A 5.4M Earthquake Shakes Up Oil And Gas Disposal Wells And Nuclear Waste Plans In The Permian Basin Of West Texas.
Regulations have not stopped the increase of earthquakes caused by extensive oil and gas operations, and the impact of these on a proposed nuclear waste disposal site needs to be re-evaluated.
In the island of West Java, part of Indonesia, a moderate earthquake of magnitude 5.6 occurred on November 21, 2022. Because population density is high, almost 300 people died and more may be buried under collapsed buildings.
A moderate earthquake of magnitude 5.4 occurred on November 16, 2022, in the desert of West Texas. Nobody died and there was little damage because the population density is low.
A rule of thumb is magnitudes greater than 3 can be felt at the earth’s surface. Greater than 4 can cause damage to buildings. Greater than 5 can result in loss of life in high-density areas. The magnitude 5.4 was felt for many miles around – from El Paso to Big Bend National Park (see Figure 1). Here are some quotes:
Lanette Brown Giese: Here in Carlsbad it was exactly like a helicopter landing next to our house. It lasted almost 20 seconds.
Mari Annelise Thomas: I can’t believe I felt it in Midland. My bed was shaking and my blinds were swaying.
Susan D Rayburn: Felt it in Alpine! It shook my bed while I was in it watching my house shake! Wild.
Lonna Edwards Gideon: My 4Runner swayed back and forth, in San Antonio
Earthquakes in the Delaware basin.
These are primarily caused by oil and gas operations, which are extensive in the Delaware basin. It’s the biggest and most active oil basin in the US.
Saltwater comes up from a well with oil and gas and must be disposed of. The cheapest way is to inject the wastewater deep underground through vertical disposal wells. As the water accumulates in a layer underground its pressure rises and it spreads outward from an injection well. When it hits a fault that is at a tipping point (close to a stress imbalance) the fault may slip and give rise to an earthquake.
Regulators monitor earthquakes using arrays of seismic detectors. When earthquake numbers or magnitudes reach a certain level they mandate that water injections into the usual rock strata be reduced or injected into another strata, to alleviate the water pressure underground.
The history of earthquakes in recent years is shown in figure 2. The bad news is that earthquakes were increasing exponentially before the Texas regulators stepped in during 2021. The good news is the regulations curtailed but did not stop, the growth of earthquakes.
But more bad news is that the pressure of injected saltwater continued to spread away from injection wells, and caused the largest earthquake yet in the Permian: 5.4 M on November 16, 2022. There are delays from 6-12 months in earthquake response to changes in water injection rates or volumes.
This pattern was a repeat of the earthquakes in Oklahoma when peak earthquakes, almost 900 > 3M, occurred in 2015. After the peak, the largest-ever earthquake occurred on September 3 of 2016: 5.8 M.
Who cares about such earthquakes?
Deep in the desert isolation of West Texas, one might guess that earthquakes don’t matter too much, even if they exceed magnitude 5. Not so!
Because of potential damage to the environment, and people, oil and gas companies have been encouraged to dispose of waste saltwater by other means. This includes on-site clean-up and recycling of dirty water to use on the next fracking job. Or sending the dirty water for commercial cleanups, such as a desalination plant.
Other than earthquakes, there are some very good reasons for this. This would save a lot of aquifer or city water that has been and continues to be used in fracking. How much water? A football stadium of water up to 40 feet over the grassed area is needed to completely frac a new-technology shale well, as used in the Delaware basin. Recycling is happening in the Delaware basin but it needs to be accelerated.
For every barrel of oil produced from a well in the Delaware basin, 3-10 barrels of water were produced. The ratio in Oklahoma was 7-20 barrels of water/oil.
In 2017, the Permian as a whole produced 63 billion gals or 1.5 billion bbl per year. A large fraction of this was injected into disposal wells. This enormous volume of water was as much as Oklahoma produced in 2015 when that state recorded 890 earthquakes of M > 3.
Although these cleanup/recycling methods are more expensive, there is pressure on the oil and gas industry to fix a problem that is not good for the industry’s image.
Nuclear waste repository.
There is also concern about a nuclear waste repository that is in the planning process. The US Nuclear Regulatory Commission (NRC) has evaluated a proposal by Holtec International to build a storage site for radioactive nuclear waste just 60 miles from Carlsbad.
The NRC has stated that a license can be issued, but the final decision will be made in early 2023.
Risks evaluated by the NRC at the Holtec site included (1) failure of storage canisters, (2) potential sinkholes opening up, (3) playa lakes and aquifer contamination, and (4) earthquake damage.
It seems the safety analysis, and the earthquake predictions were done by Holtec before the shale-oil revolution took off in the Delaware basin. In fact, one Holtec graphic of earthquake probability was dated 2009.
But earthquakes are often associated with oil and gas production, and the proposed Holtec site is close to thousands of new oil and gas wells in the Delaware basin. The earthquake swarm south of Carlsbad in Figure 1 is about 60 miles from the proposed Holtec site. So was the 5.4M quake of November 16.
So is there a risk of a large earthquake that could damage the canisters of hot radioactive material and allow it to leak out of the Holtec storage site?
For comparison, the largest three of the Oklahoma earthquakes – two of magnitude greater than 5 – caused significant damage to surface buildings.
It’s unclear whether earthquakes in the crust of magnitudes 5 or greater (as have occurred in the Delaware basin) were considered in the safety analysis of the Holtec site.
One takeaway is that oil and gas operations that trigger earthquakes down below may not be an ideal neighbor to nuclear waste storage sites up above – at least in the Permian desert of New Mexico.
New Mexico governor calls on Biden to intervene.
On November 16, the governor of New Mexico, Michelle Lujan Grisham, asked President Biden to oppose and block the Holtec initiative for a nuclear repository in southeast New Mexico.
The letter listed potential physical threats to residents living in the area plus controversial effects on people and the environment such as uranium mining and atom bomb testing related to past nuclear history.
Physical threats included accidents at the site or accidents while nuclear waste is transported to the site that could spread radioactive material. It doesn’t take much – one leaky drum at the WIPP site in southeast New Mexico closed that facility down for 3 years and cost upwards of $1 billion to clean up.
The letter did not mention earthquakes despite the appearance of two quakes with a magnitude greater than 5 which can cause damage to buildings. Fortuitously, one of these, M = 5.4, occurred on the same day, 3 pm on November 16, of the letter from the governor to the president.
Possibly thinking her state has done its share in this regard, the governor’s letter pointed out that southeastern New Mexico already has two other major nuclear facilities: the DOE’s Waste Isolation Pilot Plant (WIPP) repository and the URENCO National Enrichment Facility near Eunice.