Fracking in Arkansas has become a popular since the increasing production of the Fayetteville Shale.
- The Fayetteville Shale is a geologic formation of Mississippian age (354–323 million years ago) composed of tight shale in Arkansas. It is named for Fayetteville, Arkansas and requires hydraulic fracturing to push up the natural gas contained within. The practice of hydraulic fracturing the shale began in Arkansas in 2009.
- The Mississippian Fayetteville Shale contains gas in the Arkansas part of the Arkoma Basin. The productive section varies in thickness from 50 to 550 feet, and in depth from 1500 to 6500 ft. The shale gas was originally drilled through vertical wells, but operators are increasingly going to horizontal wells in the Fayetteville.
- In April 2009, 1- to 3-kilometer-deep fracking wastewater disposal wells were sunk in the vicinity of Guy (population 706) and Greenbrier (population 4706), Arkansas. Shortly after, there was a cluster of earthquakes near Greenbrier. The Guy-Greenbrier area had had only one quake of magnitude 2.5 or greater in 2007 and two in 2008, but there were 10 in 2009, the first year of deep disposal, and 54 in 2010. Geologists warned the Arkansas Oil and Gas Commission, the state agency that regulates deep injection, to “watch out” for more earthquakes. In October 2010, a magnitude 4.0 struck about a kilometer northeast of the deeper of the two new wells, and on November 20, a magnitude 3.9 struck 2 kilometers farther to the northeast toward Guy. Then, in February 2011, magnitude-4.1 and -4.7 quakes struck to the southwest of the deeper well, toward Greenbrier. By spring 2011, nearly 1000 recorded quakes had struck the area since the wells had started up.
- The State Oil and Gas Commission was concerned enough about a probable link between the disposal wells and the earthquakes that in July 2011 it ordered that one well be shut down, and it placed a moratorium on new ones in an 1,100-square-mile area. Three other disposal wells closed voluntarily. While small earthquakes are still occurring in the area, their frequency has declined substantially.
- An article in Science later explained that “data from the seismometer network… painted a detailed picture of exactly how the injected wastewater triggered the [Arkansas] quakes. It was injected into an aquifer 3 kilometers down, where it increased the pressure of groundwater in the rock’s pores and fractures. From there the increased pressure due to injection spread through a previously unknown buried fault into the underlying rock, triggering quakes on the fault as it went.
- In 2012, some residents of Faulkner County affected by earthquakes filed a lawsuit against subsidiaries of Chesapeake Energy, which operated two of the wells, and BHP Billiton, which acquired the wells from Chesapeake as part of a larger purchase in 2011. The suit alleges that the quakes were caused by negligence, amounted to trespassing, and created a public nuisance, and that the companies knew of the risks.
Air Pollution and Silica
- In July 2012, two federal agencies released research highlighting dangerous levels of exposure to silica sand at oil and gas well sites in five states: Colorado, Texas, North Dakota, Arkansas, and Pennsylvania. Silica is a key component used in fracking. High exposure to silica can lead to silicosis, a potentially fatal lung disease linked to cancer. Nearly 80 percent of all air samples taken by the National Institute of Occupational Safety and Health showed exposure rates above federal recommendations. Nearly a third of all samples surpassed the recommended limits by 10 times or more. The results triggered a worker safety hazard alert by the Occupational Safety and Health Administration
Fracking Legislation in Arkansas
- In October 2010 the Arkansas Oil and Gas Commission issued proposed amendments to Commission Rule B-19 “Requirements for Well Completion Utilizing Fracture Stimulation” for commentary.