- EOG’s Commitment
- How Is Water Used in a Crude Oil or Natural Gas Well?
- How Does This Compare to Other Uses of Water?
- What Sources of Water Are Used by EOG?
- Water Issues are Different in Each Geographic Region
- EOG’s Water Management Activities in the Marcellus Shale
- EOG’s Water Management Activities in the South Texas Eagle Ford
- EOG’s Water Management Activities in the North Dakota Bakken
- EOG’s Water Management Activities in the North Texas Barnett Shale
- EOG’s Water Management Activities in the West Texas and New Mexico Permian Basin
- EOG’s Water Management Activities in Colorado
- EOG’s Water Management Activities in the Horn River and Other North American Basins
EOG is committed to actively managing and conserving water resources in the communities where it operates. That is why EOG is taking steps to minimize overall water usage and protect drinking water aquifers near its operations.
EOG will continue 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 and otherwise address in a responsible manner the potential environmental and community impact of the water used, produced and disposed of during its operations.Top of Page
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, 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 carries 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 1 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 Operations– EOG’s Use of Hydraulic Fracturing) 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. Typically, hydraulic fracturing of a horizontal well in unconventional shale formations may require from 24,000 to 120,000 barrels of water.
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. All this water is either reused or properly and safely disposed of at permitted and regulated facilities in accordance with federal and state laws and regulations. EOG regularly conducts audits of these disposal facilities to verify compliance with all 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 surface casing and cementing programs. (See: Corporate Responsibility – Hydraulic Fracturing Operations– Best Practices – Well Bore Integrity)Top of Page
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 other industrial, agricultural, recreational and municipal purposes. According to the United States 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, water used for crude oil and natural gas operations typically represents less than 1 to 5 percent of total water usage. By way of comparison, in the 20-county Barnett Shale area of Texas, municipal uses unrelated to oil and gas operations account for more than 80 percent of water use. Power generation, irrigation and livestock are also significant users of water resources in this region. 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.
By way of example, the 120,000 barrels of water typically needed to drill and fracture a horizontal natural gas well is equivalent to the amount of water consumed by:
- New York City in approximately seven minutes;
- A 1,000 megawatt coal-fired power plant in 12 hours;
- A golf course in Palm Springs in 5 days; or
- A 7.5 acre field of corn in one season.
The Groundwater Protection Council has estimated that 300 million gallons of water are used to produce a single day’s supply of newsprint. While these examples represent 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.
In comparing the amount of water used to drill and complete a typical horizontal shale natural gas well to other sources of energy, the amount of water used for the natural gas well equates to about 0.8 to 1.7 gallons for every million British thermal unit (MMBTU). One MMBTU equals about 1,000 cubic feet of natural gas. To put this in perspective, this is less than 20 percent of the water needed to produce one MMBTU of coal that is ready to burn in an electric power generation plant and less than 0.1 percent of the water needed to produce the same energy equivalent of ethanol for fuel.Top of Page
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 and the reuse of produced water. The company continues to evaluate the use of discharge water from industrial or city 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 has formed a special project team, with representatives from each of EOG’s U.S. and Canadian operating areas, to accelerate our pursuit of best practices in water management. This project includes the full life cycle of water used in operations from acquisition through transportation, storage, treatment, flow back, reuse and disposal. The initial focus of the team has been to determine water quality needs, water source options and reuse options.
EOG is working with multiple technology companies to develop water reuse technologies that can accommodate high volumes of produced water. EOG is also 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 may be required in different regions.Top of Page
Water Issues are Different in Each Geographic Region
Each geographic region has unique needs and challenges when it comes to identifying sources of water, the ability to reuse or recycle water and methods for water disposal. Some areas have an abundance of water sources, but limited disposal facilities. 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 or recycling of produced water or 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.Top of Page
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 lined storage tanks and under the area where trucks deliver the fluids. Additional 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. The 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 primarily filtered and rebalanced produced water in subsequent hydraulic fracturing operations and minimize the use of surface water and groundwater. These practices avoid overloading of the 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.
In Pennsylvania and throughout North America, EOG does not dispose of any produced water in Publicly Owned Treatment Works (POTW) or commercial water disposal sites that discharge treated water into surface streams, rivers or waterways. Only properly permitted disposal injection wells operated either by EOG or reputable third parties are utilized to inject water into deep geologic formations. All injection wells used by EOG are regulated by the EPA or by state agencies pursuant to EPA regulations.
In accordance with regulatory requirements, EOG conducts pre-drilling baseline sampling of private water wells and springs and ponds used for livestock or agriculture purposes within a 2,500-foot radius of all Marcellus Shale wells. EOG also samples surface waters in areas where water wells are not prevalent.
Also in connection with its Pennsylvania operations, EOG uses various sources of water and has taken steps to minimize the use of public water supplies. For example, EOG has partnered with the Blue Valley Acid Mine Drainage (AMD) Treatment Plant and Fish Culture Station in Brockway, Penn., which treats AMD water from a former coal mining operation near Brandy Camp Creek and utilizes the treated water in its operation of a fish hatchery. EOG utilizes some of the treated water for its Pennsylvania operations, and EOG’s financial support allowed the plant to continue operations when their state grants ran out. Enough money has also been generated to continue to operate the fish hatchery at the site and feed the fish. In 2009, the hatchery raised and released over 200,000 trout into local streams. This is a win-win scenario because EOG’s financial support is keeping the plant in operation and assisting the non-profit organization that manages it in achieving its goal of improving stream quality and habitat.Top of Page
EOG’s Water Management Activities in the South Texas Eagle Ford
The company understands the importance of South Texas water resources. Where feasible, EOG’s Eagle Ford operations use non-potable or brackish water from aquifers that are not suitable for public drinking water. The availability of these aquifers differs from region to region in the Eagle Ford. EOG is also minimizing the use of surface water and is researching the purchase of municipal wastewater where available in areas near its Eagle Ford operations.
Methods are also being developed to reduce the amount of water used during the hydraulic fracturing process. Since the inception of operations in the Eagle Ford Shale, EOG has improved the efficiency of operations and has reduced water usage by up to 30 percent based on general estimates. In an effort to promote best practices by operators throughout the Eagle Ford and maintain open lines of communication with those connected with Eagle Ford Shale activities, EOG accepted an appointment to the Eagle Ford Task Force by Texas Railroad Commissioner David Porter. The Task Force is comprised of local community leaders, local elected officials, water representatives, environmental groups, oil and gas producers, pipeline companies, oil services companies (including a hydraulic fracturing company, a trucking company and a water resources management company), landowners, mineral owners and royalty owners. In announcing the formation of this task force, Commissioner Porter stated:
“The Eagle Ford Shale has the potential to be the single most significant economic development in our state’s history… and we must develop this shale responsibly, finding the proper way to develop these resources while ensuring environmental protection.”
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 significant Eagle Ford operators.Top of Page
EOG’s Water Management Activities in the North Dakota Bakken
As part of its ongoing efforts to reuse water, EOG began operating a new water facility in the Bakken in 2012. The facility, which took two and 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 November 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.
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 will also allow EOG to reduce its water disposal volumes.
These processes have been so well received that plans are already in place to expand the activities in 2013.Top of Page
EOG’s Water Management Activities in the North Texas 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 United States 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.”
Fresh water is also efficiently handled to avoid waste by installing a system of connected holding ponds lined with impermeable plastic.
EOG has also evaluated the following alternative methods for reusing water: (i) in-line filtration; (ii) centrifuge/chemical treatment; and (iii) diluted produced water fracs.
After considering the technological challenges and the availability of regulated underground 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 inject it into properly permitted and regulated disposal wells.
EOG will continue to consider alternative methods for reusing produced water and ways to minimize the use of fresh water in its Barnett Shale operations.Top of Page
EOG’s Water Management Activities in the West Texas and New Mexico Permian Basin
In the Wolfcamp Shale play in West Texas, EOG is sourcing most of its water 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. EOG is also actively reusing produced water in this area. Multiple water treatment systems have been field-tested in order to determine the best methods to facilitate water reuse. These systems include various filtering mechanisms and more complex technology capable of cleaning produced water to drinking water quality standards. EOG has also made investments in water storage infrastructure for the purpose of water reuse, including steel storage tanks to hold produced water, as well as sealed piping to carry this water to and from well sites.
In EOG’s Leonard Shale operations in New Mexico, EOG has funded and conducted numerous field trials, some of which are ongoing, to study viable water reuse technologies and is actively working with government agencies to facilitate best practices for water reuse in the area.Top of Page
EOG’s Water Management Activities in Colorado
In Colorado, EOG voluntarily participated in a groundwater quality sampling program launched last summer by the Colorado Department of Natural Resources and the Colorado Oil and Gas Association. As a result of the Colorado program, operators that drill new wells will collect groundwater samples both before and after drilling. The information is reported to the Colorado Oil and Gas Conservation Commission (COGCC) which will manage and publicize 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. The new program is 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 the rules recently adopted by the COGCC requiring the pre- and post-drilling testing of water wells in certain areas.
EOG is also conducting water sampling and testing in other operating areas as conditions warrant.Top of Page
EOG’s Water Management Activities in the Horn River and Other North American Basins
In the Horn River Basin in Canada and in other North American basins, EOG is evaluating new processes for water treatment and filtration technology and discussing with regulatory agencies the use of new technology to allow the reuse of produced water in an effort to reduce fresh water requirements and reduce the need for water disposal. The goal is to identify technology that will allow the company to economically filter and treat large quantities of produced water to the point of meeting fresh water standards.Top of Page
Hydraulic Fracturing Water Usage (FracFocus.com Chemical Disclosure Registry)
Water Use in the Barnett Shale (Texas Railroad Commission)
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)
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 Exploration and Production Technologies
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, Colorado Oil and Gas Conservation Commission
Top of Page