Upper Visean black shales (“Rudov Beds”) of the Ukrainian Dniepr-Donets Basin (DDB)

Within my PhD project, I investigate Upper Visean black shales (“Rudov Beds”)of the Ukrainian Dniepr-Donets Basin (DDB) regarding their potential as a petroleum source rock. Work performed until now focused on two aspects, (1) Rudov Beds as a potential source for hydrocarbons trapped in conventional reservoirs and (2) their relevance as a target for unconventional (shale oil/gas) production. Both aspects need to be approached in a different way.

(1)     Conventional production

To link Rudov Beds to oils, condensates and gases from producing wells, I used biomarker composition and isotope geochemistry of both source rock extracts and oils/ condensates/ gases for a correlation study (Fig. 1). Rudov Beds were then compared to other potential source rock horizons within the DDB, to estimate the most likely source for the trapped hydrocarbons. The modelled thermal history of the basin as well as structural information on producing fields was usefull to evaluate the obtained results and enhance information on the petroleum system within the DDB.

(2)     Unconventional production

To assess Rudov Beds as shale gas/liquids target, I laid stress on

·         Vertical and lateral distribution of the mineralogical composition

·         Vertical and lateral changes in total organic carbon content and thermal maturity

·         Variations in hydrocarbon generation potential throughout the basin

·      Thermal evolution of organic matter (e.g. organic matter-hosted porosity), as well as lateral variations in organic matter composition

Future work will cover a 3D thermal model of the DDB. Apart from that, I try to set up a research project on nanostructures of shales and coals, focusing on organic matter-hosted porosity and trace element storage mechanisms. This project will follow up my recent work on organic matter-hosted porosity within Rudov Beds (Fig. 2) as well as a side-study that focused on the chemical composition of coals from the Donets Basin.

Biomarker ratios (e.g. Pr/Ph) and carbon stable isotope composition are used for fingerprinting (Figure published in: “Oil/gas-source rock correlations in the Dniepr-Donets Basin (Ukraine): New insights into the petroleum system”; Misch et. al., 2015; Marine and Petroleum Geology 67, 720-742)

 

 

High resolution scanning electron microscopy (FIB/BIB-SEM) is used to visualize sub-micrometer-scale features in organic matter, including pores and authigenic minerals (Figure published in: “SEM and FIB-SEM investigations on potential gas shales in the Dniepr-Donets Basin (Ukraine): Pore space evolution in organic matter during thermal maturation”;Misch et al., 2015; IOP Conf. Ser.: Mat. Sci. Eng., in press.)