Unconventional Wells: Boon or Bane

Tags: Pennsylvania

Feb 24, 2022


Pennsylvania is no stranger to oil and gas – the state has been a center of the industry since Colonel Drake drilled the first US oil well in 1859 in Titusville. The fracking revolution of the late 2000’s brought a second gas boom to PA, providing a new method to release trapped oil and gas deposits within the Marcellus shale formation. The Keystone State has made the most of its abundant natural gas reserves, creating thousands of high-paying jobs and filling global demand for dependable and affordable energy.


Fracked (unconventional) wells can run miles horizontally and maintaining the integrity of these wells that thread through various geological formations thousands of feet underground can be difficult.

Residents near some unconventional wells have experienced contaminated drinking water, with side effects ranging from headaches to vomiting. In extreme cases, water has even become flammable due to high methane concentrations in the aquifer. These issues stem from unconventional wells with compromised integrity, namely cement failure which can allow fluids and gases to travel through leakage pathways that lead to the surface or groundwater.

Once methane and other harmful substances get into aquifers or the atmosphere, they are nearly impossible to remove.


A properly maintained well will not allow gases to leak into the aquifer: unconventional wells are designed with layers of nested steel casing, sandwiched with cement, specifically to prevent gas migration into the formation. When problems arise, typically they are from cement failure in and around the casing (annuli). Leakage pathways in annuli allow subsurface pressure to build, forcing gases up toward the surface (sustained annular pressure).

As sustained annular pressure builds, gases follow the path of least resistance, seeking an outlet. Unless gas is allowed to vent (methane emissions) or flare (carbon dioxide emissions) into the atmosphere, it is forced out into the formation. Often the path of least resistance ends up leading to groundwater, resulting in aquifer contamination.


Experts in the oil and gas industry have effectively mastered the art of accessing hydrocarbon reservoirs in these deep geological formations, but keeping their contents confined is another story. Routine monitoring of annular pressure is the only way to ensure well integrity and prevent contamination, but with over 3 million oil and gas wells throughout the U.S., effective monitoring is a huge challenge. Fortunately, many operators are now voluntarily monitoring their wells utilizing advanced technologies, but hundreds of thousands of wells still remain in the dark.

An abundance of sealing technologies exist to address well integrity issues. However, until now these technologies only formed a “cork” at the point of injection that fails to fill the crack beyond the first few millimeters. As pressure builds these plugs often fail to maintain a gas tight seal. Additionally, pressure may cause gas to branch off into connected leakage pathways that were not filled, bypassing the plug entirely. This fix addresses the symptom, but not the root cause of the pressure buildup. BioSqueeze® provides a surefire solution to this problem, penetrating hundreds of feet into the fracture network and forming a permanent seal through all connected leakage pathways. Trapping gases at their source ensures they stay sequestered far from the well, atmosphere, and vital groundwater sources. Vigilant monitoring and mitigation are absolutely vital to ensure clean and affordable energy.