Shale mineralogy and burial diagenesis of Frio and Vicksburg Formations in two geopressured wells, McAllen Ranch area, Hidalgo County, Texas
Thirty-six shale samples ranging in depth from 1454 ft to 13,430 ft from Shell Oil Company No. 1 Dixie Mortage Loan well and 33 shale samples ranging in depth from 2183 ft to 13,632 ft from Shell Oil/Delhi-Taylor Oil Corporation No. 3 A.A. McAllen well were examined by x-ray techniques to determine the mineralogical parameters of the geopressured zone in the Vicksburg Fairway. Both wells have the same weight-percent trends with depth for the mineralogy: quartz, calcite, total clay, and potassium feldspar are constant; plagioclase feldspar gradually increases; kaolinite increases; discrete illite decreases; total mixed-layer illite-smectite (I/S) decreases; illite in mixed layer I/S increases; and smectite in mixed-layer I/S decreases. Chlorite is found only in the geopressured zone of each well. The Boles and Franks model is compatible with a steady supply of original mixed-layer I/S during the depositional history of the McAllen Ranch area. The constant content with depth of calcite, quartz, and potassium feldspar indicates that limited material, if any, is supplied by the shales to surrounding sands. The ions generated by changes within the clay minerals are involved in further clay mineral reactions as outlined above. In addition, magnesium and iron are involved in forming chlorite within the shales.
- Research Organization:
- Trinity Univ., San Antonio, TX (USA)
- DOE Contract Number:
- AC08-79ET27111
- OSTI ID:
- 6334219
- Report Number(s):
- DOE/ET/27111-T1; ON: DE81025180
- Country of Publication:
- United States
- Language:
- English
Similar Records
Clay mineralogy and depositional history of the Frio Formation in two geopressured wells, Brazoria County, Texas
Secondary porosity in sandstones and acid-producing reactions in adjacent shales, Oligocene, south Texas
Related Subjects
GEOPRESSURED SYSTEMS
MINERALOGY
SHALES
DIAGENESIS
CALCITE
CHLORITE MINERALS
CLAYS
FELDSPARS
GEOTHERMAL WELLS
ILLITE
KAOLINITE
QUARTZ
SMECTITE
TEXAS
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATES
CHALCOGENIDES
ENERGY SYSTEMS
MINERALS
NORTH AMERICA
OXIDES
OXYGEN COMPOUNDS
ROCKS
SEDIMENTARY ROCKS
SILICATES
SILICON COMPOUNDS
SILICON OXIDES
SOUTHWEST REGION
USA
WELLS
Geothermal Legacy
150201* - Geology & Hydrology of Geothermal Systems- USA- (-1989)