Deposition of the Woodbine-Eagleford sandstones, Aggieland field, Brazos County, Texas

Conference · Fri Jan 01 00:00:00 EST 1988

OSTI ID:6144724

Dedominic, J R

Sandstones of the Upper Cretaceous Woodbine-Eagleford interval produce oil from a stratigraphic trap at Aggieland field. The reservoir has an overall north-south trending, ovate morphology and is composed of two elongate bodies. The sandstones are thin with an average net thickness of 16 ft (4.9 m). Grain size generally increases upward, ranging from 0.15 mm (fine grained) to 0.30 mm (medium grained). The sandstones are composed of 47% quartz, 43% matrix and are classified as a lithic greywacke. Due to the high percentage of matrix and poor sorting, permeability values are low, averaging 0.09 md. Porosity ranges from 8.6 to 17.6 percent. Based on sedimentary structures, four individual facies can be defined: (1) a massive, structureless facies, which contains numerous shale and oolitic classes; (2) a rippled facies with thinly interbedded shale laminations; (3) a thin, quartz-rich, cross-bedded facies; and (4) a bioturbated, shaly sand facies. The sandstones are encased within marine shales and were transported to a middle- to outer-shelf location by a combination of turbidity, storm and tidal currents. The eastern edge of the reservoir is truncated and unconformably overlain by the Austin Chalk. This truncation resulted from submarine erosion due to a deep seated salt uplift, which also influenced the paleotopography and deposition of the sands. The lowermost massive, clast rich facies was deposited by debris/gravity flows associated with the paleotopographic high created by the uplift. The upper portion of the sandstone was deposited as a marine bar associated with either a break in slope or intrashelf basin.

• OSTI ID: 6144724
• Report Number(s): CONF-880301-
• Resource Relation: Conference: Annual meeting of the American Association of Petroleum Geologists, Houston, TX, USA, 20 Mar 1988
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
PETROLEUM DEPOSITS
ORIGIN
SANDSTONES
TEXAS
CHEMICAL COMPOSITION
CRETACEOUS PERIOD
DEPOSITION
EXPLORATION
GEOLOGIC TRAPS
GEOPHYSICS
PETROLEUM GEOLOGY
FEDERAL REGION VI
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGY
MESOZOIC ERA
MINERAL RESOURCES
NORTH AMERICA
RESOURCES
ROCKS
SEDIMENTARY ROCKS
USA
020200* - Petroleum- Reserves
Geology
& Exploration