Archive | hazards RSS for this section

Rock, teach oil, or maybe vice versa

GG attended a workshop here at CU on lessons from mining that could help guide oil and gas development (since the conveners encouraged outcomes to be shared on social media, figure this is OK). In kind of an odd way, the focus was more on what happens at the end of mining or oil development more than what happens at the start, so that will tend to be the focus here.

So a quick summary of points GG noticed.

  • Mining is highly focused, oil and gas far more distributed with a web of infrastructure.
  • Mines active today have to meet bonding requirements and increasingly have to have reclamation plans; oil and gas wells have far less specific requirements (e.g., bonding is not by well but by state or even nation).
  • Mines are a single use of the land; oil and gas production often shares the land with other rural uses.
  • Problem mines are problems for thousands of years–there is no true long term remediation. They can foul a lot of water for a long time. Wells are more insidious, typically failing silently until you know groundwater is compromised or a house blows up.
  • Mines these days are rarely totally shut down; they frequently are mothballed and then brought back online.  Oil and gas wells are frequently plugged and closed.
  • Mining’s main impact seems to be contaminating surface waters.  Oil and gas activity mainly affects subsurface waters.
  • Modern mining remains dominantly rural [save for mining towns!], but oil and gas has moved into suburbia. However, old mines are around a lot of western towns and there is renewed activity (and opposition) from time to time.

So what would the public want for post-development lands? In both cases, one can presume a safe environment available for any subsequent use. In many cases, they might want something resembling the pre-mining landscape. How realistic is this?

For mines, it depends on the mine. Big, modern open pit mines with sulfides are likely nearly hopeless. Strip mines for coal probably can be reclaimed provided they are not in areas where erosion is likely. Many small legacy mines can be shuttered to have an acceptably low level of impact. You can probably tell when a mine can be safely shut down.

For oil and gas wells, there is a surprisingly high level of uncertainty. Modern plugging procedures will usually work for the near term, but if gas continues to migrate up the well bore, any weaknesses that develop in the well plug or around the outside of the well bore will allow the gas to vent to the surface. Degradation of the well materials will connect shallow and deep aquifers, which can be troublesome if the deep aquifers have sufficient pressure to invade a shallower drinking water aquifer.  Or if the deep aquifer has negative pressure, you can lose drinking water to the deeper aquifer. That oil and gas wells are not of the same material as the surrounding rock means that it is likely over long periods of time that some kinds of failures of the well’s plug will occur (chemistry and stress will focus on that interface).  How often is this likely? How often will a failure produce surface problems? We really aren’t certain.

One suggested solution for problem mines is to make use of the waste material. This might help for acid mine drainage, but is less helpful for some other environmental hazards from mines. It is unlikely that a plugged oil or gas well that leaks has any economic utility.

So at the end, what does full closure of mines or wells look like?  Mines are unlikely to have their footprint totally erased, and some will be problems for centuries, but many others will be available for other uses. Oil and gas wells are tougher.  Most rules require a plugged well’s pad to be returned to something looking like the original landscape. When bonding is insufficient (as has been the case in Wyoming, for instance), failed companies’ wells might not be reclaimed. But even where surface reclamation is done (and oil and gas companies like to show pictures of old well sites to show they don’t look particularly bad), the well below is still subject to failure and leaking. While some mine sites might well be safe to build on (and many mountain resort towns are in fact built on old mine sites), building on an old well is playing a bit of Russian roulette. Shallow aquifers could fail as well. Perhaps monitoring for natural gas and pollutants in the water would permit full reoccupation of well sites, but it seems just as likely that rules will prevent building on or too near old well sites.

What do local communities need to know? They should probably understand that oil and gas wells are forever–plugged wells in most cases will cause no problems, but given that we haven’t watched a bunch of wells plugged with modern techniques for a really long time, that there is a non-zero risk of future leakage, and so monitoring appropriate for the subsequent use of the land should be required. Ripping out as much of the oil and gas infrastructure as possible is wise. For mines, it kind of depends. Any mine with underground workings can later collapse, so building on top of such mines should be considered with caution. If a mine is leaking colorful water into streams, odds are this will continue for centuries and some kind of action is desirable, but know there are not, at present, permanent fixes.

Root problems of oil and gas

Here in Colorado there is a tremendous amount of anger, frustration, and finger-pointing going on over the risks and rights associated with oil and gas development. In part because of sloppy language, in part because of deliberate misrepresentation, in part because of financial gain, in part because of different assessments of risk, the controversy has people talking past one another. It reached something of a silly level when protesters in Boulder recently protested a performance of Beethoven’s Ninth Symphony because the symphony had accepted some money from an oil company. [GG isn’t sure what the message really amounted to: don’t let oil companies support the arts? Not like the symphony was investing in oil companies].

How did we end up in this mess?

Read More…

Precise Opposition

GG has previously been frustrated with the combination of imprecise speech of anti-fracking groups as well as the double speak of industry. The reason you might want to be precise might be well illustrated by a recent home explosion in Colorado.

The exploding house killed two men working on a hot water heater in the basement; usually when you hear these things, it turns out there is a gas leak or something like that in play. The startling news has been the move by Anadarko Petroleum Corp. to shut down 3000 wells they are operating while the wells are checked out (that is more than 5% of the active wells in the state). The exploded house was 170 feet from a 1993 well reactivated this past January. Although a new well can not be drilled there, houses can be built that close to existing wells (these houses are only a couple years old).

Oil companies are loathe to shut down operations (see opposition to claims of induced earthquakes, for instance). Shutting down this number of wells even as investigators are saying that they still don’t know what happened strongly suggests something may have gone wrong. Given that the oil company feels that shutting down wells is likely to reduce a risk, they are presumably not thinking that any gas leaked up around a bad casing job in the well but instead are concerned there might be leaks in the underground lines connecting wells to pipelines or storage facilities.

And here’s the thing.  This is not a modern, horizontally-drilled heavily fracked well. This is one of those older-style vertical wells. So when anti-fracking groups say they don’t want to stop oil and gas development but do want to stop fracking (as was the case in Longmont, Colorado a couple years back), this is the kind of well they think is OK. So once again a reminder: fracking is very rarely a cause of problems, but all the other stuff with oil and gas development is the real problem people are complaining about.

The irony might well be that if Anadarko’s infrastructure was the cause of the blast, there is likely to be enough of an outcry to allow far more stringent rules on any new oil and gas development–even though a blast caused by a leak of a subdivision gas supply line would probably not shut down the use of natural gas in houses. So “anti-fracking” groups might get their wish not because of fracking problems per se but because houses were built in the vicinity of active oil and gas operations.

(Equally ironic is the request from the Boulder County Board of Supervisors for companies to shut down all their vertical wells in the county–apparently unaware that it is the near-surface infrastructure that could be the problem, which can exist at both directional and vertical well pads).

It should be interesting to see what happens. Almost certainly it points to a need to check up on the older oil and gas infrastructure in the state. Whether it changes the politics of new oil and gas operations remains to be seen.

Oklahoma Yin Yang

With 2016 coming to a close, GG thought we might want to see just how things are shaking out in Oklahoma, home of the great induced earthquake experiment. And there is something for everybody, depending on how you want to look at it.

For the optimists hoping that Oklahoma’s actions to slow wastewater injection will end the plague of induced earthquakes, we have plot number one: number of quakes with a magnitude of 3.0 or higher by month:


Earthquakes within Oklahoma, by month, 2016, from U.S. Geological Survey

The rate of such earthquakes dropped from nearly 4 a day in January to about one a day this month. And you could hope that this had something to do with this:


Monthly averaged daily injection volumes of Arbuckle disposal wells in the Area of Interest for Triggered Seismicity, from Oklahoma Corporation Commission, Oil and Gas Division. (December decline probably because of incomplete reporting).

The 25% reduction during the year in the rate of injection in the area where triggered seismicity has been observed might be responsible for this.  But there are other things to watch as well.  First, these are still pretty high volumes of water going back into the Arbuckle, and all the water that went down earlier is still making its way through the subsurface.  Second, presumably a lot of produced water is going to other wells, either in the Arbuckle outside the area of interest or into other formations. Third, a decrease in the number of M3+ events is not the same thing as a decline in seismic moment:


Seismic moment release in Oklahoma in 2016, derived from USGS catalog.

The 9/3/2016 M5.8 Pawnee, Oklahoma earthquake put a big damper on any celebration of a decrease in seismicity. The overall moment release of 7.8 x 1024 dyne cm is the largest single year moment release in Oklahoma history. As we noted before, this isn’t unexpected: the Rocky Mountain Arsenal sequence in the 1960s produced its largest quakes after the injection ended.

So we enter 2017 on a note of caution.  If you bought earthquake insurance in Oklahoma, don’t let it lapse just yet. You might get shaken a bit less often, but when you do get a quake, it might still be pretty big.

P.S.: there are a couple of nice visualizations out there.  Tulsa World put together an interactive map a year ago showing how produced water injection was varying over time and by county. The Oklahoma state government has an interactive figure with recent earthquakes and disposal well locations.

Oklahoma Dreamin’

Back in September, Oklahoma had a M5.6.  Some of you might recall the difference in opinion between USGS scientist Dan McNamara, who expected continued seismicity, and Oklahoma Geological Survey director Jeremy Boak, who said “I’d be surprised if we had another 5.0 this year.”

Well, Director Boak hopefully was in the vicinity to be surprised in person by the M5.0 today that damaged buildings in Cushing, OK, site of the largest oil storage facility in the country (which at least apparently escaped any damage). Yeah, once more wishful thinking trumped by actual scientific examination….increasingly it seems the branch McNamara has climbed out on is the real stout one while the hopes of the Oklahoma injection operators rest on thin reeds.

At least nobody has died, but when you are evacuating a senior housing facility in the night and cancelling school, you know you are playing with fire.

And hey, we aren’t even done with 2016 yet.

The Peculiar Science of Global Warming…

No, not the physical science.  The social science.

For most scientists, the usual chant from those trying to get politicians to act to slow global warming is “97% of climate scientists say the earth is warming because of human emissions of carbon dioxide.” Frankly, such a pronouncement grates on the ears of most scientists.  Why?  Because it isn’t consensus but evidence that determines what is and is not the best description of how the world works. As scientists, we’d much rather that everybody have a well-informed scientific basis.  As such, we lament the poor understanding of basic climate physics in the general population and think that if only these folks were better educated about this, society would move swiftly to address this problem.

But we are wrong.

Read More…

Searching for Good Samaritans

There is something of an aside at the end of a recent story in the Denver Post on attempts to clean up the numerous mines leaking acid waste into rivers in southwestern Colorado; the story quotes Governor Hickenlooper as saying: “Lastly, we continue to support efforts by our congressional delegation to reach consensus around ‘Good Samaritan’ legislation, which is one of the most significant tools at our disposal to allow for voluntary cleanups of draining and abandoned mines.”

You might ask, what is this about? In many ways, the story starts with gold mines in the Sierra Nevada long ago before intersecting with environmental protection laws.

Read More…