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Browsing by Author "Drabina, Andrzej"

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    Budowa modeli geochemiczno-mineralogicznych na podstawie danych uzyskiwanych z zaawansowanych metod geofizyki jądrowej. Część 1
    (Institute of Nuclear Physics Polish Academy of Sciences, 2007) Woźnicka, Urszula; Cywicka-Jakiel, Teresa; Drabina, Andrzej; Dworak, Dominik; Tracz, Grzegorz; Drozdowicz, Krzysztof; Zorski, Tomasz; Ossowski, Andrzej; Środoń, Jan; Kawiak, Tadeusz; Bakowska, Dorota; Zielińska, Małgorzata; Zalewska, Jadwiga
    An extensive set of conventional and special core analysis measurements, complemented by additional chemical and mineralogical analyses was performed, forming the basis for the evaluation of the complex thin bedded gas-bearing shaly-sand formations of Miocene age in the Carpathian Foredeep region of Southern Poland. Mineralogy was established by using full elemental composition, XRD method, total surface area and cation exchange capacity (CEC). The analysis showed that the most important clay component is illite – smectite mixed layer. Statistical multivariate analysis of all data helped to set up a comprehensive general petrophysical model. For the notoriously difficult CEC information for the rock matrix we could establish a reliable correlation (corr. coefficient r2 around 0.95) between thermal neutron absorption cross section SIGMA and total natural radioactivity GR with CEC, with boron and rare earth elements the two most important SIGMA contributors in the rock matrix. This good correlation permits a continuous on-line CEC determination and therefore a reliable application of the Waxman-Smits water saturation model to properly take into account the clay mineral effects in evaluating water saturation.
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    Correlation between Measurements and Monte-Carlo Calculations for the NNTE Logging-Tool
    (Institute of Nuclear Physics Polish Academy of Sciences, 2003) Drabina, Andrzej; Zorski, Tomasz; Woźnicka, Urszula
    A correlation between Monte-Carlo simulations of the NNTE geophysical neutron logging-tool response and measurements made on the rock blocks at the calibration facility in Zielona Góra (Poland) has been examined. The NNTE tool is a recent achievement of Polish geophysicists. It is equipped with a neutron source and three detectors. The tool is designed to measure the thermal neutron absorption cross-section of geological formations in situ. The computer modelling is intended to complete the calibration measurements with simulated experiments in complicated borehole situations. A good correspondence between the simulated and real experiments is obvious demand. The simulations have been performed using the MCNP4C computer code. In the first approach elemental compositions of block rock matrices have been taken directly from the results of a chemical analysis. In the second approach boron B-10 has been added to the elemental compositions of rocks to compensate the difference between their absorption cross-section calculated from the elemental compositions and those known from the laboratory measurements. The very good agreement has been obtained between results of calculations and measurements. The high correlation creates the basis for further research on the influence of absorption cross-section of geological formation on the NNTE tool response.
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    Feasibility study of experimental detection of the hydrogen content in rock material by a pulsed neutron method
    (Institute of Nuclear Physics Polish Academy of Sciences, 2003) Drozdowicz, Krzysztof; Drabina, Andrzej; Dąbrowska, Joanna; Gabańska, Barbara; Igielski, Andrzej; Janik, Władysław; Krynicka, Ewa; Kurowski, Arkadiusz; Wiącek, Urszula; Woźnicka, Urszula
    Theoretical principles of a pulsed neutron method to measure the water or hydrogen content in a rock material have been tested on the experimental set-up at the fast neutron generator in the INP. The time decay constant of the thermal neutron flux in the samples has been measured as a function of the hydrogen content. Dry crumbled granite has been used as a rock sample. The hydrogen content has varied due to addition of a defined amount of polyethylene (0 to 20 %). A few arrangements (neutron source + sample) have been tried. A dedicated pulsed thermal neutron source has been designed and built. The measuring set-up has been chosen for a final elaboration of the method.