Reservoir heterogeneity of an Eocene mixed siliciclastic-carbonate succession, northern Pannonian Basin

The quality of any reservoir is strongly controlled by diagenetic processes, especially those that are comprised mixed siliciclastic-carbonate sequences. An Eocene sequence forms reservoirs with diverse in the Hungarian Palaeogene Basin, which found within Pannonian Basin. Late transgression established extensive shallow-marine depositional environments controlling early processes. Drill cores and cuttings were selected from several boreholes, representing a wide range lithofacies to reveal cause for heterogeneity. Petrographic, stable isotope fluid inclusion analyses performed identify processes porosity evolution reservoir, calcite neomorphism caused lateral homogeneity, whereas meteoric water incursion enhanced properties via development dissolution pores, turn resulted vertical deterioration started eogenetic realm kaolinite formation continued during mesodiagenesis as burial calcite, quartz, dolomite minor illite cement precipitated remaining pore spaces. Petrographic evidence, such transformation into dickite homogenisation temperatures highlight role temperature increase burial, effect changing chemistry basin documented chemical zonation dolomite, variation salinities fluids enclosed inclusions, well recurrent prolonged periods cementation quartz dolomite. Mesogenetic accompanied hydrocarbon emplacement late-stage pyrite. propagation faults first contributed later reduce flow, respectively. These steps collectively heterogeneous characteristic