(Image from www.moricoli.com)
June 22, 2015
Disposal of Oil and Gas Exploration Wastewater Increases Seismic Activity in Oklahoma
I just had an exchange with a friend of mine, who works in the oil and gas industry in Oklahoma, regarding the recent NPR story on Oklahoma’s earthquakes. Yes – Oklahoma has earthquakes. A recent article in Science Advances by researchers at Stanford University correlate the activities of the oil and gas industry to the dramatic increase in the number of earthquakes.
In a nutshell, the oil and gas industry drills to find oil and gas and, in the process, encounter groundwater that is not up to the standards are drinking water so they return the water to the ground. This approach sounds great until you find out that they are not returning it to the same place from which they took it. In many cases, they have delivered it to seismically inactive zones in the bedrock. Unfortunately, once we introduce water to these formations, the water acts like a lubricant and causes what barely moves to move a lot more…thus there were 500+ earthquakes of magnitude 3.0 or greater last year, up from an average of about two per year.
Once the bedrock moves, all sorts of things happen in the subsurface. Fractures that were used to storage water for eons slip and no longer serve as underground reservoirs. None of the earthquakes have caused sizable structural damage, and there is no guarantee that huge earthquakes will happen; however, there is also no guarantee that they will not occur. The bottom line is that the oil and gas industry has introduced a level of uncertainty without addressing the potential for adverse effects.
Groundwater discharge of wastewater is not new, but it is highly discouraged and the EPA is working to decommission many of these injection wells. The economy of Oklahoma depends on the oil and gas industry but what is the cost of the increase in seismic activity? We, as a society, have a tendency to be re-active rather than pro-active. As a result, we often seek the lowest short-term cost solutions to problems rather than find the “best” solution. Injecting oil and gas wastewater back into the ground is, by far, the lowest short-term cost; but it is not the “best” solution to the problem. I would argue that it is also NOT the lowest cost solution, as there are, undoubtedly, going to be downstream costs associated with not only the earthquakes but with consequences that have either not be actively publicized, as Dr. Zoback and Mr. Hall have done in their recent publication, or have yet to be realized.
A generation ago, we vented or flared methane from oil extraction and processing activities. Now that there is infrastructure established for the transportation and utilization of natural gas – as well as a political imperative to address global climate change – there is a better alternative to “wasting” it. Oklahoma is neither “water poor” nor “water rich”; there are seven major aquifers beneath its surface and numerous surface bodies that provide it’s 3.9 million people with water. Therefore, it is not an imperative to recapture the oil and gas wastewater today; however, it might prove to be a good idea today to utilize this water rather than to continually draw-down the current water supplies and face a shorter in the future.
There certainly is going to be an associated cost to treat and transport the oil and gas wastewater to where it can be put to a good use and that cost is going to be viewed by decision-makers as “unreasonably high”. The energy industry is very competitive and adding millions to the cost of the Oklahoma oil and gas will not only diminish the desire for the product, but it might also detract from the profits of the companies involved in the continued development of these resources.
The question to ask is whether that “unreasonably high” cost of finding the “best” solution in today’s currency outweighs the future costs. Social and physical scientists have already developed the tools to answer such questions, but those who hold the political and economic purse-strings have little motivation to find out the answers. For now, for many, the preferred solution is status quo; for others, the question continues to burn (or shake, as the case may be) the foundations of our civilization.