Analiza konfokalna w badaniach inkluzji węglowodorowych piaskowców Morza Bałtyckiego

Fluid inclusion studies correspond in general to determinations of temperatures of homogenization and melting after freezing. These result in the values which further may be used to the estimation of trapping conditions which may be referred to the formation of diagenetic cements. Trapping pressure and temperature conditions arc usually described using phase diagrammes and isochores. These for the aqueos solutions are entirely easy to construct (Brown, 1989. Bodnar. 1990) and their shapes are not very complicated. Quite simple computer programmes can be used for calculation of isochores. Still those for hydrocarbon inclusions arc much more complicated (Burruss. 1992). Apart from the temperature measurements, first of all it is important to know exactly mole volumes of the inclusion phases. In a normal microscope procedure two-dimension visual estimation has been usually performed. This may result, however, in errors since in fact fluid inclusions are three-dimensional in their shape. That is why petroleum inclusions from the Middle Cambrian reservoir sandstones from the Baltic Sea have been analysed by use of the newest technique proposed and described by the Newcastle Research Group (Aplin et al., 1999). The confocal laser microscope measurements were done for oil inclusions aiming at liquid and vapour mole volumes of selected individuals. These data were further used in computer simulations by Vtflinc programme resulting in phase diagrammes for each inclusion, gas-oil ratios (GOR) as well as the approximation of inclusion composition, being based, however, on the North Sea data input due to the lack of the suitable Baltic Sea data. The results arc shown in diagram (Fig. 1) and in the table (Tab. 1).