Patterns of small fault with different placing depth in typical coal fields in southern China

Abstract

Small faults are an important factor that affects the safe and efficient mining of coal mines.In recent years, although great progress has been made in seismic wave identification methods for faults including small faults, it is still a difficult problem to identify small faults with a drop of less than 5 m in coalfield.Southern coalfields generally have complex topography and well-developed fault.In order to promote the seismic exploration of small faults in southern coal fields, this paper selects a typical southern coalfield—the Liupanshui coalfield in Guizhou Province as the study area.The coal-measure stratigraphic seismic physical model is established for seismic data acquisition, processing and interpretation, from the seismic wave kinematics and dynamics.The angle identifies small faults with a drop of 5 m, 3 m, and 1 m at different depths.The research results show that it is difficult to identify small faults with a drop of 1 to 5 m by using seismic wave kinematics method because coal seam is in a low-velocity layer on the surface.However, the application of dynamic method to extract multiple seismic attributes for analysis can find that the amplitude attributes are more sensitive to the identification of small faults, and the resolution ability is strong.Through the seismic physical model test, under the condition of the seismic source frequency of 60 kHz, the small faults with a drop of less than 5 m were successfully explained, and the results are consistent with the actual small faults of the coal-measure strata seismic physical model.

Keywords

• southern coalfield
• physical modeling
• small faults
• placing depth
• throw
• attribute analysis