The 16 December 2018 Mw 5.3 Earthquake in the Southern Sichuan Basin of China Was Likely Caused by Hydraulic Fracturing

Date: 4/26/2019

Time: 06:00 PM

Room: Fifth Avenue

An M_W5.3 (CENC, 2018) earthquake was located at shallow depth near the northeast corner of the shale gas field N201 in the southern Sichuan Basin of China (SBC) on 16 December 2018. From 2015 to 2018, nearly 19,000 earthquakes were recorded by a temporary network with 21 mobile stations. As reported for western Canada, hydraulic fracturing accounts for the majority induced seismicity in the southern SBC. Previously, it was found that seismicity located to the southwest near well pad H7 of shale gas field YS108 was induced by hydraulic fracturing operations from 12 to 19 January 2017, including the M_W4.7 earthquake that occurred on 28 January 2017 (Lei et al., 2017; Meng et al., 2019). The epicenter of M_W5.3 earthquake was located, using a local seismic network, about 2.0 km away from the well pad N201H24. From this pad, there were hydraulic fracturing operations from 4 October until 9 December 2018. During the hydraulic fracturing, there was only one M_L > 3.0 event detected near this well pad, on 12 November 2018. Following completion of the hydraulic fracturing, an event of M_L3.5 was recorded on 16 December 2018, followed 17 sec later by the M_W5.3 earthquake. Another M_W5.0 (CENC, 2019) earthquake occurred in the central area of N201 on the 3 January 2019, nearly 10 km southwest of the M_W5.3 earthquake and 2 km north of an earthquake of M_W4.5 that occurred on 4 May 2017, respectively (Lei et al., 2017). In view of plans for extensive further development of these natural gas resources in the southern SBC, there is clearly a need to continue seismic monitoring in this region using a local network. Additionally, comprehensive information concerning the corresponding injection activities should be accessible in the public domain to enable an improved understanding of how these earthquakes are related to well completion operations.

Presenting Author: Lingyuan Meng

Authors