Estimating National Water Use Associated with Continuous Oil and Gas Development Active

Executive Summary

Water is a necessary component for many processes required for developing continuous oil and gas (COG) resources. Improved COG extraction techniques have greatly increased oil and gas production in the United States since the mid-2000s. However, the accompanying rapid increase in demand for large volumes of water, often in remote regions, can challenge existing infrastructure and require additional resources to meet water needs. Addressing this water need requires accurate estimates of the volumes of water used to support the various processes common to COG development in the United States in the 21st century.

In 2015, the U.S. Geological Survey (USGS) started a topical study focused on quantifying water use in areas of COG development. The topical study was supported through the USGS Water Availability and Use Science Program (WAUSP), which was authorized by the Science and Engineering to Comprehensively Understand and Responsibly Enhance Water Act (SECURE Water Act) in the Omnibus Public Land Management Act of 2009 (16 U.S.C. 1 note). In the SECURE Water Act, the USGS was tasked with conducting a National Water Census to better quantify water use in the United States, including water supporting COG development. One of the main goals of the WAUSP is to provide accurate estimates of water resources in the United States and to offer methods for determining the quantity and quality of water available for beneficial uses. This topical study to quantify water use related to COG development will help achieve that WAUSP goal. Additionally, the results from this topical study will be used to further refine the methods used in compiling water-use data for selected categories (for example, mining, domestic self-supplied, public supply, and wastewater) in the USGS’s national water-use estimates reports.

Problem

Starting in the 2000s, technological advances, scarcity of access to conventional oil and gas accumulations, and the rise of oil and gas prices resulted in development of COG accumulations. The COG resources in the United States are being produced using horizontal drilling technologies, which expose a larger amount of reservoir for thin horizontal units to the wellbore compared to vertical wells (see figure below). Once the well is drilled, fluid (typically water with additives) and proppant (solid material such as silica sand or man-made ceramics) is pumped into the well at high pressure, opening cracks that release oil, gas, or both through a process known as hydraulic fracturing (or fracking), which stimulates movement of hydrocarbons in tight (low permeability and porosity, typically shale) formations. Rapid COG development throughout the Nation has led to hundreds of thousands of wells being hydraulically fractured annually. Water availability and the potential for reduction in aquifer storage volumes are important considerations in COG settings. The process of developing an oil or gas well in a tight shale formation requires large volumes of water for initial fracturing processes: about 2 million gallons per oil well and 4.1 million gallons per gas well. Additional water is needed for re-fracturing and borehole maintenance; indirect water uses, such as crew camps and road dust abatement; and ancillary uses, such as supportive energy industries, commercial developments, and recreation (see figure below). These additional water uses have not been quantified on a regional scale.

Objectives

The objective of this topical study is to develop methods to estimate water use for COG development in the United States as a multiphase study:

• Phase I. - Quantify water use associated with COG development at a pilot site, develop an estimation model, and determine associated uncertainty. - Complete.
• Phase II. - Test the estimation model in another similar play to evaluate model capabilities for estimating water use associated with UOG development. - In progress
• Phase III. - Finalize estimation model and prepare for national assessment. - Planned

Phase I. The Williston Basin was selected as the pilot site for Phase I of this topical study. Since 2005, technological advances have rapidly expanded the production from continuous formations in the Northern Great Plains, most notably the Bakken and Three Forks Formations of the Williston Basin in North Dakota and Montana. The Williston Basin provides a unique opportunity to characterize water use associated with COG development because water use in the Williston Basin was relatively stable from year to year before 2005; therefore, any substantive change in water use since may be attributed to water-use needs to support COG development. [https://doi.org/10.3133/sir20205012]

Phase II. The Permian Basin was selected as the test site for Phase II of this topical study. The second phase of the topical study applies a similar approach and technique developed in the Williston Basin to a newly selected reservoir. The Permian Basin was selected for the second phase of water-use analysis for the following reasons: (1) the Permian Basin has the largest undiscovered technically recoverable reservoir in the United States, (2) the Permian Basin has a continuous reservoir in tight shale that primarily produces oil, and (3) the Permian Basin boundary is located within the contiguous United States. The Permian Basin represents a large basin with increasing activity over the years, which may contribute to the increasing water use. [Report in review]

Phase III. The application of the approach that was developed in phase I and verified through phase II is planned to be utilized across the contiguous United States, in an effort to characterize the water use in all major basins. This national assessment of water use will use the most current national databases to provide the most comprehensive estimates of water use. Using similar techniques and databases will allow scientists, researchers, and water managers the opportunity to compare water uses among basins and identify possible influences changes in water use may have in an area of increasing oil and gas development.

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