文献类型：期刊文献

英文题名：Brittle sedimentary strata focus a multimodal depth distribution of seismicity during hydraulic fracturing in the Sichuan Basin, Southwest China

作者：An, Mengke[1,2,3];Elsworth, Derek[2,3,4];Zhang, Fengshou[5];Huang, Rui[5];Li, Junlun[6];Xu, Zhengyu[7];Zhong, Zhen[8];He, Manchao[9]

机构：[1]Hong Kong Polytech Univ, Dept Civil & Environm Engn, Hung Hom, Kowloon, Hong Kong 100872, Peoples R China;[2]Penn State Univ, EMS Energy Inst, Dept Energy & Mineral Engn, University Pk, PA 16802 USA;[3]Penn State Univ, Ctr G3, University Pk, PA 16802 USA;[4]Penn State Univ, Dept Geosci, University Pk, PA 16802 USA;[5]Tongji Univ, Coll Civil Engn, Dept Geotech Engn, Shanghai 200092, Peoples R China;[6]Univ Sci & Technol China, Sch Earth & Space Sci, Lab Seismol & Phys Earths Interior, Hefei 230026, Peoples R China;[7]Petrochina, Hangzhou Res Inst Geol, Hangzhou 310023, Peoples R China;[8]Shaoxing Univ, Sch Civil Engn, Shaoxing 312000, Peoples R China;[9]China Univ Min & Technol, State Key Lab Geomech & Deep Underground Engn, Beijing, Peoples R China

年份：2024

卷号：880

外文期刊名：TECTONOPHYSICS

收录：SCI-EXPANDED(收录号：WOS:001235889500001)、、EI(收录号：20241815997658)、Scopus(收录号：2-s2.0-85191342844)、WOS

基金：This research is funded by the National Natural Science Foundation of China (42107163, 42320104003) , and the Fundamental Research Funds for the Central Universities. DE acknowledges support from the G. Albert Shoemaker endowment. We thank Wenming Yao and Jianye Chen for laboratory assistance. The experimental data in this paper can be found at Doi: https://doi.org/10.5061/dryad.cvdncjt9p.

语种：英文

外文关键词：Induced seismicity; Hydraulic fracturing; Multimodal earthquake distribution; Fluid diffusion; Poroelastic stress transfer; Brittle sedimentary layers

外文摘要：The number of background earthquakes (ML >= 0) in the southern Sichuan basin, southwest China, has increased thirtyfold as a result of hydraulic fracturing. Background events are originally deep (4-6 km) within the sedimentary section but build into a multimodal distribution both at depth and in the shallow stimulated reservoir (2-4 km) - representing a counterpoint to the usual triggering of seismicity on deep sub-reservoir basement faults. Surprisingly, the largest events (ML >= 3) evolve in the deep sedimentary strata (4-6 km) that are hydraulically isolated from the injection zone (2-4 km) by low permeability layers. We evaluate the friction-stability rheology of the strata within the full stratigraphic section to define the feasibility of nucleation within these shallow and deep strata. These show velocity-neutral to velocity-weakening behavior in the shallow reservoir transitioning to more strongly velocity-weakening with increase in both depth and temperature. Poroelastic stress calculations confirms that stress transfer, rather than transmitted fluid pressures, are capable of directly reactivating critically-stressed faults at depth, with fluid pressures the triggering source within the shallow reservoir.