Sand or Ceramic?

According to media reports, Consol Energy has recently been with the replacement of sand as a proppant in hydraulic fracturing by the use of ceramic materials.  Hydraulic fracturing requires a proppant to be mixed with water and then injected into the shale formation.  The result is that the proppant “props” open the cracks in the shale formation that are caused by the injection.  The natural gas is then able to flow to the surface.

Traditionally, sand has been used as the main proppant.  The Utica shale formation may be forcing a change.  The Utica formation has higher heat and pressure than the Marcellus shale, mainly due to the Utica being much deeper underground.  The high heat and pressure are causing the sand to sometimes be ineffective.  Companies have been forced to look for an alternative proppant, ceramic.  Not only do the ceramic particles withstand the pressure and heat better than the sand, but they are also perfectly round which enables the gas to move more freely in comparison to the irregularly shaped sand grains.

Ceramics also do not produce silica dust unlike sand proppant.  Silica dust can be harmful to workers and those who live near sand mining operations.  When silica is pulverized into dust and then inhaled it can cause lung cancer or silicosis, which is a scarring of the lungs.  OSHA regulates silica exposure limits and is in the process of updating its regulations on silica.  The Bureau of Air Quality within the Pennsylvania Department of Environmental Protection also monitors and regulates silica.  The oil and gas industry could find relief from these regulations if the use of ceramic materials in the proppant becomes more widespread. 

Written by - Stephen Kenney
Research Assistant
Center for Agriculture and Shale Law