Oklahoma Geological Survey
Oklahoma Geological Survey
News Article | September 22, 2016
The U.S. oil and gas industry is having a visible effect on the Earth's surface, a new review of satellite images has found. In recent years, energy companies have pumped an unprecedented volume of wastewater — a byproduct of fracking and conventional drilling — deep into underground wells. The water often can't be reused or recycled for economic or technical reasons, so many companies have found it easier to inject the water back into the ground. That process has sparked a wave of earthquakes across the central United States, transforming the Earth both above and below the surface, according to a study published Thursday in the journal Science. SEE ALSO: Oklahoma's magnitude 5.8 quake comes amid concerns around oil and gas boom Wastewater not only puts pressure on underground fault lines, causing "induced" earthquakes, but also pushes up the surface of the ground — a phenomenon called "uplifting" that can be seen from space. Researchers used satellite images of ground uplifting to show how wastewater disposal in eastern Texas eventually triggered a magnitude-4.8 earthquake in May 2012, the largest earthquake recorded in that half of the Lone Star state. "We brought a new angle to this study of 'induced seismicity,' which is monitoring the seismicity from space," said Manoochehr Shirzaei, the study's lead author and a geophysicist at Arizona University's School of Earth and Space Exploration. "This hasn't been done before," he told Mashable. The team studied surface changes near two sets of wastewater disposal wells separated by less than 15 kilometers, or about 9 miles. Using satellite-based observations from 2007, 2010 and 2014, the researchers estimated the evolution of local "pore pressure" — the pressure of fluids within the pores of a subsurface rock. Shirzaei said they estimated the pore pressure changes were strong enough to cause earthquakes, including the 2012 temblor near Timpson, Texas. The Science study comes as U.S. researchers are racing to understand how years of injecting wastewater is causing damaging earthquakes in areas that previously saw little, if any, seismic activity. Oklahoma, for instance, experienced more than 900 earthquakes of magnitude 3.0 or greater in 2015, according to the Oklahoma Geological Survey (OGS), a state agency. That's up from just one to two per year in the decades prior to the state's drilling boom. Earlier this month, the state saw a magnitude-5.8 earthquake near the town of Pawnee, the largest recorded temblor in Oklahoma. The Sept. 4 earthquake, which occurred along an unmapped fault line, is stoking fresh fears among some scientists that Oklahoma's wastewater wells could trigger other unknown faults. Scientists at OGS recently suggested that a large "pulse" of oil and gas wastewater created over the last few years may be moving deep underground, boosting the risk of seismic activity even as regulators adopt new restrictions on wastewater injections. "How long can we expect that pulse to raise the chances of having a damaging earthquake? That's an area that requires further research," Robert Williams, a geophysicist with the U.S. Geological Survey (USGS) in Golden, Colorado who is unaffiliated with the new study, told Mashable. Cumulative number of earthquakes with a magnitude of 3.0 or larger in the central and eastern United States, 1970–2016. The long-term rate of approximately 29 earthquakes per year increased sharply starting around 2009. Williams coordinates the USGS earthquake program in the region of Oklahoma and the eastern U.S. He said that the agency now spends roughly $3 million a year to study the causes and impacts of human-induced earthquakes, up from annual spending of just a few hundred thousand dollars a few years ago. Shirzaei said that, going forward, satellite-based observations could help oil and gas companies find safer places to inject their wastewater underground. The researchers developed a forecasting model that factors in where fluids would be injected and at what volume and pressure. The model forecasts how much the Earth is likely to change under the surface and where and when uplifting might occur. Shirzaei said this preventative approach is better than restricting or stopping oil and gas wastewater injections. Given the economic and political importance of U.S. oil and gas drilling, he said disposing of wastewater would continue to be necessary. "The goal is to make this part of the routine procedure for wastewater injection...to make the injections safer and to minimize the number of earthquakes," he said. "We have to do it, and we have to do it safer."
News Article | November 8, 2016
Dozens of buildings sustained "substantial damage" after a 5.0 magnitude earthquake struck an Oklahoma town that's home to one of the world's key oil hubs, but officials said Monday that no damage has been reported at the oil terminal. Cushing City Manager Steve Spears said 40 to 50 buildings were damaged in Sunday's earthquake, which was the third in Oklahoma this year with a magnitude of 5.0 or greater. No major injuries have been reported, and Spears said the damage included cracks to buildings and fallen bricks and facades. Oklahoma has had thousands of earthquakes in recent years, with nearly all traced to the underground injection of wastewater left over from oil and gas production. Sunday's quake was centered 1 mile west of Cushing and about 25 miles south of where a magnitude 4.3 quake forced a shutdown of several wells last week. Some longtime Cushing residents said Monday they've become accustomed to the unsettled ground beneath their feet. Others shrugged it off as a cost of doing business living next to an oil hub. Fearing aftershocks, police cordoned off older parts of the city about 50 miles northeast of Oklahoma City to keep gawkers away late Sunday, and geologists confirmed that several small quakes have rumbled the area. Spears said an assisted living community had been evacuated after damage was reported. The Cushing Public School District canceled Monday classes. The Oklahoma Department of Transportation reported Sunday night that no highway or bridge damage was found within a 15-mile radius of the earthquake's epicenter. The quake struck at 7:44 p.m. Sunday and was felt as far away as Iowa, Illinois and Texas. The U.S. Geological Survey initially said Sunday's quake was of magnitude 5.3 but later lowered the reading to 5.0. "I thought my whole trailer was going to tip over, it was shaking it so bad," said Cushing resident Cindy Roe, 50. "It was loud and all the lights went out and you could hear things falling on the ground. "It was awful and I don't want to have another one." In recent years, Oklahoma regulators have asked oil and gas producers to either close wastewater injection wells or cut back on the volume of fluids injected. The reductions have generally led to a drop-off in quakes and their severity, though not always. Oklahoma's strongest quake on record, a magnitude 5.8 temblor on Sept. 3, occurred in Pawnee, on the fringe of an area that had already restricted wastewater disposal. Shortly afterward, geologists speculated on whether the temblor occurred on a previously unknown fault. Oklahoma Geological Survey geophysicist Jefferson Chang said Sunday's quake and several aftershocks have been occurring on a fault line located about 2 miles west of Cushing. "The activity has been going on for the past year and a half or so," Chang said. "This is just a spike in the activity." Cushing's oil storage terminal is one of the world's largest. As of Oct. 28, tank farms in the countryside around Cushing held 58.5 million barrels of crude oil, according to data from the U.S. Energy Information Administration. The community bills itself as the "Pipeline Crossroads of the World." Cushing Assistant City Manager Jeremy Frazier said two pipeline companies had reported no trouble as of late Sunday but that the community hadn't heard from all companies. Gov. Mary Fallin tweeted that no damage was reported at the storage tanks at Cushing's oil storage terminal. Some residents tried to resume normal lives Monday, treating the earthquake as more nuisance than calamity, even though the temblor could be a predictor of more to come. "We live in Cushing," said resident Susie Wooten, who was taking pictures of the cracked bricks outside her dry cleaning business. "You can't blame the oilfields; we're on a major fault line." For truck driver James Mutters, having oil tank farms so close to where he lives is a fact of life. "If you live here, obviously you know about the oilfields," he said. "I drive a truck, so I need to have gas. You can run all the stuff you want from the sun, but most of the stuff has to be run off something." According to USGS data, there have been about two dozen earthquakes in Oklahoma in the past week. When particularly strong quakes hit, the Oklahoma Corporation Commission directs well operators to cease wastewater injections or reduce volume. "I was at home doing some work in my office and, basically, you could feel the whole house sway some," Spears, the Cushing city manager, said Sunday night. "It's beginning to become normal." Sean Murphy in Oklahoma City and Jill Bleed in Little Rock, Ark., contributed to this report.
News Article | September 3, 2016
PAWNEE, Okla. (AP) — The Latest on the large earthquake in Oklahoma (all times local): Oklahoma Gov. Mary Fallin has declared a state of emergency in Pawnee County after a magnitude 5.6 earthquake struck northwest of Pawnee. The earthquake struck at 7:02 a.m. Saturday and was felt throughout the Midwestern United States, although no severe damage or serious injuries were reported. The quake ties a 2011 earthquake for the strongest earthquake in recorded state history. Fallin's order allows state agencies to make emergency purchases for disaster relief and is the first step toward asking for federal assistance, if necessary. Fallin said in a statement that information is still being gathered and will be reviewed by her coordinating council on seismic activity. The state of emergency lasts for 30 days and additional counties may be added. The Oklahoma Corporation Commission is requiring the shutdown of 37 wastewater disposal wells in the area around the epicenter of a magnitude 5.6 earthquake. The mandate from the commission's Oil and Gas Division comes after the Saturday morning earthquake near Pawnee and includes 514 square miles under commission jurisdiction. Commission spokesman Matt Skinner says another 211 square miles in Osage County is under the jurisdiction of the Environmental Protection Agency. He says the commission is working with the EPA, which will decide what action to take there. Skinner says it isn't known how many wells in Osage County might be affected. The wells will be shut down within 10 days according to a schedule that Skinner says is necessary because seismologists have warned that a large and sudden shutdown of the wells could cause another earthquake. Skinner says the wells were directed to shut down due to scientific links that the increase to the underground disposal of wastewater from oil and gas production induces earthquakes. The commission has previously asked producers to reduce wastewater disposal volumes. The 5.6 magnitude earthquake that struck north-central Oklahoma apparently did not cause significant damage partly because of the type of rock beneath the region. Geophysicist Jefferson Chang with the Oklahoma Geological Survey said a hard, or competent, bedrock crosses north-central Oklahoma while the subsurface around Prague is softer. Chang said the harder rock absorbs more of an earthquake's energy, reducing potential damage. Emergency officials say the Saturday morning quake northwest of Pawnee led to sandstone facings of some buildings falling, but that no buildings collapsed. The quake is the same magnitude and approximately the same depth as a 2011 earthquake near Prague, about 60 miles to the south. In that quake, two towers collapsed at a university in nearby Shawnee. Officials at a nuclear power plant in the southeast corner of Nebraska say tremors from the Oklahoma earthquake were felt at the plant. Nebraska Public Power District's Cooper Nuclear Station south of Brownville declared an "unusual event" just after 7 a.m. because of the minor tremors. Officials say there was no damage to the plant or equipment, and no threat to the public or plant personnel occurred. The plant continued operating Saturday, but station personnel increased monitoring of plant equipment, per the plant's policy. Station emergency preparedness manager Jim Stough says the nuclear station was built to withstand some earthquakes and other scenarios that are likely to occur in the region. Officials say local, county, state, and federal agencies were notified of the event. The Oklahoma Corporation Commission has directed dozens of wastewater disposal wells within an approximate 500-square-mile radius of the epicenter the Oklahoma earthquake to shut down. The commission says about 35 wells are included in the directive, which was issued following the 5.6 magnitude earthquake that struck Saturday morning about nine miles northwest of Pawnee in north-central Oklahoma. The number of magnitude 3.0 or greater earthquakes has skyrocketed in Oklahoma, from a few dozen in 2012 to more than 900 last year. Commission spokesman Matt Skinner says the wells were directed to shut down due to scientific links that the increase to the underground disposal of wastewater from oil and gas production induces earthquakes. The commission has previously asked producers to reduce wastewater disposal volumes. The earthquake ties the record for the strongest earthquake in recorded Oklahoma history. No major damage was reported, and there was one minor injury. One minor injury has been reported as the result of a 5.6 magnitude earthquake in north-central Oklahoma. Pawnee County Emergency Management Director Mark Randell says a man protecting his child suffered a head injury when part of a fireplace fell on him. Randell says the man was treated at a hospital and released. The U.S. Geological Survey reports the quake struck at 7:02 a.m. about nine miles northwest of Pawnee, a town of about 2,200 about 70 miles northeast of Oklahoma City. The USGS also reports about a half-dozen aftershocks in the same area, including one that was a 3.6 magnitude at 7:58 a.m. This update has been corrected to show that the area where the earthquake hit is northeast of Oklahoma City, not northwest. Staffers at the Wolf Creek nuclear power plant in southeast Kansas found no damage to the plant after an earthquake rattled a large swath of the Midwest. Spokeswoman Jenny Hageman says Saturday's 5.6 magnitude earthquake centered in north-central Oklahoma did not shake the plant near Burlington, Kansas, enough to set off a seismic alarm but staff checked it as a precaution. KVOE reports (http://bit.ly/2bKgNRo ) the plant was shut down Friday by a water leak. Hageman says the source of the leak in the reactor cooling system inside the plant's containment area has been identified and that there was never of threat of a radiation leak. It's unclear when Wolf Creek will return to operation. A Pawnee business owner says the 5.6 magnitude earthquake shook his house "like a rubber band" and knocked items off cabinets and broke glass. Furniture store owner Lee Wills told The Associated Press he was awake when the quake struck at 7:02 a.m. Saturday and first thought it was a thunderstorm. But then his home, which is about 2½ miles outside of town, started shaking. Wills said buildings in the downtown area are cracked and sandstone facing on some buildings fell and described the scene as "a mess." The quake was felt as far away as Nebraska. The Pawnee County emergency management director says no injuries have been reported and no buildings have collapsed following a magnitude 5.6 earthquake that ties a 2011 temblor for the strongest in Oklahoma history. Mark Randell said the Saturday morning quake did cause cracks and damages to city buildings, some of which date to the early 1900s. The U.S. Geological Survey reports the quake struck at 7:02 a.m. about nine miles northwest of Pawnee, a town of about 2,200 about 70 miles northeast of Oklahoma City. The U.S.G.S. also reports a 3.6 magnitude aftershock in the same area at 7:58 a.m. This update has been corrected to show that the area where the earthquake hit is northeast of Oklahoma City, not northwest. Oklahoma Gov. Mary Fallin says that crews are checking bridges and structures for damage after the 5.6 magnitude earthquake, which ties a 2011 temblor for the biggest on record in the state. Fallin tweeted Saturday morning that the Oklahoma Department of Transportation is checking bridges in the Pawnee area for damage. The quake was centered about 9 miles northwest of the town of about 2,200 people. Fallin also tweeted that state officials want structural engineers to look at building safety in the wake of the quake, which the U.S. Geological Society happened at 7:02 a.m. No major damage was immediately reported. The quake was felt as far away as Nebraska. An earthquake has rattled a swath of the Great Plains, from Kansas City, Missouri, to central Oklahoma. The United States Geological Survey didn't immediately post data on its website about the size of the earthquake or where it was centered. People in Kansas City, Missouri, Fayetteville, Arkansas, and Norman, Oklahoma, all reported feeling the earthquake at about 7:05 a.m. Saturday.
News Article | March 28, 2016
The seismic risk maps are used by emergency management officials as well as the country's major engineering and design associations to guide how strong to construct buildings. "By including human-induced events, our assessment of earthquake hazards has significantly increased in parts of the U.S.," Mark Petersen, Chief of the USGS National Seismic Hazard Mapping Project, said in a statement. Some 7 million people in the Central and Eastern United States live or work in areas threatened by so-called induced seismicity, and in parts of these regions, the damage caused by earthquakes could be at parity with that seen in high-hazard regions of California, the USGS said. Oklahoma is at the greatest risk for hazards associated with induced seismicity, the USGS said, followed by Kansas, Texas, Colorado, New Mexico and Arkansas. Oklahoma in 2015 experienced 907 magnitude-3.0 or greater earthquakes, compared with just two of similar size in 2009. In February, a 5.1-magnitude temblor shook the area around Fairview, Oklahoma - the third strongest recorded in the state. The uptick in quakes has prompted serious concern among those near the oil storage hub at Cushing, Oklahoma, home to some 66 million barrels of oil and the delivery point for the West Texas Intermediate futures contract. "We have had some earthquakes that were way to close to those tanks," said Michael Teague, Oklahoma's Secretary of Energy and Environment. The disposal of saltwater - a natural byproduct of oil and gas drilling - into wells has been tied to earthquakes. Oklahoma regulators have already ordered many disposal wells to curb operations. "The good news is that we are already seeing a very positive response to those actions in the form of reduced seismic activity in the central and north central areas of Oklahoma," the Oklahoma Oil & Gas Association said in a statement. Saltwater injections into disposal wells is down by roughly half from a peak of 1.8 million barrels per day in 2014, the Oklahoma Geological Survey said, with half the wells shutting due to low oil prices. The USGS said building code committees are still deciding whether to include induced earthquakes in their revisions, in part because they could be temporary. The American Society of Civil Engineers' 2016 guidelines do not take into account man-made earthquakes and it does not plan to update them until 2022. "There is always a delay in design codes adapting the USGS Seismic Hazard Maps," said Muralee Muraleetharan, a civil engineering professor at the University of Oklahoma.
News Article | September 5, 2016
In the wake of a major, record-tying 5.6 magnitude Oklahoma earthquake that struck last Saturday morning, Governor Mary Fallin did not wait around to hear any more evidence about the link between seismic activity and the practice of disposing oil and gas wastewater into wells. She just went right ahead and ordered all disposal wells to shut down in Pawnee County, within a 725-square mile area in the Arbuckle shale formation. The order was included in Fallin’s state of emergency declaration. She also committed state agencies to work with EPA to develop a course of action for disposal wells in an additional area of 211 square miles in Osage County, over which EPA has jurisdiction. The US Geological Survey provides a rundown of the latest temblor to strike Oklahoma: The September 3, 2016 M 5.6 Oklahoma earthquake occurred as the result of shallow strike-slip faulting about 15 km northwest of the town of Pawnee. The earthquake occurred within the interior of the North America plate, far from any plate boundaries. That’s about all the agency can definitively determine, for now. The specific location is still up in the air: The preliminary focal mechanism solution for the earthquake indicates rupture occurred on either a left-lateral fault striking east-southeast, or on a right lateral fault striking north-northeast. USGS also notes that correlating the Oklahoma earthquake to a specific fault will have to await further study. The agency also draws attention to several smaller-magnitude earthquakes that occurred before and after the main one: In the immediate vicinity of the September 3 event, a M 3.2 earthquake occurred on September 1, 2016, just to the southwest. Within an hour of the September 3 M 5.6 earthquake, 4 aftershocks have been located, the largest being a M3.6 event 56 minutes after the mainshock. If your impulse is to link the latest Oklahoma earthquake to natural gas fracking, you’re only part right. Fracking — short for hydrofracturing, an oil and gas drilling method — has been definitively linked to seismic activity in one instance, a series of temblors that struck Ohio in 2014. However, a much more pervasive linkage has been demonstrated for the contribution that fracking makes to the wastewater stream resulting from all oil and gas operations. A growing pile of evidence has linked unusual seismic activity to the practice of disposing of oil and gas wastewater in wells. That includes wastewater from conventional drilling as well as fracking. It’s also worth noting that there is a lot of regional variation in the proportion of used fracking fluid that enters the oil and gas wastewater stream. For example, most of the wastewater currently disposed in Oklahoma wells consists of saltwater, which comes up during oil operations. Spent fracking fluid accounts for less than 10 percent of the total. So, as the latest Oklahoma earthquake demonstrates, the problem of induced seismicity is a broad issue for the oil and gas industry overall, not just for natural gas fracking. Oklahoma had a relatively quiet seismic history, right up until the recent boom in oil and gas operations. Last year, the Oklahoma Geological Survey issued a report that definitively nailed oil and gas wastewater disposal for an increase in the rate of earthquakes, from 1.5 yearly in 2008 to a current rate of 2.5 daily — yes, daily. Last year, seismologists at Stanford University also published a study linking the disposal well problem to peculiarities of the Arbuckle formation. The study offered this explanation: …wastewater disposal is increasing the pore pressure in the Arbuckle formation, the disposal zone that sits directly above the crystalline basement, the rock layer where earthquake faults lie. Pore pressure is the pressure of the fluids within the fractures and pore spaces of rocks at depth. The latest Oklahoma earthquake caps off a busy year of regulatory activity for the state’s Corporation Commission, but it may be a case of locking that barn door at the wrong time. Just last March, the agency issued a new regional plan aimed at reducing the amount of wastewater disposed in the Arbuckle formation. The final amount was to be phased in over a two-month period in order to avoid a sudden change in pressure. The March plan represented an acknowledgement that the problem is regional in scope. Earlier attempts at solving the earthquake problem were targeted more narrowly. Last Saturday’s emergency order steps up the state’s game considerably, by shutting everything down within the perimeter affected by the quake. The order only affects 37 wells, but that could just be the beginning. The Arbuckle formation currently hosts hundreds of disposal wells, and many of them are located in “areas of interest” established by the Corporation Commission. Back in March 2015, the Commission issued a directive covering 300 such disposal wells. The directive enabled the wells to keep operating if they reduced their volume. Apparently that wasn’t enough. In July 2015, the Commission expanded the areas of interest to add another 211 wells. The Commission also tacked on an additional requirement governing well depth, with this observation: There is broad agreement among seismologists that disposal below the Arbuckle poses a potential risk of causing earthquakes, as it puts the well in communication with the “basement” rock. Beginning last fall, the Commission launched a series of directives targeted at specific wells, but it looks like the state still has an induced seismicity problem. Coincidentally (or not), this year marks the first time that the US Geological Survey has included human activity in its annual seismic hazards forecast, partly in response to the amount of activity in Oklahoma. It looks like Governor Fallin and the Corporation Commission will not be pussyfooting around the issue any more, so stay tuned. Images: top (screenshot) via US Geological Survey, bottom via Stanford University. Drive an electric car? Complete one of our short surveys for our next electric car report. Keep up to date with all the hottest cleantech news by subscribing to our (free) cleantech newsletter, or keep an eye on sector-specific news by getting our (also free) solar energy newsletter, electric vehicle newsletter, or wind energy newsletter.
News Article | March 1, 2017
The earthquake risk for Oklahoma and southern Kansas is expected to remain significant in 2017, threatening 3 million people with seismic events that can produce damaging shaking, according to a new U.S. Geological Survey forecast released Wednesday. The seismic risk is forecast to be so high that the chance of damage in Oklahoma and southern Kansas is expected to be similar to that of earthquakes in California, USGS scientists writing in the journal Seismological Research Letters said Wednesday. In 2016 alone, Oklahoma experienced several damaging earthquakes, including a magnitude 5.0 temblor in November near the central oil town of Cushing — which proclaims itself the “Pipeline Crossroads of the World” — that dislodged unreinforced bricks in chimneys and storefronts, sending them tumbling onto the sidewalks. Oklahoma also saw the largest quake ever recorded in the state in 2016, when a magnitude 5.8 earthquake struck near Pawnee. The earthquakes are thought to be the result of the disposal of wastewater deep underground that are a byproduct of oil extraction. Injecting the wastewater underground is not thought to trigger earthquakes everywhere it is practiced — in North Dakota, for example — but is widely believed by scientists to be a problem in Oklahoma. According to scientists, there were only about two earthquakes a year of magnitude 2.7 or greater in Oklahoma from 1980 to 2000. But that number jumped to 2,500 in 2014 and soared to 4,000 a year later. There has recently been a decrease in wastewater being injected deep underground, either because of regulatory actions or because oil and gas extraction has declined due to falling petroleum prices. That might be a reason for the decrease in the number of Oklahoma earthquakes last year, to 2,500. In a statement, Mark Petersen of the USGS said the amount of injected wastewater in some areas has been reduced by up to 40% in 2016. But the USGS report says the forecast earthquake hazard in 2017 “is still significantly elevated” compared to the seismic risk before 2009. The Oklahoma Geological Survey’s director, Jeremy Boak, said in a statement that he expects that state directives to curtail wastewater injection rates and low oil prices “should result in further declines in the seismicity rate and limit future widespread seismic activity.” A spokeswoman with a research and education program of the Independent Petroleum Assn. of America, Katie Brown, said in an email the reduced number of earthquakes “is a clear sign that the collaborative efforts between industry, scientists, and regulators are working.” Accompanying the rise in Oklahoma’s earthquakes has been a significant jump in wastewater injected underground in increasingly deeper wells as oil companies have sought to extract untapped oil fields far underneath the state. Workers inject water at high pressure to break up the earth to tap into these deep oil wells, a process known as hydraulic fracturing, or fracking. The petroleum harvest from these wells are a mix of not only oil and gas but salt water — all part of the stew of ingredients that come from the decomposed biological components of ancient oceans, said USGS research geophysicist Justin Rubinstein, deputy chief of the agency’s induced seismicity project. Recent harvests have had a high percentage of salt water in them — requiring oil companies to deal with a significantly larger amount of wastewater than they’ve had to before. But as more wastewater has been injected deeper into the earth, underneath the ground water table, the number of earthquakes have risen in Oklahoma. Increased fluid deep underground can change the pressures on earthquake faults in a way that essentially lubricates them, making them more likely to move and resulting in an earthquake, Rubinstein said. Feeling earthquake anxiety? Here's what you can do to be prepared Santa Monica seeks to pass the nation's most extensive earthquake retrofit plan L.A. releases addresses of 13,500 apartments and condos likely to need earthquake retrofitting 3:30 p.m.: The article was updated with an explanation that the quakes are thought to be the result of disposal of wastewater that is a byproduct of oil extraction in general, not only related to fracking, and about the jump in wastewater in deeper wells and how these fluid injections can cause earthquakes. 11:10 a.m.: The article was updated with statements from the Oklahoma Geological Survey and the Independent Petroleum Assn. of America. This article was originally published at 10:20 a.m.
News Article | September 12, 2016
OKLAHOMA CITY (AP) — A 5.8-magnitude earthquake and a series of smaller aftershocks in Oklahoma led to the discovery of a new fault line and stoked fears among some scientists about activity along other unknown faults that could be triggered by oil and gas wastewater that's being injected deep underground. State and federal regulators on Monday said 32 disposal wells in northeastern Oklahoma must shut down because they are too near the newly discovered fault line that produced the state's strongest earthquake on record on Sept. 3. Jeremy Boak, head of the Oklahoma Geological Survey, said it's possible that a large "pulse" of disposed wastewater is slowly moving deep underground and triggered the temblor along the new fault located near the town of Pawnee, farther east than most of the previous earthquake activity in Oklahoma. "My inclination is to worry about the (fault) we don't know about yet, more so than about another very large earthquake in this area," Boak said. "My general feeling is that the rate of earthquakes is declining. I'm more concerned, I think, about whether there's another one of these faults out here that is cued up and ready to go." Boak said it's also possible that some aftershocks greater than magnitude 4 could still be triggered along the newly discovered fault that has yet to be named. The Pawnee quake damaged more than a dozen buildings and slightly injured one man when part of a chimney collapsed. It shook several states, including nearby Kansas, Missouri and Arkansas, and was reportedly even felt more than 1,000 miles away in places like Florida and Nevada, according to the U.S. Geological Survey. Scientists, including those at the OGS, believe the vast majority of the earthquakes in Oklahoma are triggered by the injection of wastewater from oil and gas production that is injected deep into the earth. After the Pawnee quake, state and federal regulators immediately ordered disposal wells to shut down or reduce volumes of wastewater within a 725 square-mile (1,880 sq. kilometer) area. That area was expanded on Tuesday to encompass 67 total wells in more than 1,100 square miles (2,850 sq. kilometers). Some of the disposal wells that were initially ordered to completely shut down will be allowed to resume at lower volumes, regulators said. In all, the 75,000 barrels a day of wastewater that was being injected in the area is being reduced to about 35,000 barrels a day, said Jim Marlatt with the oil and gas division of the Oklahoma Corporation Commission. Forcing oil and gas operators to stop injecting wastewater or reduce the amount they can inject means they can't produce as much oil and natural gas, which can cause a serious financial hardship, said Chad Warmington, president of the Oklahoma Oil and Gas Association. "These are multimillion-dollar wells in some cases that you can't operate any more, period," Warmington said. "If you take away your disposal activity, there's nothing else you can do with that water." Still, Warmington said the industry also is concerned about the quakes and is working with regulators to try and stop them. "As long as we're making decisions based on good data and good science, we'll live with it," Warmington said.
Cardott B.J.,Oklahoma Geological Survey
International Journal of Coal Geology | Year: 2013
Coal rank, generalized for all coal beds at or near the surface, in the eastern Oklahoma coalfield has been known since 1915. Near the surface (depths <305m, <1000ft), coal rank increases from high volatile bituminous to low volatile bituminous from west to east in the Arkoma Basin in Oklahoma. The rank of subsurface (depths >305m, >1000ft) coals in Arkoma Basin coalbed methane (CBM) prospects was previously unknown. A new Hartshorne coal (Middle Pennsylvanian) rank map is based on mean maximum vitrinite reflectance values of 0.76% to 2.41% Rmax from 70 coal samples from vertical depths of 0 (surface) to 1327m (4355ft). Hartshorne coal rank in the subsurface increases from high-volatile bituminous to semianthracite from west to east in the Arkoma Basin in Oklahoma. Bituminous rank boundaries changed considerably from earlier surface rank maps (primarily by increasing the area of medium volatile bituminous rank coal in the subsurface) and revealed a previously unknown semianthracite rank area. This discrepancy is significant because the rank of deep (>305m, >1000ft) coal resource assessments and CBM exploration projects have been based on shallow coal rank assignments.A total of 2635 Hartshorne (Hartshorne, Lower Hartshorne, and Upper Hartshorne) CBM wells have been completed in Oklahoma since 1988. Most (1610) wells are horizontal with lateral lengths ranging from 4 to 1498. m (14 to 4914. ft; an average of 669. m [2195. ft]). Coal in most Hartshorne CBM wells is medium volatile bituminous rank. Hartshorne coal is semianthracite rank in about 160 CBM wells in Le Flore County. The four Hartshorne CBM wells with the highest initial potential (IP) gas rates (48 to 65 thousand cubic meters per day, Mcmd; 1.7 to 2.3 million cubic feet per day, MMcfd) are medium volatile bituminous rank from horizontal wells in Haskell and Pittsburg counties. IP gas rates < 28.3 Mcmd (< 1 MMcfd) in low volatile bituminous and semianthracite rank Hartshorne horizontal CBM wells may be low due to complications in drilling into high rank coals with cleat spacing < 1. cm, to stimulation differences, or to gas migration into adjacent sandstone channels. © 2011.
Cardott B.J.,Oklahoma Geological Survey
International Journal of Coal Geology | Year: 2012
Being a hydrocarbon source rock and having a brittle (silica-rich) lithologic character makes the Woodford Shale (Late Devonian to Early Mississippian) an important oil and gas shale in Oklahoma. Since 2004, Woodford Shale plays have expanded from producing primarily thermogenic methane in one geologic province to producing thermogenic methane, condensate, oil and biogenic methane in four geologic provinces at thermal maturities from mature (>. 0.5% vitrinite reflectance, Ro) to post mature (2% to 3% Ro). Condensate is produced at a thermal maturity up to 1.67% Ro. Oil is produced from naturally-fractured, silica-rich shale. Biogenic methane is produced in shallow (<. 2000. ft, 610. m) reservoirs down dip from the outcrop in northeast Oklahoma. © 2012 Elsevier B.V.
News Article | January 22, 2016
"The recent series of strong quakes have spiked public concern and accusations that industry is negligent in disposing of wastewater deep underground." "Two lawsuits in Oklahoma accuse more than a dozen oil and gas companies of triggering recent earthquakes by disposing of their drilling waste in deep wells. The lawsuits filed last week come on the heels of heightened earthquake activity in Oklahoma, where more than 130 this month have registered magnitude 2.5 or higher on the Richter Scale. These events have caused property damage, knocked out the local power supply, and shaken people's faith in the state government's ability to control the situation. "It's pretty intense right now," said Jeremy Boak, a geologist at the Oklahoma Geological Survey. He explained that the state has already experienced seven earthquakes of at least magnitude 4.0 in the past three weeks—about one-quarter the total of such quakes in 2015."