Although fracing continues to be the catalyst for our dominance in global energy production, it also continues to receive persistent and almost insurmountable ESG geopolitical pressure and scrutiny by the EPA to meet or exceed clean or green parameters that threaten its very existence. One of the ways the OFS sector has combatted this aggressive agenda is by converting diesel frac fleets to electric power, to reduce GHG emissions and carbon footprint. Even though strives have been made with today’s new electric clean fleets, the focus has now migrated towards sustainability, and at the forefront of the conversation is how to address the challenges of dealing with produced water.
CHALLENGE
Produced water in the oil field is an important aspect of the oil and gas industry. It refers to the water that is brought to the surface, along with oil and gas during the extraction process. This water is typically found in underground reservoirs and is often high in salinity and may contain various impurities, Fig. 1.
Fig. 1. Produced water being pumped into holding tanks.
One of the main challenges in dealing with produced water is its large volume. In fact, for every barrel of oil produced, several barrels of water are also brought to the surface. This can lead to significant environmental and logistical challenges for oil and gas operators. Environmental concerns arise from the fact that produced water can contain harmful substances, such as heavy metals, hydrocarbons, and naturally occurring radioactive materials. If not properly treated and disposed of, these substances can have negative impacts on the surrounding ecosystems, including aquatic life and groundwater sources.
MANAGING THE BY-PRODUCT
To address these concerns, oil and gas companies have developed various techniques for managing produced water. One common method is to separate the water from the oil and gas, using specialized equipment, such as separators and tanks. This allows for the water to be further treated and recycled for use in other operations, such as hydraulic fracturing or enhanced oil recovery.
Another approach is to inject the produced water back into the ground, a process known as water reinjection. This helps to maintain reservoir pressure and can also help to reduce the environmental impact of disposing of the water on the surface. In recent years, there has been a growing emphasis on the treatment and reuse of produced water. Advances in technology have made it possible to remove a wide range of impurities from the water, making it suitable for various applications, such as agricultural irrigation or industrial processes.
However, the treatment and reuse of produced water can be costly and energy-intensive. It requires the use of specialized equipment and chemicals, as well as the implementation of effective monitoring and control systems. Furthermore, the transportation and storage of large volumes of produced water can pose logistical challenges for operators.
Produced water has been the largest-volume by-product generated in oil and gas operations. By volume, the amount of water it takes to produce one barrel of oil is extremely significant and, depending on the geological formation, the water can contain varying amounts of oil, grease, salts, and other contaminants or even rare earth metals like lithium and require up to four times the volume to produce just one barrel of oil.
There are many treatment techniques that are systematically used on virtually every well to streamline efficiencies, but even the best hydrocarbon separation, filtration and disinfection techniques yield only an approximate 20% recyclability. The remaining 80% or 25 billion bbl of contaminated water must be logistically hauled offsite to other disposal sites that include SWDs and various types of injection wells.
At current production rates, the associated domestic cost of water disposal is approximately $45 billion. Also, there are growing environmental concerns that frac water disposal presents, including perceived increased seismic activity, freshwater contamination and the regulatory permits needed for water management. The challenges are outside of current water treatment protocols and disposal techniques. So how can we reduce our carbon footprint, use less water, and appease the EPA and other governmental agencies while maintaining current production rates?
TECHNOLOGICAL SOLUTION
One way to reduce the carbon footprint associated with produced water disposal would be to minimize trucking associated with the amount of produced water that needs to be disposed, using scalable advanced water evaporation technology, Fig. 2. Instead of having to collect and move produced water to an injection site, WES has developed a water removal system that incorporates patented technology to inject the produced water directly into its Mobile Evaporation Unit (MEU), where it is evaporated on site.
Fig. 2. Innovative mobile evaporation unit.
This process is done conjunctively with a pre-treatment system that utilizes state-of-the-art patented filtration and separation technologies comprehensively to reduce the number of contaminants out of the water before the produced water is evaporated. The emitted vapor then can either be released into the atmosphere, recollected onto an existing retention pond, or recondensed and collected for reallocation without any detrimental effect to the atmosphere, Fig. 3.
Fig. 3. Emitted vapor from the MEU after the pretreatment process.
Uniquely, all MEU’s have co-gen capability to produce power that can be utilized to alleviate power supply constraints for other oilfield electrification applications, such as e-frac. This co-gen capability is a differentiator, compared to other systems that do not have scalability. For example, smaller MEU units have the capability to process up to 2,500 bbl of produced water daily. This can greatly reduce the need for, and number of, trucks for wastewater removal. With the cost of wastewater disposal ranging between $1.00 and $12/bbl, the cost associated with generating the power necessary to evaporate at this rate is much less than the cost associated with trucking the wastewater offsite, thus making it a greener, more cost-effective option for produced water disposal.
Also, with growing environmental concerns related to increased seismic activity, due to injection wells, this process can be used to alleviate some of the pressure associated with water, steam, CO2 and frac fluid storage. Other applications include food processing, agriculture, waste management and lithium mining, where this technology can minimize the amount of cost associated with water disposal without compromising the environment. For additional information visit: www.waterevaporationsystems.com
About the Authors
Dr. Ron Sickels
Water Evaporation Systems, LLC
Dr. Ron Sickels is chief technology officer for Water Evaporation Systems. He is a recognized leader in fluid quality management, technology bundling, and equipment packaging. He is a proven solution provider with over 40 years of experience and holds numerous industry credentials. Dr. Sickels earned a PhD in environmental sciences and engineering, and is laboratory-certified in numerous disciplines including: 1) A-general engineering contractor; 2) B-general contractor; 3) certified in hazardous substance removal and remediation insitu/offsite; and 4) an SP001 aboveground tank inspector. He also holds a C-61 specialty license, as well as a D-64 non-specialized subcategories. He holds numerous process and product patents. Dr. Sickels is a respected lecturer and educator on the science of fluid dynamics, fluid quality control management, renewable alternative energy, power generation, microgrid technologies in addition to petroleum and environmental integrated engineered solutions and strategies.
