Recycling/Reuse of Produced Water
Not all produced water can be recycled or reused for other drilling operations. In some cases, the salt content of the produced water is simply too high. For example, regardless of the formation, current hydraulic fracturing technologies require the use of relatively low salinity water. High salt content makes the injection fluid difficult to pump downhole, thus increasing the power requirements and resulting in higher volumes of chemicals needed to reduce friction.
State regulations also play a major role in the industry’s ability to recycle or reuse produced water.
Another factor that influences produced water management is wellsite location. For instance, in some areas of the Haynesville Shale, well locations are widely spaced. Due to this distance, the creation and operation of a centralized treatment facility would result in higher volumes of truck traffic than that associated with the disposal of the fluid in a nearby saltwater injection well (SWD).
Chesapeake’s Aqua Renew® Program
Founded to enhance our water recovery and reuse, Chesapeake’s Aqua Renew® program uses state-of-the-art technology in an effort to recycle produced water in our operations from the Barnett Shale of North-central Texas to the Marcellus Shale of northern Pennsylvania. Produced, or formation, water is a naturally occurring by-product of natural gas and oil extraction. This water is generally laden with various salts, sand and silt found naturally in the earth and travels from the producing formation through the wellbore to the surface with natural gas and oil during completion and production operations.
The quality of produced water differs greatly because of the varying amounts of salt, sand or silt and is dependent on the formation in which it is found. Due to its normally high salt content, produced water's reuse in completion operations has historically been considered impractical by the industry.
Chesapeake began to focus on developing ways to conserve and reclaim water in 2006-07. That experience, along with our involvement in the Barnett Shale Water Conservation and Management Committee, evolved into an agreement with the City of Fort Worth to study water evaporation systems as a potential way to reduce the amount of produced water being injected into saltwater disposal wells. Using an Evaporative Reduction and Solidification System (EVRAS) to capture heat generated by natural gas compressor stations (an energy source that would typically be wasted), a portion of the produced water is filtered and reduced to water vapor. The resulting clean vapor is then released into the atmosphere, where it eventually returns to the earth as rain. For more information on this technology, visit layneintevras.com/evras.html.
Since this preliminary reclamation project, our focus on reuse and water conservation has
become a company-wide endeavor to include a variety of technologies and methods.
Our Marcellus Shale operations are treating and recycling a vast majority of the produced water from our operations. At each Marcellus wellsite, produced water is collected and stored in on-site holding tanks before being transferred to central filtration locations where it is pumped through filters designed to remove any suspended solids or particles. The filtered water is then either stored in on-site tanks or transported to the next well scheduled for hydraulic fracturing. The water is tested for salt and other mineral content to determine the rate at which it can be blended with freshwater to ensure proper quality and quantity for reuse.
While we still have to mix the recycled produced water with freshwater in order to ensure the proper mixture for hydraulic fracturing, every gallon of produced water we filter and reuse is one less gallon of water that has to be trucked to a disposal well and one less gallon of freshwater we have to purchase and use.
The Aqua Renew program is expected to grow throughout our areas of operation. In addition, we are regularly evaluating new technology both on our own and through partnerships with a number of environmental organizations in an effort to expand the program.