Based on data collected from a temporal seismic network, and in addition to the data from some nearby permanent stations, we investigate the velocity structure and seismicity in the Rongchang gas field, where signific...Based on data collected from a temporal seismic network, and in addition to the data from some nearby permanent stations, we investigate the velocity structure and seismicity in the Rongchang gas field, where significant injection-induced seismicity has been identified. First, we use receiver functions from distant earthquakes to invert detailed 1-D velocity structures beneath typical stations. Then, we use the double-difference hypocenter location method to re-locate earthquakes of the 2010 MLS. 1 earthquake sequence that occurred in the region. The re-located hypocenters show that the 2010 MLS. 1 earthquake sequence was distributed in a small area surrounding major injection wells and clustered mostly along pre-existing faults. Major earthquakes show a focal depth less than 5km with a dominant depth of -2km, a depth of major reservoirs and injection wells. We thus conclude that the 2010 ML 5. 1 earthquake sequence might have been induced by the deep well injection of unwanted water at a depth - 3km in the Rongchang gas field.展开更多
基金supported by the grants of Spark Program of China Earthquake Administration ( XH12038Y )the State Key Laboratory of Earthquake Dynamic( LED2008B04)+1 种基金Science and Technology Program of Chongqing Municipality in 2011 (Grant No. CSTC,2011AC0149)Research on the New Pattern and Key Techniques of the Earthquake Emergency Decision in Southwest China (201108013)
文摘Based on data collected from a temporal seismic network, and in addition to the data from some nearby permanent stations, we investigate the velocity structure and seismicity in the Rongchang gas field, where significant injection-induced seismicity has been identified. First, we use receiver functions from distant earthquakes to invert detailed 1-D velocity structures beneath typical stations. Then, we use the double-difference hypocenter location method to re-locate earthquakes of the 2010 MLS. 1 earthquake sequence that occurred in the region. The re-located hypocenters show that the 2010 MLS. 1 earthquake sequence was distributed in a small area surrounding major injection wells and clustered mostly along pre-existing faults. Major earthquakes show a focal depth less than 5km with a dominant depth of -2km, a depth of major reservoirs and injection wells. We thus conclude that the 2010 ML 5. 1 earthquake sequence might have been induced by the deep well injection of unwanted water at a depth - 3km in the Rongchang gas field.