Tintera in the News: Still, even if researchers and regulators establish a cause-and-effect relationship between the earthquakes and the disposal wells, it is likely that any emerging regulations could target the specific geological places where the earthquakes happen, said John Tintera, who was executive director of the Railroad Commission until 2012. That means there probably would not be wide-ranging changes that hinder the Permian Basin’s oil and gas production, he said. “Good science and good facts lead to good regulations,” Tintera said. “Poor science and poor facts leads to poor regulations.” >>>>>>>>>>>>>>>>>>>>>>> North Texas quakes draw attention to injection wells BY COREY PAUL cpaul@oaoa Posted on January 19, 2014 Corey Paul by Corey Paul A swarm of recent low-intensity earthquakes in North Texas communities prompted worry that they could be a side-effect of oil and gas, bringing injection wells specifically into the spotlight. Injection wells are depleting formations filled by producers with tons of salt water to extract more oil. Texas has about 35,000 active injection wells, according to the Railroad Commission, and many are in West Texas. And even while experts agree injecting large volumes of water into the depleting formations rarely has any significant seismic effect, there is evidence in peer-reviewed studies that using injection wells for disposal can sometimes cause earthquakes. The Railroad Commission decided to hire a seismologist to study the issue about a week after a heated town meeting on Jan. 2 in one of the towns, Azle. And on Thursday, the chairman of the Texas House Committee on Energy Resources announced a new subcommittee on seismic activity to investigate the potential linkage between the earthquakes and injection wells. So what does all this mean for West Texas, home to a significant share of the state’s 7,000 injection wells used for disposal? Generally, earthquakes around disposal wells happened in areas already seismically active, and the disposal wells were close to fault lines, said Bill Ellsworth, a seismologist with the U.S. Geological Survey who researches possible injection-induced earthquakes. Odessa and Midland, along with most of the rest of the Permian Basin, are not areas that see many earthquakes big enough to feel, and Ellsworth along with several other geological experts said they do not expect that to change. But questions about the effect of oilfield activity on seismology are not alien to West Texas either. Researchers from the University of Texas at El Paso in the 1980s examined a swarm of earthquakes that happened during the last major oil boom in Wink and Ward counties to see if injection wells might be causing them. The result?: There was not enough data to know, said Diane Doser, the professor who headed that research. Better data brought by the renewed attention could lead to a greater understanding of the seismological happenings that occur underneath the Permian Basin without anybody feeling it, she said. If there is a cause-and-effect relationship to minor earthquakes, Doser said that could lead to wiser oil and gas operations: perhaps new efficiencies or an understanding of what to avoid. “It would certainly be something you would want to monitor,” Doser said. “And see if they got bigger.” Still, even if researchers and regulators establish a cause-and-effect relationship between the earthquakes and the disposal wells, it is likely that any emerging regulations could target the specific geological places where the earthquakes happen, said John Tintera, who was executive director of the Railroad Commission until 2012. That means there probably would not be wide-ranging changes that hinder the Permian Basin’s oil and gas production, he said. “Good science and good facts lead to good regulations,” Tintera said. “Poor science and poor facts leads to poor regulations.” CORRELATION VS. CAUSATION To be sure, numerous peer reviewed studies dating back as early as the 1950s show that water injected underground in large volumes can cause earthquakes, even though experts agree such instances are rare. In the 1960s, scientists with the U.S. Army Corps of Engineers actually caused minor earthquakes this way in Colorado. In Azle, there have been more than 30 earthquakes since November, with the most recent one recorded on Monday. But less clear in the seismology community is a certain cause for specific earthquakes, said Ellsworth, who released the July study “Injection-Induced Earthquakes.” An earthquake could occur much deeper than an oil well, miles away or it could happen years later, he said. “A bunch of oilfields are produced in much the same way, but only a handful of them are seeing seismic activity,” Ellsworth said. “The big question is why this field, but not that one.” In the communities in and around Azle, disposal wells in the Barnett oil play were likely lubricating fault lines and causing them to slip, according to a 2012 study by Cliff Frohlich, a senior research scientist at the University of Texas’ Institute for Geophysics. At the same time, Frohlich found an absolute link was difficult to establish. Most of the earthquakes Frohlich identified ranged in magnitude from 1.5 to 2.5, “meaning they posed no danger to the public.” But Frohlich also reported “injection-triggered earthquakes are more common than is generally recognized.” As it stands, disposal wells are governed by the federal Safe Drinking Water Act and monitored by the Railroad Commission. Most of those regulations center around protecting aquifers, with operators not required to report seismic data. That makes it difficult for scientists and for the railroad commission to get a grasp on the earthquakes, experts say. Officials with the Permian Basin Petroleum Association said they doubted oil and gas activity caused the earthquakes but supported the Railroad Commissions decision to hire a seismologist. “It’s good to examine the facts with someone who could understand and potentially make the link between actions and outcomes . . . in a more concentrated fashion than speculation,” said PBPA chairman Steve Pruett. Researchers from Southern Methodist University and the USGS have installed a network of seismic monitors around Azle and Reno, in northern Parker County. Their goal is to collect better data on earthquakes. Art McGarr, an earthquake researcher at the Geological Survey who is working on the Azle project, said researchers expect to present their findings in late April. McGarr’s research shows that the total volume of fluid injected in a well can be the biggest factor in triggering quakes, not how fast it is injected. The five disposal wells around Azle went into operation between 2005 and 2009. Three are permitted to inject up to 25,000 barrels a day. One well is limited to 15,000 barrels and another to 10,000 barrels. But all are injecting much less than their allowed maximums. PREVIOUS PERMIAN STUDIES In 1986, Doser began a new job teaching seismology at the University of Texas at El Paso. Now a tenured professor, she remembers coming across research a predecessor performed with students from the late 1970s through the early 1980s — the height of Texas’ last big oil boom. There had been a swarm of small earthquakes in areas of the Permian Basin near oil and gas activity, Doser said. None she said were bigger in than maybe a magnitude 4.0: Small, but big enough that people could feel some of them “Oh this is interesting, because it’s earthquakes and oil production,” Doser said she thought, seeing an opportunity to interest her students by applying their skill set to the petroleum industry. So Doser, with a few colleagues and up to 10 undergraduate and graduate students, continued the study until about 1993, focusing mostly on Ward and Wink counties. Doser’s name appears on peer-reviewed studies such as “The Not So Simple Relationship Between Seismicity and Oil Production in the Permian Basin” (1992). Some of the minor quakes, she reported, seemed to coincide with secondary and tertiary recovery operations — the injection wells. The earthquakes had been detected by seismology sensors, but funding had dried up by the time Doser began to follow up and the sensors had been removed. Another obstacle was data kept by oilfield companies was often scattered. A cause-and-effect analysis proved elusive. “If we saw an earthquake, we couldn’t figure out who was doing what,” Doser said. Because there simply wasn’t enough data. There were not enough seismic sensors.” In a few cases, Doser said, drilling injection wells actually seemed to coincide with the end of a swarm of earthquakes. It was possible, the researchers found, that drilling through heavy shale actually relieved pressure deep under ground. “That’s, I think, important — that you can’t start pointing fingers at anyone until you have a good set of sensors so that you can detect these earthquakes and locate them well,” Doser said. “Just people feeling them isn’t enough to locate where they are. And the second part is to have information about what the producers are doing. What are they injecting into the ground and what pressures are they at?” The Associated Press contributed to this report.
Posted on: Tue, 21 Jan 2014 03:22:13 +0000
Trending Topics
Recently Viewed Topics
© 2015