A worrying Rystad Energy analysis of seismic activity in the US’ key oil producing regions reveals that the number of noticeable earthquakes has been increasing year after year since 2017. Tremors of above the magnitude of 2 on the Richter scale quadrupled in 2020 and are on track to increase even further in frequency in 2021 if oil and gas activity sticks to its current drilling methods at the same pace.

Rystad Energy’s research, which examined data from Oklahoma, Texas, Louisiana and New Mexico, showed that earthquakes of above the given magnitude accumulated to a count of 242 in 2017, growing to 491 in 2018, 686 in 2019 and 938 in 2020. Around 570 such tremors have been recorded through the first five months of 2021, meaning we may see a new record this year if the trend continues.

The trend appears to be moving not only to more frequent, but also larger events. So far this year, there have already been 11 individual seismic events of magnitude 3.5 or greater, which can certainly be felt but may not cause any damage, a worrying sign compared to just six such events annually in 2018 and 2019, and 14 events in 2020.

The biggest oil and gas industry contributor to seismic activity is by far the saltwater disposal through underground injection, and the volume of disposed water climbed sharply from 2011 through 2019, before tapering off a little in 2020 due to lower activity caused by the Covid-19 pandemic.

While the US onshore sector’s water disposal in 2011 was limited to 7.7 billion barrels, the volumes quickly built up over the next years to around 10 billion barrels between 2014 and 2017. In 2018 disposed volumes reached 11.5 billion barrels and in 2019 about 12.4 billion barrels, before retreating to 11.3 billion barrels in 2020.

“To maintain water disposal at 2020 levels and offset its coming growth, the amount of water that is treated and recycled must instead grow going forward and the cost of doing that could accumulate to above $1 billion annually for oil and gas producers. The costs can vary per region, but the Permian Basin has very competitive economics compared to other areas,” says Ryan Hassler, shale analyst at Rystad Energy.

To offset the yearly growth of disposed water that Rystad Energy is forecasting due to the coming boom in the US shale industry, the volumes of treated water must increase from the 1.5 billion barrels seen in 2020 to 1.7 billion barrels in 2021 and 2022, 1.8 billion barrels in 2023 and then rise even further from 2024 onwards as the needs to dispose water will again exceed 12 billion barrels due to increased activity.

“Earthquakes are not the only environmental issue caused by water disposal. Fresh water sourcing in arid regions of West Texas and New Mexico threaten the water supply of local communities and essential agriculture activities, while environmental concerns surrounding the chemical composition of produced water serve only to fan the flames of public antipathy,” adds Hassler.

While ESG initiatives are positive, the real driver to increase water recycling adoption is cost. Midstream companies continue to build out pipeline infrastructure to allow operators cheaper access to produced water, while also expanding existing recycling facilities or building new ones.

Rystad Energy estimates that by the end of 2022, the Permian Basin – including both the Delaware and Midland sub-basins – could be able to meet between 40% and 43% of frac water demand from recycled produced water. To meet this target, additional investment from the midstream space will be required to drive costs down further.

There are many ideas in relation to produced water that may help alleviate the growing pains of the recycling infrastructure and the disposal seismic problem. Recently, a legislation change in Texas allowed the Texas Commission on Environmental Quality (TCEQ) to take responsibility for the permitting of produced water surface discharge for beneficial reuse.

In theory, the change in regulatory bodies (the TCEQ took over from the Environmental Protection Agency) should allow for a more streamlined permitting process, enabling operators to discharge produced water volumes into surface water to be beneficially reused for agriculture or wildlife. However, this does not appear to be the case, as the TCEQ has yet to administer a single permit since taking over responsibilities.

Currently, only Wyoming takes advantage of surface water discharge for beneficial reuse under the West of the 98th Meridian law, providing an additional market for water reuse. California, on the other hand, uses produced water for crop irrigation, which, under the Clean Water Act, does not require an NPDES (EPA) permit if not discharging to surface water such as instances of use in irrigation.

So, while there are several avenues in which produced water can be reused from an agriculture, irrigation or wildlife standpoint, the fact is that Texas – with its massive produced water volumes – is currently taking advantage of none.