Carbonate Cement in the Triassic Chaunoy Formation of the Paris Basin: Distribution and Effect on Flow Properties

  1. Sadoon Morad
  1. R. H. Worden1 and
  2. J. M. Matray2

Published Online: 17 APR 2009

DOI: 10.1002/9781444304893.ch7

Carbonate Cementation in Sandstones: Distribution Patterns and Geochemical Evolution

Carbonate Cementation in Sandstones: Distribution Patterns and Geochemical Evolution

How to Cite

Worden, R. H. and Matray, J. M. (1998) Carbonate Cement in the Triassic Chaunoy Formation of the Paris Basin: Distribution and Effect on Flow Properties, in Carbonate Cementation in Sandstones: Distribution Patterns and Geochemical Evolution (ed S. Morad), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444304893.ch7

Author Information

  1. 1

    School of Geosciences, The Queen's University of Belfast, Belfast BT7 1NN, UK

  2. 2

    Bureau Recherche Géologie et Mineralogie, DR/HGT, Orléans cedex 2, France

Publication History

  1. Published Online: 17 APR 2009
  2. Published Print: 29 MAY 1998

ISBN Information

Print ISBN: 9780632047772

Online ISBN: 9781444304893

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Keywords:

  • carbonate cement in Triassic Chaunoy Formation of Paris Basin;
  • core description and petrography;
  • Paris Basin – intracratonic basin;
  • wirleine log analysis;
  • effect of dolomite cement on reservoir properties of Chaunoy Formation

Summary

The distribution of mineral cements in oilfields is critical to the spatial variation of porosity and permeability. The authors have studied the distribution of dolomite cement within fluvial Triassic Chaunoy sandstones in the Paris Basin using core description, petrography, core analysis (porosity and permeability) and wireline data interpreted to give mineralogy, porosity and permeability. Petrographic analysis revealed that dolomite and quartz cements are the main diagenetic minerals. Using sonic transit time, density and neutron density logs we have been able to resolve the overall proportions of quartz, dolomite and shale, as well as porosity for each depth interval. Petrographic and core analysis data showed that permeability could be calculated from wireline-derived porosity and mineralogy data. There is excellent correlation between core analysis porosity and permeability and their wireline-derived equivalents. There is also excellent correlation between wireline-derived mineralogy data and quantitative petrographic mineralogy data. The wireline-derived mineralogy data show that dolomite is preferentially concentrated at the tops of most sandbodies. Porosity and permeability are consequently lowest at the tops of individual sandbodies, owing to the localized dolomite cement. There are a number of potential causes for this distribution pattern, although a combination of early pedogenetic dolomite cementation and later recrystallization, possibly due to an influx of organically derived CO2, is most likely.