English to Polish Tech/Engineering Petroleum Eng/Sci shale gas operations

In addition, as the well bore penetrates the aquifer near the surface, any produced water or hydrocarbons are separated from the aquifer by multiple layers of impermeable cement and steel casing, which is tested to ensure well integrity prior to commencing any hydraulic fracturing.

(...) The committee also concluded that hydraulic fracturing does not pose a direct risk to water aquifers, provided that the well-casing is intact. Any risks that do arise are more likely to be related to the integrity of the well, and are no different to issues encountered when exploring for and producing hydrocarbons from conventional geological formations.

(...) Impact of seismic activity on well integrity