As illustrated, these protective measures consist of multiple layers of steel casing and cement that separate the well from the aquifer and also serve to isolate production streams within the center of the well. In particular, the surface casing pipe is cemented in place to isolate the aquifer from the wellbore. Additional casing and cement are added as the well is drilled deeper to ensure integrity of the wellbore and that fluids remain within the pipe. This is not only a sound operating practice, but also a standard regulatory requirement.
These cement casings are also thoroughly tested for leak-tightness prior to operation to ensure integrity. We test the casing and cement jobs to ensure they do not create a pathway for oil and gas to enter the water table. In addition, hydraulic fracturing completions are closely monitored and managed to ensure that the pressures involved do not exceed well design parameters.
Lastly, the surface site is also designed to isolate groundwater from drilling and production operations. When the well is decommissioned, the entire wellbore is filled with cement and sealed just below the surface to provide long-term protection to both soil and groundwater aquifers.