Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

A combined diffusion/kinetic/thermodynamic framework for the prediction of porosity reduction in sedimentary basin sandstones over geologic timeframes

Conference · · Geological Society of America, Abstracts with Programs; (United States)
OSTI ID:5578787
 [1];  [2];  [3]
  1. Univ. Paul Sabatier, Toulouse (France). Lab. de Geochimie
  2. STATOIL, Stavanger (Norway). Petrology and Sedimentology
  3. Southwest Research Inst., San Antonio, TX (United States)

A combined petrographic/computational study of the Jurassic North Sea Sandstones indicates that porosity reduction in these rocks is dominated by the dissolution of quartz at mica contacts, the diffusion of dissolved silica away from these surfaces, and the subsequent precipitation of secondary quartz. In many instances the bulk of the quartz dissolution occurs at mica rich stylolites. To quantify this silica transport/porosity reduction process as a function of the time/temperature/depth history of a given sandstone, a comprehensive computational framework was developed to simultaneously solve rates of kinetically controlled mineral dissolution/precipitation reactions coupled to diffusional transport and homogeneous equilibrium of aqueous species in the solute phase. The mass conservation equations were integrated over geologic timeframes. Calculations carried out with the aid of this algorithm were used to assess the effects of mineralogy, mineral surface area, solution pH, the presence of a separate hydrocarbon phase, and distribution of diagenetic phases on the distribution of porosity and secondary quartz over the history of the North Sea basin.

OSTI ID:
5578787
Report Number(s):
CONF-921058--
Journal Information:
Geological Society of America, Abstracts with Programs; (United States), Journal Name: Geological Society of America, Abstracts with Programs; (United States) Vol. 24:7; ISSN GAAPBC; ISSN 0016-7592
Country of Publication:
United States
Language:
English