Modelling Hydrocarbon Generation in the Palaeozoic and Mesozoic Successions in Se Poland and West Ukraine

Abstract

The Lower Palaeozoic succession in SE Poland and West Ukraine has source rock potential, particularly the Ordovician and Silurian which contain oil‐prone Type II kerogen. The thermal maturity of these units ranges from early to late‐phase oil window (locally up to gas window). Within the Mesozoic succession, source rock potential is highest in the Middle Jurassic which has TOC of up to 26 wt% and a genetic potential of up to 39 mg/g of rock, with organic matter dominated by gas‐prone Type III kerogen. In SE Poland, the organic matter in this unit is generally immature, whereas maturities in West Ukraine are sufficient for hydrocarbon generation to occur. Modelling of hydrocarbon generation suggested that petroleum in Lower Palaeozoic source rocks began to be generated in the Early Carboniferous. Peak generation took place from the late Visean to the early Namurian, and terminated either as a result of source rock depletion or Variscian inversion. Expelled hydrocarbons migrated during post‐Carboniferous and Mesozoic uplift. Middle Jurassic source rocks in SE Poland have only reached the early oil window. Higher thermal maturities in the Ukraine resulted in hydrocarbon generation and expulsion. This took place after Miocene burial and maturation. A number of small hydrocarbon accumulations occur in Mesozoic reservoirs in SE Poland / West Ukraine, and hydrocarbons have migrated from Cambrian and Ordovician source rocks. However, the prospectivity of the study area is reduced as a result of phases of uplift and intense erosion which allowed hydrocarbons to escape from structural traps.

Burial and Thermal History Modelling of the Ediacaran Succession in Western and Sw Ukraine and Moldova

“…The thermal regime was calibrated with equivalent vitrinite reflectance measurements (Table 3). Because the number of measurements was not adequate to construct a reliable numerical model, measurements of Rock-Eval T max from the Polish and Ukrainian parts of the Carpathian Foredeep (Kosakowski et al, 2011(Kosakowski et al, , 2013Więcław et al, 2012) were also used. To further calibrate the thermal regime, CAI data from the Litovyzh-1, Zagaypyl-1 and Voyutyn-1 boreholes were used (Table 3) (Drygant, 1993).…”

OPTICAL KEROGEN ANALYSIS - A New Workflow In Unconventional Shale Play Analysis

“…Therefore the most reliable maturation data are the SCI data, putting the studied shales into the lower oil window, which is significantly lower than published data of Lower Silurian shales within the shale belt (e.g. Poprawa 2010, Kosakowski et al 2013.…”

Main stratigraphic levels of carbonate rocks and their connection with the possibilities of unconventional hydrocarbons deposits development in the Paleozoic sedimentary basins in Ukraine

“…The study reveals five tight carbonate levels prospective for unconventional hydrocarbons in the DDB. [3]. Thermal maturity of the Silurian formations varies significantly from 0.60 to 3.7% Rr.…”

“…An integral interpretation of well-log data from 135 wells to identify the tight reservoirs intervals prospective for unconventional hydrocarbons and total organic matter content (TOC) evaluation was performed by applying commercial and original techniques. For several stratigraphic units the Rock-Eval data were employed [1,2,3,5].…”