The upper Comanchean Buda Limestone (Cretaceous) is a known reservoir for hydrocarbons in central Texas, producing from depths as shallow as 700 ft. Understanding the character of the Buda Limestone and its complex depositional and diagenetic history is essential to developing a sound exploration strategy and to insure maximum production.

In central Texas, the Buda Limestone may be divided into a lower, micritic facies, and a dense, in places dolomitized, intrasparite upper facies. The upper Buda is more porous and contains most of the producible hydrocarbons in the formation. The upper contact is an undulating erosional surface, unconformably overlain by impermeable Woodbine shales.

Porosity enhancement appears greater in areas of faulting and fracturing, especially where occurring along erosional drainage divides. Because of the apparent correlations between favorable structure and marketable oil production, economic prospecting methods should seek to delineate zones of faulting and fracturing along areas where the upper Buda was exposed to weathering.

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