Modelling the initiation of bitumen-filled microfractures in immature, organic-rich carbonate mudrocks: The Maastrichtian source rocks of Jordan

The initiation of bitumen-filled microfractures was analysed in the organic-rich Maastrichtian carbonate mudrocks Jordan, which show great potential as source rocks and for a future unconventional hydrocarbon play. A modelling approach performed to assess possible scenarios causing horizontal small-scale (mm cm length) bitumen fractures (microfractures) at immature stage. aim back-calculate how much overpressure generation needed past initiate microfracturing, comparing those simulated parameters with actual from rock samples. results that local resulting during early catagenesis not high enough microfracturing. We hypothesise increase internal pressure caused by inability be squeezed into pore space burial. induced perturbation stable-state stress distribution around kerogen boundary eventually led along tip flakes. Subsequently, short-distance migration significant decrease have prevailed study area. This proves primary can occur long before reaches oil or gas windows, comparatively shallow burial depth. also indicates first framework pathways precursor may control flow patterns hydrocarbons within rocks. Understanding these factors is critical predicting impact microscale on expulsion storage, hence likely productivity an analogous subsurface reservoir.