Storage possible for produced water
Thinking outside of the box means heading underground when it comes to storing water needed for future industrial or agricultural uses.
Participants at the CostEffective Water Management Congress SCOOP & STACK 2018 on Thursday were briefed on the concept by representatives of the Oklahoma Department of Environmental Quality.
The process could make a difference when it comes to future operations involving exploration production companies active in Oklahoma's SCOOP, Merge and STACK plays.
Today, well operators produce oil, gas and water from completed wells. The oil and gas is harvested and sold, while most of the water gets sent to saltwater disposal wells to be injected far underground.
But a portion of the water is treated so that it can be reused to complete future wells, and that water typically is stored, at least for a time, in a man-made pit until it can be moved using either pipe or trucks from that location to another.
Depending on where that's happening, using temporary pipes can be controversial. Using trucks to move the water isn't the best idea either, no matter where that happens. Plus, at least a portion of the water is lost through evaporation as it is stored on the surface.
But what if that treated water were stored in an aquifer that contained a similar quality of water?
If the water could be safely stored in a formation without a loss, and if that water later could be pulled from that aquifer by a permitted user at a location where it's needed, that would eliminate the need for using pipes or trucks to move it around.
While congress attendees reacted somewhat incredulously
to the concept, DEQ officials told them the concept isn't theoretical.
The use of underground aquifers not used for drinking water to store saltier or dirtier water, usually referred to as brackish water, has been used in other parts of the country for years.
The officials said Blaine Gypsum Groundwater Recharge Demonstration Project in southwest Oklahoma has been operational for about 25 years, operated under the joint supervision of the U.S. Environmental Protection Agency and DEQ. The project injects runoff water into an aquifer that supplies groundwater to agricultural irrigation systems, they said.
Beyond that, recent changes made to Oklahoma's state laws enabled regulators in 2017 to develop new rules that became effective the same year to make the storage program possible.
Additional rules still are needed to permit and prescribe construction and operational standards for wells that aim specifically to recover nonpotable water (currently, you can only drill in Oklahoma either for Class II water, which has total dissolved solids of less than 5,000 parts per million, or for oil and natural gas).
Those proposals, which are
moving through a public comment period, are being developed by Oklahoma's Water Resources Board. If the board adopts them, they will be forwarded on to the Oklahoma legislature and governor for review and approval.
"There are some permitting requirements associated with this, and the applicant must conduct studies (using hydrologists and geologists) to assess water quality and the integrity of the aquifer," said Saba Tahmassebi, DEQ's chief engineer.
Attendees, however, were hesitant to stand up and cheer.
"We have got to understand the world a whole lot better," one said during the question and answer session, noting that he and other Osage County residents haven't been able to determine the source of saltwater contamination affecting the drinking water aquifer there. The man, who didn't identifying himself, also noted he hoped
Oklahoma's water would be smart enough to stay where it was placed as part of such projects.
But Tahmassebi and Shellie Chard-McClary, director of DEQ's water quality division, said the system has worked well elsewhere, including Wichita, Kansas, and San Antonio, Texas, among others.
Gage Herrmann, chief operating officer of Lagoon Water Solutions and the chair of the water conference, closed the event by saying he often finds himself thinking about what will happen to the water SCOOP and STACK wells produce when drilling and completion work stops sometime in the future.
Herrmann told conference participants he's open to any and all ideas, no matter how extreme, about how to handle that future.
"Without thinking outside the box, nothing ever is going to change," he said.