华北各矿区是我国重要的煤炭基地,主要开採石炭二迭系煤层。煤系基盘为区厚的奥陶系灰岩。奥灰岩溶发育、富水性强、水压高、遇断裂极易与石炭系灰岩沟通,以底板突水形式,直接或间接地危害矿井安全开採,造成停产、淹井、甚至人身伤亡等重大灾害。华北地区受奥灰水威胁的主要是太原群下部煤层(简称下组煤),如:峰峰的小青、大青和下架煤;肥城、淄博的九、十层煤等。为了避免水害。多年来各矿区均先採二迭系及太原群上部煤层,以致下组煤长期不能开发, Each mining area in North China is an important coal base in China, mainly exploiting the coal beds of Carboniferous-Permian. The coal-based basement is Ordovician limestone with thick area. Ordovician karst development, rich water-rich, high water pressure, in case of fracture easily communicate with the Carboniferous limestone, to the floor water inrush form, directly or indirectly, endanger the safe mining, resulting in shutdown, flooding, and even casualties Major disaster. North China is threatened by the Ordovician water is mainly the lower coal seam of Taiyuan Group (referred to as the lower group of coal), such as: Xiaoqing, Daqing and frame coal; Fengcheng, Zibo nine, ten layers of coal. In order to avoid water damage. For the past several years, mining areas have adopted the Second Diego Series and the upper coal seam of the Taiyuan Group, so that the coal of the lower group can not be developed for a long time.