Reservoir Characterization to Inexpensively Evaluate the Exploitation Potential of a Small Morrow Incised Valley-fill Field

Kansas Geological Survey
Open-file Report 2002-9

Morrow Incised Valley-Fill System in Kansas

Facies Assemblage

Morrow Sandstone facies assemblages are consistent with the wave-dominated tripartite model for IVF systems proposed by Dalrymple et al. (1992) and presented by Allen and Posamentier (1994, Figure) comprising; (1) a marine sand plug formed at the seaward, high wave energy end of the valley (estuary mouth), (2) a low-energy middle zone, characterized by fine-grained deposition (central bay), and (3) a high-energy inner zone dominated by the discharge of fluvial tributaries (bay-head delta or upper estuary channels). Local evidence of tide-dominance is also evident. Within the Morrow of SW Kansas, Buatois et al. (1999) identified fifteen facies grouped into estuarine and marine assemblages. Core (Figure) from the J.M. Huber Kendrick #23-1 (Sec. 23, T. 29 S., R. 41 W.; 5375-5460 ft) presents a complete transgressive sequence from basal conglomerates overlying the lowstand erosion surface through fluvial channel sandstones, central bay muds, estuary mouth marine sandstones, to open marine shales.

(From Buatois et al., 1999)

Facies and Reservoir Rock Properties

Using the faceis classification of Buatois et al. (1999) Morrow Sandstone estuarine and marine lithofacies generally exhibit unique suites of petrophysical properties. In general, facies exhibiting good reservoir properties with high porosity and permeability and low Swi include fluvial (facies A), upper estuary channel (facies C), and upper shoreface (facies I) sandstones. Facies exhibiting marginal reservoir properties with lower porosity and permeability, and Swi greater than 50% include estuary mouth (facies H), restricted tidal flat (facies E), and middle shoreface deposits (facies J). Non-reservoir facies, with low porosity and permeability and Swi greater than 80% include nonmarine paleosols (facies B), central estuarine bay shales (facies D), restricted tidal flat facies (E), tidal channel (facies F), and lower estuary mudstones (facies G); and marine lower shoreface (facies K and L ) and deeper water deposits (facies M, N, and O).

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Last updated March 2002