New
Techniques Hold Promise To Treat Frac Flow Back
(Tech Connections Column,
June 2011, American Oil
and Gas Reporter)
Lance Cole, who has written Tech Connections for years, has now passed the
torch. It is a time of change for PTTC, as Lance indicated in his April column.
As of mid-May, PTTC no longer is formally associated with the American
Association of Petroleum Geologists, although we continue to cooperate closely
on projects of mutual interest.
Newspapers and industry journals are full these days of concerns regarding
changes taking place in both regulatory and technology arenas related to
managing fracture flow-back water in natural gas shale plays. This is especially
true of Pennsylvania’s Marcellus Shale, but that attention is present in all
U.S. shale-gas plays. We see the dynamic playing out in Texas, Arkansas and
other statehouses where lawmakers either are changing their states’ fracturing
regulations and reporting requirements for frac treatment chemicals, or are
considering doing so.
The move to greater transparency in fracture treatment so the interested public
can learn what is being injected (and later produced) and eventually treated is
important to both the industry and the citizenry. This effort is highlighted by
the Interstate Oil & Gas Compact Commission and Ground Water Protection Council
initiating their FracFocus website.
Commercial processes are available to treat frac fluids and new technologies are
being developed all the time. Depending on the basin and prevailing state
regulations, flow back either is injected into regulated injection wells,
reconditioned and used in new frac jobs, or treated in municipal wastewater
facilities.
With the large frac jobs (exceeding 100,000 barrels) seen in some shale plays,
conserving water is a concern even in areas not normally considered arid.
Potable and agricultural water is becoming ever more precious across the
country.
Eventually, commercial treatment using filtration, reverse osmosis, ion
exchange, perhaps application in constructed wetlands, and other techniques may
allow large-scale reuse of fracture flow back in irrigation, other industrial
uses, or just release to surface waters.
PTTC usually looks for information on commercially viable technology to provide
to the oil and gas industry. Sometimes, however, we look further back in the
development cycle to see what tomorrow’s technology may be.
One such futuristic technology is being developed now. The Department of Energy
had been supporting a promising nanoengineered sorbent developed by Absorbent
Materials Corporation (ABSMaterials) called Osorb®. The initial SBIR (small
business innovative research) work led to two pilot-scale units for field tests,
the largest being a one barrel-a-minute skid-mounted unit. DOE’s support allowed
some laboratory tests on actual flow-back fluids.
The ABSMaterials’ sorbents are “swelling glasses,” which treat dissolved
organics in aqueous systems. These swellable, organically modified silicas (SOMS)
do not absorb water, but are highly effective at removing many organics from
water, swelling to eight times their original volume. SOMS are regenerated
easily through mild heating with little or no degradation for many cycles.
One of the most difficult (and toxic) contaminants in flow back from Marcellus
Shale wells is barium. The inability to remove barium is a significant obstacle
to full development. ABSMaterials has found a way to remove barium by an organic
chelation process. Thus, a two-step process to remove organics first and then
barium is technically feasible. ABSMaterials has been working with Halliburton
on the pilot unit, and with some producers for their specific flow-back water
treatment.
A commercially nearer-term water treatment system has been fielded by Altela
Inc. It, too, is recorded by DOE as a success for its program. The DOE project
was targeted specifically to the Marcellus Shale basin. The AltelaRain® system
utilizes a nonpressurized, inexpensive plastics-based distillation process that
reduces the water volume requiring disposal by up to 90 percent. The distilled
product is then available for reuse as a frac fluid or for surface disposal.
Over DOE’s demonstration period at a Pennsylvania well site, the average treated
water cost was 20 percent lower than conventional disposal costs. The operation
passed the Pennsylvania Department of Environmental Protection’s regulatory
requirements.
As a result of the DOE testing program, a much larger commercial facility was
built in Williamsport, Pa., to treat about 100,000 gallons a day of flow back
and produced water.
DOE
has several other produced water projects looking at a variety of water
treatment technologies even further into the future. Additionally, several
production companies are using proprietary water treatment technologies on their
wells. With all this activity, several winners–picked by the marketplace–will
emerge to meet the needs of producers and the public. The result will be to
protect groundwater and public health, lower operator costs, reduce water
hauling miles and the number of disposal wells, increase water availability, and
prevent contamination of surface waters–not to mention a lot of natural gas.
Then, everyone wins. |