Fracking flowback is the wastewater that returns to the surface after the process of hydraulic fracturing. This fluid is a significant byproduct of shale gas and oil extraction operations.
Understanding Flowback
During hydraulic fracturing, commonly known as fracking, large volumes of water mixed with sand and chemicals are injected deep underground at high pressure to fracture rock formations and release trapped hydrocarbons. While most of this fluid remains underground, a portion of it flows back to the surface.
According to the provided reference:
- About 15-20 percent of the water used in fracturing returns to the surface.
- This water comes back up through the steel-cased wellbore.
- The returning wastewater is temporarily stored in steel tanks or lined pits.
- The wastewater which returns to the surface after hydraulic fracturing is specifically called flowback.
Key Characteristics
Flowback water isn't just the original injected fluid. As it travels back up the well, it mixes with naturally occurring substances from the rock formation. This can include:
- Dissolved salts (making it highly saline)
- Minerals
- Naturally occurring radioactive materials (NORMs)
- Hydrocarbons (oil and gas)
- The chemicals that were part of the injected fracturing fluid
Handling and Management
Managing flowback is a critical aspect of fracking operations. Due to its complex composition and potential environmental risks, it requires careful handling. Temporary storage, as mentioned in the reference, is just the first step. Subsequent steps often involve:
- Treatment: Cleaning the water to remove contaminants.
- Disposal: Injecting it into designated disposal wells deep underground.
- Recycling: Treating it sufficiently so it can be reused in future fracking operations.
Proper treatment and disposal are essential to prevent contamination of surface water or groundwater sources. For more details on wastewater management in the industry, you might consult resources from environmental agencies or industry publications (e.g., example environmental report on flowback water - [hypothetical link here]).
In summary, flowback is the specific term for the portion of the injected fracturing fluid that returns to the surface, carrying with it a mix of original additives and naturally present subsurface materials. Its management is a key consideration in the environmental impact of hydraulic fracturing.
