煤巷前方煤层断点绕射波特征及其在极小偏移孔径下的成像方法研究

断层是煤巷掘进重大灾害事故的重要隐蔽致灾因素。受地面复杂地形、上组多煤层采空及地表沉陷等影响，地震技术进入了深部矿井。目前，受煤巷探测条件的限制，煤层断点绕射波拾取及其在极小偏移孔径条件下成像困难，进而难以准确构建断层模型。针对该问题，建立中厚煤层掘进工作面前方不同落差、倾角、倾向的断层数值模型，分析全空间条件下煤巷空腔及围岩松动圈效应耦合影响下不同激发、接收点参数的煤层断点绕射波特征，提取断点绕射波；结合地震物理模型试验，采用基于S变换的多分量极化分析法确定断点绕射波主极化方向，开展绕射波主极化方向约束的叠前偏移成像研究，以实现极小偏移孔径下煤层断点归位；融合煤层断点、断层面及煤层错断位置信息，构建断层几何模型，并计算断层落差、倾角、倾向参数；采用现场实证方法对上述研究成果进行验证和完善，以期形成一种煤巷断层超前精细定量探测方法，为井下断层精细探测提供理论指导和技术支持。

The fault is one of the important subtle disaster-causing factors in important accident of coal roadway driving. Seismic technology has been used into the deep mine, under the influence of complex terrain, upper multiple coal seams gob and surface subsidence. At present, limited to the detection conditions of coal roadway, picking of breakpoint diffraction and imaging of coal seam under small migration aperture are difficult, so the accurate construction of fault model is difficult. Aimed to solve this problem, various fall numerical models with different dips, throws and trends will be established. Under conditions of the cavity and surrounding rock loose circle effect in coal roadway, breakpoint diffraction characteristics of different shot and receiver parameters will be analyzed. The breakpoint diffraction of broken wing coal seam will be extracted. Combined with seismic physical model test, the principal polarization direction of breakpoint diffraction will be determined by S-transform multi-component analysis method. The imaging study on prestack migration restrained by principal polarization direction of diffraction will be carried out to realize breakpoint convergence under small migration aperture. Coal seam breakpoint, fault plane and coal seam dislocated location information will be merged to build fault model by point center method which based on weights-making. The accurate forecast of fault parameters, such as dip, throw and trend, will eventually be achieved. Above research results will be perfected by using a field experiment. The formation of an advanced and detailed fault detection method of coal roadway will provide theoretical guidance and technical support for the detailed detection of fault in coal mine.