0000000000328523
AUTHOR
Benoit Vincent
showing 7 related works from this author
The origin and timing of multiphase cementation in carbonates: Impact of regional scale geodynamic events on the Middle Jurassic Limestones diagenesi…
2009
The Middle Jurassic carbonates of the eastern part of the Paris Basin display surprisingly low values of porosity and permeability (Φ < 15‰ and K < 0.5 mD). The main objective of this study is to determine the causes and timing of the cementation that altered the petrophysical properties of these carbonates thereby destroying their potential as oil reservoirs; a fate that did not befall their equivalents in deeper, central parts of the Paris Basin. Using petrographic and geochemical analyses (stable O and C isotopes, Sr isotopes, major elements), we identify six calcitic spar stages, two dolomite stages, and several episodes of fracturing and stylolitization ordered in paragenetic sequence.…
Impact of basin burial and exhumation on Jurassic carbonates diagenesis on both sides of a thick clay barrier (Paris Basin, NE France).
2014
27 pages; International audience; Several diagenetic models have been proposed for Middle and Upper Jurassic carbonates of the eastern Paris Basin. The paragenetic sequences are compared in both aquifers to propose a diagenetic model for the Middle and Late Jurassic deposits as a whole. Petrographic (optical and cathodoluminescence microscopy), structural (fracture orientations) and geochemical (δ18O, δ13C, REE) studies were conducted to characterize diagenetic cements, with a focus on blocky calcite cements, and their connection with fracturation events. Four generations of blocky calcite (Cal1-Cal4) are identified. Cal1 and Cal2 are widespread in the dominantly grain-supported facies of t…
Acoustic properties of ancient shallow-marine carbonates: effects of depositional environments and diagenetic processes (Middle Jurassic, Paris Basin…
2010
17 pages; International audience; Examination of petrophysical properties (acoustic velocity, porosity, permeability, and density) and petrographical characteristics (texture, facies composition, and diagenesis) of more than 250 core plugs from the Middle Jurassic carbonates of the eastern Paris Basin provides insights into the parameters controlling acoustic velocities in relatively low-porosity carbonate rocks ({Phi} < 20%). The pore-type observations reveal distinct acoustic velocities in samples with intergranular macropores and samples with micropores in subhedral micrite, such that velocities in microporous mudstone–wackestone (lagoonal) deposits are greater than in macroporous grains…
Signification du signal isotopique (δ18O, δ13C) des carbonates néritiques : composante diagénétique et composante originelle (Jurassique supérieur de…
2004
Resume Le long d'une coupe de reference traversant les formations carbonatees du Jurassique superieur de Lorraine (forage HTM102, Nord-Est de la France), des analyses isotopiques ( δ 18 O, δ 13 C) sont realisees sur la phase carbonatee de la roche totale ( bulk analysis ). Le dechiffrage de ces signaux isotopiques dans les carbonates neritiques etudies est effectue par confrontation des donnees isotopiques obtenues sur roche totale avec differents ensembles de parametres (sedimentologiques, donnees isotopiques sur produits separes, donnees petrophysiques). Il apparait que l'utilisation du δ 18 O en tant que descripteur chimiostratigraphique est impossible, car les valeurs obtenues sont le r…
Geodynamic control on carbonate diagenesis: Petrographic and isotopic investigation of the Upper Jurassic formations of the Paris Basin (France).
2007
23 pages; International audience; The Oxfordian and Kimmeridgian carbonates of the eastern edge of the Paris Basin display poor reservoir properties (Φb15% and Kb0.1 md). The petrographic investigation and the resultant paragenetic sequence show that this is due to extensive precipitation of 2 types of almost synchronous blocky LMC (Low Magnesian Calcite) cements during mesogenesis (burial). Stable isotope investigation of these non-recrystallized cements, through both microdrilling sampling and in-situ SIMS (Secondary IonMass Spectrometry) analysis, shows that they originated from slightly buffered meteoric fluids (−3‰SMOW to −8‰SMOW) flowing through the Malm carbonate aquifers of the east…
Characterization and origin of permeability-porosity heterogeneity in shallow-marine carbonates: from core scale to 3D reservoir dimension (Middle Ju…
2014
21 pages; International audience; Nuclear magnetic resonance (NMR), stable isotope geochemistry of micro-sampled cores, NMR well-logs and 3D modeling are used to investigate the carbonate permeability-porosity heterogeneity along 230 m-thick limestones of the Paris Basin. Despite the global low porosity and permeability of the limestones, two aquifers units with porosity greater than 15% were identified. These two aquifers are very different in terms of pore through radii and NMR signal. The first one (A1: Aquifer 1) is a 7 m-thick mudstone unit, dominated by extended microporosity with pore throat radii of 0.25 μm to 0.3 μm. The second one (A2: Aquifer 2) is a 15 m-thick oolitic grainstone…
Climatic fluctuations and seasonality during the Late Jurassic (Oxfordian–Early Kimmeridgian) inferred from delta18O of Paris Basin oyster shells.
2008
10 pages; International audience; Oxygen isotope data from biostratigraphically well-dated oyster shells from the Late Jurassic of the eastern Paris Basin are used to reconstruct the thermal evolution of western Tethyan surface waters during the Early Oxfordian–Early Kimmeridgian interval. Seventy eight oyster shells were carefully screened for potential diagenetic alteration using cathodoluminescence microscopy. Isotope analyses were performed on nonluminescent parts of shells (n=264). Intra-shell δ18O variability was estimated by microsampling along a transect perpendicular to the growth lines of the largest oyster shell. The sinusoidal distribution of the δ18O values along this transect …