Hydraulic fracturing, or fracking as it is commonly known, is a technology that has been in use for more than 60 years. It is essential to producing oil and natural gas resources from tight rock and shale formations; without it, production cannot economically occur. In 2013, Anadarko participated in the drilling of more than 1,300 wells in the U.S. onshore – approximately 80 percent of which required hydraulic fracturing. Hydraulic fracturing is generally applied to formations that are more than a mile below the surface (4,000 to 14,000 feet); whereas, potential sources of ground water typically reside much closer to the surface (between 100 and 500 feet). Hydraulic fracturing involves the injection of fluid (generally consisting of water, sand and a proportionately small amount of additives) under pressure through multiple protective layers of steel pipe, cement and rock into a pre-determined oil or natural gas-bearing rock formation. The water and pressure open microscopic pathways, which are the width of a human hair and propped open by grains of sand. These pathways allow the natural gas or oil to flow to the wellbore and ultimately be produced at the surface. For a general demonstration of the hydraulic-fracturing process, please view this informational video at Energy from Shale.
Hydraulic Fracturing Committee
In October 2012, Anadarko formed a Hydraulic Fracturing Committee that continues to assist the company’s management in continuously monitoring, evaluating and addressing matters related to its hydraulic fracturing operations.
What’s in it?
Anadarko supports the public sharing of the ingredients used in hydraulic fracturing. We were instrumental in the creation of the Ground Water Protection Council’s hydraulic fracturing online registry, which makes this information available to anyone, any time at www.fracfocus.org.
The ingredients used in fracking fluids vary according to geology. In general terms, water makes up more than 90 percent of the solution; sand or proppant constitutes approximately 9 percent; and additives make up less than 1 percent of the total volume. The relatively small amount of additives generally consists of friction reducers, biocides to prevent bacterial development and scale inhibitors. This pie chart available at FracFocus shows a general breakout of typical ingredients.
Anadarko is currently the most active participant in FracFocus with data uploaded for more than 5,000 operated wells. Since 2012, approximately 100 percent of Anadarko's U.S. onshore wells that are hydraulically fractured are reported to FracFocus. As part of Anadarko’s commitment to data integrity and disclosure of chemicals used in our hydraulic fracturing operations, we believe periodic reviews of the data posted to FracFocus is important. The reviews enable us to identify areas for improvement in efficiency and they provide opportunities to strengthen our quality-control systems. These improvements help prevent potential issues by improving clarity and accuracy.
Anadarko has a strict policy against using diesel fuel in fracking fluids and has communicated this policy to the company’s contract service providers. In addition, Anadarko does not permit its vendors to inject diesel fuels as the term is defined in EPA’s “Permitting Guidance for Oil and Gas Hydraulic Fracturing Activities Using Diesel Fuels: Underground Injection Control Program Guidance #84” dated February 2014 (EPA-816-R-14-001).
Innovations in Hydraulic Fracturing Technology: Stim Center
Anadarko is pioneering the use of technology in Colorado to conduct hydraulic fracturing for multiple locations from a central facility up to a mile away, called a Stim Center. Locating multiple fracking operations to a single location reduces truck traffic and associated emissions, and also the resources required to continuously set up, break down, and move operations from one well pad to another. The location of the Stim Center is strategically chosen both to maximize the number of well pads served and to ensure adequate distance from homes, farms, ranches, businesses and other occupied dwellings. Because water can be piped to and from one Stim Center, Anadarko is able to dramatically reduce the size of a multi-well development pad from 10 acres to less than six.
In 2013, Stim Center III piloted the use of natural gas to power the surface pumping equipment instead of using diesel fuel. The trial utilized liquefied natural gas (LNG) to power 70 percent of the needs of the pumping fleet, thereby eliminating the use of 11,250 gallons of diesel fuel and an associated 60,000 lbs of CO2 emissions. In May of 2014, a “Dual-Fuel” approach of using both diesel and natural gas became standard practice at Stim Center IV, which utilized natural gas sourced entirely from within the Wattenberg field via subsurface pipelines. Through July 2014, 14 wells have been treated using the Dual-Fuel approach, eliminating the need for 120,000 gallons of diesel fuel and an associated 640,000 lbs of CO2 emissions.
Chemical Assessment Rating Evaluator
Anadarko continually strives to utilize technologies that are technically sound and have a highly positive environmental profile, which provides better economic value. We scrutinize both the material and the system when reviewing different additives and systems utilized for hydraulic fracturing operations.
Recently, Anadarko has undertaken a project to help make the assessment process more reliable and more repeatable. The Health, Safety and Environmental (HSE) Department along with chemical specialists and outside environmental consultants collaborated to develop the first version of Chemical Assessment Rating Evaluator (CARE).
CARE provides a rigorous review of chemicals and human health based on the United Nations Global Harmonized System of Classification and Labeling of Chemicals, U.S. EPA Guidelines, EPA lists of water and air pollutants and volatile organics, and utilizes other reputable U.S. and European databases. Utilizing the information provided on MSDS Sheets, each component of a product can be analyzed and the score for the product is calculated. Once a specific product has been scored, its relative environmental profile can be compared to other materials that provide the same functionality within the fracturing process. The CARE assessments enable the completion engineers to utilize this quantitative measure to improve the environmental profile of fluids and materials used in the hydraulic fracturing process.
Cross-section of a Typical Horizontal Well