lol. where have you been hiding manitou? things to make you go hmmmmm about the buda:
tidbits on the buda
Lower Cretaceous formation mapped in discontinuous, highly faulted, northeast-southwest trend in Uvalde, Medina, Bexar, Comal, and Hays Cos, TX (Ouachita tectonic belt province). Overlies Salmon Peak Limestone (Lower Cretaceous) west of Dry Frio River, overlies Devils River Limestone (Lower Cretaceous) between Dry Frio River and Medina River, overlies Edwards Limestone (Lower Cretaceous) east of Medina River, and very small local areas of Del Rio are mapped in northwestern part of map sheet in Real and Kerr Cos, TX (Kerr basin) where Del Rio overlies Segovia Member of Edwards Limestone. Overlain by Buda Limestone (Lower Cretaceous). Del Rio, Buda, and overlying Eagle Ford (Upper Cretaceous) locally faulted-out entirely (e.g. eastern Medina and western Bexar Cos, TX). Map unit described as clay, calcareous and gypsiferous becoming less calcareous and more gypsiferous upward, pyrite common, blocky, medium gray, weathers light gray to yellowish gray; some thin lenticular beds of highly calcareous siltstone; marine megafossils include abundant Exogyra arietina and other pelecypods; thickness 60-120 ft, thickens westward. [Explanation on map sheet shows Buda and Del Rio as Upper Cretaceous, but pamphlet that accompanies map shows Buda and Del Rio as Lower Cretaceous.
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.
BUDA STRIKES MAY BOOST SOUTH TEXAS ACTION
G. Alan Petzet Senior Staff Writer Cretaceous Buda limestone oil production has been established in an area of South Texas that could give further impetus to the already hot Austin chalk horizontal drilling play. Two wells almost 1 1/2 miles apart in Frio County, Tex., along the Atascosa County line have begun producing oil at high rates from Buda. The wells appear to be zone discoveries in the same fault block in Pruitt (upper Cretaceous Navarro) field, about 15 miles east of Pearsall, Tex.
The Buda formation is a naturally fractured limestone.^Initial production is limited by low matrix permeability and possible plugging of existing natural fractures during the drilling and completion of the wells.^Consequently, proppant fracturing is an integral part of the completion of Buda wells.^Within the last year, Gulf Oil Exploration and Production Company has completed 12 wells in the Buda lime.^During the fracturing treatments, 4 screenouts occurred on the first 7 wells treated.^Laboratory data indicated that a different fluid loss program minimize screenouts in naturally fractured reservoirs.^This technology was applied to the Buda wells.^Using 100 mesh particles in conjunction with fine oil soluble resins, only 1 screenout was observed in the next 5 treatments.^Laboratory data, treatment design, and well performance are presented in this paper.
