Effects of Partial Oil Saturation on Gas Productivity of Appalachian Devonian Shales

摘要

High resolution core analysis performed on samples of Devonian lower Huron Shale led to the discovery that permeability to gas varied as a function of pressure drop across the sample. In addition, the lower Huron Shale cores had less than 0.2% porosity to gas. These data strongly suggest the presence of a mobile liquid in the pores blocking gas flow. Chromatographic analysis on pulverized shale chips treated with methylene chloride revealed the liquid to be a light paraffinic petroleum similar in composition to other Appalachian Basin crudes. The Conclusion reached from this study is that shales with a moderate to high oil content will not normally produce commercial amounts of gas, despite the fact that significant quantities of gas may have been generated and trapped in the shale pores along with the oil. It appears that eastern ''oil shales'' are incompatible with eastern ''gas shales,'' and factors that make the one economical do so to the detriment of the other. 9 refs., 7 figs. (ERA citation 11:019116)