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

Ferroan carbonates formed at depth require porosity well-log correction: Hunton Group (Upper Ordovician to Lower Devonian), deep Anadarko Basin, Oklahoma and Texas

Conference · · Am. Assoc. Pet. Geol., Bull.; (United States)
OSTI ID:7084809
;
Iron in the minerals calcite and dolomite of limestones and dolostones increases bulk densities and probably also decrease resistivities recorded by logging tools. Whereas dolostones alone retain porosity (intercrystalline and moldic) in the deep Anadarko basin of southwestern Oklahoma and Texas, it is particularly important to distinguish variations in the chemical compositions of dolomite (especially of iron). Bulk densities determined by measuring proportions of major minerals (X-ray fluorescence) permit improved estimates of true porosities and water saturations. Dolomite densities range from 2.82 g/cm/sup 3/ up to 3.02 g/cm/sup 3/ for strongly ferroan dolomite. At depths exceeding 10,000 ft (3 km), ferroan dolomite and calcite in the Hunton Group carbonates are predictably associated with interbedded argillaceous zones and with the underlying marine Sylvan Shale. In the deepest of the 50 wells studied, well logs show high densities in the lowermost Hunton (above the Sylvan Shale) which can only be interpreted as the presence of iron-rich dolomite. Detailed fossil correlations by Amsden have established the relatively constant age of a single lithostratigraphic horizon locally present at the base of the Hunton Group conformably overlying the Sylvan Shale, leading us to conclude that increased temperature with depth is the predominant factor for dolomitization. The smectite-to-illite transition in the Sylvan Shale is suggested as a possible source of magnesium and iron. Preliminary shale analysis and stable-isotope-ratio analysis support the above conclusions.
Research Organization:
Rensselaer Polytechnic Inst., Troy, NY
OSTI ID:
7084809
Report Number(s):
CONF-840297-
Conference Information:
Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 68:1
Country of Publication:
United States
Language:
English

Similar Records

Interactions between early and late diagenesis in reservoir formation, Lisburne field, Prudhoe Bay, Alaska
Conference · Tue Feb 28 23:00:00 EST 1989 · AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States) · OSTI ID:5954331
Diagenetic features of Trenton Limestone in northern Indiana: petrographic evidence for Late (Mesogenetic) Dolostone
Conference · Fri Aug 01 00:00:00 EDT 1986 · Am. Assoc. Pet. Geol., Bull.; (United States) · OSTI ID:7041735
Fluid inclusion evidence for the migration of anomalously hot fluids in the Silurian/Devonian Hunton Group below the pre-Mississippian unconformity surface, Anadarko basin, Oklahoma
Conference · Mon Dec 30 23:00:00 EST 1996 · OSTI ID:425857

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATE MINERALS
CARBONATES
CHEMICAL ANALYSIS
COHERENT SCATTERING
CORRECTIONS
DIFFRACTION
DOLOMITE
ELECTRIC LOGGING
FEDERAL REGION VI
GEOLOGIC STRUCTURES
IRON COMPOUNDS
ISOTOPES
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MINERALS
NONDESTRUCTIVE ANALYSIS
NORTH AMERICA
OKLAHOMA
ORIGIN
OXYGEN COMPOUNDS
POROSITY
SCATTERING
SEDIMENTARY BASINS
STABLE ISOTOPES
TEXAS
TRANSITION ELEMENT COMPOUNDS
USA
WELL LOGGING
X-RAY DIFFRACTION
X-RAY EMISSION ANALYSIS
X-RAY FLUORESCENCE ANALYSIS