Animated Map Shows Vertical vs Horizontal Gas Wells in PA

The U.S. Energy Information Administration (EIA) has created a very cool animated map showing the transition from conventionally drilled, vertical natural gas wells to unconventional, horizontally fracked natural gas wells (Marcellus wells) from January 2005 to April 2012 (a copy of the video is embedded below). Just as cool—and startling—are a couple of bar charts (also embedded below) showing the dramatic increase in the volume of natural gas production in PA while at the same time the number of gas wells, the number of holes drilled in the ground, has gone down! How can that be?

Fracked horizontal wells drilled in shale formations are far more productive than conventional, vertically drilled wells.

The animation illustrates Pennsylvania’s relatively recent transition from conventional vertical wells (black diamonds) to horizontal wells (red diamonds), drilled mostly in sections of the Marcellus, Utica, and Geneseo/Burket shale formations located in the northeast and southwest portions of the state. The animation also shows that as horizontal drilling increased, the number of vertical wells—which are typically less productive—fell, resulting in an overall decline in the state’s new well count.

Historically, natural gas exploration and development activity in Pennsylvania was relatively steady, with operators drilling a few thousand conventional (vertical) wells annually. Prior to 2009, these wells produced about 400 to 500 million cubic feet per day of natural gas. With the shift to and increase in horizontal wells, however, Pennsylvania’s natural gas production more than quadrupled since 2009, averaging nearly 3.5 billion cubic feet per day in 2011. Natural gas wells accounted for virtually all (99%) of the horizontal wells started over this period.

graph of Pennsylvania's natural gas production, 2005-2011, as described in the article text

Source: U.S. Energy Information Administration (2005-2010); Pennsylvania Department of Environmental Protection (2011).
Note: *EIA production data are used for 2005-2010 due to reporting issues with 2010 data provided by the
Pennsylvania Department of Environmental Protection (DEP). DEP data are used for 2011 as EIA data are not yet available; EIA volumes are expected to be similar.

Drilling programs in Pennsylvania’s shale formations, like those in other, more established plays such as the Barnett and Eagle Ford in Texas, are migrating to more liquids-rich areas due to the price premium of crude oil and natural gas liquids. The effect of low natural gas prices is apparent in Pennsylvania’s 2012 well count for the first third of the year. From January through April, drilling began on 618 new natural gas wells; over 700 new natural gas wells were started over the same period in 2011. In contrast, 263 new oil and "combination" (oil and natural gas) wells were started in Pennsylvania from January through April 2012, well above the 164 new wells that began drilling during the corresponding period in 2011.

graph of Annual natural gas well starts in Pennsylvania, 2005-2011, as described in the article text

Source: U.S. Energy Information Administration, based on Pennsylvania Department of Environmental Protection.

*U.S. Energy Information Administration (May 23, 2012) – Horizontal drilling boosts Pennsylvania’s natural gas production