Originally published on oilpro.com on August 7th, 2014
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While the shale revolution involves many advanced technologies, the entire effort is underpinned by two core methodologies—horizontal drilling and hydraulic fracturing. Without either, the shale revolution would simply not have occurred.
The EIA recently reported that more than 750 Tcf of technically recoverable shale gas and 24 billion barrels of technically recoverable shale oil resources currently in exist in discovered shale plays. It can’t be overstated that the key to accessing these resources is a combination of horizontal drilling and hydraulic fracturing.
In fact, absent these technologies the US would lose 45% of domestic natural gas production and 17% of oil production within only five years.
Water is the number one consumable in the fracing process, and its importance is rising as unconventional drilling spreads. Depending on the basin and the geological formation, a typical shale gas well requires approximately 3-5 million gallons of water to drill and fracture.
Most of the water is used during the fracing process itself, with large volumes of water pumped into the well with chemicals and sand to break rocks with nano-darcy permeability and enable gas extraction. The remainder of the water is utilized during the drilling stage of the production lifecycle, with water being the major component of the drilling fluids.
3-5 million gallons of water per well sounds like a large volume. And it is. Indeed, the demand for freshwater is an issue of growing importance, especially in arid and semi-arid US shale and tight oil plays. A 2012 Ceres study found that 47% of oil and gas wells are located in high or extremely high water-stressed regions, such as the West Texas Permian Basin.
That said, recently voiced fears of freshwater depletion due to fracing fail to put the O&G industry’s use in the context of use in other industries, which can consume much more.
Increased controversy around frac demand for fresh water has created intense competition for sources and more scrutiny from municipalities on water withdrawal permits. The pressure on companies to become more efficient in both use and transportation is increasing as unconventional drilling practices spread.
How – and how much – water is used in the fracing process? How does fracing’s thirst compare to water usage in other industries? And are there new alternatives to fresh water in fracing? The rest of this post is dedicated to exploring these critical questions about fracing’s number one ingredient.
How Much Water?
According to Fracfocus (a voluntary chemical registry for disclosing fracturing fluid additives founded in 2011), water and sand comprise more than 99.5% of the fluid used to hydraulically fracture a well. Water serves as the main carrier fluid in hydraulic fracturing.
Multiple layers of cement and metal casing are placed around the wellbore during well completion. After the well is completed, a fluid comprised of water, sand and chemicals is injected under high pressure to crack the shale, increasing the permeability of the rock and thereby easing the flow of natural gas.
Because the multi-stage fracturing of a single horizontal shale gas well can use several million gallons of water, it is critical that large quantities of relatively fresh water be reasonably available. The quality of the water is very important because impurities can reduce the efficiency of the additives used in the process.
Water usage varies with horizontal lateral length and number of frac stages. Volumes pumped can also vary with the geological characteristics of the play. For example, the Haynesville Shale requires on average 1 million gallons of water during the drilling phase compared to 60,000 gallons for the Fayetteville shale. But on average, 5 million gallons of water are required to drill and frac a “typical” well, the equivalent of 1,000 water truckloads. The fracing stage is the most water intensive, using up to 90% of the total water use.
A Closer Look At The Data
A Ceres research paper published in February 2014 reported data accumulated by FRACFocus that 97 billion gallons of water were used in the fracing process from January 2011 through May 2013. Nearly half of this quantity of water was used in Texas, followed by Pennsylvania, Oklahoma, Arkansas, Colorado and North Dakota.
Among more than 250 operating companies reporting to FRACfocus in the US, Chesapeake had the largest amount of water use reported (nearly 12 billion gallons), followed by EOG Resources, XTO Energy and Anadarko. Not surprisingly, these are the independent E&Ps that have “figured out” the shale equation and are leading the US shale revolution.
Overall, Halliburton handled the largest volume of fracing water. At almost 25 billion gallons, Halliburton accounted for over a quarter of the US’s frac water usage. Halliburton was followed by Schlumberger and Baker Hughes. Again no surprise, as the Big 3 service companies run more horsepower than anyone in the industry.
The report showed that almost half of the wells fraced since 2011 were in regions with high or extremely high water stress, and over 55% were in regions experiencing drought. In Texas, which has the highest concentration of fracing activity in the US, more than half of the wells assessed by Ceres were in high or extremely high water stress regions. Over 36% of the 39,294 fraced wells in the study overlay areas experiencing groundwater depletion. This overlap has created a challenge for the industry as local regulators charged with water withdrawal permits have become more protective of water supplies.
Case Study: Water Use In Bakken Fracing
North Dakota is an especially drought-prone area, so the question of water usage in fracing is of paramount importance to Bakken operators. The Bakken is one of the busiest unconventional plays in the US, and one of the thirstiest. That said, frac water consumption in the Bakken was only 6% of irrigation consumption in the state during 2012.
The average fracing process for a single well in North Dakota requires approximately seven acre-feet of water. In 2012, records show that 12,629 acre-feet of surface and ground water were used for fracing purposes. That amounts to only 4% of the state’s consumptive water use and is dwarfed by irrigation, municipal, and power general usage.
Another interesting fact is that one day of the average daily flow of the Missouri River at Bismarck (45,480 acre-feet) is enough water to frac 6,497 wells, or 87% of all the wells that have been fraced in North Dakota.
Context Is Key: Comparatively Speaking…
The importance of discussions about the volume of water used in various industries is driven home by the fact that roughly 34% of US public water supply comes from groundwater resources, while the remainder comes from surface water bodies such as lakes, reservoirs and rivers.
Thermoelectric generation- technologies such as coal, natural gas and nuclear, which use heat to produce steam- represent approximately 40% of the freshwater withdrawals in the US.
But the large volume of water used by power plants tends not to attract the degree of criticism as its use in fracing. The relative newness of fracing compared to coal and natural gas, together with the proximity of many wells to residential areas, makes fracing more of a target.
A cost-benefit analysis pepared by the Texas Water Board took a look at the water used by fracing versus the economic benefits of the practice. The study concluded that hydraulic fracturing represents less than 1% of total water use in Texas, while providing in excess of 10% of Texas’ cumulative economic output.
Is Natural Gas Use In Power Generation Actually Saving Water?
In addition to the amount of water used in fracing contrasted to that of other thermoelectric operations, a recent UT study indicated that the water saved by shifting a power plant from coal to natural gas is 25 to 50 times as great as the volume of water used in hydraulic fracturing to extract the natural gas.
In other words, short-term depletion is converted to long-term conservation.
Bridget Scanlon, senior research scientist at UT’s Bureau of Economic Geology, which coordinated the 2013 study, said, “The bottom line is that boosting natural gas production and using more natural gas in power generation makes our electric grid more drought resilient.”
Currently, approximately one-third of Texas power plants are Natural Gas Combined Cycle plants, which consume about a third as much water as coal steam turbine plants.
Yes, it requires a lot of water to extract natural gas; but coal energy sourcing consumes much much more H2O. We can actually save water by converting from coal to natural gas.
Four Innovative Freshwater Alternatives in Fracing
1. Brackish Water
A recent study on water use for fracing by scientists at the Bureau for Economic Geology at the University of Texas at Austin found that 30% of the water used for fracing in the Midland, Texas area of the Permian Basin was brackish in 2011. In North Texas’s Barnett shale, the study says brackish water use was 3%. Brackish water’s use in South Texas’ Eagle Ford Shale was 20%.
Texas Railroad Commissioner Christi Craddick said at the time, “We’re just at the beginning of it, so I think it’s to be determined how far it goes, but I think that brackish water is an important piece.”
Producers are considering the wider use of brackish water especially in drought-prone areas such as the Permian Basin. Apache Corp, for example, is already fracing with brackish water on some of its Permian Basin spreads. Cal Cooper, Apache’s manager of special projects, said in an interview with Npr last year that brackish water “has moderately saline water, so it’s not as salty as seawater, but we pump quite a bit of that.” Apache also used “produced water,” which is groundwater with an even higher amount of dissolved solids that comes to the surface during oil and gas production. Cooper says that Apache mixes the produced and brackish water together, so “we are able to eliminate the need for freshwater to do hydraulic fracturing.”
However, fracing with brackish water presents several challenges that drillers are only beginning to address.
First, fracing with brackish water often requires the removal of chemical elements that can arrest the drilling process by creating problems such as the accretion of sediment in wells. Relatedly, the variation of water quality from site to site means that drillers need to adapt the formula of chemicals they mix into water for fracing based on the properties of each well.
There are also the related issues of accessibility and cost, as some brackish reservoirs lie deeper than freshwater resources, thus increasing the costs of drilling a well.
Additionally, it takes years to assess how brackish water, together with the underground water that lies alongside oil and gas, affects the long-term productivity of an oil or gas well.
Finally, the aforementioned UT study observed that “use of brackish water in areas with limited fresh water supplies could compete with conventional users.”
2. From The Hospital To The Oilfield: Excelyte
South-Carolina-based Integrated Environmental Technologies (IET) originally developed Excelyte as an EPA-approved solution to serve as a final surface cleaner to eliminate hospital-acquired infections, and then to prevent foodborne illnesses in food production.
Excelyte’s main active ingredient is hypochlorous acid, which is a naturally occurring molecule in the human body that combats infection.
The solution is now being tested in New Mexico and Utah, Forbes recently reported, in its first attempted application in the oil and gas sector. IET’s CEO David LaVance said that several well-known companies are using the product, but he did not identify the companies to Forbes.
IET claims that mixing water with Excelyte’s bacteria and sulfur-fighting properties instead of toxic chemicals allows for twice as much wastewater to be recovered for reuse in fracing instead of using fresh water.
Excelyte took more than five years to develop into a substance suitable for production in industrial quantities, and it is designed to leave no environmental footprint.
LaVance told Forbes, “Our product persists for only 90 days and then it disintegrates…It’s not underground for very long and things go back to normal after that. So it’s a quick-acting biocide.”
Utah is among the states that have expressed early interest in the solution, where the product is already in the pilot-testing phase. John Baza, director of the Oil, Gas and Mining Division in Utah, told Forbes, “If companies are looking at this product as a way to prevent some of those things from happening, we’re certainly in favor of it…We would encourage that kind of creative and innovative thinking.”
3. GASFRAC’s LPG Fracing Treatment
Calgary-based GASFRAC Energy Services announced in December 2013 that it had completed a Hybrid LPG fracturing treatment for Terrace Energy in South Texas’ Eagle Ford play. The company is the sole provider of waterless gelled LPG fracing technology in NAM.
GASFRAC identified several advantages of the new technology:
No water is used. It is a Liquefied Petroleum Gas gel that is “as natural to a well as soil is to the earth,” the company says. It improves performance without using water, as it is soluble in formation hydrocarbons.
Safety: GASFRAC developed a zero-oxygen, closed system and specialized equipment that ensures worker safety, eliminates post-job cleanup and requires only minimal flaring that can be decreased to zero given the right recapture facilities.
Increased Production: The ability to rapidly recover 100% of the fracing fluid results in enhanced O&G recovery, longer sustained production, and the ability to recapture, reuse or resell- a highly cost-effective benefit, especially for multi-stage horizontal wells.
4. Propane, CO2 & Nitrogen?
While GASFRAC’s innovation still remains an early-stage technology- burdened by higher initial costs than conventional fracing methods- the concept has recently been considered more seriously, especially as legislators and oil regulators focus on the large volume of water used for fracing wells.
GASFRAC’s innovation has prompted discussions about using other substances like propane, carbon dioxide or nitrogen in stead of water.
Michael Dunkel, the director of sustainable development for Pioneer Natural Resources, commented, “We’ve looked at [propane fracing], and I would say that absolutely our industry is open to all possibilities.”
Fracing, Water & The Future
As noted at the outset of this post, while much hyperbole characterizes the discussion of fracing and water supply, it is essential to recognize the need for new technologies that will enable the continued flourishing of the unconventional revolution.
The pressure to increase efficiencies is high as industry demand for water grows with the development of more wells. However, for the reasons cited throughout this post, we are optimistic that the industry’s fountain of ingenuity will not run dry when it comes to addressing these current challenges. A successful alternative to freshwater in fracing could have a very bright future and go along way to reducing criticism of the shale process.