Permeability Changes of Tianjin Typical Observation Wells and Coseismic Response Mechanism to Maduo Ms7.4 Earthquake
This article uses two methods,slug test and tide inversion,to calculate the per-meability coefficient of Wang 3 Well,Baodi New Well,and Ninghe Well at different peri-ods.Comparing the calculation results,we find that the results obtained by using two methods are comparable in overall magnitude,and the trend of change is consistent.Espe-cially for observation wells in aquifers with stable development and good continuity,the calculation results of the two methods are closer.The permeability coefficient estimated by slug test mainly reflects the permeability characteristics of the local aquifer around the wellbore during the short-term water flow process.The permeability coefficient estimated by tide inversion reflects the average permeability of a large range of aquifers over a long period of time.Therefore,in the analysis of coseismic response and abnormal verification of water pumping(injection)interference,using slug tests to estimate the permeability co-efficient of the well aquifer is more reasonable,and it is more reasonable to use tide inver-sion to estimate the permeability coefficient in analyzing regional stress field changes.We analyze the characteristics and causes of water level and permeability change char-acteristics and causes of the three observation wells,as well as,we analyze mechanism of water level coseismic response in Wang 3 Well and Baodi New Well to the Maduo Ms7.4 earthquake in Qinghai Province on May 22,2021,and the impact mechanism of the Maduo earthquake to water level in Ninghe Well.We find that factors,such as stress accumula-tion,pumping or injection water,and seismic wave propagation,can affect the permeabili-ty of aquifer medium.Moreover,the propagation process of seismic waves has different impacts on different aquifer medium,and the response characteristics and mechanisms of observation wells with the same aquifer lithology to the same earthquake are also differ-ent.
NETL
NSTL
万方数据
