were performed in the profiles of the Księżpol 15, Lubliniec 9, Markowice 2 and Opaka 1 wells, and in the Ukrainian part in the profiles of the Chornokuntsi 1, Korolyn 6, Mosty 2, Podiltsi 1 and Voloshcha 1 wells. The geochemical characteristics of the Mesozoic stratigraphical horizons revealed that the best features of source rocks were present in the Middle Jurassic strata in the Polish part of the study area and in the Middle and Upper Jurassic strata in the Ukrainian part. Within these strata, the horizons of source rocks were distinguished and their quantitative evaluations were characterized. For these horizons, reconstruction of processes for hydrocarbon generation and expulsion were performed. The source rocks in the Polish part reached maturity only in the initial phase of “oil window”. However, the maturity achieved towards the end of the Upper Jurassic was insufficient to exceed the 10% threshold of the transformation degree for hydrocarbon generation. Therefore, the amount of generated hydrocarbons was minimal. Slightly higher maturity of organic matter in the Ukrainian part resulted in exceeding the thresholds of kerogen transformation and the initiation of hydrocarbon generation and expulsion processes. The process began after the deposition of thicker Miocene formations and developed even up to the main phase of the "oil window". The amount of the generated hydrocarbons reached ca. 150 mg/g TOC with an insignificant volume of expulsion.
EN
The burial history, thermal maturity, and timing of hydrocarbon generation of four source rock successions were modelled: the Middle Cambrian, the Upper Cambrian-Tremadocian, the Upper Ordovician (Caradocian) and the lower Silurian (Llandovery and Wenlock). The 1-D modelling was carried out in profiles of eight boreholes throughout the western Baltic region. Four selected boreholes are located offshore: A8-1/83, A23-1/88, B6-1/82 and B4-2A/02, and four onshore: Bialogóra 3, Dbki 3, Leba 8 and arnowiec IG 1. The thermal maturity of source rocks is the highest in the deeper buried western part of the basin and decreases from the west to the east and north-east towards the basin margins. The lower Paleozoic source rocks contain oil-prone Type-II kerogen. The modelling indicated that the onset of petroleum generation from the lower Paleozoic source rocks occurred from the Early Devonian through the early Carboniferous period. The peak of hydrocarbon generation took place from the Late Devonian to the Tournaisian. The majority of hydrocarbons generated were expelled during the latest Early Devonian and Carboniferous, and oil has not been expelled from source rock only in the eastern offshore part of the basin.
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