诺门罕盆地找煤工作中二维地震技术应用

Application of 2D Seismic Technology in Nomonhan Basin Coal Looking

海拉尔-二连晚中生代聚煤盆地以断陷型为主,发育巨厚煤层。诺门罕盆地是海拉尔盆地群中的一个次级盆地,地表均被第四系覆盖,属全掩盖式含煤盆地。根据该盆地的地质实际情况,煤田勘查工作采用了"地震先行、钻探验证、多种手段、综合研究"的技术路线,利用二维地震技术成功地解决了该盆地的几个地质问题:如通过地震时间剖面认识到该含煤盆地煤层与基底具有相似的空间结构特征,盆地中央厚,边缘薄甚至尖灭;成煤同期断裂构造不但控制了基底形态,对煤层的形成与展布也产生了较大影响。另外,利用地震时间剖面及反演剖面,对盆地边缘的基底隆起与煤层尖灭点、分叉点进行了解释,经5个钻孔验证,符合率达到100%。

The Hailar-Erenhot late Mesozoic coal-accumulation basins are mainly fault depression typed, mostly have developed huge thick coal seams. The Nomonhan Basin is one of secondary basins in the Hailar basin group, covered by Quaternary System, thus a fully covered type coal-bearing basin. According to practical geological condition, a technological route of ＂start from seismic prospecting, verified by drilling, multiple means, comprehensive study＂ in coal exploration works has been adopted. By the use of 2D seismic technology, some geological problems in the basin have been settled： such as from seismic time section recognized coal seams and basement in the basin have similar spatial structure characteristics, thick in the basin center, thinning even pinch out to the basin margin; coal-forming contemporaneous faulted structures have not only controlled basement configuration, but also largely impacted coal seam forming and distribution. Besides, using seismic time section and inversion section have interpreted basin margin basement uplift and coal seam pinch-out, splitting points, after 5 drilling holes verification, coincidence rate 100%.