Heavy Oil Prospecting in Montana
A. E. Sandomierski, B. J. Drenth, S. P. Trisch, Department of Geological Engineering and Sciences, A. S. Wylie, Jr., Advisor
A heavy oil deposit with estimated recoverable reserves in excess of one billion barrels of oil is believed to exist in the Jurassic Swift sandstone in north central Montana. Application of conventional geologic and engineering prospecting techniques combined with tertiary recovery processes (cyclic steam) and horizontal well technology could make exploitation of this reservoir profitable. Specifically, the following questions need to be answered: How much recoverable oil is present? Is production economically viable using tertiary recovery techniques? In order to evaluate the amount of oil present, data from 80 well penetrations in a 700,000-acre area were examined. This data included core descriptions and analyses, geophysical well logs, sample descriptions, productivity tests, and previous works on the region's geology. Interpretation of this data included the creation of porosity cutoff, thickness, and structure maps. Analysis of core descriptions, interpretations of depositional environments of reservoir rocks, and recorded shows of oil were used to isolate the area of best potential for oil production. Having completed the interpretation phase, a well was drilled in the area of best potential to evaluate the porosity, oil saturation, and permeability of the Swift sandstone reservoir. Analysis of the well results is still in progress. Concurrently, we are working on a strategy for how to produce the field most efficiently. This includes consideration of how many vertical and/or horizontal wells should be drilled, how to deploy surface infrastructure including separators, tanks, pipelines, and roads, while minimizing surface impact. Evaluation of daily production rates and markets for the heavy oil are also being investigated to assure a profitable project. Submitted to 2002 Undergraduate Expo
