Stopień zmetamorfizowania bituminów śladowych jako wskaźnik w poszukiwaniach ropy naftowej

Abstract

METAMORPHISATION DEGREE OF TRACE BITUMINS AS A COEFFICIENT IN SEARCH FOR CRUDE OILSummaryInvestigations of absorption, bands within the IR range, characteristic of the main components of bituminous substance, allowed the frequency intervals of the compounds, which are extremely important in the changes of bitumines and crude oils, to be distinguished. The known, quantities of these compounds in the substances investigated may throw light on the metamorphisation degree of bituminous substance. To the highly representative for alteration of bitumens are referred the structures of saturated hydrocarbons (CH3, CH2, CH), the amount of which in bitumens increases, according to the accepted arguments, with the increase of metamorphisation of the organic substance. On the other hand, the heterogenous part of bitumens, i.e. their oxygen, sulphur and nitrogen compounds, has also been taken into account. An increased content of these compounds may point to a small metamorphisation, or to the secondary processes that decrease the degree of similarity of bitumens to crude oil. The numerical relation of two magnitudes obtained by measuring the absorption fields within the bands 2800–3000–1 and 1000–1330–1, expressed as coefficient A, makes the scale of metamorphisation of bitumens, from low-metamorphosed to crude oils. The scale here accepted allows us to distinguish five classes of bitumens – from the crude oil to low-metamorphosed bitumens. The article shows some examples of using the subdivisions of bitumens in the interpretation of geochemistry of various geological units of Poland.