Abstrakt

The main aim of this dissertation is to determine the role of mineral and organic matter constituents in kerogen transformation ratio. Practical aspects of the work include application of the results in the assessment of hydrocarbon production potential; to make process of hydrocarbon recovery more predictable consistent and efficient. The work used shale from the Vaca Muerta formation from the Nequen basin in Argentina. The formation is heterogeneous in relation to the organic and mineral matter, and also to pores structure and mechanical properties. The mineral and organic matter influences each other during kerogen transformation. As part of the evaluation of mineral and organic matter interactions author addresses the relationship between kerogen macerals and the bitumen type to which particular maceral transformed is addressed. There were two types of bitumen differentiated (bitumen I and bitumen II) using the FTIR technique. It was shown that bitumen I derive from fluorescent kerogen macerals and bitumen II from non-fluorescent macerals. During laboratory analysis the bitumen I is readily accessible by solvent extraction whereas bitumen II is retained, trapped within mineral matrix and requires alternative procedures to release it. Thus, in a real reservoir conditions bitumen II most likely will remain immobile. An important aspect of the research pertains to the analysis of potentially weak interfaces, which significantly influence the mechanical behavior of shales, including generation of branching and step-overs during hydraulic fracture propagation. This localized interface events are important to fracture length containment and the overall development of fracture geometry during fracturing operation. Most important interfaces defined in this work there are adjacent layers between rock matrix and volcanic ash, calcite veins, and between different lithologies. Understanding properties of these layers may help to estimate the economic potential of the play. This research integrates knowledge from multiple disciplines, including sedimentology, organic and mineral geochemistry, organic and mineral petrology with elements of geomechanics and provides broader characterization of shales, and to better define their producibility and economic potential. The research results not necessarily pertain to the Vaca Muerta formation only but can be generalized to enhance hydrocarbon recovery form geologically similar plays.

Autor (1)