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

Conference · Wed Jan 01 04:00:00 EST 1992 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5578787

Oelkers, E H ^[1]; Bjorkum, P A ^[2]; Murphy, W M ^[3]

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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--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 24:7
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200 -- Petroleum-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580000* -- Geosciences
ATLANTIC OCEAN
CHALCOGENIDES
DIAGENESIS
DIFFUSION
DISSOLUTION
GEOLOGIC STRUCTURES
HYDROCARBONS
KINETICS
LOSSES
MATHEMATICAL MODELS
MINERALOGY
MINERALS
NORTH SEA
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PH VALUE
POROSITY
QUARTZ
ROCKS
SANDSTONES
SEAS
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SURFACE AREA
SURFACE PROPERTIES
SURFACE WATERS
THERMODYNAMICS