基于地震勘探的岩石物理分析预测采动裂隙

Prediction of mining fractures by rock physical analysis based on seismic exploration

在煤矿采掘生产过程中,突水始终是安全生产的隐患之一。除天然的隔水层缺失外,煤层及其围岩的导水裂隙是形成突水的主要导水通道。而裂隙又分为自然裂隙和采动裂隙,绝大多数的导水裂隙是煤层采空后覆岩失去支撑,在重力和地应力作用下形成的采动裂隙,因此预测采动裂隙对煤矿水害治理和安全生产有着非常重要的意义。地震勘探是以地层或岩层的力学性质为研究对象的物探技术,地震资料中包含了丰富的地下力学信息,通过对这些信息的挖掘探索,可以获取目的地层一定的岩石物理学性质特征,对其中较为容易出现破损和裂缝的脆性带分布进行圈定,得到脆性带的分布情况。结合钻探、测井资料及目标区以往揭露导水裂隙分布情况,而对矿井的采动裂隙最可能发生的位置进行预测。

In the process of coal mining and excavating production,water outburst was always one of the biggest hidden dangers in safety production.In addition to the lack of natural aquifuge layer,the water conducting fractures of coal seam and surrounding rock were the main water conducting channel for water outburst.The fractures were divided into natural fractures and mining fractures.The vast majority of water conducting fractures were mining fractures formed under the action of gravity and ground stress after the overlying strata of coal seam losing support after mining.Therefore,it was of great significance to predict mining fractures for coal mine water damage control and safety production.Seismic exploration was a geophysical exploration technology which took the stratum or rock stratum mechanical properties as the research object.Seismic data contained abundant underground mechanical information.Through excavation and search of these information,certain petrophysical properties of the target stratum could be obtained,and the distribution of brittle zones prone to damage and cracks could be delineated to obtain the brittle zones distribution.Combined with drilling,logging data and the distribution of water conducting fractures previously revealed in the target area,the most likely location of mining fractures in the mine was predicted.