Frac fever heats up
By Catherine Watkins
- A 21st-century global oil and gas boom has resulted from new technology that allows previously unrecoverable resources in tight shale and sandstone formations to be mined.
- The process—known as hydraulic fracturing, or “fraccing”—forces pressurized fluid containing surfactants and other additives into rock, fracturing it, and thereby allowing gas and oil to flow.
- This boom is a source of great opportunity for surfactant researchers and manufacturers.
The local economy is flourishing in Midland, a small city in the middle of the large oil- and natural gas-producing area in west Texas (USA) known as the Permian Basin.
It isn’t difficult to figure out why: An online search in April 2013 found that Midland had 801 telephone listings for companies that provide services for hydraulic fracturing (or fraccing)—the activity at the heart of the city’s success. In fact, a 21st-century shale oil and gas boom (or “frac fever”) is occurring all over the world, thanks to new technology and the identification of numerous vast formations of fine-grained black shale and sandstone in which oil and natural gas were trapped millions of year ago. Because surfactants are an important component of the fluid used to fracture (frac) the oil- and gas-bearing rock, the boom is a source of great opportunity for surfactant researchers and manufacturers.
How it works
Since the 1940s, an estimated one million mainly vertical wells have been fracced in the United States alone. Most of this work, however, was done to stimulate existing wells. Beginning in the 1980s, a new technique for horizontal drilling developed by Mitchell Energy & Development allowed previously unrecoverable resources to be mined and has resulted in today’s frac fever.
Gas and oil in shale are trapped in individual pores about half the width of a human hair. Pumping pressurized water through the well fractures the rock and creates a network of interconnected spaces that allow natural gas and oil to flow, but many of the fractures snap shut as soon as the pumps are turned off. Mitchell solved that problem by adding proppant (a contraction of “propping” and “agent”; usually sand or ceramic beads) to the water, along with a cocktail of chemicals—and by drilling the well horizontally once the vertical well-bore hit the bed of gas- and oil-bearing rock. Fracced wells can reach a vertical depth and horizontal distance of up to two miles in both directions (more than 3,000 meters). This new high-volume hydraulic fracturing method not only allowed access to previously unrecoverable fossil fuels, it also used much more fluid than previous methods, at around 5 million gallons (almost 19 million liters) per well per frac.
After fracturing, the internal pressure of the shale or other formation forces the injected fraccing fluid to the surface where it is stored in tanks or pits prior to disposal or recycling. These recovered fluids are referred to as “flowback.” Disposal options for flowback include discharge into surface water or underground injection.
How much is there?
Estimates of the amount of shale gas and oil—known as unconventional resources—available for recovery using today’s technology vary widely. The most recent (2011) guesstimate by the US Energy Information Agency (EIA) of “technically recoverable shale gas resources” in 33 countries including the United States was 6,622 TCF (trillion cubic feet), or 188 trillion cubic meters. To put that in perspective, the EIA estimated that the US consumption of natural gas in 2011 was about 24 TCF. Similarly, the International Energy Agency (IEA) suggested at the end of 2011 that the global reserves of recoverable global shale oil may be more than 3 trillion barrels (480 billion cubic meters). By comparison, IEA in 2011 estimated remaining global conventional oil reserves at almost 2.3 trillion barrels.
Investment money is flowing along with shale oil and gas. Goldman Sachs Group Inc. reported that in 2011, the US oil and gas industry invested $138 billion into exploration and production of shale oil and gas. That compares to $35 billion in China, $10 billion in Russia, and $5 billion in Saudi Arabia. Testimony by the Dow Chemical Co. in February 2013 before the US Senate Energy and Natural Resources Committee attributed more than 100 new US chemical industry projects and $95 billion in new investments to frac fever. Dow itself is investing $4 billion in new US facilities related to fraccing, the company said.
To date, hydraulic fracturing has involved mostly brute force as gas and oil producers used more and more horsepower, fraccing fluid, and proppant to drive hydrocarbons out of the earth. Unlike chemically enhanced oil recovery, which is a slow and relatively expensive process, fraccing is quick and comparatively inexpensive. A further push for speed on the part of oil and gas producers is that mineral leases revert back to the owners if drilling isn’t accomplished within a defined period of time.
“Many oil and gas producers have been playing the odds,” noted one industry observer, who asked to remain anonymous. “They could drill 10 wells, and if they got several with decent returns, it would cover the ones without good returns.”
As with any new technology, the market for fraccing surfactants and additives is still very fragmented, according to consultant Neil Burns of Neil Burns LLC in Freehold Township, New Jersey, USA. “It is really the oilfield service companies that are at the nexus of this whole industry,” he said. “They are the ones that will be selecting and deploying the surfactants and other additives that will be used.” The largest service companies include Baker Hughes, Halliburton, and Schlumberger. But hundreds of small firms (remember the Midland phone listings?) able to conduct basic fraccing using simple fluid systems also exist.
Then, there are what Burns calls “satellites” around the service companies: specialty chemical manufacturers (Solvay, Clariant, and Huntsman, for example); a “host” of distributors; and secondary formulators who buy surfactants and additives and sell them to the service companies. In the background, watching all the frantic activity with great interest, sit the suppliers of basic surfactant feedstocks such as Chevron/Phillips, Shell, SABIC, and Sasol.
What is in fraccing fluid?
The precise formulation of fraccing fluid (which varies from well to well) is a trade secret held by the service companies that supply fluid to the oil and gas producers. However, chemicals commonly found in fraccing fluid are listed in Table 1.
A subcommittee of the Energy and Commerce Committee of the US Congress reported in 2011 that the 14 leading oil and gas service companies used more than 780 million gallons (almost 3 billion liters) of hydraulic fracturing products—not including water—between 2005 and 2009 in US fraccing activities. Overall, the companies employed more than 2,500 products containing 750 different components.
Of those products, 279 contained at least one chemical or component that was deemed to be proprietary. As a result, the oil and gas production companies injecting the fluids often do not know what they are injecting because they purchase the fluids from service companies such as Halliburton or Baker Hughes, who regard select ingredients as confidential business information.
Surfactants constitute the largest chemical component by weight in fraccing fluid, according to the Environmental and Energy Study Institute, a nonprofit organization founded in 1984 by a bipartisan US Congressional caucus. According to a spokesperson for Houston, Texas-based Halliburton Co., which performed two of the first commercial hydraulic fracturing treatments in 1949 and is one of the largest oilfield service providers: “The surfactant functionality is widely variable . . . . [Surfactants] can be used as emulsion breakers, emulsion formers, foamers, defoamers, surface-modifying agents, suspension aids, viscosifiers, [and for] contact angle modification, surface tension modification, [as a] mobilization aid, and [for] other functions. The applicable functionality of the surfactant used will depend on the individual well characteristics and needs of the enhanced oil recovery or stimulation treatment.”
Viscoelastic surfactant gels
Unlike smaller oilfield service companies and surfactant manufacturers, the larger companies have been working for some time on how to enhance shale oil and gas recovery. At Baker Hughes, D.V. Satya Gupta has been researching both conventional and unconventional fracturing fluids as business development director for production enhancement technology at the company’s Pressure Pumping Technology Center in Tomball, Texas, USA.
“Traditionally, surfactants have been used to lower surface tension, modify the contact angle [a quantitative measure of the wetting of a solid by a liquid], and to recover the fluid after the operation is completed,” noted Gupta. Guar or guar derivatives are added to traditional fraccing fluid (normally water) to increase viscosity to carry the proppant inside the fracture. Natural polymers, however, tend to leave residue (and serve as a food source for bacteria, necessitating the use of biocides), which blocks the pathway and reduces conductivity, hence the need for alternative surfactants.
Gupta and his team have been looking at viscoelastic surfactant (VES) gel systems to replace natural polymers in fraccing. “In principle, these gels are like the gels you see in shampoos. They are of low molecular weight and do not leave residue. They also have better suspension properties for the proppant,” he said. Further, VES gels can withstand higher temperatures, remaining stable to 275°F (135°C), and can be made with seawater or produced water (water from the formation that is brought to the surface with oil or gas).
According to Gupta, the technology of VES systems can be classified based on the structures they create: worm‐like micelles, lamellar structures, or vesicles. “As the concentration of surfactant increases in water, micelles start to form,” he noted. “Further increasing the concentration exceeds the critical micelle concentration for the surfactant in water; these molecules start interacting with each other. These interactions are based on ionic forces and can be amplified by adding electrolytes (salts) or other ionic surfactants. Depending on the ionic charges, and the size and shapes of the surfactants and these counter ions, ordered structures start to form, which increase viscosity and elasticity.”
Gupta noted that the structures can be disrupted by adding other surfactants, ionic additives, and hydrocarbons (from the rock formation or mutual solvents or other solvents) or can be diluted by additional formation water. “The most common commercial systems use cationic surfactants with inorganic salts or with anionic surfactants,” said Gupta. “Anionic surfactants with inorganic salts are also common. Zwitterionic and amphoteric surfactants in combination with inorganic salts have also been used.”
The law of unintended consequences: guar gum
The ever-increasing need for guar gum in fraccing fluids—and the resulting price volatility—has led to problems for the food industry. Guar gum is a hydrocolloid that is eight times more viscous than cornstarch and is produced from the endosperm of the guar bean. It is used as a thickener in everything from ice cream to baked goods to salad dressings . . . and hydraulic fracturing fluid.
India produces 80% of the world’s supply of guar gum. Normally, 60% of its exports go to the oil industry and 40% to the global food industry, according to The Wall Street Journal (WSJ) newspaper. Talk about volatility: In May 2012, the export price of a metric ton (MT) of guar gum was $27,000, the WSJ noted, plunging to $7,000/MT in December 2012.
In 2012, high prices meant that only 20% of India’s exports went to the food industry, which is trying to find alternatives to guar, along with the oil and gas industry.
Shale imbibition research at UND
All signs point to a future in which oil and gas producers as well as oilfield service providers make better use of research and technology for more focused fraccing efforts in order to maintain profitability.
Several US universities have active research programs, including the University of Texas in Austin, Texas A&M in College Station, and the University of North Dakota (UND) in Grand Forks. Dongmei Wang and her team at UND are studying the Bakken shale formation that lies under a good portion of North Dakota for clues about optimal surfactant formulation for shale oil recovery. They plan to investigate shale gas recovery in future studies.
Wang is a recent transplant from China, where she was a noted petroleum engineer with that country’s largest oil producer, PetroChina Co. Ltd. At UND, she and her team are determining which surfactant formulations can stimulate shale oil recovery through “imbibition,” or displacement of one fluid by another. She estimates that every 1% increase in recovery could lead to an increase of 2 to 4 billion barrels of oil production.
In an initial study presented at the Society of Petroleum Engineers (SPE) Annual Technical Conference and Exhibition (doi:10.2118/145510-MS, 2011), Wang’s group found that an ethoxylated nonionic surfactant, internal olefin sulfonated anionic surfactants, and an amine oxide cationic surfactant were more stable than the other surfactants studied for temperatures at 105–120°C. Further, for any given surfactant, “oil recovery can be maximized by identifying an optimal surfactant concentration, brine salinity, sodium metaborate concentration, and divalent cation content.”
A second study, published in SPE Reservoir Evaluation & Engineering (doi: 10.2118/153853-PA, 2012), refined the team’s initial work. “Positive results were generally observed with all four surfactants: amphoteric dimethyl amine oxide, nonionic ethoxylated alcohol, anionic internal olefin sulfonate, and anionic linear α-olefin sulfonate,” Wang and her team write. “From our work to date, no definitive correlation is evident in surfactant effectiveness vs. temperature, core porosity, core source (i.e., Upper Shale or the Middle Member), or core preservation (sealed) or cleaning before use.”
Industry observers note that one issue with transferring university-based research into widespread use is the lack of good public field data correlated to laboratory studies because producers and service companies consider oilfield data to be confidential.
Brian Mueller agrees that the days of fraccing using mainly brute force are coming to an end. Mueller is director of research and development at CorsiTech, a specialty chemicals manufacturer in Houston, Texas. CorsiTech’s primary focus is chemical additives for drilling fluids, but the company also develops specialty chemicals for mining, personal care, and asphalt additives.
“Producers and service companies are looking for technology that gives price performance in addition to enhanced recovery,” said Mueller. Another key concern to producers, he noted, is environmental friendliness, given the public furor surrounding fraccing.
“Clearly, we are heading toward a future in which the industry will be interested in customizing surfactants to specific conditions in specific formations,” he noted. “In the end, the companies that will do well are the ones with surfactant laboratories who are doing the research.”
Catherine Watkins is associate editor of Inform and can be reached at firstname.lastname@example.org.
Is it frac, frack, frac’ or ?
Anyone writing about hydraulic fracturing is faced with a consuming question at the outset—how to spell the shortened and gerund forms. Should they be frack/fracking, frac/fraccing, frac/fracing, or frac/frac’ing?
The answer depends largely on whether you are involved in the activity or not. The popular press and anti-drilling activists both use “frack/fracking.” As Andrew Maykuth of the Philadelphia Inquirer newspaper pointed out in 2011, frack sounds “harsh, threatening, and vaguely profane.” In fact, Maykuth reported that a local public relations firm tested “frack” against other resource-extraction terms and found that it scored even lower in positive characteristics than “strip mining.”
Critics of the frack/fracking form of abbreviation also point to the faux curse invented in 2004 (per Wikipedia) by writers of the science-fiction television series “Battlestar Galactica”: frak. All in all, many of those in the oil and gas recovery industry prefer any spelling other than frack.
So why did Inform relegate “frac/fracing” to the editorial scrapheap despite its frequent use in the industry? Whereas “frac” is fine, its gerund form—“fracing”—is confusing to anyone with a rudimentary knowledge of phonetics. The single consonant leads readers to believe the word rhymes with “racing” or “facing.”
Will Brackett, managing editor of the Powell Shale Digest, a trade weekly published in Fort Worth, Texas, USA, coined “frac’ing.” He wrote that he “take[s] exception to the fact that drilling opponents have taken to using frack as a euphemism for a curse word I can’t print in this family newsletter.” We find the apostrophe unsettling, though, which took frac/frac’ing out of the running.
All things considered, “frac/fraccing” was the clear winner and has duly been entered into the official Inform stylebook.
A boom goes bust
In 1969, the US Atomic Energy Commission (the predecessor to today’s Department of Energy, or DOE) detonated a 40-kiloton nuclear device 8,426 feet (2,568 meters) below the ground surface in western Colorado in an attempt to release commercially marketable quantities of natural gas. The production of natural gas stimulated by the detonation was “less than anticipated,” the DOE notes in a fact sheet. Further, “although approximately 455 million cubic feet [12.9 million cubic meters] of natural gas was produced, elevated levels of radioactivity in the gas made it unacceptable for use at that time.”
DOE continues to monitor groundwater in the area for radioactive contamination. None has been detected.
Information: Some fast facts about fraccing
• The main sources of information about the components found in fracturing fluid are FracFocus.org and FracFocus.ca. These websites are a joint project of the Ground Water Protection Council and the Interstate Oil and Gas Compact Commission. Most of the major oil and gas producers have voluntarily submitted data from more than 40,000 US and Canadian wells, although most information about surfactant usage has been deemed to be proprietary. According to ExxonMobil, oil and gas producers are “pursuing similar disclosure approaches in Europe and other areas where we are exploring internationally.”
• The Society of Petroleum Engineers hosts a wiki (a website developed collaboratively by a community of users) at PetroWiki.org. The site contains a wealth of information on fraccing fluid formulation.
• Research announcements: General Electric said in April 2013 that it will build a $110 million research center in Oklahoma to study hydraulic fracturing. FTS International (formerly Frac Tech Services) is opening a new technology center in Houston to develop new fraccing fluids and proppants.
• In 2005, hydraulic fracturing was exempted by the US Congress from any regulation under the Safe Drinking Water Act. In 2014, the US Environmental Protection Agency is scheduled to deliver a report on the potential impact of fraccing on drinking water and groundwater. In March 2013, the agency selected 31 experts in areas ranging from well drilling to toxicology to review the report. (See www2.epa.gov/hydraulicfracturing.)
• Ecolab, the industrial and institutional cleaning company based in St. Paul, Minnesota, USA, has been building its holdings in water remediation and fraccing additives. It merged with Nalco, a leading water treatment company, in 2011. In 2012, Ecolab acquired oilfield additives producer Champion Technologies (Houston, Texas, USA). In a deal with the US Department of Justice reached in April 2013, Ecolab agreed to divest certain assets, patents, and licenses to Swiss chemical producer Clariant, another supplier of oilfield chemicals, in order to maintain the competitiveness of the marketplace.
• Inform’s look at chemically enhanced oil recovery.