About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 70 (1986)

Issue: 7. (July)

First Page: 787

Last Page: 808

Title: Reservoir Facies Architecture of Microtidal Barrier Systems

Author(s): William E. Galloway (2)


Sandstone reservoirs deposited in microtidal barrier systems contain large oil and gas reserves in several Gulf Coast basin plays. Three representative Frio Sandstone reservoirs in West Ranch field show that barrier-island sand bodies are complex mosaics of barrier-core, inlet-fill, flood-tidal-delta, washover-fan, barrier-flat, and shoreface facies. The proportions of these facies differ within progradational, aggradational, and transgressive barrier sand bodies.

The 41-A reservoir is a progradational barrier sand body. The most important producing facies include the barrier core and crosscutting inlet fill. Permeability and distributions of irreducible water saturation reveal depositional patterns and subdivisions of the sand body into numerous facies-controlled compartments. Both original hydrocarbon saturation and irregularities in water encroachment show that the facies compartments locally affect fluid movement within the reservoir.

The Greta reservoir is an aggradational barrier complex. This massive sand body consists of intermixed barrier-core and inlet-fill units. Prominent resistivity compartments are dip oriented, indicating the importance of inlet development during barrier aggradation. Despite the uniform appearance of the Greta reservoir, water encroachment has been irregular.

The Glasscock reservoir is characterized by comparatively low permeability and is an atypically thin and discontinuous Frio reservoir. It is interpreted to be a transgressive barrier deposit that consists mainly of large washover-fan and associated barrier-flat sands. Hydrocarbon saturation, drainage, and injection response all reflect the facies geometry typical of a transgressive barrier complex.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24

AAPG Member?

Please login with your Member username and password.

Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].