The conductivity of the Marcellus Shale is relatively low, but varies between 0.000011 and 0.00059 feet
per day (just over 7/1000th of an inch of movement per day at its fastest), and the surrounding units also have
variable but low conductivities.17 It is more common for fluid to flow horizontally than vertically in the Marcellus Shale because of the pressures at depth and the existence of horizontal bedding planes. However, it is not
impossible for pressures at depth to create a gradient angled to some degree toward Earth’s surface in some
regions of the Marcellus or surrounding units. As the rock unit changes,
the direction of flow and conductivity can change.