Carbonate reservoirs are characteristically heterogeneous in reservoir quality and
performance owing to the variety of processes that influence pore formation.
Additionally, porosity and permeability do not conform to depositional facies boundaries
in carbonate reservoirs affected by diagenesis or fracturing; consequently, conventional
methods of petrophysical characterization of flow units based on depositional facies are
unreliable as predictors of reservoir behavior.
We provide an integrated stratigraphic, petrographic, and petrophysical study of
the San Andres reservoir at Sunflower field that identifies and quality-ranks flow units
on the basis of genetic pore types. A total of 12 full-diameter cores were analyzed
revealing three primary depositional facies and cyclical patterns of deposition identified
as parasequences. From the cores, 73 samples were chosen for thin sections. Through
petrographic analysis, pores were classified using the Ahr 2005 method and four distinct,
genetic pore types were identified. Petrophysical rock types were established by
identifying which genetic pore types correspond to high poroperm values, and where
they occur within the stratigraphic framework of the reservoir. Sixteen coherent plugs were also subjected to mercury injection capillary
pressure analysis in order to quantify pore – pore throat relationships. The data were then
evaluated by facies, porosity type, and cycle position using graphical methods, such as
k/phi, Winland R35, and Lorenz plots. The results of this study reveal that the most
effective way of characterizing petrophysical flow units is the combination of k/phi ratio
analyses and genetic pore typing.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-3177 |
| Date | 15 May 2009 |
| Creators | Humbolt, Aubrey Nicole |
| Contributors | Ahr, Wayne M. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | electronic, application/pdf, born digital |
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