Friday, March 4, 2011

Man-made tremors and drilling

Howdy friends and neighbors of the hills!

Breaking news is coming out of Little Rock, Arkansas.

At 10:30 a.m. today the Arkansas Oil and Gas Commission will be holding a special, public hearing to consider a temporary ban on two disposal wells in Faulkner County.   The commission will be considering evidence that these wells are linked to a phenomena called "induced seismicity" which is a fancy term for "man-made tremors."  Disposal wells inject wastewater from drilling operations back underground at high pressure and some scientists feel this can trigger earthquakes.

Since last September, the area between Guy and Greenbrier has been hit with over 800 quakes with the largest measuring 4.7 on the Richter scale.

The latest update on the situation was reported in Bloomberg Businessweek after two new quakes struck Thursday, March 3, 2011.

Here is a report from KATV Channel 7 "The Spirit of Arkansas"

Could such a thing happen in Montebello?

The Montebello Hills oil field contains not just two wells, but hundreds of active and abandoned wells.  Some of these are used for oil and gas production and others for wastewater disposal.  In June of 1991 the Bulletin of the Seismological Society of America published an article called "On a possible connection between three major earthquakes in California and oil production" by A. McGarr.  The article speculates that the 1987 Whittier Narrows earthquake may have had a "causal relationship" to oil drilling in the Montebello hills.

In 1992, Craig Nicholson of the University of California at Santa Barbara wrote a paper called "Earthquakes associated with deep well activities" in which he too thought there might be some connection between drilling in the Montebello hills and earthquakes.
In this paper, we survey a number of possible induced earthquakes related to adjacent deep well operations. Figure 1 shows locations within the United States and southern Canada where significant earthquakes have known to occur in close proximity to active well sites. In many cases, the only available evidence is simply a coincidence in space and time between specific earthquakes and known or inferred well activities. Few of these examples are well documented because of potential liability concerns of the respective well operators. We thus expect that many cases of such induced seismicity largely go unreported.
The Montebello hills oil field is mentioned in the book "Gas Migration Events Preceding Earthquakes" written by Leonid F. Khilyuk Ph.D. and John O. Robertson Jr. published in 1993.

Then there's a more recent example written in 2010. "Moderate-to-large seismicity induced by hydrocarbon production"  by Jenny Suckale, Massachusetts Institute of Technology.

She writes:
While a connection between production and seismicity is thought to be well established for some cases (e.g., Lacq Field near Aquitaine, France), it is very controversial for others (e.g., Coalinga, Kettleman, and Montebello fields in California).

I admire the Arkansas Oil and Gas Commission for taking the initiative to find out if drilling is related to their  earthquake troubles.  Now if only we could get our local officials to do the same for us.

Daisy Mae


The two wells have been temporarily shut down.  KUAR FM 89.1 reports the Arkansas Oil and Gas Commission "found a link between those wells, which are used to dispose of used fracking fluids under high pressure, and the recent surge in seismic activity in the area."

There will be another commission hearing on March 29th.

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