1. Diagenetic effects of compaction on reservoir properties: The case of early callovian 'Dalle Nacrée' formation (Paris basin, France)
- Author
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Fadi H. Nader, France Champenois, Mickaël Barbier, Mathilde Adelinet, Elisabeth Rosenberg, Pascal Houel, Jocelyne Delmas, and Rudy Swennen
- Subjects
010504 meteorology & atmospheric sciences ,Lithology ,Geochemistry ,010502 geochemistry & geophysics ,Cementation (geology) ,01 natural sciences ,Wackestone ,Diagenesis ,Petrography ,Paleontology ,Geophysics ,Stylolite ,Facies ,Paragenesis ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
The impact of compaction diagenesis on reservoir properties is addressed by means of observations made on five boreholes with different burial histories of the Early Callovian “Dalle Nacree” Formation in the Paris Basin. Petrographic analyses were carried out in order to investigate the rock-texture, pore space type and volume, micro-fabrics, and cement phases. Based on the acquired data, a chronologically ordered sequence of diagenetic events (paragenesis) for each borehole was reconstructed taking the burial history into account. Point counting and a segmentation algorithm (Matlab) were used to quantify porosity, as well as the amounts of grain constituents and cement phases on scanned images of studied thin sections. In addition, four key samples were analyzed by 3D imaging using microfocus X-ray computer tomography. Basin margin grainstones display a different burial diagenesis when compared to basin centre grainstones and wackestones. The former have been affected by considerable cementation (especially by blocky calcite) prior to effective burial, in contrast to the basin centre lithologies where burial and compaction prevailed with relatively less cementation. Fracturing and bed-parallel stylolitization, observed especially in basinal wackestone facies also invoke higher levels of mechanical and chemical compaction than observed in basin marginal equivalents. Compaction fluids may have migrated at the time of burial from the basin centre towards its margins, affecting hence the reservoir properties of similar rock textures and facies and resulting in cross-basin spatial diagenetic heterogeneities. more...
- Published
- 2016
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