AskChesapeake

Choose your location:

States within the Haynesville Shale

Haynesville Home

East Texas

Saltwater Disposal Wells

The management of produced water presents many challenges and can pose significant costs to operators. Operators are careful to manage produced water in ways that protect surface and groundwater resources. Whenever possible, operators seek to reduce future demands for freshwater by examining both traditional and innovative approaches to reuse or recycle by using in other production processes. Current techniques include a variety of methods such as underground injection, treatment and discharge, evaporation, reuse and recycling.

Underground injection has historically been the primary disposal option for produced water by the natural gas and oil industry. After produced water is separated from the gas, saltwater disposal wells (SWDs) are used to return the water underground into porous rock formations similar to those from which it came. SWD wells are a proven technology. The disposal of produced water through use of this method is a monitored, safe and necessary practice which is overseen and inspected regularly by the Railroad Commission of Texas (RRC) in the Haynesville Shale East Texas region.

“When wells are properly sited, constructed and operated, underground injection is an effective and environmentally safe method to dispose of wastes.” — Environmental Protection Agency (EPA)

A SWD well is considered a “Class II” injection well by the EPA. SWD wells are highly regulated and commonly used by the natural gas and oil industry to dispose of water generated during production. Tank batteries are present at each drillsite for the storage of water resulting from natural gas production.

The RRC regulates disposal wells and their construction in East Texas. These regulations are the industry standard and are considered safe and effective. Still, Chesapeake exceeds the commission’s standards by constructing SWD wells with multiple layers of protective steel casing and cement that are specifically designed and installed to protect groundwater and to ensure that the producing zone is protected from overlying formations. The layers of protection are:

Surface casing is run to a depth well below all freshwater aquifers, typically to a depth of 1,800 feet below the surface.
A layer of cement holds the surface casing in place
Production casing runs through several thousand feet of rock between the freshwater aquifer and the injecting formation
A layer of cement holds the production casing in place
A packer is installed deep within the casing to isolate the injection zone
Steel tubing is put in place
An internal plastic coating is added to the tubing to prevent corrosion

Thousands of feet of impervious rock exists between the injected water and the groundwater located in freshwater aquifers, making it virtually impossible for any produced water to come into contact with these zones.

The mechanical integrity of SWD wells is also regularly tested, and the pressure in the well is monitored continuously to ensure that all of the disposed water reaches the intended formation.

Strategically located SWD wells can reduce the miles trucks must travel in order to dispose of produced water. Connecting water pipelines from gas wellsites to SWD sites would lessen truck traffic even more dramatically, reducing emissions, traffic noise, traffic congestion and road repairs. This would result in fewer emissions, improved air quality and increased safety in East Texas.

For more information about SWD wells, contact the following organizations: