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Description of Drill Hole Abandonment <br />After the completion of a down hole survey, each drill hole was abandoned with a <br />combination of cement and bentonite. Each hole is cemented with Portland Type I /II cement <br />from the bottom of the hole to the top. The amount and types of cement to be used were <br />calculated using the following formula depending on whether there is or is not a VWP in the <br />hole. <br />Volume to be Cemented (Hole Volume) <br />Bit Diameter = 3.8 inches = 0.3167 ft <br />Bit radius = 0.15833 ft <br />Cement height = depth from [ -] depth to <br />Volume to be Cemented (Hole Volume) in ft = Pi * (Bit radius) * Cement height <br />Cement Mixtures: <br />During the 2011 drilling program the Company used two different cement mixtures as <br />described above. The VWP Cement was used to encapsulate the VWPs to ensure correct <br />operation. Abandonment Cement was used in both holes with VWPs and holes without. <br />Holes with VWPs used Abandonment Cement at the base of the hole where there were no <br />VWPs and then VWP Cement was used for the remainder of the hole. Holes without VWPs <br />were simply cemented with Abandonment Cement from bottom to top. <br />VWP cement: <br />1 x 100 Ibs bag of Portland Cement and 25 Ibs Bentonite (plug gel) and 30 gallons water <br />creating a volume of 4.7 ft mixed cement. <br />Number of Portland Cement Bags Required = Hole Volume divided by 4.7 ft <br />Weight of Bentonite required = weight of total Portland Cement required divided by 4 <br />Abandonment cement: <br />1 x 100 Ibs bag Portland Cement and 5 Ibs Bentonite (plug gel) and 7 gallons water = 1.4 ft <br />mixed cement <br />Number of Portland Cement Bags = Hole Volume divided by 1.4 ft <br />Weight of Bentonite required = weight of total Portland Cement divided by 20 <br />Calculations for a Hypothetical 668 Foot Hole with the Deepest VWP hung at 490 Feet <br />0 to 550 feet requires VWP cement to encapsulate the VWPs (60 foot buffer below VWP <br />chosen); <br />550 to 668 feet requires abandonment cement; <br />110 N. Rubey Drive Suite 201, Golden Colorado, 80403 <br />PO Box 18041, Golden Colorado, 80402 <br />Ph: (303) 279 4946 Fax: (303) 279 4934 <br />www.blackrangeminerals.com <br />