Twenty years ago the Marcellus Shale Formation didn’t look too promising to geologists. That’s because it simply wasn’t rendering much natural gas at all. The wells back then rarely produced anything in commercial amounts–but today the Marcellus Shale Formation is a major contributor. What changed?
Well, they started experimenting with horizontal drilling.
Natural gas is extracted from the Marcellus Shale in a number of ways–one of them being from fractures that break through the shale vertically. Vertically is the key word there.
These fractures are normally interconnected like a freeway system, so one well could extract gas from a large volume of shale. The key is to run into as many fractures as possible when drilling the well, but it’s not exactly the most efficient to do this with vertical drilling.
If the fractures are vertical, then a horizontal well can intersect much more of them. When companies started drilling horizontally, their wells “ran into” more of these vertical fractures. This started rendering much more natural gas, and turned the Marcellus Shale into a powerhouse yielding 14.4 billion cubic feet of natural gas per day.
Geologists estimate there’s 141 trillion cubic feet of recoverable natural gas in the Marcellus Shale, which would keep America supplied for an astounding six years.
Despite these estimates, some believe technological advances could allow us to retrieve even more natural gas from Marcellus in the coming years.