The Silver Oak No. 2 well is being cased to a depth of approximately 3,000 feet after running a suite of open hole logs. Since the first string of casing was set, strong oil and gas shows have been recorded on the mud log in the Etchegoin W5 sand and Diatomite intervals. In addition to the open hole logs, Tartan plans to conduct geochemical analyses on the drill cuttings to assist in determining the potential pay thickness of the Diatomite Interval. The suite of logs have also confirmed potential pay in the Etchegoin W5 sand. During drilling, this interval displayed strong oil and gas shows on the mudlog. The Etchegoin W5 formation, as well as a deeper structural marker, were encountered approximately 170 feet higher structurally than in the Silver Oak No. 1 well, further confirming Tartan's geologic picture.
During drilling, the Silver Oak No. 2 well has encountered significantly higher pressures at shallower depths than those encountered in the Silver Oak No. 1 well. Originally Tartan had planned to set casing at approximately 3,500 feet to isolate and protect the potential deep targets from the higher pressure intervals. It has been these higher pressure intervals that have caused the drilling delays and have required Tartan to set the second casing string approximately 500 feet higher than anticipated. After the second casing string is cemented in place, the high pressure intervals will be safely contained and drilling can continue to the first of the potential targets within the Temblor Formation, the Temblor/Devil water sands. The drill stem test originally planned for the top of the Temblor formation will likely not be run; instead the evaluation of the interval will be done with a suite of logs. The other potential target intervals to be drilled and evaluated before the next casing string is installed are the Upper Carneros, Middle Carneros, Lower Carneros and Aqua sand intervals. All of these formations are potentially productive intervals above the targeted Bloemer and Belridge 64 sands.
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