Produced water can technically come from many sources, since the term is widely used for various types of industrial waste water. Manufacturing and power generation processes can create large volumes of hazardous water that needs careful handling and treatment before it’s safe to discharge or reuse. The water generated during desalination, uranium mining, paper processing, and nuclear power generation have all been called produced water in the past. However, today the term primarily refers to water coming from the hydraulic fracturing process and other mining activities. Find out how produced water is created to get a better idea of how to approach storing it.
Hydraulic Fracturing
While all forms of drilling release some amount of water that was trapped along with the oil or gas, hydraulic fracturing creates much larger volumes of produced water. Since the fracturing process relies on the hydraulic pressure generated by pumping in fluid, extra water is forced back out of the well. The produced water in this case is a mixture of both formation water from deep underground and some of the fracturing fluid. Most of the fluid stays trapped underground, but the natural water that rises up is still high in salinity and mixed with gas or oil residues.
Underground Brine Deposits
Oil and natural gas tend to gather in caves and openings created by the accumulation of water over thousands of years. These deposits aren’t always accessible through traditional mining and drilling effects but increasing the pressure with hydraulic fracturing helps push the valuable fuels out. However, the water that trickles into these deposits has also spent all that time concentrating in mineral and salt content. That’s primarily what makes produced water so hazardous, followed by its mixture with the desirable oil or gas and the addition of any fracturing chemicals. If these brine deposits mingle with the water table naturally, they cause the same issues as if they leak from surface pits.
Oil and Chemical Contamination
The oil and gas mixed into the produced water is more than just a potential environmental hazard. It can also represent a valuable source of power or heat for processing if it’s carefully reused. Flaring processes can either create air pollution or serve a secondary purpose with a little extra planning and equipment. Of course, produced water needs liners that can withstand the high oil and grease content. Even relatively clean water can react with some liners to slowly degrade them over time.
High Volume
Produced water is generated in extremely high volumes by most operations. Even relatively small fracturing wells can use a few million gallons of freshwater and generate nearly as much in produced water. If the operation will continue long enough to reuse that produced water, the final release amount will still need handling until it’s treated enough to release. Underestimating the time each load of produced water will spend in holding before reuse can lead to overwhelmed facilities and spills that come with high environmental fines.
Potential for Reuse
Since the same processes that create produced water also demand a steady supply of water to operate, it makes sense to aim for as much reuse as possible. Treatment is usually required to bring raw produced water into parameters that meet the requirements of hydraulic fracturing and other drilling methods. Most operations begin with a steady freshwater supply, but reusing wastewater is more efficient and cost effective. It also makes hydraulic fracturing more acceptable to environmental agencies concerned about demand for agricultural and drinking water in the area.
No matter the type or source of produced water, there’s a liner to safely contain it. The particular chemical composition of your produced water will determine which liner is the best choice. Discuss your waste water challenges with us here at BTL Liners and we’ll help match you to the perfect product for your project.
