Southwest Cooke County, Texas
The Gruber Prospect has the potential of 100 MBO from multiple fractured Ellenburger dolomite zones and 40 MBO from multiple Pennsylvanian Strawn sandstones. The drill site is verified with a DHA (dense hydrocarbon activity) map and a Wave Tech EHI (Electromagnetic Hydrocarbon Indicator) log. The Gruber well is located in a shallow, low risk multiple pay oil area. The Gruber Prospect is located five (5) miles southeast of the town of Muenster, Texas in the southwest portion of Cooke County, Texas. Bordered on the east, north, and west by prolific oil production (2 multi-million barrel oil fields). Established productive zones include Pennsylvanian Strawn sandstones and Ordovician Ellenburger limestone and dolomite.
The well prospect is located on a weathered and karsted Ellenburger structure on the Muenster Arch that exhibits four way closure evidenced by the Ellenburger structure map which conforms to a strong microseepage anomaly. The Muenster Arch structure is an eroded pre-Pennsylvanian mountain chair of en echelon northwest-southwest trending Ellenburger ridges located in western Cooke County. Due to periodic uplift, tilting and erosion, structural attitude and stratigraphic succession of formations are controlled by four significant unconformities. In ascending order, they are positioned at the top of the pre-Cambrian, Ordovician Ellenburger, Pennsylvanian Strawn and Cretaceous systems. Oil production has been established in both structural and stratigraphic traps on the crest and on the flank of the Muenster Arch since 1926 and continues today with both development and wildcat wells being drilled. Production has been found in Canyon/Strawn age Pennsylvanian sandstones and Ordovician Ellenburger carbonates. The Gruber Prospect contains potential oil sand draped over an eroded, karsted Ellenburger structure with possible production in cavernous porosity developed within the carbonate.
RESERVOIR RESERVE POTENTIALS
The Gruber lease has potential production from Canyon/Strawn sands at 1100’, 1500’, and 1800’ of 25 – 40 MBO and Ellenburger dolomite 100,000 BO per well.
CONCLUSION & SUMMARY
The Gruber Prospect is located in close proximity to established commercial production from a variety of sandstone and carbonate reservoirs found in both structural and stratigraphic traps. The strong microseepage anomaly overlay on the Ellenburger structure indicates potential trapped hydrocarbons in a variety of reservoirs. A Wave Tech survey was also acquired over the microseepage anomaly with the result being 7 hydrocarbon indicators from 1800’ to 3800’. The Gruber well will offset by 500’ the Perkins 1-Gruber, drilled in 1954 and completed in Gatewood sand (Perf 1570-76’) for 4MMCFG per day. The well was shut in due to the lack of gas pipeline. The well was re-entered in 1963 by George Graham and flowed 1.2 MMCFGPD + .45 BOPD, then shut in due to lack of sales line as before. This small area is the only area in Western Cooke County where gas has been encountered and only in the Gatewood sand.
It is our belief that this reservoir is not a gas producer, but is a gas cap that sits on top of oil. The Gruber location is located 500’ SSE from the Perkins well and has a high probability of establishing production from multiple reservoirs.