Microseismic response regularity during gas extraction in geological anomaly area
Gas extraction activities are likely to change the stress distribution of coal and rock mass,leading to the expansion and development of cracks in coal and rock mass until failure,and the occurrence of high frequency micro-fracture signal of small magnitude.The microseismic monitoring technology can be used to identify the micro-fracture signal effectively,monitor the extraction process in real time,and detect geological anomaly areas and hidden structures.Under the influence of gas extraction at 15240 working face,the number of single-day microseismic events increases exponentially(2-12 times)and the time series is continuous in a certain spatial area far from the mining line,and this area is identified as a geological anomaly area under the influence of gas extraction.The response characteristics of microseismic data were summarized by analyzing the evolution characteristics of temporal and spatial series,vertical disturbance range and energy in space.With the continuation of gas extraction time series,the activity of microseismic events in geological anomaly areas changed from strong to weak,and the spatial distribution presented a"central-distributed"evolution trend.The proportion of roof 0～5 m was significantly higher than that of normal stoping stage,and the proportion of floor 5～15 m is large.The energy of microseismic events distributed in an irregular U-shaped,and the overall energy increased 3～8 times compared with the recovery data,attention should be paid to strengthening hydrogeological observations.
NETL
NSTL
万方数据
