Waterless Fracs Better In Eagle Ford Shale?
A small independent oil exploration company, Blackbrush Oil And Gas, has apparently decided that propane gel or “waterless fracs” work better in Eagle Ford Shale than traditional water – based ones. The company has entered into a long-term agreement with Canada’s GasFrac Corporation, which has developed a proprietary process that utilizes a mix of sand and propane gel instead of water to frac Eagle Ford Shale wells. Blackbrush Oil and Gas has over nine hundred drillable locations in Eagle Ford Shale, most of them located near Carrizo Springs in Dimmit County. By using waterless LPG frac technology in the Eagle Ford Shale, the company expects to see longer production curves and also reduce the expenses associated with disposing of produced water. GasFrac has already announced plans to build an operations center southeast of San Antonio Texas to service oil and gas companies in the Eagle Ford Shale. GasFrac will open a 20 acre facility in the Rancho Grande business park, just outside of Floresville Texas and plans to hire more than 100 employees over the next few weeks. The fact that GasFrac’s new operations center is located on the other end of the Eagle Ford Shale from where Blackbrush Oil and Gas’s operations are, indicates that the company must either have other deals underway or else a high degree of confidence that it will win over more Eagle Ford shale oil and gas companies with their new technology.
How Does Waterless Fracing Work?
GasFrac’s proprietary waterless hydraulic fracturing process still uses fluid and sand as a proppant. In this case the fluid is simply liquid propane gel instead of water. The propane returns to gas form, and is eventually recovered at the surface and collected for use in fracing new wells, or sold along with natural gas down the pipeline. The company claims that “all that’s left behind is sand.”
The company website describes how the process works: (from Gasfrac.com)
Storage tanks – Utilizing a boost pump and nitrogen pressurization, a series of LPG storage tanks store and feed the LPG to the specialized sand blender. A pressurized nitrogen blanket is applied to all LPG storage tanks to ensure safety.
Sand blender – This proprietary blender is a pressurized system in which proppant is preloaded, purged and pressurized with the nitrogen. A controller uses a pressurized auger system to meter the proppant into the gelled LPG, creating a gelled LPG sand laden slurry to stimulate the reservoir.
Stimulation – Specialized high pressure pumping units inject the gelled slurry into the wellbore at the required surface pressures.
Benefits Of The Waterless Frac Technology:
Produced water disposal costs in the Eagle Ford Shale account for a major part of an oil and gas company’s long term production expenses, when as much as half of of frac water used during completion is eventually returned to the surface over the life of the well. Not only could waterless frac technology save Eagle Ford shale operators a lot of money, it could also help save valuable groundwater in South Texas. In addition to the water saving benefit, operators such as Blackbrush Oil And Gas expect to see longer, more robust well production curves due to a reduction in formation damage. Also, since the process can be done with only around 30 truck visits, (compared to the hundreds of truck trips required for a conventional hydraulic fracturing operation, and subsequent water disposal,) the reduced wear and tear on South Texas roads would be another welcome benefit.
Are Conventional Water Based Fracs Damaging The Eagle Ford Shale Formation?
Blackbrush Co-Ceo, Phil Mezey, stated the following in response to the new contract with the waterless fracing company: “BlackBrush looked extensively for an alternative to “water fracs” as we recognized a definite problem in formation damage contributed by introducing water in the fracing process to the formations we are actively developing.” GasFrac has long touted the superior results of their proprietary waterless frac technology, including faster well cleanup time, less water disposal costs and lack of formation damage.
So, does using traditional water based fracing methods in the Eagle Ford Shale amount to a “slash and burn” technique that actually damages the Eagle Ford Shale formation? EOG Resources chairman Mark Papa has already stated that initial testing has indicated that ”In the Eagle Ford, laboratory tests on the rocks tell us that water injection probably isn’t going to work, so in the Eagle Ford we’re looking at something that has also been used for fifty years, but at a much lower frequency of use, (than water flooding) and that’s simply dry gas injection.” Of course Mr. Papa is talking about enhanced recovery, not initial well completion.
However, that begs the question, “if using water injection in the Eagle Ford Shale is a bad idea, then why is injecting millions of gallons into it during a frac job a good idea?” If you have ever seen shale rock cuttings that have come from an Eagle Ford Shale well, you would know that after a few days or weeks after being exposed to the elements and a rain or two, those cuttings will turn into clay soil, much the same as what the Eagle Ford Shale looks like in the community of Eagle Ford Texas, some 350 miles to the northeast, where the formation outcrops. If water turns shale into clay again, then why are oil and gas companies injecting millions of it into the Eagle Ford shale? The answer is that, up until GasFrac developed an alternative, water based hydraulic fracturing was the only means available to break apart tight shale formations such as the Eagle Ford shale and release the oil and gas trapped inside them.
Even the best multi-stage frac job in the Eagle Ford Shale only reaches out so many feet from perforations in the wellbore into the formation, hence the need for smaller well spacing to improve the overall recovery factor. “Smaller well spacing” is the new buzz word being used in investor presentations by E&P companies in the Eagle Ford Shale. Most claim that by decreasing well spacing, oil recovery can be greatly increased. EOG Resources for one, recently announced that they had doubled the estimated reserves their Eagle Ford shale acreage after decreasing the proposed well spacing. It would seem that smaller well spacing alone might not be the answer to improving recovery factor in the Eagle Ford Shale, especially if water returning to the wellbore after traditional, water based fracing methods possibly turns much of the formation into “mush.” It should be noted that the Eagle Ford Shale is not homogenous and that the lower part of the formation has a higher overall clay content, therefore possibly making it more susceptible to damage from water – based fracing methods. Perhaps some areas of the shale, those areas with higher clay content, could benefit from LPG fracs, while water could still be used elsewhere. Time will tell if this new technology lives up to its promises. I, for one will be anxiously awaiting the results from Blackbrush’s Dimmit county wells to see if they surpass those of adjacent operators using traditional fracing methods.
The author holds no positions in any of the companies mentioned and makes no express or implied recommendations of any companies mentioned in this article.