OKLAHOMA CITY (21 July 2016) – A state legislator who is terming out this year plans to convene one more public hearing to examine potential options for disposing of brine produced during oil and gas exploration.
The House Committee on Energy and Natural Resources will convene an interim legislative study on the subject later this year at the request of Rep. Richard Morrissette, D-Oklahoma City.
“This is a critical public policy issue,” he said. “Although oil and gas exploration in Oklahoma has slowed considerably in recent years, it hasn’t stopped entirely, and we can anticipate another uptick at some point in the future.”
According to Baker Hughes oilfield services company, Oklahoma had 59 active drilling rigs on July 15 (all but four of which were west of Interstate 35). In comparison, Oklahoma had 105 active rigs in mid-July 2015 and 200 in mid-July 2014. At the close of business Monday, West Texas Intermediate crude oil brought $45.24/barrel and Brent Crude commanded $46.96.
Subterranean ‘fossil water’ “is being produced now and will continue to be produced so long as drilling continues,” Morrissette said.
For example, a legal notice published July 21 announced that Delong Oil & Gas Service of Drumright has received tentative approval to develop an injection well in Payne County; the well will penetrate the second Wilcox Formation to depths of 3,634-3,674 feet and will accommodate up to 4,990 barrels of wastewater per day, injected at a maximum pressure of 500 pounds per square inch.
Although the Corporation Commission staff approved the Delong application, objections may be lodged with the commission – which regulates the oil and gas industry in Oklahoma – within 15 days.
Another legal notice, published June 30, announced that Overflow Energy of Booker, TX, applied to the Oklahoma Corporation Commission for permission to inject up to 10,000 barrels of saltwater daily into a commercial disposal well in Blaine County, at a surface pressure of 1,600 pounds per square inch.
“We need to have a thorough discussion of how ‘oil patch’ wastewater will be disposed of,” Morrissette maintained. “Injecting it back underground into disposal wells, where it can trigger seismic activity, cannot continue at previous levels.”
In April 2015 the Oklahoma Geological Survey determined that the majority of recent earthquakes in central and north-central Oklahoma “are very likely triggered by the injection of produced water in disposal wells.”
‘Produced’ Water Prolific
Many of the oil-producing formations in Oklahoma generate an average of approximately 10 barrels of produced water for every barrel of crude oil pumped out of the ground, but some sections of the Mississippi Lime formation produce as much as 50 barrels of wastewater per barrel of oil. (One barrel is equivalent to 42 gallons.) Currently that wastewater must be hauled away in tanker trucks and pumped deep underground into injection wells.
Over the last five years, approximately 205 billion gallons of wastewater were injected into disposal wells in Oklahoma, primarily in the central, north-central and western sectors of the state, records reflect.
For 30 years, 1978-2008, Oklahoma averaged fewer than two magnitude-3.0 or greater earthquakes per year. In 2015 the Oklahoma Geological Survey counted 877 earthquakes of magnitude 3.0-3.0 and 29 of magnitude 4≥. By the middle of this year the OGS had logged 394 tremors of 3.0 or greater and seven of 4≥.
“This is a political and an environmental matter that we need to address before the next oil ‘boom’ occurs,” Morrissette said.
Alternatives to Disposal Wells
Morrissette has been informed about three alternatives to disposal wells, all of which involve evaporation and distillation of the brine and crystallization of the salts.
Fairmont Brine Processing, for one, reports having received a multimillion-dollar loan to construct an oil and gas wastewater treatment facility in Oklahoma. Its distillation system removes contaminants from briny wastewater that is a by-product of oil and gas exploration. The facility burns natural gas to boil the brine and produce distilled-quality water and commercial-grade salts that can be used to melt ice on pavement. The distilled water purportedly can be used to irrigate agricultural crops, discharged into a lake or a stream, or reused in the production of more oil/gas.
The company developed a distillation facility in West Virginia. Brian Kalt, general manager of Fairmont, said design work is almost finished on a facility in Oklahoma that could process 2.5 million gallons of wastewater daily.
A 60,000 barrel-per-day facility would cost about $150 million, and Fairmont Brine Processing would need a five-year commitment for the project to be financially feasible, Kalt indicated during a public forum Morrissette convened at the State Capitol last month.
An Oklahoma company, Logic Energy Solutions, has developed evaporation technology that it claims can reduce almost all of the “fossil” wastewater to water vapor and dried salt.
Logic’s equipment is designed to evaporate up to 90% of the produced water, which can either escape as vapor or be piped through a condenser and converted into purified water, David Hill, president and chief operating officer of Logic Energy Solutions, said last year.
The water can be recycled for beneficial reuses such as crop irrigation or for further energy production, Hill said. What’s left behind is a “mineral cake” of magnesium, calcium and salt; the cake can be dumped into a landfill or perhaps used for commercial purposes because of its mineral content, he said.
Similar technology has been developed by North American Recycling Technologies of Ohio. Stephen J. Palac Jr. said NART’s system can recycle flowback or produced water at a rate of 10,000 barrels per day. The water from oil/gas wells is sufficiently treated to be discharged into a lake or river or to irrigate crops, and the salt is refined enough to be sold as a by-product, Palac said.
Injection Cheaper Than Evaporation
An evaporative system “may not be economically feasible at this time,” Morrissette said. Operators charge about 50¢ to $2 per barrel of wastewater injected into disposal wells, while the distillation process costs several dollars per barrel. However, Morrissette added, “As the technology matures, costs will decline. We have to be prepared to think ‘outside the box’.”
The three alternatives presented to Morrissette resemble desalination plants around the world that are used to convert saltwater into potable drinking water.
As Tulsa petroleum geologist Bob Jackman has written, desalination technology “has been around for centuries.” Residents of the Middle East “have long evaporated brackish groundwater or seawater, then condensed the vapor to produce salt-free water for drinking or for irrigation.”
Modern desalination plants employ reverse osmosis, in which water is pumped at high pressure through semipermeable membranes that remove salts and other minerals. A $1 billion reverse osmosis plant constructed at Carlsbad, Calif., has been providing 50 million gallons of potable water each day to San Diego residents since last December.
Recycling Skeptics Unconvinced
However, many remain skeptical that produced water from oil/gas exploration can ever be recycled, for a couple of reasons: the immense volumes of produced water generated in oil/gas exploration in Oklahoma – 115 million gallons per day, on average, over the past five years – and the fact that the salinity level of fossil water is approximately three times greater than the salt content of seawater (which is typically 35 parts salt per thousand gallons of water).
“For my entire career in oil and gas (1981 to the present), folks have claimed they could economically treat produced water for use in irrigation,” said Dr. Berton Fisher of Tulsa, a geologist, hydrogeologist and geochemist. “This can work only if salt levels are low – say, less than about 5 parts total salts per 1,000 gallons.”
The amount of energy required to separate salt from the water in which it is dissolved “is so great that it is economically not feasible to make fresh water from most of the produced water in Oklahoma (and just about anywhere else),” Fisher wrote. The Mississippi play “is already non-economic,” so incurring the additional expense of water treatment “wouldn’t make it any better,” he said.
“What would be informative is to know how much it costs to desalinate the water prior to use in the irrigation experiments,” said Fisher, who is an adjunct professor at both the University of Tulsa, where he teaches petroleum geology, and Oklahoma State University, where he teaches various courses in the Environmental Graduate Program.