Integrated core study of a fractured metamorphic HC-reservoir; Kiskunhalas-NE, Pannonian Basin

Abstract

The petrologic interpretation of the coexisting lithologies in the KIHA-NE metamorphic block suggests that two of the four rock units may have a significant role in the migration and/or storage of hydrocarbons. The strongly sheared mylonite samples exhibit remarkable fracture systems with clear evidence of one-time oil migration. In the course of the integrated core study, in addition to the petrological methods, 3D CT scans and destructive and non-destructive rock mechanical treatments were fulfilled on representative samples and evaluated. On the basis of the results we can state that the petrologically different rock types have remarkably different brittle behaviours. The orthognesis mylonite is characterised by moderate anisotropy and fracture tendency. However, the fractal dimension and cumulative fracture length values do not suggest the formation of complicated and connected fracture systems. High anisotropy and a large and possibly communicating fracture system characterise the graphitic gneiss mylonite, achieved by a much lower work investment than for any other rock type.