Safety is our priority and protecting the environment is central to our well designs. All our well designs are inspected by an independent well examiner before being sent to the Health and Safety Executive for review.
In order to recover the natural gas trapped deep below the surface in rock formations, Cuadrilla’s wells reach depths of over 10,000 feet.
Throughout Cuadrilla’s operations, robust safety measures are in place to protect the environment.
Each well we drill is lined with layers of steel casing which are cemented in to place, completely sealing the well from the rock formations.
Importantly, Cuadrilla always has at least three layers of steel casing at depths where the aquifer is found. These casings – the surface casing, the intermediate casing and the production casing – are cement-sealed and extend hundreds of feet below the aquifer. This is a comprehensive safety feature of our well designs and prevents contamination of the ground water.
Cuadrilla also always uses an intermediate casing as part of its well design. The intermediate casing creates a second steel, cement-sealed layer of well protection extending well below the level of the aquifer, ensuring environmental safety. The intermediate casing ensures that there can be no leakage path from the shale reservoir up to the aquifer – see diagram within the images on the right hand side of this page. In the US, this was recently made a requirement by New York as part of the state’s recommendation to allow fracturing to resume.
Across the world, over 2.5 million fracture treatments have taken place globally. Significantly, 60% of onshore natural-gas production comes from hydraulically fractured wells. In the US, only a handful of operations have led to the subsurface environment being contaminated with natural gas, with bad well design – not hydraulic fracturing – the cause.
For more detail on the construction of Cuadrilla’s wells, along with the safety mechanisms in place, refer to the Wellbore Integrity document.