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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 69 (1985)

Issue: 8. (August)

First Page: 1320

Last Page: 1320

Title: Relation of Lower Morrow Sandstone and Porosity Trends to Chester Paleogeomorphology, Persimmon Creek Field Area, Woodward County, Oklahoma: ABSTRACT

Author(s): Robert E. Webster

Article Type: Meeting abstract

Abstract:

Thickness and porosity trends of several lower Morrow sandstone units were strongly influenced by the paleogeomorphology of the subjacent Mississippian Chester limestone in a study area near Persimmon Creek field in T20N, R22W, southwestern Woodward County, Oklahoma. Pre-Pennsylvanian streams flowing south-southwest across the Anadarko basin shelf had created a dendritic drainage pattern with paleogradients of about 40 ft/mi (7.5 m/km), and intervening stream divides were 50-100 ft (15-30 m) above the valley floors. As the sea transgressed the area in the Early Pennsylvanian, cyclic transgressions and regressions led to deposition of four prominent lower Morrow sandstone members separated by shale units that are approximately parallel lithologic time markers.

The two lower members--a prograding beach complex and a delta front complex--experienced thicker sand deposition above the paleovalleys. In the overlying member (Brown sandstone), also a delta-front complex, thickest sand accumulation and best porosity development occur above the Chester paleodivides. The uppermost member shows little relationship to Chester paleotopography.

Persimmon Creek field is a small stratigraphic trap accumulation that occurs above a prominent southward-plunging nose or paleotopographic high on the Chester limestone surface. Four wells produce from two Brown sandstone units, a stream-mouth bar and an overlying channel sand that has prograded across the bar. Although the geometry of individual sandstone bodies such as these is almost impossible to predict prior to field development, Morrow sandstone prospects can be defined by locating the most likely sites of thick, porous sand accumulation controlled by Chester paleotopography.

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