THE APPLICATION OF 3D MODELING TO DIFFERENTIATE BETWEEN NATURALLY OCCURRING METHANE AND METHANE MIGRATION ASSOCIATED WITH NATURAL GAS DEVELOPMENT

Naturally occurring methane is found in the fresh groundwater system of northeastern Pennsylvania. However, in certain instances, natural gas drilling in the region has resulted in increased dissolved-phase methane concentrations in water supplies. The mobilization of thermogenic methane in such instances has largely been attributed to substandard gas well construction and operational practices resulting in the vertical and lateral migration of gas associated with Upper to Middle Devonian strata. This research explores how 3D modeling in the Geographic Information Systems (GIS) environment represents an effective tool for exploring the spatial relationships between water well depths and both introduced and natural occurrences of methane in fresh groundwater systems.

Ultimately, by modeling geologic structure, water and gas well construction attributes, and the distribution of shallow gas-bearing units, it is possible to gain insight regarding factors that contribute to both stray gas migration and the distribution of background methane.