南方典型煤田不同埋深小断层识别规律研究

小断层是影响煤矿安全高效开采的重要因素。近年来有关小断层的地震波识别方法取得了长足的进步，但对煤田落差5 m以内小断层的识别仍是一大难点。南方煤田一般地形复杂、断裂发育，为推进南方煤田小断层的地震勘探研究，本文选取南方典型煤田——贵州省六盘水煤田作为研究区，通过建立煤系地层地震物理模型进行地震数据采集、处理与解释，从地震波运动学和动力学的角度对不同埋深落差分别为5 m、3 m和1 m的小断层进行识别。研究结果表明:由于煤层处于地表低速层，对于落差1~5 m的小断层采用地震波运动学方法难以识别，而应用动力学方法提取多种地震属性进行分析，发现振幅类属性对于识别小断层较为敏感，分辨能力较强。通过模型试验，在震源频率为60 kHz的条件下，成功解释出落差5 m以内的小断层，结果与煤系地层地震物理模型实际小断层相吻合。

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

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.