47th Annual AAPG-SPE Eastern Section Joint Meeting

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Relationship Between Well Performance and Structural Setting in the Marcellus Shale of Greene County, Pennsylvania


Analysis of horizontal Marcellus Shale wells in Greene County, Pennsylvania suggests a correlation between estimated ultimate recovery per thousand feet of lateral (EUR/1,000 ft) and structural setting. Basement-generated anticlines and synclines of Greene County seem to have a direct effect on well performance. To test the relationship between EUR/1,000 ft and structural setting in the Marcellus Shale, 730 wells with adequate production, completion, and location information were categorized into four structural settings based on shallow residual mapping the base of the Big Injun Sand. The structural settings refer to the relative height above or below the residual trend surface of the Big Injun at a given location. The structural settings, from low to high, are (1) Below Trend (2) At or Near Trend (3) Above Trend, and (4) Well Above Trend. The Below Trend structural setting has the highest average EUR/1,000 ft and outperforms the worst structural setting, Well Above Trend, by 25%. The average EUR/1,000’ decreases with each progressively shallower structural setting. A similar relationship between horizontal well performance and structural setting has been observed in the Utica-Point Pleasant Shale (Utica Shale) in Ohio. In the Utica Shale, structurally low settings show higher total organic carbon (TOC) compared to structurally high settings. It is hypothesized that structurally low settings offer a better environment for the deposition and preservation of organics. The relationship between well performance and structural setting in the Marcellus Shale will be explored and compared to what has been observed in the Utica Shale. Further, the importance of filtering wells by structural setting prior to analyzing completion methods will be emphasized.