Water Management
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EOG’s Commitment

EOG is committed to actively managing and conserving water resources in the communities where it operates. For example, EOG has implemented a pre-drilling baseline water sampling program in all of its U.S. operations, with sampling parameters customized for each operating area based on geologic and other factors. In addition, as part of its sampling program, EOG conducts post-drilling testing based on state regulations and on a case-by-case basis as is deemed operationally appropriate.

EOG continues to test water reuse technologies, take steps to minimize overall water usage in the drilling and completion of wells, meet or exceed permit requirements, properly dispose of produced water, evaluate alternative sources of water and otherwise responsibly manage the water used, produced and disposed of during its operations to protect the environment.

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Carbon Disclosure Project Water Program

Consistent with its commitment to transparency, EOG participated in the Carbon Disclosure Project’s water program for 2014, 2015, 2016, and 2017, and expects to participate in this program in future years as well. EOG’s participation in this program allows investors and the public to better understand EOG’s water stewardship practices. EOG’s participation in this program also allows EOG to benchmark its business and operations against that of its peer companies.

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How Is Water Used in a Crude Oil or Natural Gas Well?

Water is an essential component in the development of energy resources throughout the world, including coal, nuclear, biofuels, solar, crude oil and natural gas. It is both a required resource necessary for the drilling and completion of crude oil and natural gas wells and a byproduct of the production process.

Water is used in the drilling process to help cool the drill bit as it breaks the rock and to carry rock cuttings out of the borehole to the surface.

After drilling, the target formation may be stimulated with hydraulic fracturing. A mixture – typically composed of more than 99 percent water and sand and less than one percent highly diluted chemical additives that are typically found in common household items (such as laundry detergents, cleaners and beauty products) – is pumped at a calculated rate and pressure through the wellbore into the crude oil or natural gas-bearing rock formation. (See: Corporate Responsibility – Hydraulic Fracturing – How Hydraulic Fracturing Works) This creates carefully designed millimeter-wide cracks or fractures in the target formation. The newly created fractures are propped open by the sand grains. This allows the crude oil or natural gas to flow from tight (low permeability) rock formations into the wellbore.

While the sand grains used in hydraulic fracturing remain underground in the rock formation to hold open the fractures, a percentage of the water and additives flow back through the well during the initial days of production. Also, other non-potable groundwater that is naturally present in oil and gas formations flows through the well during the production of oil and gas. These fluids are then either reused or safely disposed of at sites that are approved and permitted by the appropriate regulatory authorities. EOG regularly conducts audits of these disposal facilities to verify compliance with applicable regulations.

In order to stabilize the wellbore and protect groundwater and drinking water aquifers during drilling, completion and production operations, state regulatory authorities for many years have implemented and enforced strict requirements on how all crude oil and natural gas wells should be constructed. Each wellbore must be encased in steel casing, called surface casing, and must be surrounded by cement to create an additional safeguard for drinking water aquifers. Each state establishes casing and cementing specifications and determines the depth of the required surface casing to provide a secure barrier between the wellbore and any drinking water aquifers. EOG complies with and often exceeds state regulatory requirements by conducting additional monitoring and testing to confirm the integrity of its surface casing and cementing programs. (See: Corporate Responsibility – Hydraulic Fracturing – Best Practices – Wellbore Integrity)

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How Does This Compare to Other Uses of Water?

The water used in crude oil and natural gas operations is significantly less than the water used for the production of many other energy resources and for other industrial, agricultural, recreational and municipal purposes. According to the U.S. Department of Energy and the U.S. Geological Survey, crude oil and natural gas operations use a small amount of the nation’s water resources compared to other societal uses.

While there are regional differences, the water used for crude oil and natural gas operations typically represents less than one to five percent of total water usage. For example, hydraulic fracturing accounts for only about 0.5 percent of all the water used across Texas. As the Barnett Shale Energy Education Council has observed: “[I]rrigation is the biggest user of water in Texas, accounting for 61 percent. Municipal use follows with 27 percent, then manufacturing at 6 percent, steam electric power at 3 percent and livestock at 2 percent. The last 1 percent is made up of oil and gas and other mining activities.” As University of Texas Professor Rusty Todd wrote in The Wall Street Journal: “lawns [in Texas] consume roughly 18 times more water than fracking does.” In the Marcellus Shale area of the Appalachian Basin, electric power generation accounts for more than 70 percent of water consumption. Other industrial and municipal uses unrelated to oil and gas operations are also significant in this region.

The Ground Water Protection Council has estimated that 300 million gallons of water are used to produce a single day’s supply of newsprint. While this example represents continuing consumption, the water used for a crude oil or natural gas well is a one-time use. To provide further perspective, every seven seconds the Susquehanna River in the vicinity of the Marcellus Shale deposits 2 million gallons of water into Chesapeake Bay.

Water intensity is a commonly used metric for comparing the water consumption levels required to produce different energy sources – for example, the gallons of water used per MMBtu (million British thermal units) of energy produced. EOG’s water intensity rate – that is, the water used by EOG in completing its U.S. wells relative to the potential MMBtu value of the oil and gas reserves associated with such wells - was as follows:

  2013 2014 2015 2016
Water intensity rate

(gallons per MMBtu)
1.8 2.4 2.9 2.3

By comparison, the water intensity rates of other energy sources are as follows (according to the U.S. Department of Energy):

Energy Source Gallons of Water Used per MMBtu of Energy Produced
Coal (no slurry transport) 2-8
Coal (with slurry transport) 13-32
Nuclear (processed uranium ready to use in plant) 8-14
Synfuel (coal gasification) 11-26
Fuel Ethanol (from irrigated corn) 2,510-29,100
Biodiesel (from irrigated soy) 14,000-75,000

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What Sources of Water Are Used by EOG?

EOG uses various sources of water depending on the region where the drilling takes place. The sources of water include private and public ponds, lakes, rivers and creeks, potable and non-potable groundwater, produced water and water from production operations. In addition, the company continues to evaluate the use of discharge water from industrial or municipal wastewater treatment plants. Throughout its operations, EOG attempts to minimize the use of water from sources that are also utilized for public drinking water. For example, in a number of regions of the United States, EOG is using non-potable water from aquifers not suitable for public drinking water. The availability of these aquifers differs from region to region.

While the water used for crude oil and natural gas operations is significantly less than the water used for the production of many other energy resources and other industrial, agricultural, recreational and municipal purposes, EOG recognizes the importance of responsibly managing and conserving water resources in the communities where it operates.

EOG management formed a special project team, with representatives from each of EOG’s U.S. operating areas, to accelerate pursuit of best practices in water management. This project included the full life cycle of water used in operations from acquisition through transportation, storage, treatment, flow-back, reuse and disposal. The focus of the team was to determine water quality needs, water source options and reuse options.

EOG is also working with a number of technology companies to develop water reuse technologies that can accommodate high volumes of produced water. In addition, EOG is conducting test projects using other technologies designed to clean water for reuse. Each geographic area in North America has different challenges relating to geology, the amount of chlorides and other minerals and impurities in the water and available infrastructure, and, therefore, different technologies are required in different regions.

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Water Issues are Different in Each Geographic Region

In addition to geologic differences, each geographic region has unique needs and challenges when it comes to identifying sources of water, the ability to reuse water and methods for water disposal. Some areas have an abundance of water sources, but limited disposal facilities and other infrastructure. In other areas, climate and geographic conditions and the utilization of water for irrigation, electric power generation, industrial uses, and commercial, municipal and residential purposes results in greater competition for the sourcing and utilization of water.

As state and regional authorities and water management districts take these needs, challenges and differences into account in regulating water sourcing, usage and disposal, EOG takes steps to meet or exceed all regulatory requirements. In those instances where regulations restrict the reuse of produced water, the use of treated industrial or municipal wastewater or the use of newer technologies in water treatment, EOG has worked with regulatory authorities to promote water conservation and efficiencies.

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EOG’s Water Management Activities in the Marcellus Shale

In the Pennsylvania Marcellus Shale, EOG has implemented several practices that exceed regulatory requirements in the use, handling and disposal of water and additives used in hydraulic fracturing and the completion process.

All completion fluid and produced water is stored in lined tanks. Special protective liners are placed on the well pad under the storage tanks and under the area where trucks deliver the completion fluids. In addition, containment barriers are placed around the perimeter of each well pad.

During multi-well completions, all produced water is filtered, rebalanced and reused. As part of this process, particulates are filtered from the water, and the produced water is tested to determine appropriate quantities of additives and dilution before reuse.

During 2012, EOG completed the design and construction of a water reuse facility in Clearfield County that provides for the storage of up to five million gallons of produced water as well as facilities for filtering and rebalancing produced water for reuse. These facilities also provide for the loading and off-loading of produced water. In an effort to reduce truck traffic related to water hauling, a pipeline system has also been built to transport the water to the field. Because of these facilities, EOG is able to use filtered and rebalanced produced water in subsequent hydraulic fracturing operations and minimize the use of surface water and groundwater. These practices also avoid overloading water disposal infrastructure and reduce truck traffic on local roads.

During periods when there are no completion operations, produced water is disposed of in properly permitted and regulated injection wells. All injection wells are regulated by the U.S. Environmental Protection Agency (EPA) and applicable state agencies pursuant to EPA regulations. EOG does not dispose of any produced water in publicly owned treatment works (POTWs) or commercial water disposal sites that discharge treated water into surface streams, rivers or waterways.

In accordance with regulatory requirements, EOG conducts pre-drilling baseline sampling of private water wells and springs and ponds used for livestock or agricultural purposes within a minimum of a 2,500-foot radius of all Marcellus Shale wells. EOG also samples surface waters in areas where water wells are not prevalent.

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EOG’s Water Management Activities in the South Texas Eagle Ford

EOG understands the importance of South Texas water resources. Where feasible, EOG’s Eagle Ford operations continue to use non-potable or brackish water from aquifers that are not suitable for public drinking water. While the availability of these aquifers differs from region to region in the Eagle Ford, a large portion of the water wells used in EOG’s Eagle Ford operations are non-potable or brackish water wells. In addition, EOG has eliminated the use of surface water in its Eagle Ford operations and entered into agreements for the purchase of municipal wastewater where available in areas near its Eagle Ford operations.

EOG has also developed methods to reuse water from producing wells, where operationally feasible, to supplement its hydraulic fracturing operations in the Eagle Ford. EOG has evaluated numerous treatment technologies and has conducted multiple test programs to assess the feasibility of treating produced water in the Eagle Ford. These efforts resulted in the development of EOG’s first permanent water treatment facility in La Salle County in 2014.

In addition to its water treatment facility in La Salle County, EOG also commenced the use of mobile produced water recycling units in 2015. In 2016, one such unit processed over 117,000 barrels of water for reuse in EOG’s hydraulic fracturing operations. These units provide flexibility to EOG’s operations, as such units can transition among drilling locations in coordination with drilling and completion activities.

Along with other select STEER (South Texas Energy & Economic Roundtable) members, EOG is participating in a collaborative study with the Evergreen Underground Water Conservation District (EUWCD) that seeks to maximize the utilization of brackish water for oil and gas activities in the South Texas area. This study, which includes data sharing along with third-party water modeling and funding assistance, aims to equip EUWCD with a comprehensive, science-based regulatory management plan and permitting system that incentivizes the use of brackish water for oil and gas operations.

EOG is also participating in the Eagle Ford Water Consortium in an effort to share best practices in the management of water resources with other Eagle Ford operators.

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EOG’s Water Management Activities in the North Dakota Bakken

As part of its ongoing efforts to reuse water in the Bakken, EOG began operating a new water facility in the Bakken in 2012. The facility, which took two and a half years to design and build, allows produced water from EOG’s operations to be treated and reused as an industrial brine solution in the company’s well workover and production operations. Since the EOG facility began operations in 2012, the company has reduced the amount of brine fluid needed from third-party vendors, while at the same time reducing its water disposal volumes and its use of fresh water for workover operations.

In addition, the company has developed a process that allows it to reuse produced water to formulate fluids required for its drilling operations. This process also allows EOG to reduce its water disposal volumes.

EOG has also built a new water distribution system to support its operations in the Bakken region. This system, which consists of more than 40 miles of dual 8-inch and 12-inch pipelines, allows water used in the completion process to be carried directly to the well pads and, as a result, reduces EOG’s well completion costs. The system also reduces the amount of water transported by truck, thus reducing the amount of truck traffic in Bakken-area communities.

These infrastructure additions and processes have lowered EOG’s operating costs and provided other benefits, such as reduced truck traffic on local roads. As a result, EOG has invested in additional water sourcing, produced water gathering and water disposal infrastructure in the Bakken and is planning further water management projects for its Bakken operations.

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EOG’s Water Management Activities in the Barnett Shale

EOG is one of the founding members of the Barnett Shale Water Conservation and Management Committee. The committee’s members are committed to developing efficient and responsible best management practices for water used during drilling, completion and production operations for wells in the Fort Worth Barnett Shale. These practices are inclusive of conservation, environmental protection and safe operations.

During 2012, EOG supported the committee’s collaborative role with the Unconventional Gas Program of the Research Partnership to Secure Energy for America and the National Energy Technology Laboratory of the U.S. Department of Energy in a two-year, multi-million dollar study of how treatment and management approaches contribute to water conservation, system reliability and sustainable gas development. A news release from the committee stated:

“Technologies and knowledge from this project are important to all of us as we work to conserve and manage the water we use as well as to protect the surface and ground waters in the areas where we operate. By working together on projects like this, we are able to share information on new, innovative water management techniques.”

EOG works closely with several groundwater conservation districts spanning the Barnett Shale area in its continuing efforts to minimize and account for fresh water usage. Currently, fresh water is efficiently handled to avoid waste by installing a system of connected holding ponds lined with impermeable plastic.

EOG has evaluated in-line filtration, centrifuge/chemical treatment and diluted produced water fracs as methods for reusing water. After considering the technological challenges and the availability and proximity of regulated disposal facilities, it was ultimately determined that the safest and most economical way to handle produced water in most areas of the Barnett Shale is to transfer the water to properly permitted disposal facilities regulated by the EPA and the Railroad Commission of Texas (RRC). In addition, in an effort to minimize truck traffic related to the transportation of produced water, EOG constructed a pipeline system to transport the water to disposal facilities, significantly reducing the amount of traffic on local roads.

EOG will continue to consider methods to reuse produced water and to minimize the use of fresh water in its Barnett Shale operations. For example, EOG relinquished its rights to several Trinity Aquifer water wells to the landowners, which provides additional fresh water for domestic and livestock purposes.

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EOG’s Water Management Activities in the Permian Basin

In the Permian Basin, EOG continues to explore sourcing options from aquifers below those normally used for drinking water and continues to seek sources of non-potable water for the drilling and completion of its wells. For example, EOG has drilled, and is in the process of testing, brackish water sources. In connection with such testing efforts, EOG began using more brackish water sources in its 2017 operations, and expects to expand such use in its 2018 operations.

Multiple water treatment systems and related scale prevention chemical programs have been field-tested in order to determine the best methods to facilitate water reuse. These systems include various filtering mechanisms and more complex technologies capable of cleaning produced water to higher quality standards. EOG has also made investments in infrastructure for the purpose of water reuse, including million barrel reuse pits and aboveground steel storage tanks to hold reuse water, as well as sealed piping to carry this water to and from well sites and an extensive produced water gathering system that facilitates centralized water processing, storage and re-distribution of the cleaned, produced water to well sites.

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EOG’s Water Management Activities in Colorado and Wyoming

In Colorado, EOG voluntarily participated in a groundwater quality sampling program launched in 2012 by the Colorado Department of Natural Resources and the Colorado Oil and Gas Association. Pursuant to the program, operators that drill new wells collect groundwater samples both before and after drilling. The information is then reported to the Colorado Oil and Gas Conservation Commission (COGCC) which manages and publicizes the data. This first-of-its-kind-in-the-nation program is designed to give neighbors added assurance that the oil and gas industry is taking necessary steps designed to protect groundwater in areas where drilling is taking place. This program is also considered a strong addition to Colorado’s existing groundwater monitoring program which has previously collected data on more than 5,000 wells drilled in the state.

In addition to this voluntary program, EOG is taking steps to comply with rules adopted in 2013 by the COGCC and with rules recently adopted by the Wyoming Oil and Gas Conservation Commission, in each case requiring the pre- and post-drilling testing of water wells in certain areas. These steps are in addition to the voluntary pre-drilling and post-drilling sampling and testing program implemented by EOG in each of its U.S. operating areas discussed above.

In its Rockies plays, EOG has drilled water wells and installed water gathering and distribution infrastructure. This infrastructure allows water to be transported directly to EOG’s well sites, decreasing EOG’s need for trucking services and, as a result, EOG’s well completion costs. This infrastructure also benefits local communities by reducing the amount of truck traffic. EOG has also invested in produced water gathering, recycling and disposal infrastructure in the Rockies, providing additional cost savings to EOG and further reductions in truck traffic on local roads.

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Sources:

Hydraulic Fracturing Water Usage (FracFocus.org Chemical Disclosure Registry)

Prudent and Sustainable Water Management and Disposal Alternatives Applicable to Shale Gas Development, J. Daniel Arthur, P.E. (Presented to The Groundwater Protection Council, January 2009)

Oil and Gas in Texas: A Joint Association Message

The Groundwater Protection Council

Water Use in the United States (U.S. Geological Survey)

In the Know on H20 (Marcellus Shale Coalition)

Water Resources and Use for Hydraulic Fracturing in the Marcellus Shale Region, J. Daniel Arthur, P.E., et al (The National Energy Technology Laboratory (NETL), U.S. Department of Energy, Oil & Natural Gas Projects). See Also: NETL

Water-Thirsty Golf Courses Need to Go Green (NPR 2008)

Water Sources and Demand for the Hydraulic Fracturing of Oil and Gas Wells in Colorado from 2010 through 2015, jointly prepared by the Colorado Division of Water Resources, the Colorado Water Conservation Board, and the Colorado Oil and Gas Conservation Commission


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