Produced water is a significant issue for the oil and gas industry,
presenting environmental and logistical challenges that require careful
management and technological solutions. By implementing effective treatment and
reuse techniques, operators can minimize the environmental impact of produced
water and enhance their operations’ sustainability.
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.
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.
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.
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 WO
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.